WO2016105045A1

WO2016105045A1 - Electrostatic dust collector

Info

Publication number: WO2016105045A1
Application number: PCT/KR2015/014012
Authority: WO
Inventors: 유게세이로; 후쿠오카다이스케; 타케노시타카즈토시; 코치야마야스히코
Original assignee: 삼성전자주식회사
Priority date: 2014-12-22
Filing date: 2015-12-21
Publication date: 2016-06-30

Abstract

The present invention provides an electrostatic dust collector and the like which inhibit ozone generation and have a thin charging unit. An electrostatic dust collector (1), according to the present invention, comprises: a charging unit (10) having a high voltage electrode (11), to which a high voltage is supplied from a high voltage generating circuit (40), and an opposing electrode (12), which is formed opposite from the high voltage electrode (11) and to which a reference voltage is supplied from the high voltage generating circuit (40), generating discharging between the high voltage electrode (11) and the opposing electrode (12), and thus charging floating fine particles; and a dust collecting unit (20) disposed on the lower side in the ventilation direction of the charging unit (10) and for collecting the fine particles that have been charged by means of the charging unit (10).

Description

Electric dust collector

The present invention relates to an electrostatic precipitator.

Electrical appliances, such as an air cleaner and an air conditioner, are equipped with the electric dust collector which charges a floating fine particle using a discharge.

The electrostatic precipitator may include a charging unit configured to charge suspended fine particles by discharge; And a dust collecting part for collecting charged suspended fine particles. In the charging section of the electrostatic precipitator, a high voltage of several kV is applied between the high voltage (discharge) electrode and the 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 likely to be generated along with the discharge. Since ozone has a unique odor, when it is released indoors, the ozone concentration needs to be less than the environmental standard value (0.05 ppm).

Patent Document 1 discloses a dust collecting device comprising ion discharging means for releasing ions without corona discharge and a dust collecting portion formed downstream thereof, wherein one or more linear discharge electrodes of the ion discharging means are formed.

Electrode), the ground electrode is formed on both sides of the linear electrode, and the electrode connected to the ground is covered with an insulator or a semiconductor so that the discharge current when the high voltage is applied to the linear electrode is 1 μA or less per 0.1 m of the linear electrode. It is described.

Patent document 2 includes a filter unit having a discharge needle installed to be applied with a high voltage and having an intake grill having a shape in which the center thereof is expanded forward, a ventilated ground electrode formed on the wind side of the discharge needle, and a dust collecting filter. The intake grill is formed by arranging non-conductive ribs made of non-conductive resin and conductive ribs made of conductive in a lattice shape, and connecting the conductive ribs to the ground electrode, thereby eliminating the static electricity charged on the intake grills. An electrostatic precipitating unit is described which prevents dust from adhering to it.

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

Patent document 4 discloses an ion generator having a high voltage generating means for generating a high voltage and an ion generating electrode connected to an output of the high voltage generating means and generating ions in parallel with the ion generating electrode at the output of the high voltage generating means. An ion generator having an ozone generating electrode for generating ozone and an impedance varying means connected in series with the ozone generating electrode, the ion generator controlling the amount of ozone generated from the ozone generating electrode by varying the impedance of the impedance varying means. It is.

Non-Patent Document 1 describes a discharge in which one electrode is covered with a high resistance sheet of several M 의 / cm instead of a dielectric. Then, when driven by direct current (DC), it is described that a pulse-like discharge that repeats at several 10 kHz with a width of several μs occurs.

[Preceding technical literature]

[Patent Documents]

Patent Document 1: International Publication WO01 / 064349

Patent Document 2: Japanese Patent Application Laid-Open No. 2005-021817

Patent Document 3: Japanese Patent Application Laid-Open No. 7-5746

Patent Document 4: Japanese Patent Application Laid-Open No. 2004-216037

[Non-Patent Documents]

[Non-Patent Document 1] Monia Laroussi, Igor Alexeff, Paul Richardson, Francis F. Dyer, `` The Resistive Barrier Discharge '', ITriple is an IEEE TRANSACTION ON PLASMA SCIENCE, February 2002, Vol. 30, No. 1, p. 158-159

By the way, miniaturization of the electric dust collector is required in order to make it easy to assemble in various electrical products. In order to secure the desired dust collecting performance, it is difficult to thin the dust collecting unit. Therefore, it is desired to make the charging portion thin.

When the charging portion is made thinner, the distance between the high voltage electrode and the counter electrode becomes closer, and there is a concern that ozone generation may increase.

In addition, ultrafine particles such as PM 0.1 having a thickness of 0.1 μm or less are difficult to charge themselves, and their mass is small, so there is a fear that they cannot be efficiently collected.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic precipitator and the like capable of thinning the charged portion while suppressing ozone generation.

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

Under this object, the electrostatic 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 having a portion where a high voltage is supplied from a high voltage generation circuit and generates at least electric field concentration, a counter electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit, Discharge is generated between the counter electrodes to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit.

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. Then, a discharge is generated between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. The counter electrode in the charging portion includes a conductor portion made of a conductive material. In addition, the counter electrode covers at least the surface of the side of the conductor portion opposite to the high voltage electrode, and has a volume resistivity of 10 ¹⁴ Pa · cm or more and 10 ¹⁸ Pa, which limits the discharge current between the high voltage electrode and the counter electrode. And a resistor portion that is cm or less.

In such an electrostatic precipitator, the resistive portion of the counter electrode in the charging portion may have a relative dielectric constant of 3 or more.

In such an electrostatic precipitator, the high voltage electrode in the charging unit may be in the form of a wire.

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

In addition, a plurality of the serrated portions or a plurality of the needle-like portions intersect with the ventilation direction and are divided into a plurality of rows. And the tip of the sawtooth-shaped portion or the tip of the needle-shaped portion in each of the plurality of rows is arranged to be shifted from each other in the column direction between adjacent rows. Moreover, with respect to the length L of the said serrated part or the said needle-shaped part, the distance S between the saw-toothed parts or the tip of the said needle-shaped part between these several rows is 3L or less. The spacing P between the sawtooth portion or the needle-shaped portion in each of the plurality of rows may be 2L or more.

Thereby, compared with the case where the serrated or needle-shaped portions are arranged in parallel in the ventilation direction, and the case where the high voltage electrode and the counter electrode are arranged in the direction perpendicular to the ventilation direction, the charging portion can be made thinner. .

In addition, a plurality of the serrated portions or a plurality of the needle-like portions intersect with the ventilation direction and are divided into a plurality of rows. And the tip of the sawtooth-shaped portion or the tip of the needle-shaped portion in each of the plurality of rows is disposed so as to face between adjacent rows. Moreover, with respect to the length L of the said serrated part or the said needle-shaped part, the distance S of the tip of the said serrated part or the said needle-shaped part between these several rows is 6L or more and 8L or less. The spacing P between the sawtooth portion or the needle-shaped portion in each of the plurality of rows may be 2L or more.

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

The high voltage electrode of the charging unit may include a main high voltage electrode and a vertical high voltage electrode.

In the above high pressure electrode, the main high pressure electrode may be provided with a sawtooth portion or a needle portion, and the vertical high pressure electrode may be in a wire shape.

Further, the tip of the serrated portion or the needle-like portion in the main high pressure electrode may face the upstream side of the ventilation direction.

In addition, the longitudinal high voltage electrode may be 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 two times or more and five times or less the voltage of the vertical high voltage electrode.

The main high voltage electrode may be set to a predetermined voltage, and the vertical high voltage electrode may be in a floating state in which no voltage is set.

The conductor portion of the counter electrode in the charging portion may be composed of a plurality of flat plates arranged at intervals to ensure ventilation.

The conductor portion of the counter electrode in the electrification portion may be constituted by a mesh having an opening for ensuring ventilation.

The conductor portion of the counter electrode in the charging portion may be made of a punching metal having an opening for ensuring ventilation.

The conductor portion of the counter electrode in the charging portion may be made of expanded metal having an opening for ensuring ventilation.

The counter electrode in the charging unit may be disposed on an upstream side of the ventilation direction with respect to the high voltage electrode of the charging unit.

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. The dust collecting unit is disposed downstream of the ventilation direction of the charging unit. The dust collector is provided with another high voltage electrode to which a high voltage is supplied from another high voltage generation circuit. It is provided with the other counter electrode formed so as to oppose the said other high voltage electrode and to which the reference voltage is supplied from the said other high voltage generation circuit. The dust collecting part collects the suspended fine particles charged by the charging part. Further, among the members constituting the charging unit, the other high voltage electrode is disposed at a separation distance of 5 mm or more downstream from the end of the member closest to the dust collecting unit at a ventilation direction downstream.

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. Then, a discharge is generated between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. Moreover, it is provided with the case which consists of a resin material and accommodates the said charging part. The high voltage electrode in the charging section is formed 5 mm or more away from the case.

In such an electrostatic precipitator, the counter electrode in the charging section includes a conductor portion made of a conductive material and a resistor portion covering the surface of the conductor portion at least opposite to the high voltage electrode. In addition, the case accommodating the charging unit may be characterized in that it has an electrical contact that is conducted to the conductor portion of the counter electrode of the charging unit.

Thereby, compared with the case where a counter electrode is not connected with a case in an exposure area | region, charging by the static electricity of a case can be suppressed further.

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 located between the conductor portion and the resistor portion. .

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. And a current limiting circuit including an inductor for lowering the potential of the high voltage electrode by a pulsed current in discharge generated between the high voltage electrode and the counter electrode. Then, a discharge is generated between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit.

As a result, compared with the case where no current limiting circuit is provided, the increase in ozone generation due to the pulsed current accompanying secondary electron emission can be further suppressed.

In such an electrostatic precipitator, the current limiting circuit in the charging section may be constituted by a parallel circuit of the inductor and the diode.

The diode of the current limiting circuit in the charging section may be connected in a reverse direction with respect 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 the gate of the junction type FET. Junction FETs; And a resistor element connected between the source-gate of the junction type FET; and a circuit connected in series with the inductor and the parallel circuit of the diode.

Thereby, compared with the case where the circuit which has a junction type FET and a resistance element is not provided, the short circuit current between a high voltage electrode and a counter electrode can be suppressed.

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

As a result, the short-circuit current between the high voltage electrode and the counter electrode can be suppressed as compared with the case where the series circuit using the MOSFET and the resistance element is not provided.

The current limiting circuit in the charging section may be formed on a path from the high voltage generating circuit to the high voltage electrode.

The high voltage electrode in the charging unit may be configured 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. .

Each of the plurality of sub-high voltage electrodes of the high voltage electrode in the charging portion includes a plurality of sawtooth portions, and the current limiting circuit in the charging portion is formed for each of the sawtooth portions. It can be characterized by.

Thereby, the fall of dust collection efficiency can be suppressed compared with the case where a current limiting circuit is not formed in each of a some sub high voltage electrode.

Further, in such an electrostatic precipitator, the current limiting circuit in the charging section may be formed on a path from the high voltage generating circuit to the counter electrode.

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

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. Then, a discharge is generated between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. The counter electrode in the charging portion has a conductor portion made of a conductive material, a first member covering the counter electrode side of the conductor portion, and a second member covering the counter electrode side of the first member. In addition, the counter electrode has a contact region in which the second member is in electrical contact with the conductor portion.

In such an electrostatic precipitator, the high voltage electrode of the charging unit may include a main high voltage electrode and a longitudinal high voltage electrode.

Moreover, in the said high voltage electrode, the said main high voltage electrode may be provided with the saw tooth-shaped part or the needle-shaped part, and the said longitudinal high voltage electrode can be characterized by being wire-shaped.

The tip of the sawtooth-shaped portion or the needle-shaped portion in the main high pressure electrode is directed toward an upstream side of the ventilation direction.

In addition, the longitudinal high voltage electrode may be 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 characterized by being at least two times and at most five times the voltage of the vertical high voltage electrode.

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

The second member of the counter electrode in the charging unit 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.

The conductor portion of the counter electrode in the charging portion may be made of expanded metal composed of a conductive material having an opening for ensuring ventilation.

