KR102478243B1 - Electrostatic precipitator - Google Patents

Abstract

The present invention provides an electrostatic precipitator or the like capable of thinning a charging portion while suppressing generation of ozone.
The electrostatic precipitator 1 according to the present invention includes a high voltage electrode 11 to which a high voltage is supplied from a high voltage generator circuit 40, and a high voltage electrode 11 formed opposite to the high voltage generator circuit 40 to which a reference voltage is supplied. a charging unit (10) having a counter electrode (12) and generating electric discharge between the high-voltage electrode (11) and the counter electrode (12) to charge floating particulates; and a dust collection unit 20 disposed on a downstream side of the charging unit 10 in the ventilation direction and collecting suspended particulates charged by the charging unit 10 .

Description

Electrostatic precipitator {ELECTROSTATIC PRECIPITATOR}

The present invention relates to an electrostatic precipitator.

Electric appliances such as air purifiers and air conditioners are equipped with electrostatic precipitators that charge floating particulates using electric discharge.

Such an electrostatic precipitator includes a charging unit for charging floating particulates by discharge; and a dust collector for dust collecting the charged suspended particulates. In the charging part of the electrostatic precipitator, a high voltage of several kV is applied between a high voltage (discharge) electrode and a counter (ground) electrode to generate discharge.

In order to obtain high dust collection efficiency, when the discharge current flowing between the high-voltage electrode and the counter electrode is increased, ozone (O ₃ ) is easily generated along with the discharge. Since ozone has a unique odor, when it is emitted indoors, the ozone concentration needs to be below the environmental standard value (0.05 ppm).

Patent Document 1 is a dust collecting device composed of an ion emission means for releasing ions without corona discharge, and a dust collector formed downstream of the ion emission means, wherein the discharge electrode of the ion emission means is one or a plurality of linear electrodes. It is described that a ground electrode is formed on both sides of the linear electrode, and the electrode connected to the ground is covered with an insulator or semiconductor so that the discharge current when a high voltage is applied to the linear electrode is 1 μA or less per 0.1 m of the linear electrode. .

In Patent Document 2, an intake grill having a discharge needle installed to apply a high voltage and having a shape in which the center bulges forward, a ground electrode capable of ventilation formed on the downwind side of the discharge needle, and a filter unit equipped with a dust collection filter. The intake grill is formed by arranging non-conductive ribs made of non-conductive resin and conductive ribs made of conductive material in a lattice shape, and connecting the conductive ribs to a ground electrode so that static electricity charged in the intake grill escapes, and the intake grill An electrostatic dust collection unit that prevents dust from adhering to is disclosed.

Patent Document 3 describes a corona discharge device having a plurality of discharge members, resistors each connected to the discharge members, and a voltage source connected to the resistors.

Patent Document 4 discloses an ion generator having high voltage generating means for generating high voltage and an ion generating electrode connected to the output of the high voltage generating means and generating ions, wherein the output of the high voltage generating means is connected in parallel with the ion generating electrode. An ion generator having an ozone generating electrode connected to generate ozone and an impedance variable means connected in series with the ozone generating electrode and controlling the amount of ozone generated from the ozone generating electrode by changing the impedance of the impedance variable means is disclosed. has been

Non-Patent Document 1 describes discharge in which one side of an electrode is covered with a high-resistance sheet of several MΩ/cm instead of a dielectric. Further, it is described that when driven with direct current (DC), pulse-shaped discharges are generated that repeat at several 10 kHz with a width of several microseconds.

Patent Document 1: International Publication No. WO01/064349 Patent Document 2: Japanese Unexamined Patent Publication No. 2005-021817 Patent Document 3: Japanese Unexamined Patent Publication No. 7-5746 Patent Document 4: Japanese Unexamined Patent Publication No. 2004-216037

Non-Patent Document 1: MounirLaroussi, Igor Alexeff, Paul Richardson, Francis F. Dyer, "The Resistive Barrier Discharge", iTriple, IEEE TRANSACTION ON PLASMA SCIENCE, February 2002, Vol. 30, No. 1, p. 158-159

By the way, miniaturization of an electrostatic precipitator is requested|required in order to make it easy to assemble to various electrical appliances. In order to ensure desired dust collection performance, it is difficult to make the dust collection part thin. Therefore, it is required to thin the charging portion.

If the charging portion is made thinner, the distance between the high-voltage electrode and the counter electrode becomes shorter, and thus ozone generation may increase.

In addition, since ultrafine particles such as PM 0.1 of 0.1 μm or less are difficult to charge themselves and have a small mass, there is a possibility that they cannot be efficiently collected.

An object of the present invention is to provide an electrostatic precipitator or the like capable of thinning a charging portion while suppressing ozone generation.

Another object of the present invention is to provide an electrostatic precipitator capable of efficiently collecting ultrafine particles while suppressing ozone generation.

For this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collecting unit. The charging unit has a high-voltage electrode supplied with a high voltage from the high-voltage generating circuit and having at least a portion generating electric field concentration, and a counter electrode formed opposite to the high-voltage electrode and supplied with a reference voltage from the high-voltage generating circuit, wherein the high-voltage electrode and A discharge is generated between the counter electrodes to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collecting unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. Then, a discharge is generated between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. The counter electrode in the charging section has a conductor section made of a conductive material. In addition, the counter electrode covers at least a surface of the conductor portion on the side opposite to the high-voltage electrode, and limits the discharge current between the high-voltage electrode and the counter electrode, and has a volume resistivity of 10 ¹⁴ Ω cm or more and 10 ¹⁸ Ω Equipped with a resistance body section of cm or less.

In such an electric precipitator, the resistive body portion of the counter electrode in the charging portion may have a relative permittivity of 3 or more.

In such an electric precipitator, the high-voltage electrode in the charging section may be characterized in that it is wire-shaped.

In addition, the high-voltage electrode in the charging unit may be characterized by having a sawtooth-shaped portion with a pointed tip or a needle-shaped portion with a pointed tip.

Further, the plurality of the serrated portions or the plurality of needle-like portions intersect with respect to the ventilation direction and are divided into a plurality of rows. In each of the plurality of rows, the tip of the sawtooth portion or the tip of the needle-like portion is disposed offset from each other in the column direction between adjacent rows. Further, with respect to the length L of the serrated portion or the needle-like portion, a distance S between the tip ends of the serrated portion or the needle-shaped portion between the plurality of rows is 3L or less. Further, it may be characterized in that the distance P between the sawtooth-like portion or the needle-like portion in each of the plurality of rows is 2L or more.

As a result, the charging section can be made thinner than when the sawtooth or needle-like portions are arranged parallel to the ventilation direction and compared to the case where the high-voltage electrode and the counter electrode are arranged in a direction perpendicular to the ventilation direction. .

Further, the plurality of the serrated portions or the plurality of needle-like portions intersect with respect to the ventilation direction and are divided into a plurality of rows. And, the tips of the serrated portions or the tips of the needle-like portions in each of the plurality of rows are arranged to face each other between adjacent rows. Further, with respect to the length L of the serrated portion or the needle-like portion, a distance S between the plurality of rows of the tips of the serrated portion or the needle-like portion is 6L or more and 8L or less. Further, it may be characterized in that the distance P between the sawtooth-like portion or the needle-like portion in each of the plurality of rows is 2L or more.

As a result, the charging section can be made thinner than when the sawtooth or needle-like portions are arranged parallel to the ventilation direction and compared to the case where the high-voltage electrode and the counter electrode are arranged in a direction perpendicular to the ventilation direction. .

In addition, the high-voltage electrode in the charging unit may be characterized in that it has a brush shape.

In addition, the high-voltage electrode of the charging unit may include a main high-voltage electrode and a subordinate high-voltage electrode.

Further, in the high-voltage electrode, the main high-voltage electrode may have a sawtooth-shaped portion or a needle-shaped portion, and the vertical high-voltage electrode may have a wire shape.

Further, it may be characterized in that the front end of the sawtooth portion or the needle-like portion of the main high-voltage electrode is directed upstream in the ventilation direction.

In addition, it may be characterized in that the vertical high-voltage electrode is formed between the main high-voltage electrode and the counter electrode.

In addition, the voltage of the main high-voltage electrode may be set to 2 times or more and 5 times or less of the voltage of the subordinate high-voltage electrode.

In addition, the main high-voltage electrode may be set to a predetermined voltage, and the secondary high-voltage electrode may be in a floating state in which no voltage is set.

In addition, the conductor part of the counter electrode in the charging part may be characterized in that it is composed of a plurality of flat plates arranged at intervals to ensure ventilation.

Further, the conductor part of the counter electrode in the charging part may be characterized in that it is composed of a net having an opening for ensuring ventilation.

In addition, the conductor portion of the counter electrode in the charging portion may be characterized in that it is made of a punched metal having an opening for ensuring ventilation.

In addition, the conductor portion of the counter electrode in the charging portion may be characterized in that it is made of expanded metal having an opening for ensuring ventilation.

In addition, the counter electrode in the charging section may be characterized in that it is disposed on an upstream side in the ventilation direction with respect to the high-voltage electrode of the charging section.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collection unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. The dust collecting unit is disposed on the downstream side of the ventilation direction of the charging unit. And, the dust collector includes another high-voltage electrode to which a high voltage is supplied from another high-voltage generating circuit. Further, another counter electrode is formed to face the other high voltage electrode and to which a reference voltage is supplied from the other high voltage generating circuit. Then, the dust collection unit collects the floating particulates charged in the charging unit. Further, among the members constituting the charging unit, the other high-voltage electrode of the dust collecting unit is disposed downstream in the ventilation direction from the end of the member closest to the dust collecting unit with a separation distance of 5 mm or more.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collection unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. Then, a discharge is generated between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. Further, a case made of a resin material and accommodating the charging unit is provided. And, the high-voltage electrode in the charging section is formed 5 mm or more apart from the case.

In this electric precipitator, the counter electrode in the charging section includes a conductor section made of a conductive material and a resistor section covering at least a surface of the conductor section opposite to the high-voltage electrode. Further, the case accommodating the charging unit may have electrical contact with the conductive unit of the opposite electrode of the charging unit to conduct electricity.

In this way, compared to the case where the counter electrode is not connected to the case in the exposed region, charging of the case due to static electricity can be further suppressed.

The counter electrode may include a conductor portion made of a conductive material, a resistor portion covering at least a surface of the conductor portion opposite to the high-voltage electrode, and an insulator portion positioned between the conductor portion and the resistor portion. .

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collection unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. Further, a current limiting circuit including an inductor and reducing the potential of the high-voltage electrode by a pulse-shaped current in a discharge generated between the high-voltage electrode and the opposite electrode is provided. Then, a discharge is generated between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit.

Accordingly, it is possible to further suppress an increase in ozone generation due to a pulse-shaped current accompanying emission of secondary electrons, compared to a case where the current limiting circuit is not provided.

In this electrostatic precipitator, the current limiting circuit in the charging section may be characterized in that it is composed of a parallel circuit of the inductor and diode.

The diode of the current limiting circuit in the charging unit may be connected in a reverse direction to the high voltage.

Further, the current limiting circuit in the charging section includes a junction type FET; and a resistance element connected between the source and gate of the junction type FET. junction type FET; and a resistance element connected between the source and gate of the junction type FET; a circuit having the inductor and the diode is connected in series to the parallel circuit.

Accordingly, the short-circuit current between the high-voltage electrode and the counter electrode can be suppressed compared to the case where the circuit including the junction-type FET and the resistance element is not provided.

The current limiting circuit in the charging unit may further include a series circuit of a MOSFET and a resistance element connected in series to the parallel circuit of the inductor and the diode.

Accordingly, the short-circuit current between the high-voltage electrode and the counter electrode can be suppressed compared to a case in which a series circuit using a MOSFET and a resistance element is not provided.

In addition, the current limiting circuit in the charging unit may be formed on a path from the high voltage generating circuit to the high voltage electrode.

In addition, the high-voltage electrode in the charging unit may be composed of a plurality of sub-high-voltage electrodes, and the current limiting circuit in the charging unit may be formed for each of the plurality of sub-high-voltage electrodes. .

And, each of the plurality of sub high-voltage electrodes of the high-voltage electrode in the charging section has a plurality of serrated portions, and the current limiting circuit in the charging portion is formed for each of the serrated portions. It can be characterized as being

Accordingly, a decrease in dust collection efficiency can be suppressed compared to the case where no current limiting circuit is provided for each of the plurality of sub high voltage electrodes.

Further, in this electric precipitator, the current limiting circuit in the charging section may be characterized in that it is formed on a path from the high voltage generating circuit to the counter electrode.

The counter electrode in the charging unit may be composed of a plurality of sub counter electrodes, and the current limiting circuit may be formed for each of the plurality of sub counter electrodes.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collecting unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. Then, a discharge is generated between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. The counter electrode in the charging section has a conductor part made of a conductive material, a first member covering the counter electrode side of the conductor part, and a second member covering the counter electrode side of the first member. Also, the counter electrode has a contact area where the second member electrically contacts the conductor portion.

In the electric precipitator, the high-voltage electrode of the charging unit may include a main high-voltage electrode and a secondary high-voltage electrode.

Further, in the high-voltage electrode, the main high-voltage electrode may have a sawtooth-shaped portion or a needle-shaped portion, and the vertical high-voltage electrode may have a wire shape.

Further, it is characterized in that the front end of the sawtooth-shaped portion or the needle-shaped portion in the main high-voltage electrode faces an upstream side in the ventilation direction.

Further, it may be characterized in that the vertical high-voltage electrode is formed between the main high-voltage electrode and the counter electrode in the high-voltage electrode.

In addition, the voltage of the main high-voltage electrode may be 2 times or more and 5 times or less of the voltage of the subordinate high-voltage electrode.

In addition, the main high-voltage electrode may be set to a predetermined voltage, and the secondary high-voltage electrode may be in a floating state with no voltage set.

In such an electric precipitator, the second member of the counter electrode in the charging section may have a smaller volume resistivity than the first member.

Further, the second member of the counter electrode in the charging section may have a surface resistivity of 1 GΩ/cm or more when 5 kV is applied between the high voltage electrode and the counter electrode.

In addition, the conductor part of the counter electrode in the charging part may be characterized in that it is composed of a plurality of flat plates arranged at intervals to secure ventilation.

In addition, the conductor part of the counter electrode in the charging part may be characterized in that it is composed of a net having an opening for ensuring ventilation.

In addition, the conductor portion of the counter electrode in the charging portion may be characterized in that it is made of a punched metal having an opening for ensuring ventilation.

In addition, the conductor portion of the counter electrode in the charging portion may be characterized in that it is made of expanded metal made of a conductive material having an opening for securing ventilation.

Accordingly, the breakdown voltage between the high voltage electrode and the counter electrode can be further increased compared to the case where the first member is not provided.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collecting unit. The charging section has a high voltage electrode to which a high voltage is supplied from the high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generation circuit. The charging unit generates a discharge between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. The counter electrode in the charging section includes a base material that sets the shape of the counter electrode, a first member formed on a surface of the base material that does not face the high-voltage electrode, and a surface of the base material that does not face the high-voltage electrode. and a conductive second member formed thereon.

And, for this purpose, the electric precipitator to which the present invention is applied includes a charging unit and a dust collection unit. The charging section has a high voltage electrode to which a high voltage is supplied from the high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generation circuit. The charging unit generates a discharge between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. The counter electrode in the charging section includes a base material for setting the shape of the counter electrode, a first member formed on a surface of the base material that faces the high-voltage electrode, and a surface of the base material that does not face the high-voltage electrode. It has a second conductive member covering it.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collecting unit. The charging unit includes a high-voltage electrode to which a high voltage is supplied from a high-voltage generating circuit. In addition, a counter electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generating circuit is provided. Further, a current limiting circuit including an inductor and reducing the potential of the high-voltage electrode by a pulse-shaped current in a discharge generated between the high-voltage electrode and the opposite electrode is provided. Then, a discharge is generated between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collecting unit is disposed on the downstream side of the ventilation direction of the charging unit. And, the dust collector includes another high-voltage electrode to which a high voltage is supplied from another high-voltage generating circuit. And, the dust collector includes another counter electrode formed to face the other high voltage electrode and to which a reference voltage is supplied from the other high voltage generating circuit. And, the dust collection unit collects the floating particulates charged in the charging unit. Further, a case made of a resin material and accommodating the charging unit is provided. And, the high-voltage electrode in the charging section has a plurality of sawtooth-like parts or a plurality of needle-like parts, each of which is made of a conductive material and has a sharp tip. While the serrated portion or the needle-shaped portion crosses with respect to the ventilation direction, the plurality of serrated portions or the plurality of needle-shaped portions are divided into a plurality of rows. The tip of the sawtooth portion or the tip of the needle-like portion in each of the plurality of rows is disposed offset from each other in the row direction between adjacent rows. With respect to the length L of the serrated portion or the needle-shaped portion, a distance S between tips of the serrated portion or the needle-shaped portion between the plurality of rows is 3L or less. On the other hand, the distance P between the sawtooth-like portion or the needle-like portion in each of the plurality of rows is 2L or more. And, the high-voltage electrode is formed 5 mm or more apart from the case. The counter electrode covers a conductor portion made of a conductive material, and a surface of at least a side of the conductor portion opposite to the high-voltage electrode, and limits a discharge current between the high-voltage electrode and the counter electrode, and has a volume resistivity of 10 ¹⁴ Ω cm. or more and 10 ¹⁸ Ω·cm or less. Further, among the members constituting the charging unit, the other high-voltage electrode of the dust collecting unit is disposed downstream in the ventilation direction from the end of the member closest to the dust collecting unit with a separation distance of 5 mm or more.

Further, for this purpose, an electric precipitator to which the present invention is applied includes a charging unit and a dust collection unit. The charging section has a high voltage electrode to which a high voltage is supplied from the high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and to which a reference voltage is supplied from the high voltage generation circuit. The charging unit generates a discharge between the high-voltage electrode and the counter electrode to charge the floating particulates. The dust collection unit is disposed on the downstream side of the ventilation direction of the charging unit and collects the floating particulates charged by the charging unit. In the charging portion, the high-voltage electrode has a sawtooth-shaped portion or a needle-shaped portion, and the counter electrode has a flat sub-counter electrode made of a conductive material. A plurality of serrated or needle-shaped portions of the high-voltage electrode and the sub counter electrode are disposed in a direction crossing the ventilation direction. A sawtooth-shaped portion or a needle-shaped portion of the high-voltage electrode is disposed parallel to the surface of the planar sub-opposite electrode.

In this electrostatic precipitator, the tip of the serrated portion or the tip of the needle-shaped portion of the high-voltage electrode in the charging section is directed upstream in the ventilation direction, and the plate-shaped sub counter electrode is upstream in the ventilation direction. It may be characterized in that it is located on the downstream side of the stage.

Further, the sub counter electrode in the charging section extends from the tip of the sawtooth portion or the tip of the needle-like portion of the high-voltage electrode to the downstream side in the ventilation direction, at least along the length of the sawtooth portion or needle-like portion. It can be characterized as being arranged.

And, among the members constituting the charging unit, the high-voltage electrode of the dust collecting unit may be disposed with a separation distance of 5 mm or more downstream from the end of the member closest to the dust collecting unit to the downstream in the ventilation direction.

In addition, the charging unit may include an inductor and a current limiting circuit that lowers the potential of the high-voltage electrode by a pulse-shaped current in a discharge generated between the high-voltage electrode and the opposite electrode.

According to the present invention, it is possible to provide an electrostatic precipitator or the like capable of thinning a charging portion while suppressing ozone generation.

Further, according to the present invention, it is possible to provide an electrostatic precipitator capable of efficiently collecting ultrafine particles while suppressing ozone generation.