Thereby, the breakdown voltage between the high voltage electrode and the counter electrode can be made higher than in the case where the first member is not provided.

Also for this purpose, the electrostatic 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 a high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. The charging unit generates a discharge between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. The counter electrode in the electrification portion includes a substrate which sets the shape of the counter electrode, a first member formed on a surface of the substrate that does not oppose the high voltage electrode, and a surface that does not oppose the high voltage electrode on the substrate. It has a conductive 2nd member formed in the.

For this purpose, the electrostatic 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 a high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. The charging unit generates a discharge between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. The counter electrode in the charging unit includes a substrate for setting the shape of the counter electrode, a first member formed on a surface of the substrate that faces the high voltage electrode, and a surface that does not face the high voltage electrode of the substrate. It has a conductive 2nd member to cover.

Also for this purpose, the electrostatic 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 the high voltage generation circuit. It is also provided with a counter electrode formed opposite to the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. And a current limiting circuit including an inductor for lowering the potential of the high voltage electrode by a pulsed current in discharge generated between the high voltage electrode and the counter electrode. Then, a discharge is generated between the high voltage electrode and the counter electrode to charge the suspended fine particles. The dust collecting unit is disposed downstream of the ventilation direction of the charging unit. The dust collector is provided with another high voltage electrode to which a high voltage is supplied from another high voltage generation circuit. The dust collector is provided with the other counter electrode formed to face the other high voltage electrode and supplied with a reference voltage from the other high voltage generation circuit. The dust collecting part collects the suspended fine particles charged by the charging part. Moreover, it is comprised from the resin material, and is provided with the case which accommodates the said charging part. The high voltage electrode in the charging section includes a plurality of serrated portions or a plurality of needle-shaped portions each made of a conductive material and each of which has a sharp tip. The saw tooth portion or the needle portion intersect with the ventilation direction, and the plurality of saw tooth portions or the plurality of needle portions are divided into a plurality of rows. The tip of the sawtooth-shaped portion or the tip of the needle-like portion in each of the plurality of rows is arranged to be shifted from each other in the column direction between adjacent rows. The distance S between the sawtooth portion or the tip of the needle-shaped portion between the plurality of rows is 3 L or less with respect to the length L of the sawtooth portion or the needle-shaped portion. On the other hand, the spacing P of the sawtooth-shaped portion or the needle-shaped portion in each of the plurality of rows is 2L or more. The high voltage electrode is formed at least 5 mm away from the case. The counter electrode has a volume resistivity of 10 ¹⁴ Pa · cm, covering a conductor portion made of a conductive material and at least a surface of the conductor portion opposite to the high voltage electrode and limiting a discharge current between the high voltage electrode and the counter electrode. And a resistor portion of not less than 10 ¹⁸ Pa · cm. Further, among the members constituting the charging unit, the other high voltage electrode is disposed at a separation distance of 5 mm or more downstream from the end of the member closest to the dust collecting unit at a ventilation direction downstream.

Also for this purpose, the electrostatic 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 a high voltage generation circuit, and an opposite electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit. The charging unit generates a discharge between the high voltage electrode and the counter electrode to charge the suspended fine particles. A dust collecting unit collects the suspended fine particles charged on the downstream side in the ventilation direction of the charging unit and charged by the charging unit. In the charging section, 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. The plurality of serrated or needle-like portions of the high voltage electrode and the sub counter electrode are arranged in the direction crossing in the ventilation direction. A serrated portion or a needle-like portion of the high voltage electrode is disposed in parallel with the surface of the sub counter electrode in a planar shape.

In such an electrostatic precipitator, the distal end of the serrated portion or the distal end of the needle-like portion of the high voltage electrode in the electrification portion faces the upstream side of the ventilation direction, and the upstream of the ventilation direction of the plate-shaped sub counter electrode. It can be characterized by being located downstream from the stage.

Moreover, the said sub counter electrode in the said electrification part extends at least the length of the said serrated part or needle-shaped part to the downstream side of the said ventilation direction from the tip of the serrated part of the high voltage electrode, or the tip of the needle shaped part. It is characterized by being arranged.

The high-voltage electrode of the dust collector is disposed at a separation distance of 5 mm or more downstream from the end of the member closest to the dust collector, among the members constituting the charging unit.

The charging unit may include a current limiting circuit including an inductor and lowering a potential of the high voltage electrode by a pulse current in a discharge generated between the high voltage electrode and the counter electrode.

According to the present invention, it is possible to provide an electrostatic precipitator and the like which can reduce the charge portion while suppressing ozone generation.

In addition, according to the present invention, it is possible to provide an electrostatic precipitator capable of efficiently collecting ultra-fine particles while suppressing ozone generation.

1 is a diagram illustrating an example of an electric dust collector to which the first embodiment is applied.

2A and 2B are plan views of the high voltage electrode and the counter electrode of the charging unit, respectively, FIG. 2A is the high voltage electrode, and FIG. 2B is the counter electrode.

3A and 3B are cross-sectional views illustrating the charging unit in detail, FIG. 3A is a charging unit of the electrostatic precipitator to which the first embodiment is applied, and FIG. 3B is a charging unit of the electrostatic precipitator of the comparative example to which the first embodiment is not applied. .

4 is a diagram showing a relationship between ozone concentration and dust collection efficiency in the electrostatic precipitator of Example 1 and the electrostatic precipitator of Comparative Example 1. FIG.

Fig. 5 is a diagram showing the relationship between the material (resistance member material) constituting the resistor portion of the counter electrode, the ion generating voltage (kV) and the ionized water (× 10 ³ pieces / cm ³ ) in the ozone generating voltage.

6 is a perspective view of a charging unit of the electrostatic precipitator of the third embodiment.

7A and 7B are plan views of each of the high voltage electrode and the counter electrode in the electrostatic precipitator of the third embodiment. 7A is a high voltage electrode, and FIG. 7B is an opposite electrode.

8 is a diagram showing a relationship between dust collection efficiency and ozone concentration in the electrostatic precipitator of Example 3. FIG.

9 is a perspective view of a charging unit of the electrostatic precipitator of the fourth embodiment.

10A and 10B are plan views of the high voltage electrode and the counter electrode respectively in the electrostatic precipitator of the fourth embodiment, FIG. 10A is the high voltage electrode, and FIG. 10B is the counter electrode.

FIG. 11 is a diagram showing a relationship between dust collection efficiency and ozone concentration in the electrostatic precipitator of Example 4. FIG.

12A to 12C show a modification of the charging unit of the electrostatic precipitator of the fourth embodiment, 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. Sectional view on the XIIC-XIIC line.

13A and 13B are views illustrating a charging unit of the electrostatic precipitator of the fifth embodiment, FIG. 13A is a perspective view of the charging unit, and FIG. 13B is a sectional view taken along the line XIIIB-XIIIB of FIG. 13A.

14A and 14B are plan views of the high voltage electrode and the counter electrode of the electrostatic precipitator of Example 5, and FIG. 14A is the high voltage electrode, and FIG. 14B is the counter electrode.

15A and 15B are views showing a modification of the high voltage electrode in the electrification portion of the electrostatic precipitator, FIG. 15A is a view in which the teeth are arranged in a different arrangement from FIG. 2A, and FIG. 15B is a view in which the teeth are configured in a different arrangement from FIG. 10A. Drawing.

16A and 16B show another modified example of the high voltage electrode in the electrification portion of the electrostatic precipitator, and FIG. 16A is composed of a plurality of needle rows each having a plurality of needles, and the tip of the needle is adjacent to each other. It is a figure comprised so that it may oppose between needle rows, and FIG. 16B is a figure comprised from the several needle row provided with a some needle, and the tip of a needle was comprised by the zigzag between adjacent needle rows.

It is a figure explaining the modification of the counter electrode in the electrification part of an electrostatic precipitator.

It is a figure which shows an example of the electric dust collector to which 2nd Embodiment is applied.

It is a figure which shows the relationship of the dust collection efficiency of an electrostatic precipitator, and ozone concentration with respect to the spacing P of the tooth in a tooth row.

It is a figure which shows the relationship of the dust collection efficiency and ozone concentration of an electrostatic precipitator with respect to the distance S between tooth rows.

21A to 21D are diagrams schematically illustrating the discharge state in the charging section, FIG. 21A is a plan view seen from the high voltage electrode side, and FIG. 21B is a sectional view taken along the line XXIB-XXIB in FIG. 21A.

It is a figure which shows an example of the electric dust collector to which 3rd Embodiment is applied.

23 is a diagram schematically illustrating a discharge state in a charging unit.

It is a figure which shows an example of the electrical dust collector to which 4th Embodiment is applied.

25 is an equivalent circuit relating to a charging unit of an electrostatic precipitator.

It is a figure which shows an example of the high voltage electrode with which the current limiting circuit by the parallel circuit of an inductor and a diode was connected.

27 is an equivalent circuit of a charging unit including a current limiting circuit by a resistance.

28A and 28B are diagrams showing a time change of the inter-electrode voltage in the charging section of each of the electrostatic precipitator of Example 7 and the electrostatic precipitator of Comparative Example 3, and FIG. 28A shows Example 7, and FIG. 28B shows Comparative Example 3; to be.

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

30 is a diagram illustrating an example of a high voltage electrode in which a current limiting circuit is connected for each tooth row in the charging section of the electrostatic precipitator according to the eighth embodiment.

FIG. 31 is a diagram showing an example of a high voltage electrode in which a current limiting circuit is connected for each tooth in the charging section of the electrostatic precipitator of Example 9. FIG.

32 is a charging unit equivalent circuit in the electrostatic precipitator to which the fifth embodiment is applied.

33 is a diagram illustrating a time change of the inter-electrode voltage in the charging unit of the electrostatic precipitator of the tenth embodiment.

34 is a diagram illustrating a time change of the inter-electrode voltage due to a short circuit in the charging unit of the electrostatic precipitator of the tenth embodiment.

35 is a diagram illustrating 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 section and the short circuit current limiting section in the current limiting circuit of FIG. 36b shows a case where the current limiting circuit is connected to the counter electrode, and FIG. 36c shows a case where a high voltage electrode and a counter electrode are formed between the secondary electron current limiting section and the short-circuit current limiting section in the current limiting circuit.

It is a schematic diagram for demonstrating the charging part of the electric dust collector to which 6th Embodiment is applied.

38A and 38B are diagrams showing the ionized water generated in the charging section of each of the electrostatic precipitator of Example 11 and the electrostatic precipitator of Comparative Example 4, and FIG. 38A shows Example 11 and FIG. 38B shows comparative example 4. FIG.

39A and 39B are views for explaining an electrification section in the electrostatic precipitator according to the twelfth embodiment, Fig. 39A is a perspective view of the electrification section, and Fig. 39B is a sectional view taken along the line XXXIXB-XXXIXB of the counter electrode.

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

41A and 41B are views for explaining a charging unit in the electrostatic precipitator according to the fourteenth embodiment.

42A and 42B are views illustrating a charging unit in the electrostatic precipitator of the fifteenth embodiment, FIG. 42A is a perspective view of the charging unit, and FIG. 42B is a sectional view taken along the line XLIIB-XLIIB in FIG. 42A.

It is a figure explaining the relationship between the inter-electrode voltage (kV) applied between the high voltage electrode and the conductor part of a counter electrode, and the ozone generation amount (microgram / h) per tooth.

44A and 44B are views for explaining a charging unit in the electrostatic precipitator according to the seventeenth embodiment, FIG. 44A is a perspective view of a charging unit, and FIG. 44B is a sectional view of a part of the counter electrode.

45A and 45B are views illustrating a charging unit in the electrostatic precipitator according to the eighteenth embodiment, FIG. 45A is a perspective view of the charging unit, and FIG. 45B is a sectional view of the counter electrode in the XLVB-XLVB line in FIG. 45A.

46A and 46B are views for explaining the charging portion in the electrostatic precipitator according to the nineteenth embodiment, FIG. 46A is a perspective view of the charging portion, and FIG. 46B is a sectional view of the counter electrode in the XLVIB-XLVIB line in FIG. 46A.