1 is a diagram showing an example of an electric precipitator to which a first embodiment is applied.
2A and 2B are plan views of a high-voltage electrode and a counter electrode of a charging unit, respectively. FIG. 2A is a high-voltage electrode and FIG. 2B is a counter electrode.
3A and 3B are cross-sectional views illustrating a charging part in detail, FIG. 3A is a charging part of an electric precipitator to which the first embodiment is applied, and FIG. 3B is a charging part of an electric precipitator of a comparative example to which the first embodiment is not applied. .
Fig. 4 is a diagram showing the relationship between ozone concentration and dust collection efficiency in the electric precipitator of Example 1 and the electric precipitator of Comparative Example 1;
Fig. 5 is a diagram showing the relationship between a material constituting the resistor part of the counter electrode (resistor sub-material), an ozone generating voltage (kV), and the number of ions (x10 ³ /cm ³ ) in the ozone generating voltage.
6 is a perspective view of a charging unit of the electrostatic precipitator of Example 3;
7A and 7B are plan views of a high-voltage electrode and a counter electrode in the electric precipitator of Example 3, respectively. 7A is a high-voltage electrode, and FIG. 7B is a counter electrode.
Fig. 8 is a diagram showing the relationship between dust collection efficiency and ozone concentration in the electric precipitator of Example 3;
9 is a perspective view of a charging unit of the electrostatic precipitator of Example 4;
10A and 10B are plan views of a high-voltage electrode and a counter electrode, respectively, in the electric precipitator of Example 4. FIG. 10A is a high-voltage electrode and FIG. 10B is a counter electrode.
Fig. 11 is a diagram showing the relationship between dust collection efficiency and ozone concentration in the electric precipitator of Example 4;
12A to 12C are views showing a modified example of a charging unit of the electrostatic precipitator of Example 4, FIG. 12A is a perspective view of the charging unit, FIG. 12B is a view of the charging unit viewed from the counter electrode side, and FIG. 12C is a view of the counter electrode 12 It is a cross section along line XIIC-XIIC.
13A and 13B are diagrams for explaining the charging part of the electrostatic precipitator of Example 5. FIG. 13A is a perspective view of the charging part, and FIG. 13B is a cross-sectional view taken along line XIIIB-XIIIB in FIG. 13A.
14A and 14B are plan views of a high-voltage electrode and a counter electrode of the electric precipitator of Example 5, respectively. FIG. 14A is a high-voltage electrode and FIG. 14B is a counter electrode.
15A and 15B are views showing a modified example of a high-voltage electrode in a charging section of an electrostatic precipitator. FIG. 15A is a view in which teeth are arranged in a different arrangement from FIG. 2A, and FIG. 15B is a view in which teeth are arranged in a different arrangement than in FIG. 10A. it is a drawing
16A and 16B are diagrams showing another modification of the high-voltage electrode in the charging section of the electrostatic precipitator, and FIG. 16A is composed of a plurality of needle rows each having a plurality of needles, and the tips of the needles are adjacent to each other. 16B is a view in which needle rows are arranged to face each other, and FIG. 16B is composed of a plurality of needle rows having a plurality of needles, and the tips of the needles are zigzag between adjacent needle rows.
Fig. 17 is a diagram explaining a modified example of a counter electrode in a charging section of an electric precipitator.
18 is a diagram showing an example of an electric precipitator to which the second embodiment is applied.
Fig. 19 is a diagram showing the relationship between the dust collection efficiency of the electric precipitator and the ozone concentration with respect to the spacing P of the teeth in the tooth row.
Fig. 20 is a diagram showing the relationship between the dust collection efficiency of the electric precipitator and the ozone concentration with respect to the distance S between the rows of teeth.
21A to 21D are diagrams schematically explaining the state of discharge in the charging section, FIG. 21A is a plan view viewed from the high-voltage electrode side, and FIG. 21B is a cross-sectional view taken along the line XXIB-XXIB in FIG. 21A.
22 is a diagram showing an example of an electric precipitator to which the third embodiment is applied.
Fig. 23 is a diagram schematically illustrating the state of discharge in a charging section.
24 is a diagram showing an example of an electric precipitator to which a fourth embodiment is applied.
Fig. 25 is an equivalent circuit of a charging section of an electric precipitator.
26 is a diagram showing an example of a high-voltage electrode to which a current limiting circuit formed by a parallel circuit of an inductor and a diode is connected.
27 is an equivalent circuit of a charging unit including a current limiting circuit by a resistor.
28A and 28B are diagrams showing a change in voltage between electrodes over time in a charging section of the electrostatic precipitator of Example 7 and the electrostatic precipitator of Comparative Example 3, respectively. FIG. 28A is Example 7 and FIG. 28B is Comparative Example 3 to be.
29 is another equivalent circuit of a charging unit including a current limiting circuit.
Fig. 30 is a diagram showing an example of a high-voltage electrode connected to a current limiting circuit for each tooth row in the charging section of the electrostatic precipitator of Example 8;
Fig. 31 is a diagram showing an example of a high-voltage electrode connected to a current limiting circuit for each tooth in the charging section of the electrostatic precipitator of Example 9;
32 is an equivalent circuit of a charging unit in an electric precipitator to which the fifth embodiment is applied.
Fig. 33 is a diagram explaining the temporal change of the interelectrode voltage in the charging section of the electrostatic precipitator of Example 10;
Fig. 34 is a diagram explaining the time change of the interelectrode voltage due to short circuit in the charging section of the electrostatic precipitator of Example 10.
Fig. 35 is a diagram showing an example of a high voltage electrode to which a current limiting circuit is connected.
36A to 36C are other equivalent circuits of the charging unit including the current limiting circuit, and FIG. 36A is a case where the connection order of the secondary electron current limiting unit and the short-circuit current limiting unit in the current limiting circuit of FIG. 32 are exchanged. 36b shows a case where the current limiting circuit is connected to the opposite electrode, and FIG. 36c shows a case where a high voltage electrode and a counter electrode are formed between the secondary electron current limiting unit and the short-circuit current limiting unit in the current limiting circuit.
Fig. 37 is a schematic diagram for explaining a charging part of an electric precipitator to which a sixth embodiment is applied.
38A and 38B are diagrams showing ionized water generated in the charging section of the electrostatic precipitator of Example 11 and the electrostatic precipitator of Comparative Example 4, respectively. FIG. 38A is Example 11 and FIG. 38B is Comparative Example 4.
39A and 39B are diagrams for explaining the charging part in the electric precipitator according to the twelfth embodiment. FIG. 39A is a perspective view of the charging part, and FIG. 39B is a cross-sectional view of the counter electrode along the line XXXIXB-XXXIXB.
40A and 40B are diagrams for explaining the charging section in the electric precipitator according to the thirteenth embodiment, FIG. 40A is a perspective view of the charging section, and FIG. 40B is a cross-sectional view of a part of the counter electrode.
41A and 41B are diagrams for explaining a charging section in the electric precipitator according to the 14th embodiment.
42A and 42B are diagrams for explaining the charging part in the electrostatic precipitator of Example 15. FIG. 42A is a perspective view of the charging part, and FIG. 42B is a cross-sectional view along the line XLIIB-XLIIB in FIG. 42A.
43 is a diagram explaining the relationship between the interelectrode voltage (kV) applied between the high-voltage electrode and the conductor portion of the counter electrode and the amount of ozone generated per tooth (μg/h).
44A and 44B are diagrams for explaining the charging part in the electric precipitator according to the seventeenth embodiment, and FIG. 44A is a perspective view of the charging part, and FIG. 44B is a cross-sectional view of a part of the counter electrode.
45A and 45B are diagrams for explaining the charging part in the electric precipitator according to the eighteenth embodiment. FIG. 45A is a perspective view of the charging part, and FIG. 45B is a cross-sectional view of the counter electrode along the line XLVB-XLVB in FIG. 45A.
46A and 46B are diagrams for explaining the charging part in the electric precipitator according to the 19th embodiment, FIG. 46A is a perspective view of the charging part, and FIG. 46B is a cross-sectional view of the counter electrode along the line XLVIB-XLVIB in FIG. 46A.
47 is a diagram showing an example of an electric precipitator to which a seventh embodiment is applied.
48 is a diagram showing an example of an electric precipitator to which an eighth embodiment is applied.
49A to 49C are perspective views of main parts of the charging section in the electrostatic precipitator according to Example 20 and Comparative Examples 6 and 7, and FIG. 49A is Example 20, FIG. 49B is Comparative Example 6, and FIG. 49C is Comparative Example 7. .
Fig. 50 is a diagram explaining the dust collection efficiency determined for each ozone concentration and particle size in the electric precipitator according to Example 20 and Comparative Examples 6 and 7;
Fig. 51 is a diagram explaining the operation of the vertical high-voltage electrode.
52 is a diagram showing a modified example of an electric precipitator to which an eighth embodiment is applied.
53 is a diagram showing a modified example of an electric precipitator to which a ninth embodiment is applied.
54 is a cross-sectional view of a main portion of a charging unit and a dust collecting unit in the ventilation direction in the electric precipitator according to Example 21;
55A and 55B are perspective views of main parts of charging parts in the electrostatic precipitator according to Example 21 and Comparative Example 7, and FIG. 55A is Example 21 and FIG. 55B is Comparative Example 7.
Fig. 56 is a diagram explaining the dust collection efficiency determined for each ozone concentration and particle diameter in the electric precipitator according to Example 21 and Comparative Example 7;

EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, embodiment of this invention is described in detail.

[First Embodiment]

1 is a diagram showing an example of an electrostatic precipitator 1 to which the first embodiment is applied. Here, the case 30 is indicated by a broken line, and the configuration of the charging unit 10 and the dust collection unit 20 formed inside the case 30 is made visible.

The electrostatic precipitator 1 includes a charging unit 10, a dust collecting unit 20, and a case 30 accommodating the charging unit 10 and the dust collecting unit 20. That is, the electrostatic precipitator 1 is a two-stage electrostatic precipitator method in which the charging unit 10 and the dust collecting unit 20 are separated.

Here, the direction (ventilation direction) of the air flow (ventilation) is set from the charging unit 10 toward the dust collecting unit 20 (from left to right in the page of FIG. 1). Ventilation is performed by a fan (not shown) formed on the downstream side of the dust collector 20 in the ventilation direction.

And, for convenience of description, as shown in FIG. 1, the vertical directions of the paper surface are indicated as upper and lower directions, and the left and right directions orthogonal to the vertical directions with respect to the ventilation direction are expressed as left and right.

On the other hand, as long as ventilation is not hindered, the electrostatic precipitator 1 may be disposed in any direction.

(Electrical part (10))

The charging unit 10 includes a high-voltage electrode 11 and a counter electrode 12 opposing the high-voltage electrode 11 . On the other hand, since the high voltage electrode 11 is an electrode to which a high voltage is applied, it is also called a high voltage electrode, and since it is an electrode that generates discharge, it is also called a discharge electrode. Also, since the counter electrode 12 is grounded (GND) in some cases, it is also called a ground electrode.

Then, as a direct current (DC) high voltage is applied between the high voltage electrode 11 and the counter electrode 12, a corona discharge (discharge) occurs between the high voltage electrode 11 and the counter electrode 12. Then, the floating particulates are charged by the generated corona discharge.

The high-voltage electrode 11 includes, for example, a plurality of tooth rows 113 (# in FIG. 5 columns of 1 to #5) are provided. The longitudinal direction of each row of teeth 113 is directed in the left-right direction. In FIG. 1, the uppermost tooth row 113 (#1 in FIG. 1) in the vertical direction has a plurality of teeth 111 (ten in FIG. 1) arranged downward. The lowermost tooth row 113 (#5 in Fig. 1) in the vertical direction has a plurality of teeth 111 (ten in Fig. 1) arranged upward. The tooth rows 113 (#2 to #4 in FIG. 1) between the plurality of teeth 111 (10 in FIG. 1) arranged upward and the plurality of teeth 111 arranged downward ( In FIG. 1, 10) are provided.

On the other hand, the sawtooth 111 and/or its tip are an example of a site that generates electric field concentration.

On the other hand, the number of tooth rows 113 and the number of teeth 111 in the tooth row 113 are set to a predetermined number.

A plurality of teeth 111 in each row of teeth 113 is connected to a connecting portion 112 . And, the end of each connection part 112 is fixed to the support part 14 made of an insulating material. The support portion 14 is provided with a circuit board (printed wiring board (PCB)) provided with wiring. Via the wiring of the circuit board, the row of teeth 113 is connected to the anode of the high voltage generator circuit 40 that supplies DC high voltage.

On the other hand, the support portion 14 may be part of the case 30 .

Each tooth 111 is formed in a direction orthogonal to the ventilation direction. In addition, each tooth 111 is located between adjacent tooth rows 113, for example, between the tooth row 113 (#1) and the tooth row 113 (#2) so that the ends face each other. is formed

On the other hand, each tooth 111 may be formed in an oblique direction with respect to the ventilation direction. That is, each tooth 111 is formed in a direction crossing the ventilation direction.

The teeth 111 of the high-voltage electrode 11 and the connecting portion 112 are integrally made of a conductive material. On the other hand, the support portion 14 may be formed of a conductive material integrally with the teeth 111 and the connection portion 112 without being a separate member.

The counter electrode 12 is a member made of a conductive material having an opening (hole) 124 therethrough to ensure ventilation, and a member made of a resistive material formed to cover the surface and functioning as a resistance to current ( resistor) (refer to the conductor portion 121 and resistor portion 122 of FIG. 2 described later). And, the counter electrode 12 is connected to the cathode of the high voltage generating circuit 40 .

On the other hand, the absence of the resistive material limits the discharge current and suppresses ozone generation. Therefore, characteristics such as volume resistivity for the member of the resistive material are set in consideration of the relationship between dust collection efficiency and ozone concentration.

In FIG. 1 , the counter electrode 12 is, for example, a wire mesh (mesh) in which the conductor portion 121 is made of a conductive material. On the other hand, in FIG. 1 (FIG. 2B to be described later is the same), the mesh (opening 124) is shown large. However, the size of the mesh (opening 124) is set in consideration of the discharge generated between the high-voltage electrodes 11.

The distance G is between the high voltage electrode 11 and the counter electrode 12 .

(Dust collecting unit 20)

The dust collector 20 includes flat plate-shaped high-voltage electrodes 21 and plate-shaped counter electrodes 22, which are alternately laminated and whose surface is covered with a film of an insulating material. A ventilation direction is provided between the high-voltage electrode 21 and the counter electrode 22 . On the other hand, since the counter electrode 22 is sometimes grounded (GND), it is also called a ground electrode.

A high voltage of direct current (DC) is applied between the high voltage electrode 21 and the counter electrode 22 by the high voltage generating circuit 50 . Then, the floating particulates charged in the charging unit 10 are attached to the surface of the counter electrode 22 by static electricity. As a result, floating particulates are collected.

On the other hand, polyethylene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), or the like can be used for the film of insulating material covering the surface of the high-voltage electrode 21 .

The dust collection unit 20 is formed on the downstream side of the charging unit 10 in the ventilation direction. Among the high-voltage electrode 21 and the counter electrode 22 of the dust collecting unit 20, the electrode closest to the charging unit 10 is the closest member to the dust collecting unit 20 among the members constituting the charging unit 10. It may be arranged at a predetermined distance from the end to the downstream side in the ventilation direction. This relationship is the same also in other embodiments described below. In this case, the preset separation distance may be 5 mm or more.

(Case (30))

The case 30 accommodates the charging unit 10 and the dust collecting unit 20 . A plurality of gratings (grills) 31 are formed on the front portion facing the charging unit 10 . On the other hand, it is preferable that the grating 31 is formed to prevent a user from contacting the charging unit 10 and to have low resistance to ventilation.

The case 30 is made of, for example, a resin material such as ABS (acrylonitrile, butadiene, styrene copolymer).

2A and 2B are plan views of the high voltage electrode 11 and the counter electrode 12 of the charging unit 10, respectively. FIG. 2A shows the high-voltage electrode 11, and FIG. 2B shows the counter electrode 12.

As shown in FIG. 2A, the high-voltage electrode 11 is provided with tooth rows 113 (#1 to #5 in FIG. 2) each having a plurality of teeth 111 formed thereon. And, between the adjacent tooth rows 113, the tips of the respective teeth 111 are formed to face each other (to face each other).

Then, L (length L) is the length from the front end of the tooth 111 to the connecting portion 112, and the spacing (pitch) between the teeth 111 in the tooth row 113 is P (interval P). In addition, between adjacent tooth rows 113, the distance between the tips of the teeth 111 in the direction perpendicular to the tooth row is S (distance S).

As shown in FIG. 2B, the counter electrode 12 includes, for example, a conductor portion 121, which is a wire mesh (mesh) made of a conductive material, and a resistor portion 122 covering the surface thereof. The upper and lower end portions are conductor exposed regions 123 in which the surface of the conductor portion 121 is exposed. On the other hand, it is also possible to form conductor exposed regions 123 exposing the surface of the conductor portion 121 at the left and right end portions.

On the other hand, the conductor exposed region 123 exposing the surface of the conductor portion 121 may be formed only at a part of the end of the counter electrode 12 .

The conductor exposed region 123 may be formed by removing the formed resistance body portion 122, or may be formed so that the resistance body portion 122 is not formed (eg, not coated).

Forming the resistor portion 122 on the counter electrode 12 is for limiting the discharge current and suppressing the generation of ozone. Therefore, as will be described later, the member constituting the resistor portion 122 preferably has a dielectric constant of 3 or more and a volume resistivity of 10 ¹⁴ Ω·cm or more and 10 ¹⁸ Ω·cm or less. On the other hand, the resistance value in the thickness direction changes according to the thickness of the resistor unit 122 . Accordingly, the value of the discharge current can be set according to the thickness of the resistor unit 122 .

On the other hand, that the volume resistivity is 10 ¹⁴ Ω·cm means that it is in the range of 10 ¹⁴ Ω·cm. The same applies to other volume resistivity values.

3A and 3B are cross-sectional views illustrating the charging unit 10 in detail. FIG. 3A shows the charging part 10 of the electric precipitator 1 to which the first embodiment is applied, and FIG. 3B shows the charging part 10 of the electric precipitator 1 to which the first embodiment is not applied.

The high-voltage electrode 11 has a plurality of teeth 111. 3A and 3B, each tooth 111 appears not electrically connected. However, as described in FIGS. 1, 2A and 2B, the high voltage electrodes 11 are electrically connected.

The counter electrode 12 includes a conductor portion 121 and a resistor portion 122 formed to cover the surface of the conductor portion 121 . Meanwhile, in FIGS. 3A and 3B , the conductor parts 121 appear not to be electrically connected to each other. However, as described in FIGS. 1, 2A, and 2B, the conductor portion 121 is a wire mesh (mesh) made of a conductive material and is electrically connected thereto.

In the charging section 10 of the electrostatic precipitator 1 to which the first embodiment shown in FIG. 3A is applied, the high-voltage electrode 11 passes through the insulating spacer 32 composed of the above insulating member (insulator) to the case 30. is attached to Therefore, the high voltage electrode 11 does not come into direct contact with the case 30 . Meanwhile, the supporting portion 14 may be an insulating spacer 32 , or the supporting portion 14 may be attached to the case 30 via the insulating spacer 32 .

As the insulating spacer 32, any material having high insulating properties may be used, and it is preferable to be made of ceramics, a resin material, air, or the like.

On the other hand, the insulating spacer 32 is an example of an insulating member.

Meanwhile, the counter electrode 12 is attached to the case 30 such that the conductor exposed region 123 where the conductor portion 121 is exposed electrically contacts the case 30 . And, it is connected to the ground terminal E in the conductor exposed area 123. Meanwhile, the ground terminal E may not be grounded.

Further, a member (resin member) made of a resin material, such as the case 30, is not formed within a range of a predetermined distance r from the tip of the tooth 111. The resin member here is not limited to the member constituting the case 30, but includes those formed in the case 30.

On the other hand, in the charging portion 10 in the electric precipitator 1 of Comparative Example 1 shown in FIG. 3B, the end portion of the counter electrode 12 did not expose the conductor portion 121. That is, in the electrostatic precipitator 1 of Comparative Example 1, the counter electrode 12 does not have a conductor exposed region.

And, the high-voltage electrode 11 is attached so as to directly contact the case 30 .

On the other hand, the counter electrode 12 is attached so as to come into contact with the case 30 via the resistor unit 122 . In addition, the counter electrode 12 is connected to the ground terminal E except for a portion in contact with the case 30 . Meanwhile, the ground terminal E may not be grounded.

(Example 1)

Next, an electric precipitator 1 to which the first embodiment is applied (the electric precipitator 1 of Example 1) and an electric precipitator 1 to which the first embodiment is not applied (the electric precipitator 1 of Comparative Example 1) ) and the results of measuring the concentration of ozone.

The electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of Comparative Example 1 are different as shown in FIG. 3 in each charging part 10 . However, other configurations are the same.

In the charging section 10 of the electrostatic precipitator 1, the size of the support section 14 of the high-voltage electrode 11 viewed from the ventilation direction was about 400 mm in the left-right direction and about 300 mm in the vertical direction. Then, the grid 31 was arranged so that a plurality of openings of 40 mm × 125 mm were formed on the surface of the case 30 .

The teeth 111 and the connecting portion 112 of the high-voltage electrode 11 in the charging portion 10 were made of plate-shaped stainless steel (SUS) with a thickness of 0.5 mm. In addition, the length of the teeth 111 from the tip to the connecting portion 112 was about 10 mm. Then, the distance S between the tips of the teeth 111 between the rows of teeth 113 was set to about 30 mm.

In the counter electrode 12 in the charging section 10, the conductor section 121 is a wire mesh (mesh) made of SUS with an aperture ratio of 87.1%. The resistance body portion 122 covering the surface of the conductor portion 121 was made of polyimide resin with a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Ω·cm.

The distance G between the high-voltage electrode 11 and the counter electrode 12 was about 5 mm.

Then, a DC voltage of about 4 kV was applied between the high-voltage electrode 11 and the counter electrode to generate corona discharge.

The high voltage electrode 21 and the counter electrode 22 in the dust collector 20 had a width of 20 mm in the ventilation direction and a length of about 400 mm in a direction orthogonal to the ventilation direction. In addition, the distance between the high-voltage electrode 21 and the counter electrode 22 was set to about 1.5 mm. Then, a DC voltage of about 6 kV was applied between the high-voltage electrode 21 and the counter electrode 22 .

In the electrostatic precipitator 1 of Example 1, the resin member constituting the case 30 or the like is not formed within a range of about 5 mm (distance r) from the tip of the teeth 111.

Fig. 4 is a diagram showing the relationship between dust collection efficiency and ozone concentration in the electric precipitator 1 of Example 1 and the electric precipitator 1 of Comparative Example 1. The wind speed in the ventilation direction is 1 m/s.

Here, the ozone concentration was determined using an ozone concentration meter from the amount of ozone measured by the ozone concentration meter and the amount of air blown in by the ozone concentration meter. In addition, the dust collection efficiency is determined by counting the number of floating particulates upstream (before entering the electrostatic precipitator 1) and downstream (after exiting the electrostatic precipitator 1) in the ventilation direction of the electrostatic precipitator 1 by means of a particle counter. and saved

As can be seen from Fig. 4, the electric precipitator 1 of Example 1 had an ozone concentration of 2.0 ppb or less even when it was operated in a state where almost 100% dust collection efficiency was obtained. This value is far below the environmental standard (0.05 ppm).

On the other hand, in the electric precipitator 1 of Comparative Example 1, the dust collection efficiency was saturated at about 50%. And, although the dust collection efficiency is about 50%, the ozone concentration is higher than that of the electric precipitator 1 of Example 1. On the other hand, also in the electrostatic precipitator 1 of Comparative Example 1, the maximum ozone concentration in the measurement range is 2.0 ppb, which is below the environmental standard value (0.05 ppm).

In the electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of Comparative Example 1, the ozone concentration is suppressed lower than the environmental standard value. This is considered to be because the counter electrode 12 of the charging section 10 is provided with the resistor section 122 covering the surface of the conductor section 121, thereby limiting the discharge current.

On the other hand, the difference in dust collection efficiency between the electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of Comparative Example 1 is that the electrostatic precipitator 1 of Comparative Example 1 compared to the electrostatic precipitator 1 of Example 1, case It is considered that (30) is easily charged with static electricity.

In the electrostatic precipitator 1 of Comparative Example 1, the high-voltage electrode 11 is in direct contact with the case 30. Further, the DC high voltage supplied from the high voltage generating circuit 40 is insulated by the resin material constituting the case 30 . For this reason, the case 30 is not connected to the ground terminal E.

The resin material constituting the case 30 has a high electrical resistivity and is difficult to conduct electricity. For this reason, the surface of the case 30 is easily charged with static electricity. Since the case 30 is not connected to the ground electrode, charged static electricity cannot escape. In other words, it is considered that the charging efficiency of the suspended particulates deteriorates and the dust collection efficiency decreases due to the charging of the case 30, particularly the charging of the case 30 in the vicinity of the high-voltage electrode 11.

On the other hand, in the electrostatic precipitator 1 of the first embodiment, the high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 . Therefore, the high voltage electrode 11 and the case 30 do not electrically contact each other. Also, since the case 30 is connected to the counter electrode 12, charged static electricity can escape. In addition, the resin member constituting the case 30 or the like was not formed within a range of a predetermined distance r (5 mm in the first embodiment) from the tip of the tooth 111, which is the high-voltage electrode 11.

Therefore, it is considered that the case 30 is suppressed from being charged with static electricity, and the charging of floating particulates is less likely to be inhibited, and the dust collection efficiency is improved.

As described above, in the electrostatic precipitator 1 to which the first embodiment is applied, the counter electrode 12 of the charging section 10 is formed to cover the conductor section 121 and the surface of the conductor section 121. It is constituted by one resistance body part (122). Therefore, the discharge current is suppressed to be small compared to the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed to a low level.

And, the high-voltage electrode 11 of the charging unit 10 is fixed to the case 30 via an insulating spacer 32 . In addition, the resin member constituting the case 30 or the like is not formed within a range of a predetermined distance r from the tip of the tooth 111 of the high-voltage electrode 11 . In addition, the counter electrode 12 is in electrical contact with the case 30 in the conductor exposed region 123 so as to conduct. Accordingly, the case 30 is suppressed from being charged with static electricity, and the dust collection efficiency is improved.

In addition, since the high-voltage electrode 11 of the charging unit 10 has the tips of the teeth 111 facing each other between the rows of teeth 113, the teeth 111 in one direction (for example, the lower side) are not used. Compared to the case where the discharge does not occur, the area where the discharge occurs is wider.

In the electrostatic precipitator 1 to which the first embodiment is applied, in the charging section 10, the high-voltage electrode 11 and the counter electrode 12 are disposed in the ventilation direction. In addition, a portion of the high-voltage electrode 11 that generates discharge is referred to as a sawtooth 111, and the sawtooth 111 is disposed orthogonally or inclined with respect to the ventilation direction. Therefore, the distance G between the high voltage electrode 11 and the counter electrode 12 can be set as short as 5 mm, for example. Accordingly, the electric precipitator 1 can be miniaturized.

In addition, unlike the electric precipitator 1 to which the first embodiment is applied, the resistance body portion 122 formed to cover the surface of the conductor portion 121 of the counter electrode 12 is not formed, and the high-voltage electrode 11 When the gap between the and the counter electrode 12 is brought closer, the discharge current increases and the generation of ozone increases.

(Example 2)

As described above, the counter electrode 12 is composed of a conductor portion 121 and a resistor portion 122 covering the surface of the conductor portion 121 .

In Example 2, the material of the resistor portion 122 covering the surface of the counter electrode 12 will be described.

5 shows the relationship between the material constituting the resistor portion 122 of the counter electrode 12 (resistor sub-material), the ozone generation voltage (kV), and the number of ions (×10 ³ units/cm ³ ) in the ozone generation voltage. it is a drawing On the other hand, in FIG. 5, volume resistivity (Ω·cm) and relative permittivity are shown as characteristics of the material constituting the resistor portion 122 (resistor submaterial). In addition, in FIG. 5, the distance G (mm) between the high-voltage electrode 11 and the counter electrode 12 is shown. Here, the distance G between the high-voltage electrode 11 and the counter electrode 12 is fixed to 5 mm.

The ozone generating voltage is a voltage at which the ozone generation starts to be detected by the ozone concentration meter when the DC voltage applied between the high voltage electrode 11 and the counter electrode 12 is gradually raised (increased).

In addition, the number of ions at the ozone generation voltage is the number of ions generated between the high voltage electrode 11 and the counter electrode 12 when the ozone generation voltage is applied between the high voltage electrode 11 and the counter electrode 12. (×10 ³ /cm ³ ). Ionized water was measured with an ion counter.

In the electrostatic precipitator 1, it is preferable that the ozone generating voltage is high and the number of ions generated at the ozone generating voltage is large.

Here, the electrostatic precipitator 1 shown in FIG. 1 was used except for the materials constituting the resistor portion 122 of the counter electrode 12 in the charging portion 10. The high-voltage electrode 11 of the charging unit 10 has teeth 111, and the counter electrode 12 is a wire mesh (mesh) in which the conductor unit 121 is made of a conductive material.

The high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 . The counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E.

The materials of the resistor unit 122 include “None”, “Alkyd resin”, “Acrylic resin”, “Polyimide”, “Polyester”, “PTFE” (polytetrafluoroethylene)” was used.

The thickness of each resistor portion 122 was about 50 μm.

When the resistor section 122 was "None", the ozone generation voltage was 3.2 kV, and the number of ions at the ozone generation voltage was zero. That is, when the DC voltage between the high-voltage electrode 11 and the counter electrode 12 was gradually raised, ozone started to be generated at 3.2 kV. However, no ions were generated at the ozone generating voltage.

When the resistor portion 122 was an alkyd resin, the ozone generation voltage was 4.0 kV, and the number of ions at the ozone generation voltage was 1040×10 ³ ions/cm ³ . That is, when the DC voltage between the high-voltage electrode 11 and the counter electrode 12 was gradually increased, ozone started to be generated at 4.0 kV. However, ions started to be generated at a DC voltage lower than the ozone generation voltage.

When the resistor portion 122 was made of acrylic resin, the ozone generating voltage was 4.5 kV, and the number of ions at the ozone generating voltage was 1400×10 ³ ions/cm ³ . That is, when the DC voltage between the high-voltage electrode 11 and the counter electrode 12 was gradually raised, ozone started to be generated at 6.0 kV. However, ions started to be generated at a DC voltage lower than the ozone generating voltage.

When the resistor portion 122 was made of polyimide resin, the ozone generation voltage was 6.0 kV, and the number of ions at the ozone generation voltage was 1600×10 ³ /cm ³ . That is, when the DC voltage between the high-voltage electrode 11 and the counter electrode 12 was gradually raised, ozone began to be generated at 4.5 kV. However, ions started to be generated at a DC voltage lower than the ozone generation voltage.

In the case where the resistor portion 122 is made of polyester resin or PTFE, even if a DC voltage of up to 10 kV is applied between the high-voltage electrode 11 and the counter electrode 12, ozone and ions are not generated. On the other hand, in the case of polyester resin, by forming the conductor exposed region 123, even if a DC voltage of up to 10 kV is applied between the high-voltage electrode 11 and the counter electrode 12, ozone is not generated, but ions can be generated. there was. That is, when the DC voltage between the high-voltage electrode 11 and the counter electrode 12 was 10 kV, the number of ions was 2000×10 ³ /cm ³ .

From the above, as the material (resistor sub-material) of the resistor unit 122 shown in Fig. 5, the ozone generating voltage is the highest in the polyimide resin, and the number of ions in the ozone generating voltage is also large. That is, polyimide resin is the most preferable material for the resistor portion 122. Next, an acrylic resin and an alkyd resin are preferable in this order. In addition, by forming the conductor exposed region 123, a polyester resin can also be used.

In terms of characteristics, it is preferable that the dielectric constant is 3 or more and the volume resistivity is 10 ¹² Ω·cm or more and 10 ¹⁸ Ω·cm or less. About the volume resistivity, 10 ¹⁴ Ω·cm or more and 10 ¹⁸ Ω·cm or less are more preferable.

On the other hand, when the conductor exposed region 123 is not provided, when the volume resistivity of the resistor portion 122 exceeds 10 ¹⁷ Ω cm, the resistor portion 122 functions as an insulator, and the high voltage electrode 11 and the counter electrode (12) It is thought that the generation of discharge between them is inhibited. Therefore, in this case, it is necessary to form the conductor exposed region 123.

(Example 3)

In Example 3, the relationship between the dust collection efficiency and the ozone concentration between the case where the counter electrode 12 in the charging unit 10 has the resistor unit 122 and the case where it does not have it will be explained. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of the third embodiment.

6 is a perspective view of the charging unit 10 of the electrostatic precipitator 1 of Example 3. In the electrostatic precipitator 1 shown in FIG. 1, the ventilation direction was from right to left on the ground. However, in FIG. 6, the ventilation direction is described as a direction from upper side to lower side in the paper.

And, the high-voltage electrode 11 of the electric precipitator 1 has a structure shown in FIGS. 1 and 2 . That is, it has a plurality of teeth rows 113 each having a plurality of teeth 111. The teeth 111 are arranged so that their tips face each other between the tooth rows 113.

On the other hand, in the counter electrode 12 of the electrostatic precipitator 1, the conductor portion 121 is made of expanded metal. The expanded metal is a wire mesh-shaped member in which a diamond-shaped opening 124 is formed by inserting and stretching cutting lines in a plate made of a conductive material.

7A and 7B are plan views of the high-voltage electrode 11 and counter electrode 12 in the electric precipitator of Example 3, respectively. 7A shows the high-voltage electrode 11, and FIG. 7B shows the counter electrode 12.

The high-voltage electrode 11 shown in FIG. 7A is the same as the high-voltage electrode 11 shown in FIG. 2A.

The counter electrode 12 shown in FIG. 7B includes a conductor portion 121 made of expanded metal and a resistor portion 122 formed to cover the surface thereof. On the other hand, part of the conductor portion 121 (upper and lower sides in the vertical direction) is a conductor exposed region 123 that does not include the resistor portion 122 .

The high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 . The counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E (see Fig. 3).

The size of the support portion 14 of the high-voltage electrode 11 was about 400 mm in the left-right direction and about 300 mm in the vertical direction.

The high-voltage electrode 11 was made of SUS with a thickness of 0.5 mm. The distance S between the tips of the teeth 111 between the teeth rows 113 was set to about 30 mm. And, the high-voltage electrode 11 is provided with 5 rows of sawtooth rows 113 (#1 to #5).

The conductor portion 121 of the counter electrode 12 was made of SUS expanded metal, and the size of the opening 124 was 4 mm x 8 mm.

The resistor portion 122 covering the conductor portion 121 of the counter electrode 12 was made of polyimide resin with a thickness of 50 μm.

On the other hand, the polyimide resin used as the resistor portion 122 has a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Ω·cm.

The distance G between the high-voltage electrode 11 and the counter electrode 12 was 5 mm.

When a DC voltage of about 4 kV was applied between the high-voltage electrode 11 and the counter electrode 12, ions started to be generated and the floating particulates could be charged.

Then, as shown in FIG. 1 , the dust collection unit 20 was formed on the downstream side of the ventilation direction, and air was blown while the charging unit 10 and the dust collection unit 20 were energized, thereby removing suspended particulates in the air.

Fig. 8 is a diagram showing the relationship between the dust collection efficiency and the ozone concentration in the electric precipitator 1 of Example 3. In FIG. 8, the electrostatic precipitator 1 having the above structure is shown as Example 3, and the electrostatic precipitator 1 in which the resistance body part 122 is not formed on the counter electrode 12 of the charging part 10 is shown as Comparative Example 2 indicated by On the other hand, also in the electrostatic precipitator 1 of Comparative Example 2, the counter electrode 12 of the charging section 10 is attached so as to be connected to the case 30, and the attached portion is connected to the ground terminal E.

In the electric precipitator 1 of Example 3, the ozone concentration was 3 ppb or less even when operated in a state in which almost 100% dust collection efficiency was obtained. This value is far below the environmental standard (0.05 ppm).

On the other hand, in the electric precipitator 1 of Comparative Example 2, the ozone concentration exceeds 7 ppb when operated in a state where almost 100% dust collection efficiency is obtained. Although this value is less than the environmental standard value (0.05 ppm), it is more than twice that of the electrostatic precipitator 1 of Example 3.

As described above, in the electrostatic precipitator 1 of the third embodiment, by providing the counter electrode 12 of the charging section 10 with the resistor section 122, high dust collection efficiency can be obtained while suppressing the ozone concentration to a low level.

(Example 4)

Here, the relationship between dust collection efficiency and ozone concentration in the case where the electric precipitator 1 and the high-voltage electrode 11 of the charging section 10 have different shapes will be described. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of Example 4.

9 is a perspective view of the charging unit 10 of the electrostatic precipitator 1 of Example 4. Also in FIG. 9, the ventilation direction is described as a vertical direction.

The high-voltage electrode 11 of the electrostatic precipitator 1 has a plurality of teeth rows 113 each having a plurality of teeth 111. Each row of teeth 113 has teeth 111 directed upwards and downwards. The tips of the teeth 111 are arranged to be zigzag (staggered) with each other between the tooth rows 113. That is, the tips of the teeth 111 do not face each other between the teeth rows 113, and between the tips of the teeth 111 of one tooth row 113, the teeth 111 of the other tooth row 113 The tip is arranged. That is, between the rows of teeth 113, the teeth 111 are arranged offset from each other in the row direction.

On the other hand, in the counter electrode 12 of the electrostatic precipitator 1, as in the third embodiment, the conductor portion 121 is an expanded metal.

10A and 10B are plan views of the high-voltage electrode 11 and the counter electrode 12 in the electric precipitator of Example 4, respectively. FIG. 10A shows the high-voltage electrode 11 and FIG. 10B shows the counter electrode 12.

As shown in Fig. 10A, by forming the teeth 111 in the vertical direction of all the teeth rows 113, the number of teeth 111 is larger than in the case of the third embodiment.

The high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 . The counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E.

The size of the support portion 14 of the high-voltage electrode 11 was about 400 mm in the left-right direction and about 300 mm in the vertical direction.

The high-voltage electrode 11 was made of SUS with a thickness of 0.5 mm. The distance S between the tips of the teeth 111 between the rows of teeth 113 was 20 mm. The high-voltage electrode 11 has five rows of toothed rows 113 (#1 to #5).

In the counter electrode 12, the conductor portion 121 was made of SUS expanded metal, and the size of the opening 124 was about 4 mm x about 8 mm. The resistor portion 122 covering the surface of the conductor portion 121 of the counter electrode 12 was made of polyimide resin with a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Ω·cm.

Fig. 11 is a diagram showing the relationship between the dust collection efficiency and the ozone concentration in the electric precipitator 1 of Example 4. On the other hand, here, the electrostatic precipitator 1 according to the above structure is shown as Example 4. In addition, the electrostatic precipitator 1 of Example 3 and the electrostatic precipitator 1 of Comparative Example 2 are shown together.

As can be seen from Fig. 11, in the electric precipitator 1 of Example 4, the ozone concentration was 2 ppb or less even when operated in a state where almost 100% dust collection efficiency was obtained. This ozone concentration is lower than that of the electrostatic precipitator 1 of Example 3.

This is considered to be due to the fact that the teeth 111 in the tooth row 113 of the high-voltage electrode 11 are arranged zigzag with each other between the tooth rows 113. That is, between the high-voltage electrode 11 and the counter electrode 12, the region (range) in which corona discharge is formed is wider than in the case where the teeth 111 are opposed to each other between the teeth rows 113. It is thought that

As described above, in the electric precipitator 1 of Example 4, by changing the shape of the high-voltage electrode 11, high dust collection efficiency can be obtained while suppressing the ozone concentration to a lower level.

12A to 12C are diagrams showing modified examples of the charging unit 10 of the electrostatic precipitator 1 of the fourth embodiment. FIG. 12A is a perspective view of the charging unit 10, FIG. 12B is a view of the charging unit 10 viewed from the counter electrode 12 side, and FIG. 12C is a cross-sectional view of the counter electrode 12 along the line XIIC-XIIC.

The conductor portion 121 of the counter electrode 12 is composed of a plurality of flat plates, and a resistor portion 122 is laminated on the surface of each flat plate constituting the plurality of flat plates. And, each flat plate is arranged so that it may become a pair with each row of teeth 113. Further, each flat plate is formed in a plane at a distance G from the high-voltage electrode 11. At this time, the width W of the conductor portion 121 is preferably smaller than the distance Q between the tips of the teeth 111 in the width direction of the conductor portion 121 in the tooth row 113 facing the conductor portion 121. Do.

On the other hand, a part of the conductor portion 121 (rear side with respect to the tooth row 113 side) is a conductor exposed region 123 that does not include the resistor portion 122. And, the counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E. On the other hand, the conductor exposed region 123 is formed so that discharge does not directly occur between the high voltage electrodes 11 . That is, the conductor exposed region 123 of the counter electrode 12 is exposed at a portion that does not cause dielectric breakdown, and the insulation distance between the high voltage electrode 11 and the conductor exposed region 123 of the counter electrode 12 is maintained. there is.

(Example 5)

In Examples 1 to 4, teeth 111 were used for the high-voltage electrode 11 in the charging section 10 of the electrostatic precipitator 1.

Next, the case where the wire 114 is used for the high voltage electrode 11 in the charging part 10 of the electrostatic precipitator 1 is demonstrated. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of the fifth embodiment.

13A and 13B are diagrams for explaining the charging unit 10 of the electrostatic precipitator 1 of the fifth embodiment. FIG. 13A is a perspective view of the charging unit 10, and FIG. 13B is a cross-sectional view along line XIIIB-XIIIB of FIG. 13A. Also in FIG. 13A, the ventilation direction is described from the upper side to the lower side in the paper.

As shown in FIG. 13A, the high-voltage electrode 11 of the charging part 10 of the electric precipitator 1 is provided with a plurality of wires 114. A plurality of wires 114 are formed in the left and right directions. Also, both ends of the plurality of wires 114 are fixed to the support part 14 . In addition, DC voltage is supplied to the plurality of wires 114 through wires formed on the circuit board of the support part 14 .

In the counter electrode 12 of the charging unit 10, the conductor unit 121 is a wire mesh (mesh) made of a conductive material. Also, the counter electrode 12 includes a resistor portion 122 formed to cover the surface of the conductor portion 121 (see FIGS. 14A and 14B to be described later).

As shown in the cross-sectional view of FIG. 13B, the counter electrode 12 is curved in a semi-cylindrical shape with a radius M so as to surround the plurality of wires 114, respectively. Here, the radius M is set to 1/2 of the distance S between the wires 114. Meanwhile, the counter electrode 12 may be formed in a semicircular shape surrounding the plurality of wires 114 .

The wire 114 of the high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 . Meanwhile, the support part 14 may be attached to the case 30 through the insulating spacer 32 . Further, the support portion 14 may be part of the case 30 .

On the other hand, the counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E.

14A and 14B are plan views of the high-voltage electrode 11 and the counter electrode 12 of the electrostatic precipitator 1 of Example 5, respectively. 14A shows the high voltage electrode 11, and FIG. 14B shows the counter electrode 12.

The high-voltage electrode 11 shown in FIG. 14A has a plurality of wires 114.

The counter electrode 12 shown in FIG. 14B is a wire mesh (mesh) in which the conductor portion 121 is made of a conductive material. And, it is provided with the resistor part 122 which covers the surface of the conductor part 121. On the other hand, as shown in FIG. 13B, when the counter electrode 12 is formed in a semi-cylindrical shape, the portion where the counter electrode 12 contacts the case 30 is a conductor exposed region (not provided with the resistor portion 122). 123).

Also in the electric precipitator 1 of Example 5, high dust collection efficiency was obtained while suppressing the ozone concentration to a low level.

This is due to the fact that the counter electrode 12 of the charging section 10 is provided with the resistor section 122 covering the surface of the conductor section 121, thereby limiting the discharge current. Then, it is considered that corona discharge is generated in the space surrounding each wire 114 by forming the counter electrode 12 in a semi-cylindrical shape on each of the plurality of wires 114 .

(Modified Example of High Voltage Electrode 11 in Charging Unit 10)

15A and 15B are views showing modified examples of the high-voltage electrode 11 in the charging section 10 of the electric precipitator 1. FIG. 15A is a view in which the teeth 111 are arranged in a different arrangement from those in FIG. 2A, and FIG. 15B is a view in which the teeth 111 are arranged in a different arrangement than in FIG. 10A.

First, Fig. 15A will be described.