It is a figure which shows an example of the electrical dust collector to which 7th Embodiment is applied.

48 is a diagram illustrating an example of an electric dust collector to which the eighth embodiment is applied.

49A to 49C are perspective views of main portions of the charging unit in the electrostatic precipitators according to Example 20 and Comparative Examples 6 and 7, wherein FIG. 49A is Example 20, and FIG. 49B is Comparative Example 6 and FIG. 49C is Comparative Example 7. .

It is a figure explaining the dust collection efficiency calculated | required for every ozone concentration and particle diameter in the electrostatic precipitator which concerns on Example 20, the comparative examples 6 and 7. FIG.

It is a figure explaining the operation | movement of a longitudinal high voltage electrode.

It is a figure which shows the modified example of the electrostatic precipitator to which 8th Embodiment is applied.

It is a figure which shows the modification of the electric dust collector to which the 9th Embodiment is applied.

Fig. 54 is a sectional view of the charging direction of the electrostatic precipitator according to the twenty-first embodiment, and the ventilation directions of the main parts of the dust collector;

55A and 55B are perspective views of main parts of the charging unit 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.

It is a figure explaining the dust collection efficiency calculated | required for every ozone concentration and particle diameter in the electrostatic precipitator which concerns on Example 21 and the comparative example 7. FIG.

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

[First Embodiment]

FIG. 1: is a figure which shows an example of the electric dust collector 1 to which 1st Embodiment is applied. Here, the case 30 is shown with a broken line, and the structure of the charging part 10 and the dust collector 20 formed in the inside of the case 30 is shown.

The electrostatic precipitator 1 is provided with the case 30 which accommodates the charging part 10, the dust collecting part 20, the charging part 10, and the dust collecting part 20. As shown in FIG. That is, the electrostatic precipitator 1 is a two-stage electrostatic precipitating method in which the charging unit 10 and the dust collecting unit 20 are separated.

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

And for convenience of explanation, as shown in FIG. 1, the left-right direction orthogonal to an up-down direction and orthogonal to an up-down direction with respect to a ventilation direction is described as left and right as shown in FIG.

On the other hand, as long as ventilation is not impaired, the electrostatic precipitator 1 may be arrange | positioned in what direction.

(The front part (10))

The charging unit 10 includes a high voltage electrode 11 and a counter electrode 12 that faces 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 which generates a discharge, it is also called a discharge electrode. In addition, since the counter electrode 12 may be grounded (GND), it is also called a ground electrode.

And a high voltage of direct current (DC) is applied between the high voltage electrode 11 and the counter electrode 12, and a corona discharge (discharge) is generated between the high voltage electrode 11 and the counter electrode 12. As shown in FIG. Then, the suspended fine particles are charged by the generated corona discharge.

For example, the high voltage electrode 11 has a plurality of tooth rows 113 (see FIG. 1 in FIG. 1) provided with a plurality of toothed portions 111 (hereinafter referred to as teeth 111) each having a sharp tip. 5 rows of 1 to # 5). The longitudinal direction of each tooth row 113 is directed to the left and right directions. In FIG. 1, the uppermost tooth row 113 (# 1 in FIG. 1) in the up-down direction is provided with a plurality of teeth 111 (10 in FIG. 1) arranged downward. The lowest tooth row 113 (# 5 in FIG. 1) in the up-down direction is provided with a plurality of teeth 111 (10 in FIG. 1) arranged toward the upper side. The tooth rows 113 (# 2 to # 4 in Fig. 1) between are a plurality of teeth 111 (10 in Fig. 1) arranged toward the upper side and a plurality of teeth 111 (arranged toward the lower side) ( In FIG. 1, 10 pieces are provided.

On the other hand, the tooth 111 and / or its tip is an example of a site for generating 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.

The plurality of teeth 111 in each tooth row 113 are connected to the connecting portion 112. And the edge part of each connection part 112 is being fixed to the support part 14 which consists of insulating materials. The support part 14 is equipped with the circuit board (printed wiring board (PCB)) provided with wiring. Through the wiring of the circuit board, the tooth row 113 is connected to the anode of the high voltage generating circuit 40 which supplies a high voltage of DC.

In addition, the support part 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 arranged so that the ends thereof face each other between adjacent tooth rows 113, for example, between tooth rows 113 (# 1) and tooth rows 113 (# 2). Formed.

In addition, each tooth 111 may be formed in the inclination direction with respect to the ventilation direction. That is, each tooth 111 is formed in the direction crossing in the ventilation direction.

The teeth 111 and the connection portion 112 of the high voltage electrode 11 are integrally formed of a conductive material. In addition, the support part 14 may not be a separate member, but may be comprised with the tooth | gear 111 and the connection part 112, and may be comprised with a conductive material.

The counter electrode 12 is formed of a member made of a conductive material having a penetrating opening (hole) 124 and a member made of a resistive material formed so as to cover the surface thereof and functioning as a resistance to current. Resistor) (see conductor portion 121 and resistor portion 122 in FIG. 2 described later). 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 the dust collection efficiency and the 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. In addition, in FIG. 1 (also FIG. 2B mentioned later), the mesh (opening 124) is largely described. However, the size of the mesh (opening 124) is set in consideration of the discharge occurring between the high voltage electrodes 11.

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

(Dust collecting part 20)

The dust collecting part 20 is provided with the plate-shaped high voltage electrode 21 by which the surface was coat | covered by the film | membrane of insulating material, and the counter electrode 22 which were laminated alternately. The ventilation direction is between the high voltage electrode 21 and the counter electrode 22. On the other hand, since the counter electrode 22 may be 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 generation circuit 50. Then, the suspended fine particles charged by the charging unit 10 adhere to the surface of the counter electrode 22 by static electricity. As a result, suspended fine particles are collected.

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

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

(Case (30))

The case 30 accommodates the charging unit 10 and the dust collecting unit 20. In addition, a plurality of gratings (grills) 31 are formed on the front surface portion facing the charging unit 10. On the other hand, the grating 31 is preferably formed so that the resistance to the ventilation is small while preventing the user from contacting the charging unit 10.

The case 30 is comprised from resin materials, such as ABS (acrylonitrile, butadiene, styrene copolymer), for example.

2A and 2B are plan views of each of the high voltage electrode 11 and the counter electrode 12 of the charging unit 10. 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 a tooth row 113 (# 1 to # 5 in FIG. 2) in which a plurality of teeth 111 are formed. The tip of each tooth 111 is formed to face (facing each other) between adjacent tooth rows 113.

The length from the tip of the tooth 111 to the connection portion 112 is L (length L), and the interval (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 rows is set to S (distance S).

As shown in FIG. 2B, the counter electrode 12 includes, as an 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 constitute the conductor exposed region 123 in which the surface of the conductor portion 121 is exposed. In addition, you may form the conductor exposure area | region 123 which exposed the surface of the conductor part 121 also in the left-right side edge part.

In addition, you may form the conductor exposure area | region 123 which exposed the surface of the conductor part 121 only in the edge part of the counter electrode 12. As shown in FIG.

The conductor exposed region 123 may be formed by removing the formed resistor portion 122, and may be formed so as not to form the resistor portion 122 (for example, not to be coated).

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

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

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

The high voltage electrode 11 has a plurality of teeth 111. In FIGS. 3A and 3B, each tooth 111 does not appear to be electrically connected. However, as described in FIGS. 1, 2A and 2B, the high voltage electrode 11 is electrically connected.

The counter electrode 12 is provided with the conductor part 121 and the resistor part 122 formed so that the surface of the conductor part 121 may be covered. 3A and 3B, the conductor portions 121 do not appear to be electrically connected to each other. However, as described with reference to Figs. 1, 2A and 2B, since the conductor portion 121 is a wire mesh (mesh) made of a conductive material, it is electrically connected.

In the charging portion 10 of the electrostatic precipitator 1 to which the first embodiment shown in FIG. 3A is applied, the high voltage electrode 11 is connected to the case 30 through an insulating spacer 32 composed of the insulating member (insulator). Is attached to. Therefore, the high voltage electrode 11 is not in direct contact with the case 30. In addition, the support part 14 may be the insulating spacer 32, and the support part 14 may be attached to the case 30 via the insulating spacer 32. As shown in FIG.

As the insulating spacer 32, any of the above insulating properties may be used, and it is preferable that the insulating spacer 32 is 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.

On the other hand, the counter electrode 12 is attached to the case 30 such that the conductor exposed region 123 exposing the conductor portion 121 is in electrical contact with the case 30. And it is connected to the ground terminal E in the conductor exposed area | region 123. As shown in FIG. On the other hand, the ground terminal E may not be grounded.

In addition, the member (resin member) which consists of resin materials, such as the case 30, is not formed in the range of predetermined distance r from the front-end | tip of the tooth | gear 111. As shown in FIG. The resin member here is not limited to the member which comprises the case 30, What is formed in the case 30 is included.

On the other hand, in the electrification part 10 in the electrostatic precipitator 1 of the comparative example 1 shown in FIG. 3B, the edge part of the counter electrode 12 did not expose the conductor part 121. FIG. That is, in the electrostatic precipitator 1 of the comparative example 1, the counter electrode 12 does not have a conductor exposed area | region.

The high voltage electrode 11 is attached to the case 30 directly.

On the other hand, the counter electrode 12 is attached to contact the case 30 through the resistor portion 122. The counter electrode 12 is connected to the ground terminal E except for the part in contact with the case 30. On the other hand, the ground terminal E may not be grounded.

(Example 1)

Next, the electrostatic precipitator 1 to which the first embodiment is applied (the electrostatic precipitator 1 of Example 1) and the electrostatic precipitator 1 to which the first embodiment is not applied (the electrostatic precipitator 1 of Comparative Example 1) are applied. Explain the results of measuring dust collection efficiency and ozone concentration.

The electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of Comparative Example 1 differ from each other as shown in FIG. However, other configurations are the same.

The charging section 10 of the electrostatic precipitator 1 had the size of the support section 14 of the high voltage electrode 11 viewed from the ventilation direction as about 400 mm in the left and right directions and about 300 mm in the vertical direction. And the grating 31 was arrange | positioned so that the some opening part of 40 mm x 125 mm may be formed in the case 30 surface.

The teeth 111 and the connection part 112 of the high voltage electrode 11 in the charging part 10 were comprised with plate-shaped stainless steel (SUS) of thickness 0.5mm. And the tooth | gear 111 made the length from the tip to the connection part 112 about 10 mm. The distance S between the tips of the teeth 111 between the teeth rows 113 was set to about 30 mm.

The counter electrode 12 in the charging unit 10 used the conductor portion 121 as a wire mesh (mesh) made of SUS having an opening ratio of 87.1%. The resistor portion 122 covering the surface of the conductor portion 121 was made of polyimide resin having a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Pa · 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 in the ventilation direction of 20 mm and a length in a direction orthogonal to the ventilation direction of about 400 mm. And the space | interval of 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 the electrostatic precipitator 1 of Example 1, the resin member constituting the case 30 or the like was not formed in the range of about 5 mm (distance r) from the tip of the tooth 111.

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

Here, ozone concentration was calculated | required from the amount of ozone which the ozone concentration meter measures, and the amount of air blown in by an ozone concentration meter using an ozone concentration meter. In addition, the dust collection efficiency measures the number of suspended particulates in the 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 a particle counter. Saved it.

As can be seen from FIG. 4, even when the electrostatic precipitator 1 of Example 1 was operated in a state where nearly 100% dust collection efficiency was obtained, the ozone concentration was 2.0 ppb or less. This value is significantly below the environmental standard (0.05 ppm).

On the other hand, in the electrostatic precipitator 1 of the comparative example 1, dust collection efficiency was saturated at about 50%. And although the dust collection efficiency is about 50%, ozone concentration is large compared with the electrostatic precipitator 1 of Example 1. FIG. On the other hand, also in the electrostatic precipitator 1 of the comparative example 1, the maximum ozone concentration in a measurement range is 2.0 ppb, and is less than an environmental reference value (0.05 ppm).