In FIG. 2A, the connecting portions 112 of the uppermost and lowermost tooth rows 113 (#1 and #5 in FIG. 2) are formed by approaching or contacting the support portion 14. For this reason, in the uppermost and lowermost tooth rows 113 (#1 and #5 in Fig. 2A), only the teeth 111 in either the upper or lower direction are formed.

In contrast, in the high-voltage electrode 11 shown in Fig. 15A, all tooth rows 113 have teeth 111 both in the upward direction and in the downward direction.

Next, Fig. 15B will be described.

In Fig. 10A, all tooth rows 113 have teeth 111 in both upward and downward directions.

In contrast, in the high-voltage electrode 11 shown in FIG. 15B, the connection portions 112 of the uppermost and lowermost teeth rows 113 (#1 and #6 in FIG. 15B) approach or come into contact with the support portion 14. are forming For this reason, in the uppermost and lowermost tooth rows 113 (#1 and #6 in FIG. 15B), only the teeth 111 in either the upper or lower direction are formed.

Even if such a high-voltage electrode 11 is applied to the electric precipitator 1 of each of Example 1, Example 3, and Example 4, high dust collection efficiency can be obtained while suppressing the ozone concentration to a low level.

16A and 16B are views showing another modified example of the high-voltage electrode 11 in the charging section 10 of the electric precipitator 1. 16A is a view in which a plurality of needle rows 117 each having a plurality of needles 115 are formed, and the tips of the needles 115 are opposed between adjacent needle rows. 16B is a view in which a plurality of needle rows 117 including a plurality of needles 115 are formed, and the tips of the needles 115 are zigzag between adjacent needle rows 117.

The needle 115 and/or its tip are examples of sites that generate electric field concentration.

FIG. 16A shows that the teeth 111 of the high-voltage electrode 11 shown in FIG. 2A are replaced with needles 115. On the other hand, the needle 115 is a needle-shaped member with a sharp tip. In the needle row 117, the connecting portion 116 connecting the plurality of needles 115 is, for example, a circuit board on which wiring is formed, and the plurality of needles 115 and the wiring are connected.

FIG. 16B shows that the teeth 111 of the high-voltage electrode 11 shown in FIG. 10A are replaced with needles 115. Other configurations are the same as those of FIG. 10A, so descriptions are omitted.

Even if these high-voltage electrodes 11 are applied to the electrostatic precipitators 1 of each of Example 1, Example 3 and Example 4, high dust collection efficiency can be obtained while suppressing the ozone concentration to a low level.

On the other hand, the arrangement of the needles 115 shown in Figs. 16A and 16B may be changed to the arrangement of the teeth 111 shown in Figs. 15A and 15B, respectively.

In addition, instead of the sawtooth 111 or the needle 115 of the high voltage electrode 11, the high voltage electrode 11 may be, for example, a brush shape in which conductive carbon wire is coupled. On the other hand, a brush-shaped portion and/or its tip are examples of a portion generating electric field concentration.

(Modified Example of Counter Electrode 12 in Charging Unit 10)

FIG. 17 is a diagram explaining a modified example of the counter electrode 12 in the charging section 10 of the electrostatic precipitator 1. As shown in FIG.

The counter electrode 12 shown in FIG. 17 includes a conductor portion 121 which is a plate made of a conductive material having a plurality of openings 124 formed thereon, and a resistor portion 122 formed on the surface thereof. The opening 124 is formed through the plate serving as the conductor portion 121 . On the other hand, part of the conductor portion 121 (both ends in the left and right directions) is a conductor exposed region 123 that does not include the resistor portion 122 .

And, the counter electrode 12 is attached so that the conductor exposed region 123 is connected to the case 30, and the attached portion is connected to the ground terminal E.

On the other hand, the resistor unit 122 is formed to suppress a discharge current between the high voltage electrode 11 and the counter electrode 12 . Therefore, it is required that discharge does not occur between the high-voltage electrode 11 and the conductor portion 121 of the counter electrode 12 at least. From this, it is preferable that the resistor portion 122 is formed so as to cover at least the surface of the conductor portion 121 (plate) on the side facing the high voltage electrode 11.

The high-voltage electrode 11 and the counter electrode 12 described above may be used in combination, respectively.

In addition, the numerical value shown in Examples 1-5 is an example, and it is clear that it is not limited to these.

[Second Embodiment]

In the second embodiment, it is assumed that the high-voltage electrode 11 is composed of a plurality of tooth rows 113 each having a plurality of teeth 111, and the requirements set for the arrangement of the teeth 111 will be described. Here, it is assumed that the tips of the teeth 111 are displaced from each other between the rows of teeth 113. For example, between the rows of teeth 113, the ends of the teeth 111 are arranged in a zigzag pattern.

Fig. 18 is a diagram showing an example of the electrostatic precipitator 1 to which the first embodiment is applied. Here, the case 30 is indicated by a broken line, and the configuration of the charging unit 10 and the dust collection unit 20 formed inside the case 30 is made visible.

As for the structure of the electrostatic precipitator 1, the same code|symbol is attached|subjected to the same part as what was demonstrated in 1st Embodiment, and description is abbreviate|omitted, and a different part is demonstrated.

(Electrical part (10))

The charging unit 10 includes a high-voltage electrode 11 and a counter electrode 12 opposing the high-voltage electrode 11 .

The high-voltage electrode 11 has a plurality of teeth rows 113 (5 rows of #1 to #5 in FIG. 18) having a plurality of teeth 111 each having a pointed tip. Between adjacent tooth rows 113, in the direction of the tooth rows 113, the tips of the respective teeth 111 are formed to shift. In FIG. 18, between adjacent tooth rows 113, the tip of the tooth 111 in one tooth row 113 is arranged at the center of the tip of the tooth 111 in the other tooth row 113. there is. That is, between the adjacent tooth rows 113, the tip of each tooth 111 is arranged in a zigzag pattern.

Then, L (length L) is the length from the front end of the tooth 111 to the connecting portion 112, and the spacing (pitch) between the teeth 111 in the tooth row 113 is P (interval P). In addition, between adjacent tooth rows 113, the distance between the tips of the teeth 111 in the direction perpendicular to the tooth row is S (distance S).

The counter electrode 12 includes, for example, a conductor portion 121 made of a conductive material, which is an expanded metal, and a resistor portion 122 covering the surface thereof.

That is, the high voltage electrode 11 and counter electrode 12 in the charging unit 10 described in the second embodiment are the same as those in FIGS. 10A and 10B in Example 4 described in the first embodiment.

The distance G is between the high voltage electrode 11 and the counter electrode 12 .

And, as shown in FIG. 3A, the high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 made of an insulating material. The counter electrode 12 is attached so that the conductor exposed region 123 where the conductor portion 121 is exposed is electrically connected (conducted) to the case 30, and the attached portion (electrical contact) is connected to the ground terminal E. is connected to

(dust collection efficiency and ozone concentration)

Next, in the electric precipitator 1 to which the first aspect is applied, the results of measuring the dust collection efficiency and ozone concentration will be described. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of the sixth embodiment.

(Example 6)

In the charging section 10 of the electrostatic precipitator 1, the outer shape of the supporting section 14 of the high-voltage electrode 11 as viewed from the ventilation direction was approximately 400 mm in the left-right direction and approximately 300 mm in the vertical direction.

The teeth 111 and the connecting portion 112 of the high-voltage electrode 11 in the charging portion 10 were made of plate-shaped stainless steel (SUS) with a thickness of 0.5 mm. Then, the length L of the teeth 111 was set to 10 mm. Then, as in Figs. 10A and 10B and Fig. 18, five rows of tooth rows 113 were formed.

In the counter electrode 12 in the charging section 10, the conductor section 121 was made of an expanded metal made of SUS with an opening 124 of 4 mm x 8 mm. The resistance body portion 122 covering the surface of the conductor portion 121 was made of polyimide resin with a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Ω·cm.

The distance G between the high-voltage electrode 11 and the counter electrode 12 was 5 mm.

The high voltage electrode 21 and the counter electrode 22 in the dust collector 20 had a width of 20 mm in the ventilation direction and a length of about 400 mm in a direction orthogonal to the ventilation direction. Also, the distance between the high-voltage electrode 21 and the counter electrode 22 was about 1.5 mm. Then, a DC voltage of about 6 kV was applied between the high-voltage electrode 21 and the counter electrode 22 .

In addition, in the electrostatic precipitator 1 of Example 6, the resin member constituting the case 30 and the like was not formed in a range of about 5 mm (distance r) from the tip of the teeth 111.

Then, the charging unit 10 and the dust collection unit 20 were energized, and air was blown. The wind speed in the ventilation direction is 1 m/s.

In this state, when a DC voltage of about 4 kV is applied between the high-voltage electrode 11 and the counter electrode in the charging unit 10, ions start to be generated and floating particulates can be charged.

FIG. 19 is a diagram showing the relationship between the dust collection efficiency of the electric precipitator 1 and the ozone concentration with respect to the spacing P of the teeth 111 in the tooth row 113. As shown in FIG. The vertical axis on the left side of the figure represents dust collection efficiency (%), and the vertical axis on the right side of the figure represents ozone concentration (ppb). Also, the horizontal axis is the spacing P of the teeth 111. On the other hand, the horizontal axis shows the distance P between the teeth 111 based on the length L of the teeth 111.

Here, the ozone concentration was determined using an ozone concentration meter from the amount of ozone measured by the ozone concentration meter and the amount of air blown in by the ozone concentration meter. In addition, the dust collection efficiency is determined by counting the number of floating particulates upstream (before entering the electrostatic precipitator 1) and downstream (after exiting the electrostatic precipitator 1) in the ventilation direction of the electrostatic precipitator 1 by means of a particle counter. and saved

Here, the dust collection efficiency and ozone concentration were measured with the spacing P of the teeth 111 in the tooth row 113 set to 15 mm (1.5 L), 22.5 mm (2.25 L), and 35 mm (3.5 L). On the other hand, the distance S between the tips of the teeth 111 between the teeth rows 113 was fixed to 20 mm (2L).

As can be seen from FIG. 19, the dust collection efficiency increases as the distance P between teeth 111 increases. When the spacing P between teeth 111 is 2L or more, the dust collection efficiency is 90% or more.

In addition, the ozone concentration decreases as the distance P between teeth 111 increases. On the other hand, the ozone concentration in the measured range is 10 ppb or less, far below the environmental standard value (0.05 ppm). And, when the distance P between the teeth 111 is 2L or more, the ozone concentration is 5 ppb or less, which is detected by the human sense of smell.

FIG. 20 is a diagram showing the relationship between the dust collection efficiency of the electric precipitator 1 and the ozone concentration with respect to the distance S between the rows of teeth 113. As shown in FIG. The vertical axis on the left side of the figure represents dust collection efficiency (%), and the vertical axis on the right side of the figure represents ozone concentration (ppb). Also, the horizontal axis is the distance S between the rows of teeth 113. On the other hand, the horizontal axis shows the distance S between the tips of the teeth 111 between the teeth rows 113 based on the length L of the teeth 111.

Here, the dust collection efficiency and ozone concentration were measured with the distance S between the tips of the teeth 111 between the rows of teeth 113 being 10 mm (1 L), 20 mm (2 L), 30 mm (3 L), and 40 mm (4 L). . On the other hand, the spacing P between the teeth 111 in the tooth row 113 was fixed to 35 mm (3.5 L).

As can be seen from Fig. 20, when the distance S between the rows of teeth 113 is 3L or less, the dust collection efficiency is 90% or more. However, when the distance S between the rows of teeth 113 exceeds 3L, the dust collection efficiency decreases.

The ozone concentration hardly depends on the distance S between the rows of teeth 113, and the larger the distance P between the teeth 111, the smaller it is. On the other hand, the ozone concentration in the measured range is 5 ppb or less detected by the human sense of smell.

(discharge area 13)

21A to 21D are diagrams schematically explaining the state of discharge in the charging unit 10. Fig. 21A is a plan view seen from the high-voltage electrode 11 side, and Fig. 21B is a cross-sectional view along the line XXIB-XXIB in Fig. 21A. FIG. 21c shows a case in which the spacing of teeth 111 is a narrower (smaller) spacing P' than the spacing P in FIG. 21a, and FIG. ' is the case.

As shown in FIGS. 21A and 21B, the discharge region 13 between the high-voltage electrode 11 and the counter electrode 12 widens in the direction away from the tip of the tooth 111 in the high-voltage electrode 11. , it is considered that it faces the counter electrode 12 obliquely.

Here, as shown in Fig. 18, the teeth 111 are arranged perpendicularly or obliquely to the ventilation direction (counter electrode 12). For this reason, the line of electric force from the front end of the saw tooth 111 cannot be directed toward the opposite electrode 12 from the front end of the saw tooth 111 vertically. That is, the line of electric force spreads from the front end of the sawtooth 111 toward a direction away from the front end, and faces the counter electrode 12 at an angle.

Therefore, as shown in FIG. 21C, if the spacing of the teeth 111 in the tooth train 113 is set to a spacing P' that is narrower (smaller) than the spacing P in FIG. 21A, adjacent teeth in the tooth train 113 Discharge regions 13 of teeth 111 overlap each other, resulting in interference. Accordingly, as shown in Fig. 19, it is considered that when the spacing P between the teeth 111 becomes smaller, the dust collection efficiency decreases and the ozone concentration increases.

On the other hand, as shown in FIG. 21D, if the distance between the tips of the teeth 111 between the rows of teeth 113 is set to a distance S' that is wider (larger) than the distance S in FIG. 21A, the area of the high-voltage electrode 11 ( area in a direction orthogonal to the ventilation direction), the proportion occupied by the discharge region 13 decreases. For this reason, as shown in FIG. 20, when the distance S between the rows of teeth 113 increases, it is considered that the dust collection efficiency decreases.

As described above, when the tips of the teeth 111 are shifted in the direction of the tooth row 113, the distance P between the teeth 111 in the tooth row 113 is 2L or more, and the tooth row 113 It is preferable that the distance S between them is 3L or less.

On the other hand, the arrangement of the teeth 111 of the high-voltage electrode 11 may be an arrangement shown in FIG. 15B different from that in FIG. 10A.

Also, the teeth 111 shown in Fig. 10A may be replaced with needles 115 as shown in Fig. 16B. It is also possible to replace the teeth 111 shown in FIG. 15B with needles 115.

Even in this case, when the length of the needle 115 is L (length L), the interval P between the needles 115 in the needle row 117 is 2L or more, and the needles between the needle rows 117 ( 115), the ozone concentration can be kept low while obtaining high dust collection efficiency by setting the distance S between the ends to 3 L or less.

Incidentally, the counter electrode 12 may be substituted with those shown so far.

As described above, in the electrostatic precipitator 1 to which the second embodiment is applied, the counter electrode 12 of the charging section 10 is formed to cover the conductor section 121 and the surface of the conductor section 121. It is constituted by one resistance body part (122). Therefore, the discharge current is suppressed to be small compared to the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed to a low level.

And, the high-voltage electrode 11 of the charging unit 10 is fixed to the case 30 via an insulating spacer 32 . In addition, the resin member constituting the case 30 or the like is not formed within a range of a predetermined distance r from the tip of the tooth 111 of the high-voltage electrode 11 . In addition, the counter electrode 12 is electrically connected (connected) to the case 30 in the conductor exposed region 123. Accordingly, the case 30 is suppressed from being charged with static electricity, and the dust collection efficiency is improved.

In the electrostatic precipitator 1 to which the second embodiment is applied, in the charging section 10, the high-voltage electrode 11 and the counter electrode 12 are disposed in the ventilation direction. In addition, the portion of the high-voltage electrode 11 that generates discharge is made of sawtooth 111, and the sawtooth 111 is arranged orthogonally or inclined (crossed) with respect to the ventilation direction. Therefore, the distance G between the high voltage electrode 11 and the counter electrode 12 can be set as short as 5 mm, for example. Accordingly, the electric precipitator 1 can be miniaturized.

In addition, the numerical value shown in 2nd Embodiment is an example, and it is clear that it is not limited to these.

[Third Embodiment]

In the second embodiment, the teeth 111 of the high-voltage electrode 11 in the charging section 10 are arranged offset from each other with respect to the direction of the teeth rows 113 between the rows of teeth 113 .

In the third embodiment, the arrangement between the tooth rows 113 of the teeth 111 of the high-voltage electrode 11 in the charging section 10 is different from that in the second embodiment. In this case, the requirements set for the arrangement of the teeth 111 will be described.

Fig. 22 is a diagram showing an example of the electrostatic precipitator 1 to which the third embodiment is applied. Here, the case 30 is indicated by broken lines, and the configurations of the charging unit 10 and the dust collecting unit 20 formed inside the case 30 are shown.

As for the structure of the electrostatic precipitator 1, the same code|symbol is attached|subjected to the same part as what was demonstrated in 1st embodiment and 2nd embodiment, and description is abbreviate|omitted, and a different part is demonstrated.

(Electrical part (10))

The charging unit 10 includes a high-voltage electrode 11 and a counter electrode 12 opposing the high-voltage electrode 11 .

The high-voltage electrode 11 has a plurality of teeth rows 113 (#1 to #5 in FIG. 22) having a plurality of teeth 111. The longitudinal direction of each row of teeth 113 is directed in the left-right direction. The uppermost tooth row 113 (#1 in FIG. 22) has a plurality of teeth 111 (10 in FIG. 22) arranged toward the lower side. The lowermost tooth row 113 (#5 in FIG. 22) has a plurality of teeth 111 (10 in FIG. 22) arranged upward. In addition, the tooth rows 113 (#2 to #4 in FIG. 22) in between include a plurality of teeth 111 (10 in FIG. 22) arranged upward and a plurality of teeth 111 arranged downward. ) (10 in Fig. 22).

The high-voltage electrode 11 is formed so that the tips of the teeth 111 face each other between adjacent teeth rows 113.

That is, the high-voltage electrode 11 in the charging section 10 described in the third embodiment is the same as that described in FIG. 2A in the first embodiment.

The counter electrode 12 is the same as in the second embodiment. That is, the counter electrode 12 in the charging section 10 described in the third embodiment is the same as in FIG. 10B in Example 4 described in the first embodiment.

(discharge area 13)

FIG. 23 is a diagram schematically illustrating the state of discharge in the charging unit 10. As shown in FIG.

In the high-voltage electrode 11 of the charging section 10 in the third embodiment, the tips of the teeth 111 face each other between the tooth rows 113. Accordingly, the discharge regions 13 are also opposed to each other between the rows of teeth 113. For this reason, if the distance S between the tooth rows 113 is shortened (small), the discharge regions 13 overlap each other between the opposing teeth 111.

Therefore, when the tips of the teeth 111 are opposed to each other between the rows of teeth 113, compared to the case where the tips of the teeth 111 are arranged in a zigzag pattern between the rows of teeth 113, the teeth between the rows of teeth 113 ( 111) The distance S between the tips must be increased.

(dust collection efficiency and ozone concentration)

Similar to the electrostatic precipitator 1 shown in the second embodiment, the teeth 111 and the connecting portion 112 of the high-voltage electrode 11 in the charging portion 10 are made of plate-shaped stainless steel (SUS) with a thickness of 0.5 mm. made up Then, the length L of the teeth 111 was set to 10 mm. Then, as shown in Figs. 1 and 2A, five rows of sawtooth rows 113 were formed.

In the counter electrode 12 in the charging section 10, the conductor section 121 was made of an expanded metal made of SUS with an opening 124 of about 4 mm x about 8 mm. The resistance body portion 122 covering the surface of the conductor portion 121 was made of polyimide resin with a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Ω·cm.

The distance G between the high-voltage electrode 11 and the counter electrode 12 was 5 mm.

About the dust collection part 20, it was carried out similarly to 1st Embodiment.

Then, the charging unit 10 and the dust collection unit 20 were energized, and air was blown. The wind speed in the ventilation direction is 1 m/s.

Then, when a DC voltage of about 4 kV was applied between the high-voltage electrode 11 and the counter electrode in the charging unit 10, ions started to be generated and the floating particulates could be charged.

Dust collection efficiency and ozone concentration with the distance S between the tips of the teeth 111 between the rows of teeth 113 being 50 mm (5L), 60 mm (6 L), 70 mm (7 L), 80 mm (8 L), and 90 mm (9 L) was measured. On the other hand, the spacing P between the teeth 111 in the tooth row 113 was fixed to 35 mm (3.5 L).

When the teeth 111 are opposed between the teeth rows 113, the distance S between the tips of the teeth 111 between the teeth rows 113 is preferably 6L or more and 8L or less. In this range, the dust collection efficiency was 90% or more, and the ozone concentration was 5 ppb or less, which is detected by the human sense of smell.

On the other hand, if the distance S between the tips of the teeth 111 between the teeth rows 113 is less than 6L, electric fields interfere with each other between the opposing teeth 111, and the discharge current tends to flow. Accordingly, the ozone concentration increased.

On the other hand, when the distance S between the tips of the teeth 111 between the rows of teeth 113 exceeded 8 L, the ratio of the discharge region 13 occupied by the high-voltage electrode 11 decreased, and the dust collection efficiency decreased.

On the other hand, the spacing P of the teeth 111 in the direction along the tooth row 113 is the same as in the first embodiment.

On the other hand, the high-voltage electrode 11 may have the arrangement of teeth 111 shown in FIG. 15A different from FIG. 2A.

Also, the teeth 111 shown in Fig. 2A may be replaced with needles 115 as shown in Fig. 16A. It is also possible to replace the teeth 111 shown in FIG. 15A with needles 115.

Even in this case, when the length of the needles 115 is L (length L), the distance P between the needles 115 in the needle rows 117 is 2L or more, and the needles 115 between the needle rows 117 ), by setting the distance S between the ends to 6 L or more and 8 L or less, the ozone concentration can be suppressed to a low level while obtaining high dust collection efficiency.

Incidentally, the counter electrode 12 may be substituted with those shown so far.

As described above, in the electrostatic precipitator 1 to which the third embodiment is applied, the counter electrode 12 of the charging section 10 is formed to cover the conductor section 121 and the surface of the conductor section 121. It is constituted by one resistance body part (122). Therefore, the discharge current is suppressed to be small compared to the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed to a low level.

And, the high-voltage electrode 11 of the charging unit 10 is fixed to the case 30 via an insulating spacer 32 . In addition, the resin member constituting the case 30 or the like is not formed within a range of a predetermined distance r from the tip of the tooth 111 of the high-voltage electrode 11 . In addition, the counter electrode 12 is electrically connected (connected) to the case 30 in the conductor exposed region 123. Accordingly, the case 30 is suppressed from being charged with static electricity, and the dust collection efficiency is improved.

In the electrostatic precipitator 1 to which the third embodiment is applied, in the charging section 10, the high-voltage electrode 11 and the counter electrode 12 are disposed in the ventilation direction. In addition, the portion of the high-voltage electrode 11 that generates discharge is made of sawtooth 111, and the sawtooth 111 is arranged orthogonally or inclined (crossed) with respect to the ventilation direction. Therefore, the distance G between the high voltage electrode 11 and the counter electrode 12 can be set as short as 5 mm, for example. Accordingly, the electric precipitator 1 can be miniaturized.

In addition, the numerical value shown in 3rd embodiment is an example, and it is clear that it is not limited to these.

[Fourth Embodiment]

In the fourth embodiment, a current limiting circuit for suppressing generation of pulse-shaped current due to random secondary electron emission from the high-voltage electrode or the like will be described. The generation of ozone becomes remarkable by the generation of a pulse-shaped current due to random secondary electron emission from a high-voltage electrode or the like.

24 is a diagram showing an example of the electric precipitator 1 to which the fourth embodiment is applied. Here, the case 30 is indicated by a broken line, and the configuration of the charging unit 10 and the dust collection unit 20 formed inside the case 30 is made visible.

As for the structure of the electrostatic precipitator 1, the same code|symbol is attached|subjected to the same part as what was demonstrated in 1st - 3rd embodiment, and description is abbreviate|omitted, and a different part is demonstrated.

(Electrical part (10))

The charging unit 10 includes a high-voltage electrode 11 and a counter electrode 12 opposing the high-voltage electrode 11 . The high-voltage electrode 11 and the counter electrode 12 are arranged to face each other.

As an example, the high voltage electrode 11 includes a plurality of toothed rows 113 (#1 to # in FIG. 24) having a plurality of sawtooth-shaped portions 111 (hereinafter referred to as sawtooth 111) each having a sharp tip. 5) is provided. Each row of teeth 113 is oriented in a left-right direction. Further, each tooth row 113 includes a plurality of teeth 111 arranged upward and a plurality of teeth 111 arranged downward.

Each tooth 111 is formed in a direction orthogonal to the ventilation direction. In addition, the tips of the respective teeth 111 are arranged to be offset from each other with respect to the direction of the teeth rows 113 between adjacent tooth rows 113, for example, between #1 and #2 of the tooth rows 113. has been

On the other hand, in FIG. 24, between adjacent tooth rows 113, the tip of the tooth 111 in one tooth row 113 is disposed at the center of the tip of the tooth 111 in the other tooth row 113. has been That is, between the adjacent teeth rows 113, the tips of the respective teeth 111 are arranged in a zigzag pattern.

Each tooth 111 may be formed in an oblique direction with respect to the ventilation direction. That is, each tooth 111 is formed in a direction crossing the ventilation direction.

A plurality of teeth 111 in each row of teeth 113 is connected to a connecting portion 112 . One end of each connecting portion 112 is connected to a wiring 17 formed on a circuit board 15 described later (see FIG. 26 described later). This wiring 17 is connected to a high voltage terminal 18 and , connected to the anode (high voltage supply terminal) of the high voltage generating circuit 40.

The plurality of teeth 111 and the connecting portion 112 are integrally made of a conductive material. Therefore, here, the plurality of teeth 111 and the connecting portion 112 are integrated and expressed as a tooth row 113.

And, the row of teeth 113 and the circuit board 15 are fixed to the support part 14 . On the other hand, the support portion 14 may be part of the case 30 .

On the other hand, the number of tooth rows 113 and the number of teeth 111 in the tooth row 113 are set to a predetermined number.

The counter electrode 12 is composed of a member (conductor portion) made of a conductive material having an opening (hole) 124 through which ventilation is possible, and a resistive material formed to cover the surface and functioning as a resistance to current. A member (resistor body part) is provided. The conductor portion of the counter electrode 12 is connected to the negative electrode (reference voltage supply terminal) of the high voltage generating circuit 40 of the charging portion 10 .

Forming the resistor portion on the counter electrode 12 is to limit the discharge current and suppress the generation of ozone. Accordingly, characteristics such as the volume resistivity of the resistive body portion are set in consideration of the relationship between dust collection efficiency and ozone concentration. For example, the member constituting the resistor portion preferably has a relative permittivity of 3 or more and a volume resistivity of 10 ¹⁴ Ω·cm or more and 10 ¹⁸ Ω·cm or less. On the other hand, the resistance value in the thickness direction changes according to the thickness of the resistor body portion. Therefore, the limiting discharge current can be set according to the thickness of the resistive body portion.

On the other hand, it is not necessary to form the resistance body part.

In Fig. 24, the counter electrode 12 is made of a plurality of rectangular plate-like members arranged in parallel as an example. A space between the plate-like members functions as an opening 124 . On the other hand, the width (size) of the rectangular plate-shaped member and the size of the opening 124 are set in consideration of the discharge generated between the high-voltage electrodes 11.

The distance G is between the high voltage electrode 11 and the counter electrode 12 .

In the charging section 10 of the electrostatic precipitator 1, the high-voltage electrode 11 is attached to the support section 14 via an insulating spacer made of the above insulating material (insulation spacer 32 shown in FIG. 3). And, the support part 14 is attached to the case 30. On the other hand, the support portion 14 may be part of the case 30 . Further, the supporting portion 14 may be an insulating spacer.

On the other hand, the counter electrode 12 forms a conductor exposed region exposing the conductor portion, and is attached to the case 30 such that the conductor exposed region electrically contacts (conducts) the case 30 .

(current limiting circuit 16)

Ozone generation becomes remarkable by a pulse-shaped current or the like resulting from random secondary electron emission from the high-voltage electrode 11.

The charging section 10 of the electrostatic precipitator 1 described in the fourth embodiment forms a current limiting circuit 16 that limits a pulse-shaped current. This further suppresses the generation of ozone.

25 is an equivalent circuit of the charging section 10 of the electrostatic precipitator 1.

Here, the space (discharge space) between the high-voltage electrode 11 and the counter electrode 12 where discharge is generated is replaced with a capacitor C. That is, one terminal of the capacitor C serves as the high voltage electrode 11 and the other terminal serves as the counter electrode 12.

And, the current limiting circuit 16 is formed on the high-voltage electrode 11 side of the condenser C.

The high voltage generating circuit 40 includes a voltage source 40A, a resistor R0, and a capacitor C0.

The + side of the voltage source 40A is connected to one terminal of the resistor R0. The other terminal of resistor R0 is connected to one terminal of capacitor C0. The negative side of the voltage source 40A is connected to one terminal of the capacitor C0. One terminal of the capacitor C0 is the anode 40B of the high voltage generator circuit 40, and the other terminal of the capacitor C0 is the cathode 40C.

Here, the resistor R0 limits the current from the high voltage generator circuit 40, and the capacitor C0 stabilizes the DC high voltage (DC voltage) output from the high voltage generator circuit 40.

The current limiting circuit 16 has a parallel circuit of an inductor Ls and a diode Ds. One terminal of the parallel circuit of the inductor Ls and the diode Ds is connected to the anode 40B of the high voltage generator circuit 40, and the other terminal is connected to the cathode 40C of the high voltage generator circuit 40. .

The diode Ds has an anode connected to the high voltage electrode 11 and a cathode connected to the anode 40B of the high voltage generator circuit 40. That is, in a normal state where the potential of the anode 40B of the high voltage generator circuit 40 is higher (greater) than the potential of the high voltage electrode 11, the diode Ds is connected in a reverse direction in which no current flows.

The operation of the current limiting circuit 16 will be described.

The voltage (inter-electrode voltage) between the high-voltage electrode 11 and the counter electrode 12 fluctuates according to the current flowing between the high-voltage electrode 11 and the counter electrode 12 . When a discharge occurs between the high-voltage electrode 11 and the counter electrode 12, electrons generated by the discharge collide with the high-voltage electrode 11 to emit secondary electrons. The amount of these secondary electrons fluctuates depending on the discharge state. When the number of secondary electrons increases, the discharge current increases and the generation of ozone increases.

Therefore, in order to suppress ozone generation, it is necessary to limit the discharge current that increases with secondary electron emission. For this reason, when the discharge current increases, it is effective to lower the potential of the high-voltage electrode 11 and decrease the discharge current. The discharge current that increases with the emission of secondary electrons is a pulse-like current that is generated in a pulse shape. The pulse-shaped current contains a high-frequency component (high-frequency current).

The inductor Ls has high impedance with respect to high-frequency components. Therefore, the high frequency current is limited by the inductor Ls.

Therefore, the charging section 10 of the electrostatic precipitator 1 to which the fourth embodiment is applied is provided with the current limiting circuit 16 having the inductor Ls.

On the other hand, when the current does not flow, the inductor Ls tries to maintain the current flowing state and generates counter-electromotive force. The counter electromotive force makes the potential of the high voltage electrode 11 higher (greater) than the potential of the anode 40B of the high voltage generating circuit 40. Accordingly, the inter-electrode voltage between the high-voltage electrode 11 and the counter electrode 12 becomes higher (greater) than a predetermined voltage. Then, the discharge current increases and the generation of ozone increases.

Accordingly, the current limiting circuit 16 has a diode Ds connected in parallel to the inductor Ls. As described above, the diode Ds is connected in the direction (sequential direction) in which the current flows with respect to the counter electromotive force generated in the inductor Ls. Therefore, it functions to dissipate the counter electromotive force generated in the inductor Ls.

On the other hand, the inductor Ls has a small impedance in a normal state in which DC or low-frequency component current flows. Therefore, the inductor Ls does not affect the operation of the charging section 10 in a normal state.

In addition, in the case where counter electromotive force is not generated by the inductor Ls, that is, in a normal state where the potential of the anode 40B of the high voltage generator circuit 40 is higher (larger) than the potential of the high voltage electrode 11, the diode Ds ) is reverse connected. Therefore, the diode Ds does not affect the operation of the charging section 10 in a normal state.

As described above, the inductor Ls in the current limiting circuit 16 suppresses the pulse-shaped current generated along with secondary electron emission. Further, the diode Ds connected in parallel to the inductor Ls suppresses an increase in voltage between electrodes due to counter electromotive force generated by the inductor Ls. Accordingly, in the charging unit 10, an increase in ozone generation due to the pulse-shaped current is suppressed.

Next, specific operations of the current limiting circuit 16 will be described.

(Example 7)

Fig. 26 is a diagram showing an example of the high-voltage electrode 11 to which the current limiting circuit 16 by the parallel circuit of the inductor Ls and the diode Ds is connected. In FIG. 26, the high voltage generating circuit 40 is also shown. Here, the electrostatic precipitator 1 having the high-voltage electrode 11 in which the current limiting circuit 16 is formed is referred to as the seventh embodiment.

On the other hand, the number of teeth 111 and the number of teeth rows 113 are simplified and expressed.

The high voltage generating circuit 40 generates a DC voltage of 4 to 7 kV.

A plurality of teeth 111 in the high-voltage electrode 11 and a tooth row 113 to which these teeth 111 are connected were constituted by plate-shaped stainless steel (SUS) having a thickness of 0.5 mm.

On the circuit board 15, a current limiting circuit 16 and wiring 17 were formed. Then, the plurality of rows of teeth 113 were connected by wiring 17 on the circuit board 15 . One terminal of the parallel circuit of the inductor Ls and the diode Ds constituting the current limiting circuit 16 is connected to the wiring 17. The other terminal of the parallel circuit was connected to the high voltage terminal (18). The high voltage terminal 18 is connected to the anode 40B of the high voltage generator circuit 40. On the other hand, the diode Ds is connected in the direction described in FIG. 25 .

Here, the length L from the tip of the tooth 111 to the connecting portion 112 was 10 mm, and the distance P between the teeth 111 in the tooth row 113 was 34.6 mm. Further, between adjacent tooth rows 113, the distance S between the tips of the teeth 111 in the direction perpendicular to the tooth rows 113 was set to 30 mm.

The inductor Ls in the current limiting circuit 16 was 100 µH or more. The diode Ds had a reverse breakdown voltage of 7 kV or more. On the other hand, the diode Ds may be configured by connecting a plurality of diodes in series so that the reverse withstand voltage is 7 kV or higher.

Conductor portions of a plurality of rectangular plate-like members of the counter electrode 12 were each made of SUS with a width of 10 mm. On the other hand, the resistor part was made of polyimide resin with a thickness of 50 μm.

The distance G between the high-voltage electrode 11 and the counter electrode 12 was 5 mm.

(Comparative Example 3)

Here, the electrostatic precipitator 1 of Comparative Example 3 to which the fourth embodiment is not applied will be described.

The electrostatic precipitator 1 of Comparative Example 3 has a current limiting circuit 16 composed of a resistor R1.

27 is an equivalent circuit of the charging unit 10 including the current limiting circuit 16 by resistance.

In the charging section 10 shown in FIG. 27, in the current limiting circuit 16 of the charging section 10 shown in FIG. 25, the parallel circuit of the inductor Ls and the diode Ds is replaced with a resistor R1. . Since the other configurations are the same, the same reference numerals are attached and descriptions are omitted.

On the other hand, the resistance R was 1 MΩ.

(Comparison between Example 7 and Comparative Example 3)

Example 7 and Comparative Example 3 The electric precipitator 1 was operated by supplying electricity to the charging section 10 and the dust collection section 20 of each electrostatic precipitator 1 .

When a DC voltage of about 4 kV was applied from the high voltage generating circuit 40 to the charging unit 10, ions started to be generated and the floating particulates could be charged.

When a DC voltage of 5 kV or more is applied from the high voltage generating circuit 40 to the charging section 10, a random pulse-like current accompanying secondary electron emission is generated.

However, in both the electrostatic precipitators 1 of Example 7 and Comparative Example 3, the current limiting circuit 16 functioned, and the increase in ozone due to the pulsed current was suppressed.

28A and 28B are diagrams showing temporal changes in the voltage between electrodes in the charging section 10 of the electrostatic precipitator 1 of Example 7 and the electrostatic precipitator 1 of Comparative Example 3, respectively. 28A is Example 7, and FIG. 28B is Comparative Example 3. The horizontal axis is time (ns), and the vertical axis is voltage between electrodes (kV).

In the electrostatic precipitator 1 of Example 7, a voltage drop of about 270 V occurs when a pulse-shaped current due to secondary electron emission is generated around 100 ns. That is, the inductor Ls of the current limiting circuit 16 is enabled to lower the potential of the high-voltage electrode 11. Then, when the pulse-like current stops, the high-voltage electrode 11 returns to the original voltage within 10 ns.

In addition, generation of overvoltage (overshoot) to the high voltage side due to the counter electromotive force of the inductor Ls is not seen in the interelectrode voltage. This is because the counter electromotive force is extinguished by the diode Ds.

On the other hand, also in the electrostatic precipitator 1 of Comparative Example 3, when a pulse-shaped current due to secondary electron emission is generated around 100 ns, a voltage drop of about 270 V occurs. That is, the resistor R1 of the current limiting circuit 16 functions to lower the potential of the high-voltage electrode 11. However, when the pulsed current stops, the high-voltage electrode 11 returns to the original voltage in 50 ns or more. This is because the time constant of the capacitor (condenser C in Fig. 25) and the resistor R1 constituted between the high voltage electrode 11 and the counter electrode 12 is large.

That is, since the impedance of the inductor Ls to DC or low-frequency current is smaller than that of the resistor R1, the time until the voltage returns to the original voltage can be shortened (shortened).

Thereby, the ratio of the period during which the electrostatic precipitator 1 exhibits the dust collecting function is increased, and the decrease in the dust collection efficiency is suppressed.

On the other hand, when the high voltage generating circuit 40 supplies a DC voltage of 4 to 7 kV, it is preferable that the inductor Ls causes a potential drop of 200 to 300 V.

29 is another equivalent circuit of the charging unit 10 including the current limiting circuit 16.

In FIG. 25 , the current limiting circuit 16 is connected on the path to the high voltage electrode 11 , but in FIG. 29 , the current limiting circuit 16 is connected on the path to the counter electrode 12 .

Even in this case, the operation is similar to that in the case of FIG. 25 .

(Example 8)

In the charging section 10 in the electrostatic precipitator 1 of Example 7, one current limiting circuit 16 is formed for the high voltage electrode 11. In the charging section 10 of the electrostatic precipitator 1 according to the eighth embodiment, a current limiting circuit 16 is formed for each row of teeth 113 of the high-voltage electrode 11.

Fig. 30 is a diagram showing an example of the high-voltage electrode 11 connected to the current limiting circuit 16 for each row of teeth 113 in the charging section 10 of the electrostatic precipitator 1 of Example 8.

Here, the high-voltage electrode 11 has a plurality of teeth rows 113. Corresponding to each tooth row 113, a current limiting circuit 16 formed by a parallel circuit of an inductor Ls and a diode Ds is formed on the circuit board 15. Then, each of the plurality of gear trains 113 is connected to a corresponding current limiting circuit 16. A plurality of current limiting circuits 16 are connected to a wire 17 connected to a high voltage terminal 18. The high voltage terminal 18 is connected to the anode 40B of the high voltage generating circuit 40 .

That is, in the electrostatic precipitator 1 of the eighth embodiment, the high-voltage electrode 11 of the charging section 10 is divided, and the current limiting circuit 16 is formed in each divided section. Here, the row of teeth 113 is an example of a sub high-voltage electrode in which the high-voltage electrode 11 is divided.

In this way, even if a drop in potential occurs in one row of teeth 113 due to a pulse current or the like caused by emission of secondary electrons, a drop in potential does not occur in the other row of teeth 113.

That is, since the drop in the voltage between electrodes (potential drop) shown in FIG. 28A occurs in the inductor Ls of the current limiting circuit 16, it does not affect the potential of the anode 40B of the high voltage generator circuit 40. . Thus, the other tooth rows 113 remain normal. Thereby, the fall of the dust collection efficiency of the electric precipitator 1 is suppressed.

On the other hand, in Fig. 30, the current limiting circuit 16 is formed for each gear row 113, but it is also possible to form the current limiting circuit 16 for each group by making the gear row 113 a group.

(Example 9)

In the charging section 10 in the electrostatic precipitator 1 of Example 8, a current limiting circuit 16 is formed for each of the plurality of teeth rows 113 of the high-voltage electrode 11. In the charging section 10 of the electrostatic precipitator 1 according to the ninth embodiment, the current limiting circuit 16 is formed on each of the plurality of teeth 111 in the tooth row 113.

Fig. 31 is a diagram showing an example of a high-voltage electrode 11 connected to a current limiting circuit 16 for each tooth 111 in the charging section 10 of the electrostatic precipitator 1 of Example 9.

The current limiting circuit 16 is a parallel circuit of an inductor Ls and a diode Ds.

As shown in Fig. 31, the high-voltage electrode 11 has a plurality of teeth rows 113 each having a plurality of teeth 111. Here, the part of the tooth 111 is marked as the high-voltage electrode 11.

In the tooth row 113, a plurality of teeth 111 are fixed to the circuit board 15 and connected to the wiring 17 on the circuit board 15. In addition, each tooth 111 is connected to a current limiting circuit 16 configured on a circuit board 15, respectively. The current limiting circuit 16 has a parallel circuit of an inductor Ls and a diode Ds.

The plurality of toothed rows 113 are fixed to the high voltage terminal 18 at one end of the circuit board 15 . And, the wiring 17 of the circuit board 15 is connected to the high voltage terminal 18. And, the high voltage terminal 18 is connected to the anode 40B of the high voltage generating circuit 40 .

The circuit board 15 is, for example, a base member of a printed wiring board (PCB), and printed wiring may be used as the wiring 17 . In addition, the high voltage terminal 18 is made of a conductive material such as copper plate.

In this way, even if a potential drop occurs in one tooth 111 due to a pulse current or the like caused by secondary electron emission, the potential drop does not occur in the other tooth 111. Thus, the other teeth 111 remain normal. Thereby, the fall of the dust collection efficiency of the electric precipitator 1 is further suppressed.

That is, also in the electrostatic precipitator 1 of the ninth embodiment, the high-voltage electrode 11 of the charging section 10 is divided, and the current limiting circuit 16 is formed in each divided section. Here, the tooth 111 is another example of a sub high-voltage electrode in which the high-voltage electrode 11 is divided.

For example, the total length D of the teeth 111 is 10 mm, the length L from the tip of the teeth 111 to the circuit board 15 is 5 mm, and the distance P between the teeth 111 in the tooth row 113 is You can do it with 30mm. And, the distance S between the tips of the teeth 111 between the teeth rows 113 can be 30 mm.