In the electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of the comparative example 1, ozone concentration is suppressed low compared with an environmental reference value. This is considered to be because the counter current 12 of the charging section 10 includes the resistor portion 122 covering the surface of the conductor portion 121, thereby limiting the discharge current.

On the other hand, the dust collection efficiency of the electrostatic precipitator 1 of Example 1 and the electrostatic precipitator 1 of Comparative Example 1 is different from that of the electrostatic precipitator 1 of Comparative Example 1, It is considered that 30 is easy to charge 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. The high voltage of DC 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. FIG.

The resin material constituting the case 30 has a high electrical resistivity and is difficult to flow electricity. For this reason, the surface of the case 30 is easy to charge with static electricity. Since the case 30 is not connected to the ground electrode, the charged static electricity cannot escape. That is, it is thought that the charging efficiency of the floating fine particles worsened and the dust collection efficiency fell due to the charging of the case 30, in particular the charging of the case 30 in contact with 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 the insulating spacer 32. Therefore, the high voltage electrode 11 and the case 30 do not electrically contact. In addition, since the case 30 is connected to the counter electrode 12, the charged static electricity may escape. In addition, the resin member which comprises the case 30 etc. was not formed in the range of predetermined distance r (5 mm in Example 1) from the tip of the tooth | gear 111 which is the high voltage electrode 11. As shown in FIG.

Therefore, it is considered that the charging of the case 30 by static electricity is suppressed, the charging of the suspended fine particles is less likely to be inhibited, and the dust collection efficiency is increased.

As described above, in the electrostatic precipitator 1 to which the first embodiment is applied, the counter electrode 12 of the charging unit 10 is formed so as to cover the surface of the conductor portion 121 and the conductor portion 121. It consists of one resistor part 122. Therefore, the discharge current is suppressed smaller than that in the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed low.

The high voltage electrode 11 of the charging unit 10 is fixed to the case 30 via the insulating spacer 32. In addition, the resin member which comprises the case 30 etc. is not formed in the range of 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. This suppresses charging of the case 30 by static electricity and improves dust collection efficiency.

In addition, the high voltage electrode 11 of the charging unit 10 opposes the distal end of each of the teeth 111 between the teeth rows 113, so that the teeth 111 in one direction (for example, the lower side) are not used. Compared with the case where it is not, the area | region where discharge generate | occur | produces is large.

In the electrostatic precipitator 1 to which the first embodiment is applied, the high voltage electrode 11 and the counter electrode 12 are arranged in the ventilation direction in the charging unit 10. Moreover, the part which generate | occur | produces the discharge of the high voltage electrode 11 is set to the tooth | gear 111, and the tooth | gear 111 is arrange | positioned orthogonally or inclined with respect to a ventilation direction. Therefore, the distance G of the high voltage electrode 11 and the counter electrode 12 can be set short, for example to 5 mm. Thereby, the electrostatic precipitator 1 can be miniaturized.

In addition, unlike the electrostatic precipitator 1 to which the first embodiment is applied, the high voltage electrode 11 is not formed without forming the resistor portion 122 formed to cover the surface of the conductor portion 121 of the counter electrode 12. Approaching between and the counter electrode 12, the discharge current increases, the ozone generation 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 Embodiment 2, the material of the resistor portion 122 covering the surface of the counter electrode 12 will be described.

FIG. 5 shows the relationship between the material (resistance member material) constituting the resistor portion 122 of the counter electrode 12 and the ionized water (× 10 ³ pieces / cm ³ ) in the ozone generating voltage (kV) and the ozone generating voltage. Drawing. 5, the volume resistivity (kcm) and the dielectric constant are shown as a characteristic of the material (resistance material) which comprises the resistor part 122. As shown in FIG. 5, the distance G (mm) of 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 at 5 mm.

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

In addition, 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 is measured. (× 10 ³ pcs / cm ³ ). Ion water was measured with an ion counter.

In the electrostatic precipitator 1, it is preferable that the ozone generating voltage is high and the ion water generated at the ozone generating voltage is large.

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

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

The material of the resistor portion 122 is "none", "alkyd resin", "acrylic resin", "polyimide", "polyester", "PTFE" (Polytetrafluoroethylene) ”was used.

The thickness of the resistor part 122 was about 50 micrometers, respectively.

When the resistor portion 122 was "none", the ozone generating voltage was 3.2 kV, and the ionized water at the ozone generating voltage was 0. In other words, when the DC voltage between the high voltage electrode 11 and the counter electrode 12 was gradually raised, ozone began 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 generating voltage was 4.0 kV, and the ionized water at the ozone generating voltage was 1040 × 10 ³ pieces / cm ³ . In other words, when the DC voltage between the high voltage electrode 11 and the counter electrode 12 was gradually increased, ozone began to be generated at 4.0 kV. However, ions began to generate at DC voltages below the ozone generating voltage.

When the resistor portion 122 was an acrylic resin, the ozone generating voltage was 4.5 kV, and the ionized water at the ozone generating voltage was 1400 × 10 ³ holes / cm ³ . In other words, when the DC voltage between the high voltage electrode 11 and the counter electrode 12 was gradually raised, ozone began to be generated at 6.0 kV. However, ions began to generate at DC voltages below the ozone generating voltage.

When the resistor portion 122 was a polyimide resin, the ozone generating voltage was 6.0 kV, and the ionized water at the ozone generating voltage was 1600 × 10 ³ pieces / cm ³ . In other words, 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 began to generate at DC voltages below the ozone generating voltage.

And when the resistor part 122 is a polyester resin or PTFE, even if the DC voltage between the high voltage electrode 11 and the counter electrode 12 is applied to 10 kV, ozone does not generate | occur | produce and neither ion generate | occur | produced. On the other hand, in the case of a polyester resin, even when a DC voltage between the high voltage electrode 11 and the counter electrode 12 is applied up to 10 kV by forming the conductor exposed region 123, 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, ionized water was 2000x10 <^3> / cm <^3> .

As mentioned above, as a material (resistance material) of the resistor part 122 shown in FIG. 5, the polyimide resin has the highest ozone generation voltage, and the ion water in an ozone generation voltage is large. That is, polyimide resin is most preferable as a material of 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.

From the characteristics, it is preferable that the relative dielectric constant is 3 or more, and the volume resistivity is 10 ¹² Pa · cm or more and 10 ¹⁸ Pa · cm or less. As for volume resistivity, 10 ¹⁴ Pa.cm or more and 10 ¹⁸ Pa.cm or less are more preferable.

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

(Example 3)

In Example 3, the relationship between the dust collection efficiency and ozone concentration in the case where the counter electrode 12 in the charging part 10 has the resistor part 122, and does not have is demonstrated. The electrostatic precipitator 1 described here will be 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 the third embodiment. In the electrostatic precipitator 1 shown in FIG. 1, the ventilation direction was a direction from right to left in the ground. However, in FIG. 6, the ventilation direction is described in the direction from the upper side to the lower side in the ground.

In addition, the high voltage electrode 11 of the electrostatic precipitator 1 is the structure shown in FIG. That is, a plurality of tooth rows 113 each having a plurality of teeth 111 are provided. The teeth 111 are arranged so that the ends thereof face each other between the teeth 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. Expanded metal is a wire mesh-like member in which a rhombus opening 124 is formed by inserting a cutting line into a plate made of a conductive material.

7A and 7B are plan views of each of the high voltage electrode 11 and the counter electrode 12 in the electrostatic precipitator of the third embodiment. FIG. 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, a part (upper and lower side in the up-down direction) of the conductor portion 121 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 the insulating spacer 32. The counter electrode 12 is attached so that the conductor exposed area | region 123 is connected to the case 30, and the attached part is connected to the ground terminal E (refer FIG. 3).

The size of the support part 14 of the high voltage electrode 11 was made into about 400 mm in the left-right direction, and about 300 mm in the up-down direction.

The high voltage electrode 11 was made of SUS having 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. The high voltage electrode 11 includes five rows of teeth 113 (# 1 to # 5).

The conductor part 121 of the counter electrode 12 was comprised with the expanded metal of SUS, and the dimension 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 a polyimide resin having 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 Pa · cm.

The distance G of 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 began to be generated and charging of the fine particles became possible.

And as shown in FIG. 1, the airborne particle | grains were formed in the dust collection part 20 downstream of the ventilation direction, and it was made to air flow through the electrification part 10 and the dust collecting part 20, and the airborne fine particles were removed.

8 is a diagram showing a relationship between dust collection efficiency and ozone concentration in the electrostatic precipitator 1 of the third embodiment. In FIG. 8, the electrostatic precipitator 1 by the said structure is shown as Example 3, and the electrostatic precipitator 1 which did not form the resistor part 122 in the counter electrode 12 of the charging part 10 was compared. Represented by. On the other hand, also in the electrostatic precipitator 1 of the comparative example 2, the counter electrode 12 of the charging part 10 is attached so that it may be connected to the case 30, and the attached part is connected to the ground terminal E. FIG.

In the electrostatic precipitator 1 of Example 3, the ozone concentration was 3 ppb or less even when operating in a state where nearly 100% dust collecting efficiency was obtained. This value is significantly below the environmental standard (0.05 ppm).

On the other hand, in the electrostatic precipitator 1 of the comparative example 2, when it operates in the state which nearly 100% dust collection efficiency is obtained, an ozone concentration exceeds 7 ppb. This value is less than the environmental standard value (0.05 ppm), but is twice or more that of the electrostatic precipitator 1 of the third embodiment.

As described above, the electrostatic precipitator 1 of the third embodiment includes the resistor portion 122 in the counter electrode 12 of the charging portion 10, so that high dust collection efficiency can be obtained while suppressing the ozone concentration low.

(Example 4)

Here, the relationship between the dust collection efficiency and ozone concentration in the case where the shape of the high voltage electrode 11 of the electrostatic precipitator 1 and the charging part 10 differs is demonstrated. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of the fourth embodiment.

9 is a perspective view of the charging unit 10 of the electrostatic precipitator 1 of the fourth embodiment. Also in FIG. 9, the ventilation direction is described in the up-down 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 tooth row 113 is provided with the teeth 111 which face an upper direction and a lower direction. The tip ends of the teeth 111 are arranged to be zigzag (stagger) with each other between the teeth rows 113. That is, the tip of the teeth 111 does not oppose each other between the teeth rows 113, and the teeth 111 of the teeth row 113 of the other teeth between the tips of the teeth 111 of the one teeth row 113. The tip is arranged. That is, between the tooth rows 113, the teeth 111 are arranged to be shifted from each other in the column 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 expanded metal.

10A and 10B are plan views of each of the high voltage electrode 11 and the counter electrode 12 in the electrostatic precipitator of the fourth embodiment. 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 becomes larger than in the case of the third embodiment.

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

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

The counter electrode 12 comprised the conductor part 121 from the expanded metal of SUS, and made the dimension of the opening 124 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 having a thickness of about 50 μm. This polyimide resin was dielectric constant 3.3 and volume resistivity 10 ¹⁶ Pa.cm.

11 is a diagram showing a relationship between dust collection efficiency and ozone concentration in the electrostatic precipitator 1 of the fourth embodiment. In addition, the electrostatic precipitator 1 by the said structure is shown as Example 4 here. Moreover, the electrostatic precipitator 1 of Example 3 and the electrostatic precipitator 1 of the comparative example 2 are shown together.

As can be seen from FIG. 11, in the electrostatic precipitator 1 of Example 4, the ozone concentration was 2 ppb or less even when operating in a state where nearly 100% dust collecting efficiency was obtained. This ozone concentration is lower than the electrostatic precipitator 1 of the third embodiment.

It is considered that this is because the teeth 111 in the tooth row 113 of the high voltage electrode 11 are arranged in a zigzag pattern between the tooth rows 113. That is, the area (range) in which corona discharge is formed between the high voltage electrode 11 and the counter electrode 12 becomes wider than the case where the teeth 111 face each other between the teeth rows 113. I think.

As described above, the electrostatic precipitator 1 of the fourth embodiment can obtain a high dust collection efficiency while suppressing the ozone concentration lower by changing the shape of the high pressure electrode 11.

12A to 12C are views showing modifications of the charging unit 10 of the electrostatic precipitator 1 of the fourth embodiment. 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 in the XIIC-XIIC line.

The conductor portion 121 of the counter electrode 12 is composed of a plurality of flat plates, and a resistor portion 122 is stacked on the surface of each flat plate constituting the plurality of flat plates. Each plate is arranged to be paired with each tooth row 113. In addition, each flat plate is formed in the plane of 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 tip ends 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 having no resistor portion 122. And the counter electrode 12 is attached so that the conductor exposure area | region 123 may be connected with the case 30, and the attached part is connected to the ground terminal E. FIG. 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 high voltage electrode 11 and the conductor exposed region 123 of the counter electrode 12 are maintained at an insulating distance. have.

(Example 5)

In Example 1 thru | or 4, the tooth | gear 111 was used for the high voltage electrode 11 in the charging part 10 of the electrostatic precipitator 1. As shown in FIG.

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

As shown in FIG. 13A, the high voltage electrode 11 of the charging unit 10 of the electrostatic precipitator 1 includes a plurality of wires 114. The plurality of wires 114 are formed in the left and right directions. And both ends of the plurality of wires 114 are fixed to the support 14. The plurality of wires 114 are supplied with a DC voltage through the wirings formed on the circuit board included in the support 14.

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

As shown in the cross-sectional view of FIG. 13B, the counter electrode 12 is curved in a semi-cylindrical shape having a radius M so as to surround each of the plurality of wires 114. Here, the radius M is set to 1/2 of the distance S between the wires 114. On the other hand, the counter electrode 12 may be comprised in the semicircle shape which surrounds the some wire 114. As shown in FIG.

The wire 114 of the high voltage electrode 11 is attached to the case 30 via the insulating spacer 32. In addition, the support part 14 may be attached to the case 30 via the insulating spacer 32. As shown in FIG. In addition, the support part 14 may be part of the case 30.

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

14A and 14B are plan views of each of the high voltage electrode 11 and the counter electrode 12 of the electrostatic precipitator 1 of the fifth embodiment. 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 the resistor part 122 which covers the surface of the conductor part 121 is provided. On the other hand, as shown in FIG. 13B, when the counter electrode 12 is semi-cylindrical, the portion where the counter electrode 12 is in contact with the case 30 has a conductor exposed region (not including the resistor portion 122). 123).

Also in the electrostatic precipitator 1 of Example 5, high dust collection efficiency was obtained, suppressing ozone concentration low.

This is because the counter electrode 12 of the charging section 10 includes a resistor section 122 covering the surface of the conductor section 121, whereby the discharge current is limited. And by forming the counter electrode 12 in semi-cylindrical shape in each of the some wire 114, it is thought that corona discharge arises in the space which surrounds each wire 114. FIG.

(Modified example of the high voltage electrode 11 in the charging unit 10)

15A and 15B are views showing a modification of the high voltage electrode 11 in the charging section 10 of the electrostatic precipitator 1. FIG. 15A is a diagram in which the teeth 111 are configured in a different arrangement from FIG. 2A, and FIG. 15B is a diagram in which the teeth 111 are configured in a different arrangement from FIG. 10A.

First, FIG. 15A will be described.

In FIG. 2A, the connection part 112 of the top and bottom tooth row 113 (# 1, # 5 in FIG. 2) was made to approach or contact the support part 14. In FIG. For this reason, in the uppermost and lowermost tooth row 113 (# 1, # 5 in FIG. 2A), only the tooth | gear 111 of either the upper direction or the lower direction was formed.

On the other hand, in the high voltage electrode 11 shown to FIG. 15A, all the tooth rows 113 are equipped with the tooth | gear 111 of both the upper direction and the lower direction.

Next, Fig. 15B will be described.

In FIG. 10A, all the tooth rows 113 were provided with teeth 111 in both the upward direction and the downward direction.

On the other hand, in the high voltage electrode 11 shown in FIG. 15B, the connection part 112 of the uppermost and lowest tooth line 113 (# 1, # 6 in FIG. 15B) approaches or contacts the support part 14, Forming. For this reason, in the uppermost and lowermost tooth row 113 (# 1, # 6 in FIG. 15B), only the tooth 111 of either the upper direction or the lower direction was formed.

Even when such a high voltage electrode 11 is applied to each of the electrostatic precipitators 1 of the first, third and fourth embodiments, high dust collection efficiency can be obtained while suppressing the ozone concentration low.

16A and 16B show another modified example of the high voltage electrode 11 in the charging unit 10 of the electrostatic precipitator 1. FIG. 16A is a diagram of a plurality of needle rows 117 each provided with a plurality of needles 115, and the tip of the needles 115 are opposed to each other between adjacent needle rows. FIG. 16B is a diagram composed of a plurality of needle rows 117 including a plurality of needles 115, and the tip of the needles 115 are arranged in a zigzag between adjacent needle rows 117. FIG.

The needle 115 and / or its tip is an example of a site that generates electric field concentration.

FIG. 16A replaces the tooth 111 of the high voltage electrode 11 shown in FIG. 2A with the needle 115. On the other hand, the needle 115 is a needle-shaped member having a sharp tip. And the connection part 116 which connects the some needle 115 in the needle row 117 is a circuit board in which the wiring was formed, for example, and the some needle 115 and the wiring are connected.

FIG. 16B is a case where the teeth 111 of the high voltage electrode 11 shown in FIG. 10A are replaced with the needle 115. Since other configurations are the same as those in FIG. 10A, the description is omitted.

Even when these high voltage electrodes 11 are applied to each of the electrostatic precipitators 1 of the first, third and fourth embodiments, high dust collection efficiency can be obtained while suppressing the ozone concentration low.

In addition, you may change the arrangement | positioning of the needle 115 shown to FIG. 16A and FIG. 16B to the arrangement of the tooth | gear 111 shown to FIG. 15A and FIG. 15B, respectively.

The high voltage electrode 11 may be, for example, a brush shape in which conductive carbon wires are bonded instead of the teeth 111 or the needle 115 of the high voltage electrode 11. On the other hand, the brush-shaped part and / or its tip is an example of the site | part which produces electric field concentration.

(Modified example of the counter electrode 12 in the charging unit 10)

FIG. 17: is a figure explaining the modification of the counter electrode 12 in the electrification part 10 of the electrostatic precipitator 1. FIG.

The counter electrode 12 shown in FIG. 17 is provided with the conductor part 121 which is a board which consists of electroconductive material in which the some opening 124 was formed, and the resistor part 122 formed in the surface. The opening 124 is formed through the plate that is the conductor portion 121. On the other hand, a part (both ends in the left and right directions) of the conductor portion 121 is a conductor exposed region 123 having no resistor portion 122.

And the counter electrode 12 is attached so that the conductor exposure area | region 123 may be connected to the case 30, and the attached part is connected to the ground terminal E. FIG.

On the other hand, the resistor portion 122 is formed to suppress the discharge current between the high voltage electrode 11 and the counter electrode 12. Therefore, at least, it is required that no discharge occurs between the high voltage electrode 11 and the conductor portion 121 of the counter electrode 12. From this, the resistor portion 122 is preferably 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 which were mentioned above may be used in combination, respectively.

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

Second Embodiment

In 2nd Embodiment, suppose that the high voltage electrode 11 is comprised from the several tooth row 113 which each provided the some tooth 111, The requirement set by the arrangement | positioning of the tooth 111 is demonstrated. Here, it is assumed that the tip ends of the teeth 111 are arranged to be offset from each other between the teeth rows 113. For example, the tip of the tooth 111 is arranged in a zigzag between the tooth rows 113.

18 is a diagram illustrating an example of the electric dust collector 1 to which the first embodiment is applied. Here, the case 30 is shown with a broken line, and the structure of the charging part 10 and the dust collector 20 formed in the inside of the case 30 is shown.

In the structure of the electrostatic precipitator 1, the same part as what was demonstrated in 1st Embodiment attaches | subjects the same code | symbol, abbreviate | omits description, and demonstrates a different part.

(The front part (10))

The charging unit 10 includes a high voltage electrode 11 and a counter electrode 12 that faces the high voltage electrode 11.

The high voltage electrode 11 includes a plurality of teeth rows 113 (five rows of # 1 to # 5 in FIG. 18) each having a plurality of teeth 111 having sharp ends. Between adjoining tooth rows 113, the distal ends of the teeth 111 are alternately formed in the direction of the tooth rows 113. In FIG. 18, between the teeth rows 113 adjacent to each other, the tip of the teeth 111 in one tooth row 113 is disposed at the center of the tip of the teeth 111 in the other tooth row 113. have. That is, the tip of each tooth 111 is arranged in a zigzag between adjacent tooth rows 113.

The counter electrode 12 is provided with the conductor part 121 which is an expanded metal comprised from an electroconductive material as an example, and the resistor part 122 which covers the surface.

That is, the high voltage electrode 11 and the counter electrode 12 in the electrification part 10 demonstrated in 2nd Embodiment are the same as that of FIG. 10A and 10B in Example 4 demonstrated in 1st Embodiment.

3A, the high voltage electrode 11 is attached to the case 30 via an insulating spacer 32 made of an insulating material. The opposite electrode 12 is attached so that the conductor exposed area 123 on which 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, the result of having measured the dust collection efficiency and ozone concentration in the electrostatic precipitator 1 to which a 1st form is applied is demonstrated. The electrostatic precipitator 1 described here is referred to as the electrostatic precipitator 1 of the sixth embodiment.

(Example 6)

The charging section 10 of the electrostatic precipitator 1 made the external shape of the support section 14 of the high voltage electrode 11 viewed in the ventilation direction about 400 mm in the left and right directions and about 300 mm in the vertical direction.

The teeth 111 and the connection part 112 of the high voltage electrode 11 in the charging part 10 were comprised with plate-shaped stainless steel (SUS) of thickness 0.5mm. And the length L of the tooth | gear 111 was made into 10 mm. Then, as in FIGS. 10A, 10B, and 18, five rows of teeth 113 were formed.

The counter electrode 12 in the charging unit 10 was made of an expanded metal composed of SUS having an opening 124 of 4 mm x 8 mm in the conductor portion 121. The resistor portion 122 covering the surface of the conductor portion 121 was made of polyimide resin having a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Pa · cm.

In addition, in the electrostatic precipitator 1 of Example 6, the resin member which comprises the case 30 etc. was not formed in the range of about 5 mm (distance r) from the distal end of the tooth 111.

Then, the electrification section 10 and the dust collection section 20 were energized to flow air. 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 section 10, ions start to be generated and charging of the fine particles becomes possible.

FIG. 19: is a figure which shows the relationship between the dust collection efficiency of the electrostatic precipitator 1, and ozone concentration with respect to the space | interval P of the tooth | gear 111 in the tooth row 113. As shown in FIG. The vertical axis on the left side of the figure is dust collection efficiency (%), and the vertical axis on the right side is ozone concentration (ppb). In addition, the horizontal axis is the space | interval P of the tooth | gear 111. As shown in FIG. In addition, the space | interval P of the tooth | gear 111 based on the length L of the tooth | gear 111 is shown on the horizontal axis.

Here, the dust collection efficiency and ozone concentration were measured by making the space P of the teeth 111 in the tooth row 113 into 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 tooth rows 113 was fixed at 20 mm (2 L).

As can be seen from FIG. 19, the dust collection efficiency increases as the spacing P of the teeth 111 increases. If the space | interval P of the tooth | gear 111 is 2L or more, dust collection efficiency will be 90% or more.

In addition, the ozone concentration is smaller as the interval P of the teeth 111 becomes larger. On the other hand, the ozone concentration in the measured range is 10 ppb or less, which is far below the environmental standard value (0.05 ppm). And, if the spacing P of the teeth 111 is 2L or more, the ozone concentration is 5ppb or less detected by the human sense of smell.