Meanwhile, in FIG. 31 , the current limiting circuit 16 is formed for each tooth 111, but it is also possible to form the current limiting circuit 16 for each group by making the tooth 111 a group.

In the fourth embodiment, it is assumed that the high-voltage electrode 11 has a plurality of teeth rows 113 including a plurality of teeth 111 . Instead of the sawtooth 111, the high-voltage electrode 11 may be a pointed needle. In addition, the high-voltage electrode 11 may be a linear wire made of a conductive material instead of the row of teeth 113.

Incidentally, the counter electrode 12 may be substituted with those shown so far.

And the numerical value shown in 4th Embodiment is an example, and it is clear that it is not limited to these.

[Fifth Embodiment]

In the fourth embodiment, the current limiting circuit 16 includes a parallel circuit of an inductor Ls and a diode Ds, and suppresses generation of pulse-shaped current due to random secondary electron emission from the high-voltage electrode.

In the fifth embodiment, the current limiting circuit 16 further includes a circuit for suppressing short-circuit current when the high-voltage electrode 11 and the counter electrode 12 are short-circuited.

Other configurations are the same as those in the fourth embodiment, so descriptions are omitted.

32 is an equivalent circuit of the charging unit 10 in the electric precipitator 1 to which the fifth embodiment is applied.

Here, as shown in Example 8 or Example 9, the high-voltage electrode 11 is divided into a plurality of parts (cogwheel 113, sawtooth 111), and the current limiting circuit 16 is provided in each part. It was said that it corresponds to the case where it is formed. For this reason, two current limiting circuits 16 (referred to as current limiting circuits 16-1 and 16-2 in Fig. 32) are indicated. Since the current limiting circuits 16-1 and 16-2 have the same configuration, they are referred to as current limiting circuits 16 when not distinguished.

That is, the current limiting circuit 16-1 is connected to the capacitor C1 replacing the space where discharge is generated (discharge space), and the current limiting circuit 16-2 is connected to the capacitor C2 replacing the other discharge space. is connected to Configurations other than the current limiting circuit 16 are the same as those in the description in FIG. 25 of the fourth embodiment, so the same reference numerals are given and descriptions are omitted.

The current limiting circuit 16 is explained by the current limiting circuit 16-1.

The current limiting circuit 16 includes a secondary electron current limiting portion 16A and a short-circuit current limiting portion 16B. The secondary electron current limiting section 16A is a parallel circuit of an inductor Ls and a diode Ds that suppresses an increase in discharge current due to a pulse current or the like caused by secondary electron emission described in the fourth embodiment.

The short-circuit current limiting unit 16B includes a field effect transistor (FET), a resistor (resistor element) Rs, and a capacitor Cs. Also, the drain of the FET serves as one terminal of the short-circuit current limiting section 16B. The source of the FET is connected to one terminal of a parallel circuit of a resistor Rs and a capacitor Cs. Also, the gate of the FET is connected to the other terminal of the parallel circuit of the resistor Rs and the capacitor Cs. The gate of the FET and one terminal of the parallel circuit of the resistor Rs and capacitor Cs serve as one terminal of the short-circuit current limiting unit 16B. A resistor Rs is connected between the source and gate of the FET.

That is, in the short-circuit current limiting section 16B, the FET and the resistor Rs form a series circuit.

The secondary electron current limiting portion 16A and the short-circuit current limiting portion 16B are connected in series. In FIG. 32 , one terminal (the anode side of the FET side) of the short-circuit current limiting section 16B is connected to the anode 40B of the high voltage generator circuit 40 . Further, one terminal (the gate side of the FET) of the short-circuit current limiting section 16B is one terminal of the parallel circuit of the inductor Ls and the diode Ds of the short-circuit current limiting section 16B (the far side from the capacitor C1). ) is connected. The other terminal of the parallel circuit of the inductor Ls and the diode Ds (far from the capacitor C1) is connected to the high-voltage electrode 11.

Here, as the FET, a normally on n-channel junction type FET (JFET) or a normally on MOSFET can be used. In a normally on FET, current flows between the source and the drain even if the potential (gate voltage) of the gate to the source is the same (the gate voltage is set to 0V). Then, the conductivity between the source terminal and the drain terminal changes according to the potential of the gate relative to the source (gate voltage). That is, the higher the gate voltage, the higher the conductivity and the higher the current flowing between the source and the drain. In a normally-on FET, when the gate potential is lowered (the gate voltage becomes negative) than the source potential, the current flowing between the source and drain decreases.

Here, the operation of the current limiting circuit 16 is explained.

The secondary electron current limiting section 16A has been described in the fourth embodiment. Therefore, the short-circuit current limiting unit 16B will be described.

A case where no short circuit occurs between the high voltage electrode 11 and the counter electrode 12 is assumed to be a normal state. In this normal state, the discharge current flows from the anode 40B of the high voltage generator circuit 40 via the high voltage electrode 11, the condenser C (discharge space), and the counter electrode 12 to the high voltage generator circuit 40. ) flows to the cathode 40C.

At this time, the potential of the gate of the FET becomes slightly lower than the potential of the source due to the potential drop of the resistor Rs. However, since the current value is small, the potential drop across the resistor Rs is small. Therefore, the discharge current continues to flow.

Next, when a short circuit occurs between the high voltage electrode 11 and the counter electrode 12, that is, when a short circuit current greater than the normal discharge current flows, a large potential drop is generated by the resistor Rs. For this reason, the potential of the gate of the FET moves to a lower side than that of the source. Accordingly, the conductivity of the FET decreases and the current flowing through the FET decreases. Thus, the short-circuit current is limited.

At this time, charge is accumulated in the capacitor Cs at a voltage corresponding to the potential drop caused by the resistor Rs. That is, the capacitor Cs maintains the potential of the gate.

This state is maintained as long as the short circuit is not resolved.

However, when the short circuit is eliminated, the current flowing through the resistor Rs decreases, and the potential drop caused by the resistor Rs decreases. Accordingly, the charge accumulated in the capacitor Cs connected in parallel is consumed by the resistor Rs, and the potential of the gate of the FET approaches the potential of the source. Accordingly, the conductivity between the source and drain of the FET increases (increases), and the potential of the high voltage electrode 11 rises toward the value of the anode 40B of the high voltage generator circuit 40.

On the other hand, since the pulse current and the like due to secondary electron emission contain high-frequency components, in the current limiting circuit 16, via the FET, capacitor Cs, and inductor Ls, the high-voltage electrode 11 flows Therefore, the resistance Rs has no effect on the pulse-shaped current. That is, the secondary electron current limiting unit 16A operates without being affected by the short-circuit current limiting unit 16B.

In addition, the resistor Rs causes a potential drop by the current flowing at the time of short circuit, and controls the conductivity of the FET. Therefore, it is okay to set the value of the resistor Rs corresponding to the current that can flow in the event of a short circuit.

A change in voltage between electrodes will be described for the electrostatic precipitator 1 provided with the charging section 10 having the current limiting circuit 16 represented by the equivalent circuit in FIG. 32 (the electrostatic precipitator 1 of Example 10).

Fig. 33 is a diagram explaining the temporal change of the interelectrode voltage in the charging section 10 of the electrostatic precipitator 1 of the tenth embodiment. The horizontal axis is time (μs), and the vertical axis is voltage between electrodes (kV). The temporal change of the interelectrode voltage in the charging section 10 was obtained by simulation.

Here, it is assumed that in one discharge space (corresponding to the capacitor C1), a pulse-shaped current due to secondary electron emission is generated. Then, as indicated by "C1" in Fig. 33, the voltage between the electrodes is reduced by about 270V by the inductor Ls of the current limiting circuit 16.

However, in the other discharge space (corresponding to the capacitor C2), as indicated by "C2" in Fig. 33, there is no change in the voltage between electrodes.

That is, even if a pulse-shaped current due to secondary electron emission or the like is generated in one discharge space, its effect does not affect other discharge spaces. Therefore, a decrease in the dust collection efficiency of the electric precipitator 1 due to the generation of pulse-shaped current is suppressed.

FIG. 34 is a diagram for explaining the temporal change of the voltage between electrodes due to a short circuit in the charging section 10 of the electrostatic precipitator 1. As shown in FIG. The horizontal axis is time (μs), and the vertical axis is voltage between electrodes (kV). The temporal change of the interelectrode voltage in the charging section 10 was obtained by simulation.

Here, it is assumed that a short circuit has occurred between the high-voltage electrode 11 and the counter electrode 12 in one discharge space (corresponding to the capacitor C1). Then, as indicated by "C2" in Fig. 34, the voltage between electrodes in this discharge space decreases to 0V.

However, in the other discharge space (corresponding to capacitor C2), as indicated by "C2" in Fig. 34, there is no change in the voltage between electrodes.

That is, even if a short circuit occurs in one discharge space, the effect does not affect other discharge spaces. Therefore, even if a short circuit occurs in one discharge space, it is suppressed that the electric precipitator 1 becomes unusable.

35 is a diagram showing an example of the high-voltage electrode 11 to which the current limiting circuit 16 is connected. In Fig. 35, the high voltage generating circuit 40 is also shown.

As shown in Fig. 35, the high-voltage electrode 11 has a plurality of teeth rows 113 each having a plurality of teeth 111.

A plurality of current limiting circuits 16 corresponding to a plurality of tooth rows 113 are formed on the circuit board 15, similarly to Example 8 in the fourth embodiment. On the other hand, except for the current limiting circuit 16, other configurations are the same as those of Example 8 in the fourth embodiment, and thus descriptions are omitted.

The current limiting circuit 16 includes a secondary electron current limiting unit 16A including an inductor Ls and a diode Ds; and a short-circuit current limiting unit 16B including an FET, a resistor Rs, and a capacitor Cs.

In this way, the increase in ozone generation due to the pulse current accompanying secondary electron emission or the like is suppressed, and even if a short circuit occurs between the high-voltage electrode 11 and the counter electrode 12, the electrostatic precipitator 1 action can continue. Further, when the short circuit between the high voltage electrode 11 and the counter electrode 12 is temporary, when the short circuit condition is eliminated, the original state is automatically restored, and the operation of the electrostatic precipitator 1 continues.

36A to 36C are other equivalent circuits of the charging unit 10 including the current limiting circuit 16. FIG. 36A shows a case in which the connection order of the secondary electron current limiting section 16A and the short-circuit current limiting section 16B in the current limiting circuit 16 of FIG. 32 is interchanged. 36B shows a case where the current limiting circuit 16 is connected to the counter electrode 12. 36C shows a case where the high voltage electrode 11 and the counter electrode 12 are formed between the secondary electron current limiting section 16A and the short circuit current limiting section 16B in the current limiting circuit 16.

On the other hand, in Figs. 36A, 36B and 36C, description of the high voltage generator circuit 40 is omitted, and the discharge space is set to one.

As shown in FIG. 36A, even if the connection order of the secondary electron current limiting section 16A and the short-circuit current limiting section 16B in the current limiting circuit 16 of FIG. 32 is exchanged, the operation is similar to that described in FIG. do.

Also, as shown in FIG. 36B, even if the current limiting circuit 16 is connected to the counter electrode 12, the operation is similar to that described in FIG. 32. At this time, the secondary electron current limiting portion 16A and the short-circuit current limiting portion 16B may be formed interchangeably.

24, when the counter electrode 12 is composed of a plurality of rectangular plate-like members, the current limiting circuit 16 may be formed for each of the rectangular plate-like members. On the other hand, each rectangular plate-like member is an example of a sub counter electrode.

Then, as shown in FIG. 36C, a high-voltage electrode 11 and a counter electrode 12 are formed between the secondary electron current limiting portion 16A and the short-circuit current limiting portion 16B in the current limiting circuit 16. It operates in the same way as described in FIG. 32. At this time, the secondary electron current limiting portion 16A and the short-circuit current limiting portion 16B may be formed interchangeably.

As described above, also in the fifth embodiment, the high-voltage electrode 11 may be a pointed needle instead of the saw tooth 111 . In addition, the high-voltage electrode 11 may be a linear wire made of a conductive material instead of the row of teeth 113.

In addition, as the counter electrode 12, the counter electrode 12 described above can be used.

[Sixth Embodiment]

In the first to fifth embodiments, the charging unit 10 in the electric precipitator 1 includes a counter electrode 12, a conductor unit 121, and a resistor unit 122. The resistor portion 122 is formed so as to cover at least the conductor portion 121 facing the high-voltage electrode 11 . In this way, the discharge current between the high-voltage electrode 11 and the counter electrode 12 is restricted, and generation of ozone is suppressed.

The counter electrode 12 in the sixth embodiment further includes an insulator portion 125 between the conductor portion 121 and the resistor portion 122 .

Meanwhile, the resistor unit 122, which is an example of the second member, has a smaller volume resistivity than the insulator unit 125, which is an example of the first member.

37 is a schematic diagram for explaining the charging unit 10 of the electric precipitator 1 to which the sixth embodiment is applied. The charging unit 10 includes a high-voltage electrode 11 and a counter electrode 12 opposing the high-voltage electrode 11 .

Here, the high-voltage electrode 11 is shown as an example with a sawtooth 111 whose front end faces the counter electrode 12 side (downward in the drawing sheet). The high voltage electrode 11 is connected to the anode of the high voltage generating circuit 40 .

On the other hand, the high-voltage electrode 11 may be a wire made of a conductor or a needle with a sharp tip, in addition to the teeth 111. At this time, the sawtooth 111 and the needle may be disposed such that their ends face the counter electrode 12, or may be disposed so as to face a direction parallel to the counter electrode 12.

The counter electrode 12 is formed by sequentially stacking a conductor portion 121, an insulator portion 125, and a resistor portion 122. Meanwhile, the conductor part 121 and the resistor part 122 come into direct contact in a predetermined contact area 126 .

In the counter electrode 12, the side of the resistor unit 122 faces the high-voltage electrode 11. Then, the conductor portion 121 is connected to the negative electrode of the high voltage generating circuit 40 .

The discharge generated between the high-voltage electrode 11 and the counter electrode 12 is explained with reference to FIG. 37 . When the voltage between the high voltage electrode 11 and the counter electrode 12 is increased by the high voltage generating circuit 40, corona discharge is generated from the vicinity of the tip of the high voltage electrode 11. At this time, light emission may be seen in the corona region 131 near the tip of the high-voltage electrode 11 .

Corona discharge is generated when a non-uniform electric field is generated around the sharp tip of the high-voltage electrode 11. That is, when the voltage applied to the high-voltage electrode 11 increases, electrons (indicated by - in the drawing) are emitted from the sharp tip of the high-voltage electrode 11 . The emitted electrons are accelerated and collide with air molecules around the tip. Then, air molecules are ionized and positive and negative ions are generated.

On the other hand, these positive and negative ions attach to the floating fine particles and charge the floating fine particles.

However, positive ions are attracted to the counter electrode 12 and collide with the counter electrode 12 . At this time, electrons for neutralizing positive ions are supplied through the resistor unit 122 . In addition, the counter electrode 12 emits secondary electrons when positive ions collide with each other.

That is, the current flowing between the high-voltage electrode 11 and the counter electrode 12 is determined by the movement of positive and negative ions generated by ionization of air molecules and secondary electrons generated by collisions between electrons neutralizing positive ions and positive ions.

In the sixth embodiment, electrons that neutralize positive ions and secondary electrons generated by collision of positive ions flow through the resistor portion 122 of the counter electrode 12 (current I). However, since the counter electrode 12 includes the insulator portion 125, the current I does not flow in the vertical direction, which is the thickness direction of the resistor portion 122, and as shown by the arrow in FIG. 37, the resistor portion (122) in the transverse direction (rightward direction in the drawing). Then, the current (I) flows to the conductor portion 121 through the contact area 126.

The current I flowing through the resistor unit 122 causes a voltage drop. Then, the voltage applied to the space between the high-voltage electrode 11 and the counter electrode 12 decreases (falls). Accordingly, the current of corona discharge (discharge current) is limited, and the transition from corona discharge to arc discharge (spark) is suppressed.

Also, since the discharge current is limited, ozone generation is suppressed. That is, as the insulator part 125 is disposed between the conductor part 121 and the resistor part 122, generation of ozone is minimized.

In addition, the current (I) is determined by the resistance of the resistor unit 122 in the transverse direction. In the paper of FIG. 37, the resistor unit 122 has a dimension (length) from the left end to the right contact area 126 in the horizontal direction set to be 100 to 1000 times larger than the vertical dimension (thickness) has been Therefore, when resistance of a predetermined resistance value is formed by the resistance body portion 122 between the high voltage electrode 11 and the conductor portion 121 of the counter electrode 12, when the insulator portion 125 is not formed In comparison, a material with a small volume resistivity can be selected. That is, when the insulator portion 125 is formed, the range of selection of materials constituting the resistor portion 122 is widened.

In addition, a voltage drop generated in the resistor portion 122 in the counter electrode 12 occurs in the horizontal direction on the page of FIG. 1 . Therefore, the electric field generated in the transverse direction on the surface of the resistor unit 122 is smaller than the electric field generated in the thickness direction of the resistor unit 122 when the insulator unit 125 is not formed. Accordingly, when the insulator portion 125 is formed, dielectric breakdown in the resistor portion 122 is less likely to occur than when the insulator portion 125 is not formed.

In addition, the discharge between the high-voltage electrode 11 and the counter electrode 12 may stop due to a voltage drop of the resistor portion 122 in the counter electrode 12 . However, when the voltage applied to the space between the high-voltage electrode 11 and the counter electrode 12 recovers, discharge resumes. Thereafter, the discharge may stop again due to a voltage drop across the resistor portion 122 of the counter electrode 12 . In this way, the discharge is stopped and restarted repeatedly. That is, the high voltage generating circuit 40 supplies DC voltage between the high voltage electrode 11 and the counter electrode 12, but the discharge can be stopped and resumed repeatedly in an AC manner.

On the other hand, as the charge gradually accumulates in the resistor section 122, the discharge gradually weakens and eventually stops. Therefore, it is necessary to pass the current I from the resistor portion 122 to the conductor portion 121 so that charges do not accumulate in the resistor portion 122 .

(Example 11)

In the case where the counter electrode 12 of the charging unit 10 includes a conductor portion 121, an insulator portion 125 covering the conductor portion 121, and a resistor portion 122 covering the insulator portion 125 , the effect of electrically contacting (conducting) the conductor portion 121 and the resistor portion 122 will be described.

Here, the electrostatic precipitator 1 having the counter electrode 12 electrically contacting the conductor portion 121 and the resistor portion 122 is referred to as the electrostatic precipitator 1 of the eleventh embodiment. An electric precipitator 1 having a counter electrode 12 that does not electrically contact the conductor portion 121 and the resistor portion 122 is referred to as the electrostatic precipitator 1 of Comparative Example 4.

38A and 38B are views showing ionized water generated in the charging section 10 of the electrostatic precipitator 1 of Example 11 and the electrostatic precipitator 1 of Comparative Example 4, respectively. 38A is Example 11, and FIG. 38B is Comparative Example 4. The horizontal axis is time (s), and the vertical axis is the number of ions (×10 ³ /cm ³ ).

As shown in FIG. 38A, at the end of the counter electrode 12, when the conductor portion 121 and the resistor portion 122 are brought into contact in the contact area 126, ions are generated at about 2.4 s. After that, the generation of ions continued.

This is because the conductor portion 121 and the resistor portion 122 are brought into electrical contact, so that charge does not accumulate in the resistor portion 122. That is, the voltage acting on the space between the high-voltage electrode 11 and the counter electrode 12 is maintained, and the discharge continues.

On the other hand, as shown in Fig. 38B, in the counter electrode 12, when the conductor portion 121 and the resistor portion 122 are not brought into contact, ions start to be generated at about 2.8 s, but from about 8 s later. , the number of ions decreases, and generation of ions is not seen after about 28 s.

This is because the conductor portion 121 and the resistor portion 122 do not electrically contact each other, so charges are accumulated in the resistor portion 122 . That is, the voltage acting on the space between the high-voltage electrode 11 and the counter electrode 12 decreases, and discharge is stopped.

(Example 12)

39A and 39B are views explaining the charging unit 10 in the electrostatic precipitator 1 according to the twelfth embodiment. FIG. 39A is a perspective view of the charging unit 10, and FIG. 39B is a cross-sectional view of the counter electrode 12 along the line XXXIXB-XXXIXB.

As shown in FIG. 39A, in the charging unit 10 in the electric precipitator 1 of the twelfth embodiment, the high-voltage electrode 11 is constituted by a wire 114. And, the conductor portion 121 of the counter electrode 12 is a plate-like member (punching metal) made of a conductive material in which a plurality of openings 124 are formed in a zigzag pattern. Then, an insulator part 125 and a resistor part 122 are sequentially formed on the surface of the conductor part 121 . Meanwhile, a contact area 126 for contacting the conductor portion 121 and the resistor portion 122 is formed on a part of the conductor portion 121 without forming the insulator portion 125 . In addition, a conductor exposed region 123 exposing the conductor portion 121 is formed at an end of the conductor portion 121 . The conductor exposed region 123 is connected to the cathode of the high voltage generating circuit 40 .

The wire 114 is an example of a site that generates electric field concentration.

Here, the wire 114 serving as the high-voltage electrode 11 was made of SUS with a diameter of 0.2 mm.

On the other hand, in the counter electrode 12, the conductor portion 121 is made of an aluminum plate with a width of 30 mm, and circular openings 124 having an inner diameter of 3 mm are arranged in a zigzag pattern. Then, aluminum of the conductor portion 121 was anodized (armite treatment) to form an insulator portion 125 made of aluminum oxide on the surface. Further, the resistor portion 122 was formed by coating the insulator portion 125 with a polyimide resin having a thickness of 50 μm.