FIG. 20 is a diagram showing the relationship between the dust collection efficiency and the ozone concentration of the electrostatic precipitator 1 with respect to the distance S between the tooth rows 113. The vertical axis on the left side of the figure is dust collection efficiency (%), and the vertical axis on the right side is ozone concentration (ppb). In addition, the horizontal axis is the distance S between the tooth rows 113. On the other hand, on the horizontal axis, the distance S between the tips of the teeth 111 between the tooth rows 113 on the basis of the length L of the teeth 111 is also shown.

Here, dust collection efficiency and ozone concentration were measured by setting the distance S between the tip ends of the teeth 111 between the tooth rows 113 to 10 mm (1 L), 20 mm (2 L), 30 mm (3 L), and 40 mm (4 L). . In addition, the space | interval P of the tooth | gear 111 in the tooth | gear row 113 was fixed to 35 mm (3.5L).

As can be seen from FIG. 20, when the distance S between the tooth rows 113 is 3L or less, the dust collection efficiency is 90% or more. However, when the distance S between the tooth rows 113 exceeds 3L, dust collection efficiency will fall.

The ozone concentration hardly depends on the distance S between the tooth rows 113, and the smaller the interval P of the teeth 111 is, 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 illustrating a discharge state in the charging unit 10. 21A is a plan view seen from the high voltage electrode 11 side, and FIG. 21B is a sectional view taken along the line XXIB-XXIB in FIG. 21A. FIG. 21C shows that when the spacing of the teeth 111 is an interval P ′ which is narrower (smaller) than the spacing P of FIG. 21A, FIG. 21D shows that the distance between the teeth rows 113 is larger (greater) than the distance S of FIG. 6A. '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 extends in a direction far from the tip of the tooth 111 in the high voltage electrode 11. It is thought that the counter electrode 12 faces inclinedly.

Here, as shown in FIG. 18, the tooth | gear 111 is arrange | positioned in the orthogonal or inclined direction with respect to the ventilation direction (opposing electrode 12). For this reason, the electric line of force from the distal end of the tooth 111 cannot vertically face the counter electrode 12 from the distal end of the tooth 111. That is, the electric line of force extends from the distal end of the tooth 111 toward the direction away from the distal end, and faces the opposite electrode 12 inclinedly.

Therefore, as shown in FIG. 21C, when the distance of the teeth 111 in the tooth row 113 is set to the interval P 'which is narrower (smaller) than the interval P in FIG. 21A, it is adjacent in the tooth row 113. The discharge regions 13 of the teeth 111 overlap each other, and interference occurs. As a result, as shown in FIG. 19, when the spacing P of the teeth 111 decreases, it is considered that dust collection efficiency decreases and ozone concentration increases.

On the other hand, as shown in FIG. 21D, when the distance between the tip ends of the teeth 111 between the tooth rows 113 is a distance S 'which is wider (greater) than the distance S of FIG. 21A, the area of the high voltage electrode 11 ( Area in the direction orthogonal to the ventilation direction), the proportion of the discharge region 13 is small. For this reason, as shown in FIG. 20, when the distance S between the tooth rows 113 becomes large, it is thought that dust collection efficiency falls.

As described above, in the case where the distal ends of the teeth 111 are arranged in the direction of the teeth row 113, the spacing P of the teeth 111 in the teeth row 113 is 2L or more, and the teeth row 113 is also present. It is preferable that the distance S between them is 3L or less.

In addition, the high voltage electrode 11 may be set as the arrangement shown in FIG. 15B different from FIG. 10A.

The tooth 111 shown in FIG. 10A may be replaced with the needle 115 as shown in FIG. 16B. In addition, the tooth 111 shown in FIG. 15B may be replaced with the needle 115.

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

The counter electrode 12 may be replaced with the one 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 unit 10 is formed so as to cover the surface of the conductor portion 121 and the conductor portion 121. It consists of one resistor part 122. Therefore, the discharge current is suppressed smaller than that in the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed low.

The high voltage electrode 11 of the charging unit 10 is fixed to the case 30 via the insulating spacer 32. In addition, the resin member which comprises the case 30 etc. is not formed in the range of 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 to the case 30 in the conductor exposed region 123 (conducting). This suppresses charging of the case 30 by static electricity and improves dust collection efficiency.

In the electrostatic precipitator 1 to which the second embodiment is applied, the high voltage electrode 11 and the counter electrode 12 are arranged in the ventilation direction in the charging section 10. Moreover, the part which generate | occur | produces the discharge of the high voltage electrode 11 is set as the tooth | gear 111, and the tooth | gear 111 is arrange | positioned orthogonally or inclined (intersected) with respect to a ventilation direction. Therefore, the distance G of the high voltage electrode 11 and the counter electrode 12 can be set short, for example to 5 mm. Thereby, the electrostatic precipitator 1 can be miniaturized.

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

[Third Embodiment]

In 2nd Embodiment, the tooth | gear 111 of the high voltage electrode 11 in the charging part 10 was arrange | positioned mutually shift | deviated with respect to the direction of the tooth | column row 113 between tooth rows 113. As shown in FIG.

In 3rd Embodiment, arrangement | positioning between the tooth rows 113 of the tooth | gear 111 of the high voltage electrode 11 in the charging part 10 differs from 2nd Embodiment. In this case, the requirements set by the arrangement of the teeth 111 will be described.

FIG. 22: is a figure which shows an example of the electrostatic precipitator 1 to which 3rd Embodiment is applied. Here, the case 30 is shown with a broken line, and the structure of the charging part 10 and the dust collecting part 20 formed in the inside of the case 30 is shown.

In the configuration of the electrostatic precipitator 1, the same parts as those described in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted, and different parts are described.

(The front part (10))

The high voltage electrode 11 has a plurality of teeth rows 113 (# 1 to # 5 in FIG. 22) provided with a plurality of teeth 111. The longitudinal direction of each tooth row 113 is directed to the left and right directions. The uppermost tooth row 113 (# 1 in FIG. 22) is provided with a plurality of teeth 111 (10 in FIG. 22) arranged downward. The lowermost tooth row 113 (# 5 in FIG. 22) includes a plurality of teeth 111 (10 in FIG. 22) arranged toward the upper side. The tooth rows 113 (# 2 to # 4 in FIG. 22) between the 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 tip of each tooth 111 opposes between adjacent tooth rows 113.

That is, the high voltage electrode 11 in the electrification part 10 demonstrated in 3rd Embodiment is the same as that of FIG. 2A demonstrated in 1st Embodiment.

The counter electrode 12 is the same as that of 2nd Embodiment. That is, the counter electrode 12 in the electrification part 10 demonstrated in 3rd Embodiment is the same as FIG. 10B in Example 4 demonstrated in 1st Embodiment.

(Discharge area 13)

23 is a diagram schematically illustrating a discharge state in the charging unit 10.

In the high voltage electrode 11 of the charging unit 10 according to the third embodiment, the tip ends of the teeth 111 face each other between the tooth rows 113. Thus, the discharge regions 13 also face each other between the tooth rows 113. For this reason, when the distance S between the tooth rows 113 is shortened (small), the discharge regions 13 overlap each other between the opposing teeth 111.

Therefore, in the case where the distal ends of the teeth 111 are opposed to each other between the rows of teeth 113, the teeth between the rows of teeth 113 are compared with the case in which the distal ends of the teeth 111 are arranged zigzag between the rows of teeth 113. 111) The distance S between the tips cannot 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) having a thickness of 0.5 mm. Configured. The length L of the teeth 111 was set to 10 mm. 1 and 2A, five rows of teeth 113 were formed.

The counter electrode 12 in the charging unit 10 was made of an expanded metal composed of SUS having an opening 124 of about 4 mm x about 8 mm in the conductor portion 121. The resistor portion 122 covering the surface of the conductor portion 121 was made of polyimide resin having a thickness of about 50 μm. This polyimide resin had a dielectric constant of 3.3 and a volume resistivity of 10 ¹⁶ Pa · cm.

About the dust collector 20, it carried out similarly to 1st Embodiment.

Then, when a DC voltage of about 4 kV is applied between the high voltage electrode 11 and the counter electrode in the charging section 10, ions start to be generated and charging of the fine particles becomes possible.

The dust collection efficiency and ozone concentration are set so that the distance S between the tips of the teeth 111 between the teeth rows 113 is 50 mm (5 L), 60 mm (6 L), 70 mm (7 L), 80 mm (8 L), and 90 mm (9 L). Was measured. In addition, the space | interval P of the tooth | gear 111 in the tooth | gear row 113 was fixed to 35 mm (3.5L).

In the case where the teeth 111 are opposed between the teeth rows 113, the distance S between the tip ends 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, when the distance S between the tips of the teeth 111 between the teeth rows 113 is less than 6L, the electric fields interfere with each other between the teeth 111, and the discharge current easily flows. Thus, the ozone concentration increased.

On the other hand, when the distance S between the tips of the teeth 111 between the tooth rows 113 exceeds 8L, the ratio of the discharge region 13 to the high voltage electrode 11 was lowered, and the dust collection efficiency was lowered.

In addition, about the space | interval P of the tooth | gear 111 of the direction which concerns on the tooth | gear row 113, it is the same as that of 1st Embodiment.

In addition, the high voltage electrode 11 may be set as the arrangement shown in FIG. 15A different from FIG. 2A.

In addition, the tooth 111 shown in FIG. 2A may be replaced with the needle 115 as shown in FIG. 16A. In addition, the tooth 111 shown in FIG. 15A may be replaced with the needle 115.

Even in such a case, when the length of the needle 115 is set to L (length L), the interval P of the needle 115 in the needle string 117 is 2L or more and the needle 115 between the needle strings 117. By setting the distance S between the ends of the tip to 6L or more and 8L or less, the ozone concentration can be kept low while obtaining high dust collection efficiency.

The counter electrode 12 may be replaced with the one 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 unit 10 is formed so as to cover the surface of the conductor portion 121 and the conductor portion 121. It consists of one resistor part 122. Therefore, the discharge current is suppressed smaller than that in the case where the resistor portion 122 is not formed, and the ozone concentration is suppressed low.

In the electrostatic precipitator 1 to which the third embodiment is applied, the high voltage electrode 11 and the counter electrode 12 are arranged in the ventilation direction in the charging unit 10. Moreover, the part which generate | occur | produces the discharge of the high voltage electrode 11 is set as the tooth | gear 111, and the tooth | gear 111 is arrange | positioned orthogonally or inclined (intersected) with respect to a ventilation direction. Therefore, the distance G of the high voltage electrode 11 and the counter electrode 12 can be set short, for example to 5 mm. Thereby, the electrostatic precipitator 1 can be miniaturized.

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

Fourth Embodiment

In the fourth embodiment, a current limiting circuit for suppressing the generation of a pulsed current resulting from random secondary electron emission or the like from the high voltage electrode will be described. Ozone generation is remarkable due to the generation of a pulsed current resulting from random secondary electron emission or the like from the high voltage electrode.

FIG. 24 is a diagram illustrating an example of the electric dust collector 1 to which the fourth embodiment is applied. Here, the case 30 is shown with a broken line, and the structure of the charging part 10 and the dust collector 20 formed in the inside of the case 30 is shown.

In the configuration of the electrostatic precipitator 1, the same parts as those described in the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted, and different parts are described.

(The front part (10))

The charging unit 10 includes a high voltage electrode 11 and a counter electrode 12 that faces 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 is provided with a plurality of tooth rows 113 (# 1 to # in FIG. 24) each provided with a plurality of tooth-shaped portions 111 (hereinafter referred to as teeth 111) each having a sharp tip. 5) is provided. Each tooth row 113 is directed in the horizontal direction. 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, each tooth 111 is arranged so that the distal ends thereof are shifted with respect to the direction of the tooth row 113 between adjacent tooth rows 113, for example, between # 1 and # 2 of the tooth rows 113. It is.

On the other hand, in FIG. 24, the tip of the tooth 111 in one tooth row 113 is disposed between the adjacent tooth rows 113 in the center of the tip of the tooth 111 of the other tooth row 113. It is. That is, the tip of each tooth 111 is arranged in a zigzag between adjacent tooth rows 113.

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

The plurality of teeth 111 in each tooth row 113 are connected to the connecting portion 112. One end of each connection portion 112 is connected to a wiring 17 formed on a circuit board 15 to be described later (see FIG. 26 to be described later). The wiring 17 is connected to a high voltage terminal 18. And the positive electrode (high voltage supply terminal) of the high voltage generation circuit 40.

The several teeth 111 and the connection part 112 are comprised integrally with electroconductive material. Therefore, in this case, the plurality of teeth 111 and the connecting portion 112 are collectively referred to as a tooth row 113.

The tooth row 113 and the circuit board 15 are fixed to the support 14. In addition, the support part 14 may be part of the case 30.

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

The formation of the resistor portion in the counter electrode 12 is for limiting the discharge current and suppressing ozone generation. Therefore, characteristics such as volume resistivity for the resistor portion are set in consideration of the relationship between the dust collection efficiency and the ozone concentration. For example, the members constituting the resistor portion preferably have a relative dielectric constant of 3 or more and a volume resistivity of 10 ¹⁴ Pa · cm or more and 10 ¹⁸ Pa · cm or less. On the other hand, the resistance value in the thickness direction changes depending on the thickness of the resistor portion. Therefore, the discharge current to be limited can be set by the thickness of the resistor portion.

On the other hand, the resistor portion may not be formed.

In FIG. 24, the counter electrode 12 is formed as a plurality of rectangular plate members arranged in parallel as an example. Between the plate members function as the 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.

In the charging portion 10 of the electrostatic precipitator 1, the high voltage electrode 11 is attached to the support portion 14 via an insulating spacer (insulation spacer 32 shown in FIG. 3) made of the above insulating material. The support 14 is attached to the case 30. In addition, the support part 14 may be part of the case 30. In addition, the support part 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 so that the conductor exposed region is in electrical contact with the case 30 (conducts).

(Current limiting circuit 16)

Ozone generation is remarkable due to a pulsed 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 for limiting a pulse current. This further suppresses ozone generation.

25 is an equivalent circuit relating to the charging unit 10 of the electrostatic precipitator 1.

Here, the space (discharge space) in which the discharge between the high voltage electrode 11 and the counter electrode 12 is generated is replaced with the capacitor C. As shown in FIG. That is, one terminal of the capacitor C is the high voltage electrode 11 and the other terminal is the counter electrode 12.

The current limiting circuit 16 is formed on the high voltage electrode 11 side of the capacitor C. As shown in FIG.

The high voltage generation 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 the resistor R0 is connected to one terminal of the 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 positive electrode 40B of the high voltage generating circuit 40 and the other terminal of the capacitor C0 is the negative electrode 40C.

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

The current limiting circuit 16 includes a parallel circuit of the inductor Ls and the diode Ds. One terminal of the parallel circuit of the inductor Ls and the diode Ds is connected to the positive electrode 40B of the high voltage generator circuit 40, and the other terminal is connected to the negative electrode 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 generation circuit 40. That is, in the normal state in which the potential of the positive electrode 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 the 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 changes in accordance with 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 varies depending on the discharge state. As the number of secondary electrons increases, the discharge current increases and ozone generation increases.

Therefore, in order to suppress ozone generation, it is necessary to limit the discharge current which 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 increasing with this secondary electron emission is a pulse current generated in a pulse shape. The pulsed current contains a high frequency component (high frequency current).

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

Therefore, the charging part 10 of the electric dust collector 1 to which 4th Embodiment is applied is provided with the current limiting circuit 16 which has the inductor Ls.

On the other hand, when the inductor Ls does not flow, the inductor Ls tries to maintain the state in which the current has flowed, 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. Therefore, the inter-electrode voltage between the high voltage electrode 11 and the counter electrode 12 becomes higher (greater) than the predetermined voltage. As a result, the discharge current increases, and ozone generation increases.

Therefore, the current limiting circuit 16 includes a diode Ds connected in parallel to the inductor Ls. As described above, the diode Ds is connected in the direction in which the current flows (the order direction) 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 a current of DC or low frequency component flows. Therefore, the inductor Ls does not affect the operation of the charging unit 10 in the normal state.

In addition, when the counter electromotive force is not generated by the inductor Ls, that is, in the normal state in which the potential of the anode 40B of the high voltage generating circuit 40 is higher (greater) than the potential of the high voltage electrode 11, the diode Ds. ) Is a reverse connection. Therefore, the diode Ds does not affect the operation of the charging unit 10 in the normal state.

As described above, the inductor Ls in the current limiting circuit 16 suppresses the pulsed current generated by the secondary electron emission. The diode Ds connected in parallel with the inductor Ls suppresses the increase in the voltage between electrodes due to the counter electromotive force generated by the inductor Ls. This suppresses the increase in ozone generation by the pulsed current in the charging unit 10.

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

(Example 7)

FIG. 26 shows an example of the high voltage electrode 11 to which the current limiting circuit 16 is connected by the parallel circuit of the inductor Ls and the diode Ds. In FIG. 26, the high voltage generation circuit 40 is also shown. Here, the electric dust collector 1 provided with the high voltage electrode 11 in which the current limiting circuit 16 was formed is shown as Example 7. FIG.

In addition, the number of the teeth 111 and the number of the teeth rows 113 are simplified and described.

The high voltage generation circuit 40 generates a DC voltage of 4-7 kV.

The plurality of teeth 111 in the high voltage electrode 11 and the teeth row 113 to which the teeth 111 were connected were made of plate-shaped stainless steel (SUS) having a thickness of 0.5 mm.

On the circuit board 15, the current limiting circuit 16 and the wiring 17 were formed. The plurality of tooth rows 113 were connected to the wirings 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 was 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 was connected to the positive electrode 40B of the high voltage generation circuit 40. In addition, the diode Ds was connected in the direction demonstrated in FIG.

Here, the length P from the tip of the tooth 111 to the connection part 112 was 10 mm, and the space P between the teeth 111 in the tooth row 113 was 34.6 mm. In addition, 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 set to 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 breakdown voltage is 7 kV or more.

The conductor portions of the plurality of rectangular plate-shaped members of the counter electrode 12 were each composed of SUS having a width of 10 mm. On the other hand, the resistor portion was a polyimide resin having a thickness of 50 µm.

(Comparative Example 3)

Here, the electrostatic precipitator 1 of the comparative example 3 to which 4th embodiment is not applied is demonstrated.

The electrostatic precipitator 1 of the comparative example 3 is equipped with the current limiting circuit 16 comprised from the resistor R1.

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

The charging unit 10 shown in FIG. 27 replaces the parallel circuit of the inductor Ls and the diode Ds with the resistor R1 in the current limiting circuit 16 of the charging unit 10 shown in FIG. . Since other configurations are the same, the same reference numerals are used to omit the description.

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

(Comparison of Example 7 and Comparative Example 3)

The electric dust collector 1 was operated by energizing the charging part 10 and the dust collecting part 20 of each electric dust collector 1 of Example 7 and the comparative example 3, respectively.

When a DC voltage of about 4 kV is applied to the charging unit 10 from the high voltage generating circuit 40, ions start to be generated and charging of the fine particles becomes possible.

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 current accompanying the secondary electron emission is generated.

However, also in any of the electrostatic precipitators 1 of Example 7 and Comparative Example 3, the current limiting circuit 16 functions, and the increase of ozone by the pulse current is suppressed.

28A and 28B are diagrams showing a time change of the inter-electrode voltage in the charging unit 10 of each of the electrostatic precipitator 1 of Example 7 and the electrostatic precipitator 1 of Comparative Example 3. FIG. 28A is Example 7, FIG. 28B is Comparative Example 3. FIG. The horizontal axis represents time (ns) and the vertical axis represents the inter-electrode voltage (kV).

In the electrostatic precipitator 1 of the seventh embodiment, when a pulse current is generated by secondary electron emission in the vicinity of 100 ns, a voltage drop of about 270 V occurs. That is, the inductor Ls of the current limiting circuit 16 can be made to lower the potential of the high voltage electrode 11. Then, when the pulsed current stops, the high voltage electrode 11 returns to its original voltage within 10 ns.

In the inter-electrode voltage, occurrence of overvoltage (overshoot) to the high voltage side due to the counter electromotive force of the inductor Ls is not seen. This is because the counter electromotive force is dissipated by the diode Ds.

On the other hand, even in the electrostatic precipitator 1 of the comparative example 3, when the pulse-shaped current by secondary electron emission generate | occur | produces in the vicinity of 100 ns, the voltage drop of about 270V will generate | occur | produce. That is, the resistance 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 takes over 50 ns and returns to the original voltage. This is because the time constant due to the capacitor R (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 inductor Ls has a smaller impedance for current of DC or lower frequency than the resistor R1, the time until returning to the original voltage can be shortened (small).

Thereby, the ratio of the period in which the electrostatic precipitator 1 exerts a dust collecting function becomes large, and it is suppressed that the dust collection efficiency falls.

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

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 same operation as in the case of FIG.

(Example 8)

In the charging unit 10 in the electrostatic precipitator 1 of the seventh embodiment, one current limiting circuit 16 was formed for the high voltage electrode 11. In the charging unit 10 of the electrostatic precipitator 1 according to the eighth embodiment, a current limiting circuit 16 is formed for each tooth row 113 of the high voltage electrode 11.

FIG. 30: is a figure which shows an example of the high voltage electrode 11 which connected the current limiting circuit 16 for every tooth row 113 in the charging part 10 of the electrostatic precipitator 1 of Example 8. FIG.

Here, the high voltage electrode 11 includes a plurality of tooth rows 113. The circuit board 15 is provided with a current limiting circuit 16 by a parallel circuit of the inductor Ls and the diode Ds corresponding to each tooth row 113. Each of the plurality of tooth rows 113 is connected to a corresponding current limiting circuit 16. The plurality of current limiting circuits 16 are connected to a wiring 17 connected to the high voltage terminal 18. The high voltage terminal 18 is connected to the anode 40B of the high voltage generation circuit 40.

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

By doing in this way, even if a potential drop generate | occur | produces in one tooth row 113 by the pulsed current etc. by secondary electron emission, the potential drop does not generate | occur | produce in the other tooth row 113. FIG.

That is, since the drop (potential drop) of the inter-electrode voltage 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 generating circuit 40. . Therefore, the other tooth row 113 maintains a normal state. Thereby, the fall of the dust collection efficiency of the electrostatic precipitator 1 is suppressed.

In FIG. 30, the current limiting circuit 16 is formed for each tooth row 113, but the current limiting circuit 16 may be formed for each group using the tooth rows 113 as a group.

(Example 9)

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

FIG. 31: is a figure which shows an example of the high voltage electrode 11 which connected the current limiting circuit 16 for every tooth | gear 111 in the charging part 10 of the electrostatic precipitator 1 of Example 9. FIG.

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

As shown in FIG. 31, the high voltage electrode 11 is provided with a plurality of tooth rows 113 each having a plurality of teeth 111. Here, the part of the tooth | gear 111 is described with the high voltage electrode 11. As shown in FIG.

In the tooth row 113, the plurality of teeth 111 is 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 formed on the circuit board 15, respectively. The current limiting circuit 16 includes a parallel circuit of the inductor Ls and the diode Ds.

In the plurality of tooth rows 113, one end portion of the circuit board 15 is fixed to the high voltage terminal 18. The wiring 17 of the circuit board 15 is connected to the high voltage terminal 18. The high voltage terminal 18 is connected to the positive electrode 40B of the high voltage generation circuit 40.

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

By doing in this way, even if a potential drop generate | occur | produces in one tooth | gear 111 by pulse shape current etc. by secondary electron emission, the potential drop does not generate | occur | produce in another tooth | gear 111. Therefore, the other tooth 111 maintains a normal state. Thereby, the fall of the dust collection efficiency of the electrostatic 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 unit 10 is divided, and the current limiting circuit 16 is formed for each divided portion. Here, the tooth 111 is another example of the 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 teeth row 113 is determined. Can be 30mm. The distance S between the tips of the teeth 111 between the teeth rows 113 can be 30 mm.