The high-voltage electrode 11 is attached to the case 30 via an insulating spacer 32 made of an insulating material. The counter electrode 12 is attached so as to be electrically connected (conductive) to the case 30 by the conductor exposed region 123 where the conductor portion 121 is exposed. By doing this, the case 30 is suppressed from being charged by static electricity.

(Example 13)

40A and 40B are diagrams for explaining the charging unit 10 in the electrostatic precipitator 1 according to the thirteenth embodiment. 40A is a perspective view of the charging unit 10, and FIG. 40B is a cross-sectional view of a part of the counter electrode 12.

As shown in FIG. 40A , in the charging section 10 in the electric precipitator 1 of the thirteenth embodiment, the high-voltage electrode 11 is constituted by a wire 114, as in the eleventh embodiment.

The conductor portion 121 of the counter electrode 12 is a wire mesh (mesh) made of a conductive material. Here, as the counter electrode 12, the external shape of the conductor portion 121 is a square SUS304 wire mesh having a side of 100 mm.

Incidentally, the cross-sectional view of a portion of the counter electrode 12 shown in FIG. 40B shows a cross section of one line (wire) portion of the wire mesh (mesh) constituting the conductor portion 121 of the counter electrode 12. Here, the polyimide resin applied so as to cover the conductor portion 121 was used as the insulator portion 125, and the acrylic resin applied so as to cover the insulator portion 125 was used as the resistor portion 122.

A part of the counter electrode 12 is caulked to form an electrical contact 127 . And, the electrical contact 127 is connected to the negative electrode of the high voltage generating circuit 40 .

By caulking a part of the counter electrode 12, the insulator portion 125 and the resistor portion 122 applied to the conductor portion 121 are destroyed, and the resistor portion 122 is electrically connected to the conductor portion 121. In addition to (conductivity), a part of the conductor portion 121 is exposed. That is, in Example 12, the contact area 126 and the conductor exposed area 123 shown in Figs. 39A and 39B are collectively formed by caulking.

(Example 14)

41A and 41B are views explaining the charging unit 10 in the electrostatic precipitator 1 according to the fourteenth embodiment. 41A is a perspective view of the charging unit 10, and FIG. 41B is a cross-sectional view of a part of the counter electrode 12.

As shown in FIG. 41A, in the charging section 10 in the electrostatic precipitator 1 of the 14th embodiment, the high-voltage electrode 11 is constituted by a wire 114, as in the 12th and 13th embodiments.

The conductor portion 121 of the counter electrode 12 is an expanded metal in which the conductor portion 121 is made of a conductive material. Here, as the counter electrode 12, the outer shape of the conductor portion 121 is made of an expanded metal made of square aluminum with a side of 100 mm.

Incidentally, the cross-sectional view of a portion of the counter electrode 12 shown in FIG. 41B shows a cross section of a portion of one line of the expanded metal constituting the counter electrode 12 . Here, aluminum oxide obtained by anodizing the conductor portion 121 made of expanded metal is used as the insulator portion 125, and polyimide resin is applied to cover the insulator portion 125 to form the resistor portion 122.

A part of the counter electrode 12 is caulked to form an electrical contact 127 . And, the electrical contact 127 is connected to the negative electrode of the high voltage generating circuit 40 .

By caulking a part of the counter electrode 12, the insulator portion 125 and the resistor portion 122 applied to the conductor portion 121 are destroyed, and the resistor portion 122 is electrically connected to the conductor portion 121. In addition to (conducting), a part of the conductor portion 121 is exposed. That is, in Example 12, the contact area 126 and the conductor exposed area 123 shown in Figs. 39A and 39B are collectively formed by caulking.

(Example 15)

42A and 42B are diagrams for explaining the charging unit 10 in the electrostatic precipitator 1 according to the fifteenth embodiment. FIG. 42A is a perspective view of the charging unit 10, and FIG. 42B is a cross-sectional view along the XLIIB-XLIIB line of FIG. 42A.

As shown in FIG. 42A, in the charging section 10 in the electrostatic precipitator 1 of Example 15, the high-voltage electrode 11 is constituted by a plurality of teeth rows 113 having a plurality of teeth 111. has been Here, the row of teeth 113 of the high-voltage electrode 11 was made of SUS with a thickness of 0.5 mm. Then, each tooth 111 of the tooth row 113 is arranged in a direction orthogonal to the ventilation direction.

The counter electrode 12 is a member (punched metal) made of a plate-shaped conductive material in which a conductor portion 121 and a plurality of openings 124 are formed in a zigzag pattern. Here, the conductor portion 121 of the counter electrode 12 is made of an aluminum plate having a planar shape of 200 mm x 400 mm in which circular openings 124 with an inner diameter of 3 mm are arranged in a zigzag pattern. Then, aluminum of the conductor portion 121 was anodized (armite treatment) to form an insulator portion 125 made of aluminum oxide on the surface. In addition, the resistor portion 122 was formed by coating the insulator portion 125 with a polyimide resin.

On the other hand, with respect to the high-voltage electrode 11, a contact region 126 electrically contacting (conducting) the conductor portion 121 and the resistor portion 122 is provided at a portion corresponding to the back side of the conductor portion 121. formed

Further, at the end of the conductor portion 121, the conductor exposed region 123 exposing the conductor portion 121 was formed without forming the insulator portion 125 and the resistor portion 122. Then, the conductor exposed region 123 is connected to the negative electrode of the high voltage generating circuit 40 .

The distance G between the high-voltage electrode 11 and the counter electrode 12 was 5 mm.

Fig. 43 explains the relationship between the inter-electrode voltage (kV) applied between the high-voltage electrode 11 and the conductor portion 121 of the counter electrode 12 and the amount of ozone generated per tooth 111 (μg/h). it is a drawing In Fig. 43, the counter electrode 12 of the electrostatic precipitator 1 and the charging part 10 of the fifteenth embodiment is not provided with an insulator part 125 made of aluminum oxide and a resistor part 122 made of polyimide resin. The electrostatic precipitator 1 is shown as the electrostatic precipitator 1 of Comparative Example 5. On the other hand, in Comparative Example 5, the counter electrode 12 is made of aluminum punched metal.

As shown in Fig. 43, in Example 15, even when the voltage between electrodes is 7 kV, the amount of ozone generated is almost zero. On the other hand, in Comparative Example 5, the amount of ozone generated increases as the inter-electrode voltage increases.

That is, by configuring the counter electrode 12 with the conductor portion 121, the insulator portion 125, and the resistor portion 122, the amount of ozone generated is suppressed.

The surface resistivity of the resistor portion 122 is preferably 1 GΩ/cm or more when the voltage applied between the high-voltage electrode 11 and the counter electrode 12 (inter-electrode voltage) is 5 kV. In this case, the ozone generation amount can be suppressed to 1 μg/h or less. On the other hand, since the surface resistivity of the resistor portion 122 changes with the voltage between electrodes, it is expressed here as the surface resistivity of the resistor portion 122 at an interelectrode voltage of 5 kV.

Table 1 is a table showing a comparison of dielectric breakdown voltages. The dielectric breakdown voltage is a voltage that shifts from corona discharge to arc discharge.

Table 1 shows Example 15, Comparative Example 5 and Example 16. Example 15 and Comparative Example 5 were described above. In the electrostatic precipitator 1 of Example 16, the conductor portion 121 of the counter electrode 12 in the charging portion 10 is made of aluminum punched metal, polyimide resin is applied to the surface, and the resistor portion 122 ) is an electric precipitator (1). That is, it is the electrostatic precipitator 1 demonstrated in 1st Embodiment.

As shown in Table 1, the electrical breakdown voltage of the charging section 10 in the electrostatic precipitator 1 of Example 15 is 10 kV or higher. Also in the electrostatic precipitator 1 of Example 16 not provided with the insulator portion 125, the dielectric breakdown voltage is 8 kV.

However, in the electrostatic precipitator 1 of Comparative Example 5 not provided with the resistor portion 122 and the insulator portion 125, the dielectric breakdown voltage is as low as 5.5 kV.

That is, when the counter electrode 12 includes the resistor portion 122, the dielectric breakdown voltage increases, and when the counter electrode 12 includes the insulator portion 125, the dielectric breakdown voltage further increases.

Example 15 Comparative Example 5 Example 16 conductor part aluminum
punching metal aluminum
punching metal aluminum
punching metal insulator part aluminum oxide - - resistance part polyimide resin - polyimide resin dielectric breakdown voltage 10 kV or more 5.5 kV 8kV

(Example 17)

44A and 44B are views explaining the charging unit 10 in the electric precipitator 1 according to the seventeenth embodiment. 44A is a perspective view of the charging unit 10, and FIG. 44B is a cross-sectional view of a part of the counter electrode 12.

As shown in FIG. 44A, in the charging section 10 in the electrostatic precipitator 1 of the seventeenth embodiment, the high-voltage electrode 11 has a plurality of teeth having a plurality of teeth 111, as in the fifteenth embodiment. It consists of a row (113). Therefore, detailed description is omitted.

In the counter electrode 12, the conductor portion 121 is a wire mesh (mesh) made of a conductive material. Here, as in the thirteenth embodiment, the counter electrode 12 was made of a wire mesh made of SUS304 in a square shape with a conductor portion 121 having a side of 100 mm. Therefore, detailed description is omitted.

(Example 18)

45A and 45B are views explaining the charging unit 10 in the electrostatic precipitator 1 according to the eighteenth embodiment. Fig. 45A is a perspective view of the charging section 10, and Fig. 45B is a cross-sectional view of the counter electrode 12 along the line XLVB-XLVB in Fig. 45A.

As shown in FIG. 45A, in the charging section 10 in the electrostatic precipitator 1 of the eighteenth embodiment, the high-voltage electrode 11 has a plurality of teeth having a plurality of teeth 111, as in the fifteenth embodiment. It consists of a row (113). Here, the row of teeth 113 of the high-voltage electrode 11 was made of SUS with a thickness of 0.5 mm. And the teeth 111 of each row of teeth 113 are arranged in a direction orthogonal to the ventilation direction.

The counter electrode 12 is composed of a plate-shaped resin material member (punching board) in which a resistor portion 122 and a plurality of openings 124 are formed in a zigzag pattern. Here, the resistor portion 122 of the counter electrode 12 was made of an acrylic resin plate having a planar shape of 200 mm x 400 mm and a thickness of 2 mm. Further, circular openings 124 having an inner diameter of 3 mm are arranged in a zigzag pattern on the acrylic resin plate serving as the resistor portion 122 of the counter electrode 12 . Then, a conductive film having an adhesive layer having a thickness of 20 μm and a conductive layer made of a conductive material was adhered to the back side of the acrylic resin plate serving as the resistor portion 122 of the counter electrode 12 with respect to the high-voltage electrode 11. .

The conductive layer of the conductive film is the conductor portion 121 . And, the adhesive layer of the conductive film is the insulator part 125 . Therefore, the conductive layer of the conductive film serving as the conductor portion 121 is connected to the anode of the high voltage generating circuit 40 .

Here, the resistor portion 122 is an example of the substrate, the insulator portion 125 is an example of the first member, and the conductor portion 121 is an example of the second member.

On the other hand, in the conductive film, an opening having a larger diameter (for example, 3.5 mm) than the opening 124 formed in the acrylic resin plate is formed to face the opening 124 formed in the acrylic resin plate. That is, as shown in FIG. 45B, the adhesive layer and the conductive layer of the conductive film do not protrude into the opening formed in the acrylic resin when viewed from the high-voltage electrode 11 side.

When the conductive layer of the conductive film protrudes to the inside of the opening 124 of the resistor unit 122, a discharge occurs between the high voltage electrode 11 and the conductive layer of the conductive film, limiting the discharge current of the resistor unit 122. function will be lost.

(Example 19)

46A and 46B are views explaining the charging unit 10 in the electrostatic precipitator 1 according to the nineteenth embodiment. 46A is a perspective view of the charging unit 10, and FIG. 46B is a cross-sectional view of the counter electrode 12 along the line XLVIB-XLVIB in FIG. 46A.

As shown in FIG. 46A, in the charging section 10 in the electrostatic precipitator 1 of the nineteenth embodiment, the high-voltage electrode 11 has a plurality of teeth having a plurality of teeth 111, as in the fifteenth embodiment. It consists of a row (113). Here, the row of teeth 113 of the high-voltage electrode 11 was made of SUS with a thickness of 0.5 mm. And the teeth 111 of each row of teeth 113 are arranged in a direction orthogonal to the ventilation direction.

The counter electrode 12 is a plate-shaped member (punching board) in which an insulator portion 125 and a plurality of openings 124 are formed in a zigzag pattern, made of the above insulating material. Here, the insulator portion 125 of the counter electrode 12 was made of a ceramic plate having a planar shape of 200 mm x 400 mm and a thickness of 2 mm. Further, in the ceramic plate serving as the insulator portion 125 of the counter electrode 12, circular openings 124 having an inner diameter of 3 mm are arranged in a zigzag pattern.

Further, a conductor portion 121 made of a conductive material of a copper plate was adhered to the back side of the high-voltage electrode 11 of the ceramic plate serving as the insulator portion 125 of the counter electrode 12. On the other hand, an opening is formed in the copper plate as the conductor portion 121 corresponding to the opening 124 formed in the ceramic plate as the insulator portion 125.

Then, the periphery of the ceramic plate serving as the insulator portion 125 was coated with polyimide resin to form the resistor portion 122 . On the other hand, the resistor portion 122 made of polyimide resin is formed to cover the copper plate serving as the conductor portion 121 and the opening 124 . That is, except for the conductor exposed region 123 of the conductor portion 121, the surface of the counter electrode 12 is covered with the resistor portion 122 made of polyimide resin.

Here, the insulator portion 125 is an example of the base material, the resistor portion 122 is an example of the first member, and the conductor portion 121 is an example of the second member.

As described above, one of the conductor part 121, the insulator part 125, and the resistor part 122 is a hard member (base member), and the other is a film adhered on the base member or a film applied (layer ) is also free. Further, a plurality of the conductor portion 121, the insulator portion 125, and the resistor portion 122 are hard members (base members), and these may be laminated.

Further, the conductor portion 121 may be formed of a conductive material, that is, a good conductor. The insulator portion 125 may be any one that suppresses the flow of electrons (current) in the resistor portion 122 so that it does not directly go to the conductor portion 121 . In addition, the resistor unit 122 may be anything capable of suppressing the generation of ozone by limiting the discharge current.

[Seventh Embodiment]

In the first to sixth embodiments, in the charging section 10 of the electric precipitator 1, the high-voltage electrode 11 is disposed upstream and the counter electrode 12 is disposed downstream with respect to the ventilation direction. there was.

The high-voltage electrode 11 and the counter electrode 12 may be arranged opposite to the ventilation direction.

47 is a diagram showing an example of an electric precipitator to which a seventh embodiment is applied.

Here, the high voltage electrode 11 and the counter electrode 12 in the charging section 10 of the electrostatic precipitator 1 shown in FIG. 1 are arranged opposite to the ventilation direction. That is, with respect to the ventilation direction, the counter electrode 12 is arranged on the upstream side and the high-voltage electrode 11 is arranged on the downstream side.

Since the other configurations are the same as those in the first embodiment, the same reference numerals are assigned and descriptions are omitted.

Even if the high-voltage electrode 11 and the counter electrode 12 are disposed in the charging section 10 in this way, the electrostatic precipitator 1 operates similarly to that described in the first embodiment.

[Eighth Embodiment]

In the electrostatic precipitator 1 to which the first to seventh embodiments are applied, in the charging unit 10, the high-voltage electrode 11 and the counter electrode 12 are disposed in the ventilation direction.

For example, in the first embodiment shown in FIG. 1 , the high-voltage electrode 11 provided with sawtooth 111 was formed on the upstream side in the ventilation direction, and the counter electrode 12 was formed on the downstream side.

In contrast, in the electrostatic precipitator 1 of the eighth embodiment, in the charging section 10, the high-voltage electrode 11 and the counter electrode 12 are arranged so as to intersect with respect to the ventilation direction.

Further, the high-voltage electrode 11 includes a main high-voltage electrode 11A and a subordinate high-voltage electrode 11B.

48 is a diagram showing an example of an electric precipitator 1 to which an eighth embodiment is applied.

The high-voltage electrode 11 in the charging unit 10 includes a plurality of main high-voltage electrodes 11A and a plurality of subordinate high-voltage electrodes 11B. Also, the counter electrode 12 includes a plurality of sub counter electrodes 12A. The high-voltage electrode 11 and the counter electrode 12 are arranged so as to intersect in the ventilation direction (orthogonal in FIG. 48 ).

The dust collector 20 is the same as the electric precipitator 1 to which the first to seventh embodiments are applied. Therefore, the description of the dust collector 20 is omitted.

On the other hand, the electrostatic precipitator 1 is not limited to the arrangement shown in FIG. 48, and may be arranged in any direction as long as ventilation is ensured.

The main high-voltage electrode 11A in the high-voltage electrode 11 is provided with a plurality of teeth 111, as shown in FIG. 48, for example. Then, each of the plurality of teeth 111 is connected to the connecting portion 112 and constitutes a tooth row 113. The vertical high-voltage electrode 11B in the high-voltage electrode 11 is equipped with a wire 114, as shown in FIG. 48, for example.

Although illustration is omitted for each sub counter electrode 12A of the counter electrode 12, for example, the counter electrode 12 of the charging section 10 in the electrostatic precipitator 1 to which the sixth embodiment is applied and Similarly, a plate-shaped conductor portion, an insulator portion formed to cover both surfaces of the conductor portion, and a resistor portion formed to cover the surface of the insulator portion are provided. That is, in the sub counter electrode 12A, an insulator portion and a resistor portion are formed in this order on the surface of the conductor portion. And the shape of the sub counter electrode 12A is a plate shape.

As shown in Fig. 48, the counter electrode 12 has a plurality of sub counter electrodes 12A formed side by side in a direction crossing the ventilation direction (orthogonal in Fig. 48) so that each surface follows the ventilation direction. . On the other hand, the surface of the counter electrode 12 may not be parallel to the ventilation direction, and may be inclined with respect to the ventilation direction as long as predetermined ventilation is obtained.

In the high-voltage electrode 11, the main high-voltage electrode 11A is disposed between two adjacent sub counter electrodes 12A, and between the main high-voltage electrode 11A and the sub counter electrode 12A. A vertical high-voltage electrode 11B is arranged thereon.

On the other hand, the surface of the sub counter electrode 12A that does not face the main high-voltage electrode 11A and the vertical high-voltage electrode 11B does not need to be covered with an insulator portion and/or a resistor portion on the surface of the conductor portion. .

The teeth 111 of the main high-voltage electrode 11A are arranged so that their ends face the ventilation direction (downstream of the ventilation direction).

And the wire 114 which is a subordinate high-voltage electrode 11B is formed so that it may follow the tooth row 113 which the sawtooth 111 in the main high-voltage electrode 11A constitutes. On the other hand, the wire 114 serving as the secondary high-voltage electrode 11B may be formed along the tooth row 113 in the vicinity of the tip end of the tooth 111 in the main high-voltage electrode 11A.

On the other hand, in the electrostatic precipitator 1 shown in FIG. 48, in the charging section 10, the main high-voltage electrode 11A of the high-voltage electrode 11 is two, and the vertical high-voltage electrode 11B is Although the number of sub counter electrodes 12A of the counter electrode 12 is three, the number is shown, but is not limited to this number.

49A to 49C are perspective views of main parts of the charging unit 10 in the electrostatic precipitator 1 according to Example 20 and Comparative Examples 6 and 7. 49A shows Example 20, FIG. 49B shows Comparative Example 6, and FIG. 49C shows Comparative Example 7.

Here, one main high-voltage electrode 11A and two sub counter electrodes 12A formed to face the main high-voltage electrode 11A are shown.

An electric precipitator 1 according to Example 20 is an electric precipitator 1 to which the eighth embodiment is applied, as shown in FIG. 49A. In Example 20, a vertical high-voltage electrode 11B is provided between the sub counter electrode 12A and the main high-voltage electrode 11A.

And, as described above, the main high-voltage electrode 11A has a tooth row 113 configured by connecting the tooth 111 to the connecting portion 112. And, the front end of the teeth 111 is arranged so as to face the downstream side of the ventilation direction.

On the other hand, the vertical high-voltage electrode 11B is a wire 114. Here, as an example, a tungsten (W) wire having a diameter of 0.2 mm was used.

And, the sub counter electrode 12A is a laminated body in which an insulator portion and a resistor portion are formed in this order on the surface of the conductor portion.

The distance between the main high-voltage electrode 11A and the sub counter electrode 12A was 20 mm.

On the other hand, the vertical high-voltage electrode 11B was in a state in which no voltage was applied, that is, in a floating (floating) state.

As shown in FIG. 49B, the electric precipitator 1 according to Comparative Example 6 has the configuration of Example 20 except for the vertical high-voltage electrode 11B. That is, it has a configuration in which the row of teeth 113 serves as the main high-voltage electrode 11A (high-voltage electrode 11). Also in this case, the distance between the main high-voltage electrode 11A (high-voltage electrode 11) and the sub counter electrode 12A was 20 mm.

And, "(layered body)" was written on the sub counter electrode 12A in FIGS. 49A and 49B.

As shown in FIG. 49C, the electrostatic precipitator 1 according to Comparative Example 7 includes a tooth row 113 as the main high-voltage electrode 11A (high-voltage electrode 11) in Comparative Example 6 in FIG. 49B. It is made into wire 114. And the sub counter electrode 12A is made into a conductor part which does not have an insulator part and a resistor part. On the other hand, the conductor part is made of Al. Therefore, "(Al)" was marked on the sub counter electrode 12A.

Also in this case, the distance between the main high-voltage electrode 11A (high-voltage electrode 11) and the counter electrode 12A was 20 mm.

Fig. 50 is a diagram explaining the dust collection efficiency determined for each ozone concentration and particle size in the electric precipitator 1 according to Example 20 and Comparative Examples 6 and 7. On the other hand, in Fig. 50, in Example 20 and Comparative Example 6, the sub counter electrode 12A is expressed as "(layered body)".

In Comparative Example 7, the sub counter electrode 12A is indicated as "Al".

Here, the electrostatic precipitator 1 was installed in a test wind tunnel, the wind speed was set to 1 m/s by a fan, and wind was passed through the dust collector 20 from the charging unit 10 once (one pass).

The dust collection efficiency is calculated by forming sampling ports on the upstream and downstream sides of the test wind tunnel and measuring the number of suspended particles by particle size using a Scanning Mobility Particle Sizer (SMPS) through the sampling ports. did.

The ozone concentration was obtained from the difference between the ozone concentrations on the upstream and downstream sides measured using an ozone concentration meter through sampling ports provided on the upstream and downstream sides of the test wind tunnel.

In Example 20 in which the vertical high-voltage electrode 11B is formed, when 8.0 kV to 8.2 kV is applied to the main high-voltage electrode 11A, to the floating high-voltage electrode 11B, A voltage of 1.8 kV to 2.5 kV was generated.

In addition, the ozone concentration was 9.2 ppb even when 300 μA was applied to the main high-voltage electrode 11A. In this case, the dust collection efficiency was 97% for a particle diameter of 20 nm and 99% or more for other particle diameters (50 nm, 100 nm, and 300 nm).

In Comparative Example 6 excluding the secondary high-voltage electrode 11B from Example 20, when 300 µA was applied to the main high-voltage electrode 11A as in Example 20, the ozone concentration was 22.9 ppb. The dust collection efficiency was 76% for a particle diameter of 20 nm and 80% for other particle diameters (50 nm, 100 nm, and 300 nm).

That is, when the vertical high voltage electrode 11B is not used (Comparative Example 6), the ozone concentration increases and the dust collection efficiency decreases. In particular, the dust collection efficiency of ultrafine particles having a small particle diameter is reduced.

In Comparative Example 7 in which the main high-voltage electrode 11A is made of wire 114 and the sub counter electrode 12A is made of Al, the wire 114 of the main high-voltage electrode 11A is By increasing the current, the dust collection efficiency is improved regardless of the particle size. For example, if the current to be passed through the main high-voltage electrode 11A is 5000 μA, the dust collection efficiency of ultrafine particles with a particle diameter of 20 nm increases from 75% to 93% when the current is 440 μA. That is, it becomes a dust collection efficiency of 90% or more. On the other hand, the ozone concentration greatly increases from 9.2 ppb when the current is 440 μA to 190 ppb.

As described above, by using the vertical high-voltage electrode 11B and making the sub counter electrode 12A a laminated body in which an insulator portion and a resistor portion are formed in this order on the surface of the conductor portion, the ozone concentration is suppressed to a low level. The dust collection efficiency of ultra-fine particles with a particle diameter of 0.1 μm or less can be improved.

Fig. 51 is a diagram explaining the operation of the vertical high-voltage electrode 11B. Here, the voltage is shown on the vertical axis, and the positions of the main high-voltage electrode 11A, the vertical high-voltage electrode 11B, and the sub counter electrode 12A are schematically shown on the horizontal axis.

As described above, when a voltage of 8.0 kV to 8.2 kV is applied to the main high-voltage electrode 11A, a voltage of 1.8 kV to 2.5 kV is induced in the suspended subordinate high-voltage electrode 11B. As a result, the potential gradient from the main high-voltage electrode 11A to the sub counter electrode 12A does not become uniform and becomes two-step. That is, the high potential gradient region α having a potential difference of 5.7 kV to 6.2 kV from the main high-voltage electrode 11A to the subordinate high-voltage electrode 11B and the sub-opposite from the vertical high-voltage electrode 11B A low potential gradient region β with a potential difference of 1.8 kV to 2.5 kV toward the electrode 12A is created.

It is presumed that the reason why ultrafine particles with a particle diameter of 0.1 μm or less are efficiently charged is that the discharge space is widened (extended) by generating discharge in stages through the vertical high-voltage electrode 11B. That is, the potential gradient in the high potential gradient region α is larger than the potential gradient in the case where the vertical high-voltage electrode 11B is not used (potential gradient indicated by a broken line as Comparative Example 6). Accordingly, discharge is likely to start. Due to this discharge, a discharge occurs between the vertical high-voltage electrode 11B and the sub counter electrode 12A. In this way, the discharge space is widened (extended) by generating the discharge step by step.

Further, it is presumed that the reason why the ozone concentration can be suppressed is that the resistance of the discharge space (space resistance) is high and the electric field concentration on the sub counter electrode 12A (counter electrode 12) is alleviated. That is, by making the sub counter electrode 12A a laminate in which an insulator portion and a resistor portion are formed in this order on the surface of the conductor portion, the surface resistance is increased and the resistance (space resistance) of the discharge space is increased. Further, by forming the vertical high-voltage electrode 11B, the electric field concentration between the vertical high-voltage electrode 11B and the sub counter electrode 12A (counter electrode 12) is alleviated. As a result, it is considered that the ratio at which the supply and disappearance of electric charges are balanced by ionization is increased, and the generation amount of electrons serving as the starting point of ozone generation is suppressed.

As described above, by forming the vertical high-voltage electrode 11B and forming regions having different potential gradients (regions α and β in FIG. 51 ), the efficiency of collecting ultrafine particles is improved. Therefore, the main high-voltage electrode 11A may be provided with a needle-shaped portion instead of a saw-toothed portion, or may have another shape such as a wire shape or a brush shape. Similarly, the vertical high-voltage electrode 11B is not limited to the wire 114, but may be an electrode having a sawtooth portion or a needle-like portion.

On the other hand, regions with different potential gradients are not limited to two as shown in FIG. 51 . For example, another vertical high-voltage electrode may be formed between the main high-voltage electrode 11A and the secondary high-voltage electrode 11B, and three or more regions having different potential gradients may be formed.

In addition, the ozone concentration is suppressed by increasing the resistance (space resistance) of the discharge space and mitigating the electric field concentration on the counter electrode 12 (sub counter electrode 12A). Therefore, the counter electrode 12 (sub counter electrode 12A) may have a structure in which an insulator is formed on the surface of the conductor instead of a laminate in which an insulator and a resistor are formed in this order on the surface of the conductor.

Next, a modified example of the electrostatic precipitator 1 to which the eighth embodiment is applied will be described.

Fig. 52 is a diagram showing a modified example of the electrostatic precipitator 1 to which the eighth embodiment is applied.

In the electrostatic precipitator 1 shown in FIG. 48, the tip of the teeth 111 of the main high-voltage electrode 11A in the high-voltage electrode of the charging section 10 faces the downstream side in the ventilation direction. In the electrostatic precipitator 1 shown as a modified example shown in FIG. 52, the tip of the teeth 111 of the main high-voltage electrode 11A in the high-voltage electrode of the charging section 10 faces upstream in the ventilation direction. .

Even in this case, the same results as in Example 20 shown in FIG. 50 were obtained.

In the electrostatic precipitator 1 to which the above eighth embodiment is applied, as described in the twentieth embodiment, the vertical high-voltage electrode 11B was left in a floating state without applying a voltage.

However, a voltage may be applied to the vertical high-voltage electrode 11B. In this case, suppressing the ozone concentration may be 1/2 or less of the voltage applied to the main high-voltage electrode 11A. That is, the voltage applied to the main high-voltage electrode 11A may be at least twice the voltage applied to the subordinate high-voltage electrode 11B. On the other hand, it is more preferable that the voltage applied to the main high-voltage electrode 11A is 2 times or more and 5 times or less of the voltage applied to the subordinate high-voltage electrode 11B.

When a voltage is applied to the vertical high-voltage electrode 11B, discharge can be made more stable than when it is in a floating state.

[Ninth Embodiment]

53 is a diagram showing an example of an electric precipitator 1 to which the ninth embodiment is applied.

The high-voltage electrode 11 in the charging unit 10 has, for example, a plurality of saw teeth 111 (tooth-shaped portion). And each of the plurality of teeth 111 is connected to the connecting portion 112, and constitutes a plurality of tooth rows 113. On the other hand, since the high-voltage electrode 11 is composed of sawtooth rows 113, it is denoted as 11 (113) in FIG.

As in the eighth embodiment, the counter electrode 12 includes a plurality of sub counter electrodes 12A. The sub counter electrode 12A has a flat plate shape and is made of a conductive material.

The sawtooth 111 (tooth-shaped portion) of the high-voltage electrode 11 is formed so as to be parallel to the plane of the sub counter electrode 12A. Further, the sawtooth 111 (tooth-shaped portion) of the high-voltage electrode 11 and the sub counter electrode 12A are arranged in a direction crossing in the ventilation direction (orthogonal in Fig. 53).

Also, the tips of the teeth 111 face upstream in the ventilation direction. And, the front end of the sawtooth 111 is located on the downstream side of the upstream end of the plate-shaped sub counter electrode 12A in the ventilation direction. Further, the sub counter electrode 12A is formed extending at least along the length (distance) from the tip of the tooth 111 (tooth-shaped portion) to the connecting portion 112.

The dust collector 20 is the same as the electric precipitator 1 to which the first to eighth embodiments are applied. Therefore, the description of the dust collector 20 is omitted.

On the other hand, among the members constituting the charging unit 10, the high voltage electrode 21 of the dust collecting unit 20 is formed with a predetermined separation distance from the end of the member closest to the dust collecting unit downstream in the ventilation direction. In this case, the preset separation distance may be 5 mm or more.

The electrostatic precipitator 1 is not limited to the arrangement shown in FIG. 53, and may be arranged in any direction as long as ventilation is ensured.

In addition, the charging section 10 includes the inductor Ls shown in the fourth or fifth embodiment, and the pulse-shaped current in the discharge generated between the high-voltage electrode 11 and the counter electrode 12 A current limiting circuit 16 for lowering the potential of the high-voltage electrode 11 may be provided.

As a result, ozone generation is further suppressed.

On the other hand, in the electrostatic precipitator 1 shown in FIG. 53, in the charging section 10, the number of tooth rows 113 of the high voltage electrode 11 is two, and the number of sub counter electrodes 12A of the counter electrode 12 is three. Individual cases are shown, but are not limited to this number.

In addition, the sawtooth 111 which is a sawtooth-like part may be a needle-like part or a brush-like part.

54 is a cross-sectional view of the main parts of the charging unit 10 and the dust collecting unit 20 in the ventilation direction in the electric precipitator 1 according to the 21st embodiment.

In the electrostatic precipitator 1 according to Embodiment 21, the charging section 10 includes a high-voltage electrode 11 and a counter electrode 22 having a plurality of sub counter electrodes 12A made of a flat conductive material. . The high-voltage electrode 11 has a tooth row 113 having a plurality of teeth 111 with the tip facing upstream in the ventilation direction.

The rows of teeth 113 in the high voltage electrode 11 are made of stainless steel, and the sub counter electrode 12A is made of aluminum. The distance G between the high voltage electrode 11 and the sub counter electrode 12A is 15 mm. The length L of the high-voltage electrode 11 from the tip of the tooth 111 to the connecting portion 112 is 3 mm. And, the tip of the tooth 111 is located 2 mm downstream from the end of the upstream side in the ventilation direction of the sub counter electrode 12A (a distance indicated by T1 in FIG. 54). Further, from the tip of the tooth 111 to the end of the sub counter electrode 12A on the downstream side in the ventilation direction is 5 mm (a distance indicated by T2 in Fig. 54).

In addition, a plurality of gratings (grills) 31 of the case 30 made of a resin material are placed at a position of 3 mm from the end of the sub counter electrode 12A on the upstream side in the ventilation direction (a distance indicated by T3 in FIG. 54). The provided case 30 is formed. When the grating (grill) 31 is disposed in a position facing the teeth 111 of the high-voltage electrode 11 and the sub counter electrode 12A in the vertical direction shown in FIG. It is preferable because it is inhibited from contacting.

Meanwhile, the dust collector 20 has a structure in which a high-voltage electrode 21 made of a non-conductive material and a counter electrode 22 made of a conductive material are alternately laminated.

55A and 55B are perspective views of main parts of the charging unit 10 in the electrostatic precipitator 1 according to Example 21 and Comparative Example 7. 55A is Example 21, and FIG. 55B is Comparative Example 7. On the other hand, Comparative Example 7 is the same as the electrostatic precipitator 1 according to Comparative Example 7 described in the eighth embodiment (see Fig. 49C). That is, in the electrostatic precipitator 1 according to Comparative Example 7 shown in FIG. 55B, the row of teeth 113, which is the high-voltage electrode 11 in the electrostatic precipitator 1 according to Example 21 in FIG. 55A, has a diameter of 0.2 mm. The wire 114 is made of tungsten (W).

On the other hand, in the electrostatic precipitator 1 according to Example 21 and Comparative Example 7, the sub counter electrode 12A is made of Al. Therefore, in Fig. 55A and Fig. 55B, "(Al)" is marked on the sub counter electrode 12A.

In Fig. 55A, the arrangement of the rows of teeth 113 of the high voltage electrode 11 and the sub counter electrode 12A of the counter electrode 12 in Figs. 53 and 54 is shown rotated by 90°. In FIG. 55B, the arrangement of the wire 114 and the sub counter electrode 12A in FIG. 49C is shown rotated by 90°.

Fig. 56 is a diagram explaining the dust collection efficiency determined for each ozone concentration and particle size in the electric precipitator 1 according to Example 21 and Comparative Example 7.

Here, too, the electrostatic precipitator 1 was installed in a test wind tunnel, and the wind speed was set to 1 m/s by a fan, and wind was passed through the dust collector 20 from the charging unit 10 once (one pass).

The dust collection efficiency was calculated by forming sampling ports on the upstream and downstream sides of the test wind tunnel and measuring the number of suspended particles for each particle size using a scanning nanoparticle diameter distribution analyzer (SMPS) through the sampling ports.

The ozone concentration was obtained from the difference between the ozone concentrations on the upstream and downstream sides measured using an ozone concentration meter through sampling ports provided on the upstream and downstream sides of the test wind tunnel.

Comparative Example 7 in FIG. 56 is a case where the currents of the high-voltage electrode 11 (main high-voltage electrode) of Comparative Example 7 in FIG. 50 are 440 μA and 5000 μA.

As shown in Fig. 56, in the electric precipitator 1 according to Example 21, compared to Comparative Example 7, the ozone concentration is suppressed to 3.0 ppb, and the dust collection efficiency is improved to 90% or more regardless of the particle size.

The reason for improving the dust collection efficiency is that the tips of the teeth 111 are directed upstream in the ventilation direction, and the positions of the tips of the teeth 111 and the sub-opposite electrode 12A are optimized so that the ions generated from the tips of the teeth 111 are generated at high pressure. This is considered to be due to the fact that it is easier to spread between the electrode 11 (row of teeth 113) and the sub counter electrode 12A, the charging effect is improved, and the charging efficiency of ultrafine particles of 0.1 μm or less is improved.

In addition, the reason for suppressing the ozone concentration is that the high-voltage electrode 11 is used as the sawtooth 111 to increase the electric field concentration and the distance between the sawtooth 111 and the sub counter electrode 12A is increased, thereby reducing the space resistance during discharge. This is considered to be due to the fact that the amount of electrons serving as the starting point of ozone generation is suppressed even under discharge conditions in which generation of high-density ions is obtained.

On the other hand, also in Comparative Example 7, if the current (discharge current) is increased (eg, 5000 µA), the dust collection efficiency can be increased regardless of the particle size. However, the ozone concentration is 60 times higher than that of Example 21. That is, in the electrostatic precipitator 1 according to Comparative Example 7 using the wire 114 for the high-voltage electrode 11, the ozone concentration increases when the ion density is increased (if the current is increased) in order to charge particles with a small particle diameter. do.

In contrast, in the electrostatic precipitator 1 to which the ninth embodiment is applied (the electrostatic precipitator 1 according to the 21st embodiment), the ozone concentration is suppressed (dissociation and excitation of oxygen molecules are suppressed) even in a state where the ion density is high. A possible discharge is formed.

Further, in the electrostatic precipitator 1 to which the ninth embodiment is applied, since it is not necessary to cover the counter electrode 12 (sub counter electrode 12A) with an insulator portion, it is advantageous in terms of cost, productivity, and the like. there is

The numerical values shown in the first to ninth embodiments are examples, and it is clear that they are not limited thereto.

In addition, various combinations or modifications may be performed as long as they do not contradict the spirit of the present invention.

1: electrostatic precipitator 10: electrifying part
11, 21: high-voltage electrode 11A: main high-voltage electrode
11B: vertical high-voltage electrode 12, 22: counter electrode
12A: sub counter electrode 13: discharge area
14: support 15: circuit board
16, 16-1, 16-2: current limiting circuit 16A: secondary electronic current limiting unit
16B: short-circuit current limiting unit 17: wiring
18: high voltage terminal 20: dust collection unit
30 Case 31 Grid
32: insulating spacer 40, 50: high voltage generating circuit
111: teeth 112, 116: connection
113: tooth row 114: wire
115: needle 117: needle row
121: conductor part 122: resistor part
123 Conductor exposure area 124 Opening
125: insulator part 126: contact area

Claims (20)

It has a high-voltage electrode supplied with a high voltage from a high-voltage generating circuit and a counter electrode formed to face the high-voltage electrode and supplied with a reference voltage from the high-voltage generating circuit. a charging unit for charging;
a dust collection unit disposed on a downstream side of the ventilation direction of the charging unit and collecting the floating particulates charged by the charging unit; and
Including; a case accommodating the charging unit and the dust collecting unit,
the counter electrode includes a conductor portion made of a conductive material, and a resistor portion covering at least a portion of the surface of the conductor portion and limiting a discharge current between the high-voltage electrode and the counter electrode;
An electric precipitator in which the conductor portion and the case are electrically connected through a conductor exposure region where the conductor portion is exposed. According to claim 1,
The resistive body part has a volume resistivity of 10 ¹⁴ Ω·cm or more and 10 ¹⁸ Ω·cm or less. According to claim 1,
The high-voltage electrode is a wire-shaped or brush-shaped electric precipitator. According to claim 1,
The high-voltage electrode is an electric precipitator having a sawtooth-shaped portion with a sharp tip or a needle-shaped portion with a pointed tip. According to claim 4,
A plurality of the serrated portions or a plurality of the needle-like portions intersect with respect to the ventilation direction and are divided into a plurality of rows, and the tip of the serrated portion or the needle-shaped portion in each of the plurality of rows. The tips of the electric precipitators are arranged to be offset from each other in the column direction between adjacent rows or to face each other. According to claim 1,
The electric precipitator, characterized in that the high-voltage electrode comprises a main high-voltage electrode and a secondary high-voltage electrode. According to claim 6,
In the high-voltage electrode, the main high-voltage electrode has a sawtooth-shaped portion or a needle-shaped portion, and the longitudinal high-voltage electrode is wire-shaped. According to claim 1,
The electric precipitator of claim 1, wherein the conductor portion is composed of a plurality of flat plates disposed at intervals to ensure ventilation, a net having openings, a punching metal having openings, or an expanded metal having openings. According to claim 1,
The electric precipitator according to claim 1, wherein the counter electrode is disposed on an upstream side in the ventilation direction with respect to the high-voltage electrode. According to claim 1,
The electrostatic precipitator wherein the case is made of a resin material. According to claim 1,
The counter electrode further includes a first member covering the high-voltage electrode side of the conductor portion, and a second member covering the high-voltage electrode side of the first member,
The counter electrode has a contact area in which the second member electrically contacts the conductor portion. According to claim 1,
The counter electrode has a base material for setting the shape of the counter electrode, a first member formed on a surface of the base material that does not face the high-voltage electrode, and a conductive second member formed on the base material. According to claim 1,
The counter electrode includes a substrate for setting the shape of the counter electrode, a first member formed on a surface of the substrate facing the high-voltage electrode, and a conductive second member formed on a surface of the substrate not facing the high-voltage electrode. Electrostatic precipitator having. According to claim 1,
The high-voltage electrode has a sawtooth-shaped part or a needle-like part, the counter electrode has a flat plate-shaped sub-counter electrode made of a conductive material, and the plurality of sawtooth-shaped parts or needle-shaped parts of the high-voltage electrode and the sub-counter electrode The electrostatic precipitator is disposed in a direction crossing the ventilation direction, and a serrated portion or a needle-shaped portion of the high-voltage electrode is disposed parallel to the surface of the flat sub-counter electrode. According to claim 14,
The front end of the sawtooth portion or the tip of the needle-shaped portion of the high-voltage electrode faces upstream in the ventilation direction, and is located downstream of the upstream end of the flat plate-shaped sub counter electrode in the ventilation direction. According to claim 14,
The sub counter electrode is disposed downstream in the ventilation direction from the tip of the sawtooth portion or the tip of the needle portion of the high voltage electrode, at least over the length of the sawtooth portion or needle portion. According to claim 1,
The counter electrode includes an insulator portion positioned between the conductor portion and the resistor portion, and the insulator portion has a larger volume resistivity than the resistor portion. delete delete delete

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