In FIG. 31, the current limiting circuit 16 is formed for each tooth 111, but the current limiting circuit 16 may be formed for each group with the teeth 111 as a group.

In 4th Embodiment, it was said that the high voltage electrode 11 is equipped with the some tooth row 113 provided with the some tooth 111. As shown in FIG. The high voltage electrode 11 may be a needle with a sharp front instead of the tooth 111. In addition, the high-voltage electrode 11 may be a linear wire made of a conductive material instead of the tooth row 113.

The counter electrode 12 may be replaced with the one shown so far.

In addition, the numerical value shown in 4th Embodiment is an example, 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 the inductor Ls and the diode Ds, and suppresses the generation of the pulsed current caused by random secondary electron emission or the like from the high voltage electrode.

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

Since the other structure is the same as that of 4th Embodiment, description is abbreviate | omitted.

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

Here, as shown in the eighth embodiment or the ninth embodiment, the high voltage electrode 11 is divided into a plurality of parts (tooth rows 113 and teeth 111), and a current limiting circuit 16 is provided in each of the parts. It was said to correspond to the case where it was formed. For this reason, two current limiting circuits 16 (denoted by 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 the current limiting circuit 16 when not distinguishing them.

That is, the current limiting circuit 16-1 is connected to the capacitor C1 replacing the space (discharge space) where the discharge is generated, and the current limiting circuit 16-2 replaces the capacitor C2 replacing the other discharge space. Is connected to. Since the structure other than the current limiting circuit 16 is the same as that of description in FIG. 25 of 4th Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

The current limiting circuit 16 will be described by the current limiting circuit 16-1.

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

The short-circuit current limiter 16B includes a field effect transistor (FET), a resistor (resistive element) Rs, and a capacitor Cs. The drain of the FET is one terminal of the short-circuit current limiting portion 16B. The source of the FET is connected to one terminal of the parallel circuit of the resistor Rs and the capacitor Cs. The gate of the FET is connected to the other terminal of the parallel circuit of the resistor Rs and the capacitor Cs. One terminal of the parallel circuit of the gate and the resistor Rs of the FET and the capacitor Cs is one terminal of the short-circuit current limiting portion 16B. The resistor Rs is connected between the source-gate of the FET.

That is, in the short-circuit current limiting section 16B, the FET and the resistor Rs constitute 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 on the FET side) of the short-circuit current limiting portion 16B is connected to the anode 40B of the high voltage generation circuit 40. One terminal (the gate side of the FET) of the short-circuit current limiting portion 16B is far from the one terminal (capacitor C1) of the parallel circuit of the inductor Ls and the diode Ds of the short-circuit current limiting portion 16B. ) The other terminal (far side from the capacitor C1) of the parallel circuit of the inductor Ls and the diode Ds is connected to the high voltage electrode 11.

Here, a normally-on n-channel junction type FET (JFET) or a normally-on MOSFET can be used as the FET. In a normally on FET, current flows between the source and the drain even if the potential (gate voltage) to the source of the gate is the same (the gate voltage is 0V). Then, the conductivity between the source terminal and the drain terminal changes depending on the potential (gate voltage) with respect to the source of the gate. In other words, as the gate voltage is higher (large), the conductivity is increased, and the current flowing between the source and the drain increases. In a normally on FET, when the potential of the gate is lower than the potential of the source (the gate voltage is negative), the current flowing between the source and the drain decreases.

Here, the operation of the current limiting circuit 16 will be described.

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

The case where a short circuit does not generate | occur | produce between the high voltage | voltage electrode 11 and the counter electrode 12 is made into a normal state. In this normal state, the discharge current is transmitted from the anode 40B of the high voltage generating circuit 40 to the high voltage generating circuit 40 via the high voltage electrode 11, the capacitor C (discharge space), and the counter electrode 12. Flows through the cathode 40C.

At this time, the gate of the FET is 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 in the resistance Rs is small. Thus, 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 larger than the discharge current in the normal state flows, a large potential drop occurs due to the resistance Rs. For this reason, the potential of the gate of the FET moves to the side lower than the potential of the source. As a result, the conductivity of the FET decreases and the current flowing through the FET decreases. Thus, short circuit current is limited.

At this time, charges are stored 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 remains as long as the short 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. As a result, electric charges accumulated in the capacitors Cs connected in parallel are consumed by the resistor Rs, and the potential of the gate of the FET approaches the potential of the source. As a result, the conductivity between the source and the drain of the FET increases (larger), and the potential of the high voltage electrode 11 rises toward the value of the anode 40B of the high voltage generating circuit 40.

On the other hand, since the pulsed current due to secondary electron emission and the like contain a high frequency component, in the current limiting circuit 16, the high voltage electrode 11 is supplied via the FET, the capacitor Cs, and the inductor Ls. Flow. Therefore, the resistance Rs does not affect the pulsed current. That is, the secondary electron current limiting portion 16A operates without being affected by the short circuit current limiting portion 16B.

In addition, the resistor Rs causes a potential drop by the current flowing in the short circuit, and controls the conductivity of the FET. Therefore, you may set the value of the resistance Rs corresponding to the electric current which can flow at the time of a short circuit.

The change of the inter-electrode voltage with respect to the electrostatic precipitator 1 (the electrostatic precipitator 1 of the tenth embodiment) provided with the charging unit 10 having the current limiting circuit 16 represented by the equivalent circuit of FIG.

FIG. 33 is a diagram illustrating a time change of the inter-electrode voltage in the charging unit 10 of the electrostatic precipitator 1 of the tenth embodiment. The horizontal axis represents time (μs), and the vertical axis represents inter-electrode voltage (kV). The time change of the voltage between electrodes in the charging section 10 was obtained by simulation.

Here, in one discharge space (corresponding to capacitor C1), a pulse-like current due to secondary electron emission is generated. Then, as shown by "C1" in FIG. 33, the inter-electrode voltage decreases about 270V by the inductor Ls of the current limiting circuit 16. As shown in FIG.

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

In other words, even if a pulse current is generated by secondary electron emission or the like in one discharge space, the influence does not extend to the other discharge space. Therefore, the fall of the dust collection efficiency of the electrostatic precipitator 1 is suppressed by generation | occurrence | production of a pulse-shaped current.

34 is a diagram illustrating a time change of the inter-electrode voltage due to a short circuit in the charging unit 10 of the electrostatic precipitator 1. The horizontal axis represents time (μs), and the vertical axis represents inter-electrode voltage (kV). The time change of the voltage between electrodes in the charging section 10 was obtained by simulation.

Here, in one discharge space (corresponding to capacitor C1), a short circuit occurs between the high voltage electrode 11 and the counter electrode 12. Then, as shown by "C2" in FIG. 34, the voltage between electrodes in this discharge space falls to 0V.

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

That is, even if a short circuit occurs in one discharge space, the influence does not extend to the other discharge space. Therefore, even if a short circuit occurs in one discharge space, the electrostatic precipitator 1 cannot be used.

35 is a diagram illustrating 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 includes a plurality of tooth rows 113 each having a plurality of teeth 111.

Similarly to the eighth embodiment in the fourth embodiment, the circuit board 15 is provided with a plurality of current limiting circuits 16 corresponding to the plurality of tooth rows 113. In addition, since the other structure except the current limiting circuit 16 is the same as that of Example 8 in 4th Embodiment, it abbreviate | omits description.

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

By doing in this way, while suppressing the increase of ozone generation by the pulse-shaped current accompanying secondary electron emission etc., even if a short circuit occurs between the high voltage electrode 11 and the counter electrode 12, the electrostatic precipitator 1 The operation can continue. In addition, when a short circuit between the high voltage electrode 11 and the counter electrode 12 is temporary, when a short circuit condition is canceled, it will return to an original state automatically, and the operation | movement of the electric dust collector 1 will continue.

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

In addition, in FIG. 36A, 36B, and 36C, description of the high voltage generation circuit 40 was abbreviate | omitted and discharge space was made into one.

As shown in FIG. 36A, even if the connection order of the secondary electron current limiting portion 16A and the short-circuit current limiting portion 16B in the current limiting circuit 16 of FIG. do.

In addition, as shown in FIG. 36B, even if the current limiting circuit 16 is connected to the counter electrode 12, it operates in the same manner as described with reference to FIG. At this time, the secondary electron current limiting portion 16A and the short circuit current limiting portion 16B may be replaced with each other.

In addition, as shown in FIG. 24, when the counter electrode 12 is comprised by the some rectangular plate-shaped member, you may form the current limiting circuit 16 with respect to each rectangular plate-shaped member. On the other hand, each rectangular plate-shaped member is an example of a sub counter electrode.

36C, the high voltage electrode 11 and the 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. Fig. 32 also operates in the same manner 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 replaced with each other.

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

In addition, the counter electrode 12 demonstrated so far can be used for the counter electrode 12.

[Sixth Embodiment]

In the first to fifth embodiments, the counter electrode 12 includes the conductor portion 121 and the resistor portion 122 in the electrification portion 10 of the electrostatic precipitator 1. The resistor portion 122 was formed so as to cover at least the conductor portion 121 facing the high voltage electrode 11. Thereby, the discharge current between the high voltage electrode 11 and the counter electrode 12 was restrict | limited, and ozone generation was 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.

On the other hand, the resistor portion 122, which is an example of the second member, has a smaller volume resistivity than the insulator portion 125, which is an example of the first member.

FIG. 37: is a schematic diagram for demonstrating the charging part 10 of the electrostatic precipitator 1 to which 6th Embodiment is applied. The charging unit 10 includes a high voltage electrode 11 and a counter electrode 12 that faces the high voltage electrode 11.

Here, as an example, the high voltage electrode 11 is represented by the teeth 111 with the tip facing the counter electrode 12 side (downward in the drawing plane). The high voltage electrode 11 is connected to the anode of the high voltage generation circuit 40.

On the other hand, the high voltage electrode 11 may be a wire having a conductor or a needle having a sharp tip, in addition to the teeth 111. At this time, the teeth 111 and the needle may be arranged so that the distal end faces the counter electrode 12, and may be arranged so as to face the direction parallel to the counter electrode 12.

The counter electrode 12 is configured by stacking the conductor portion 121, the insulator portion 125, and the resistor portion 122 in this order. On the other hand, the conductor portion 121 and the resistor portion 122 are in direct contact with the predetermined contact region 126.

In the counter electrode 12, the resistor portion 122 side faces the high voltage electrode 11. The conductor portion 121 is connected to the cathode of the high voltage generation circuit 40.

37, the discharge which arises between the high voltage electrode 11 and the counter electrode 12 is demonstrated. When the voltage between the high voltage electrode 11 and the counter electrode 12 is increased by the high voltage generation 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 occurs when an uneven 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 becomes high, electrons (denoted by-in the drawing) are emitted from the pointed tip of the high voltage electrode 11. The emitted electrons are accelerated and impinge on the air molecules around the tip. Air molecules are then ionized to generate positive ions.

On the other hand, these positive ions adhere to the suspended fine particles, thereby charging the suspended fine particles.

However, positive ions are attracted to the opposite electrode 12 side and collide with the opposite electrode 12. At this time, electrons that neutralize the cation are supplied through the resistor unit 122. In addition, the counter electrode 12 emits secondary electrons when cations collide.

That is, the current flowing between the high voltage electrode 11 and the counter electrode 12 is determined by the movement of the positive ions generated by ionizing the air molecules, the electrons neutralizing the cations, and the secondary electrons generated by the cation colliding.

In the sixth embodiment, electrons neutralizing cations and secondary electrons generated by collision of cations 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 in the thickness direction of the resistor portion 122, and as shown by an arrow in FIG. 37, the resistor portion 122 flows in the horizontal direction (the right direction in the drawing plane). The current I then flows to the conductor portion 121 through the contact region 126.

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

In addition, since the discharge current is limited, ozone generation is suppressed. That is, as the insulator portion 125 is disposed between the conductor portion 121 and the resistor portion 122, ozone generation is minimized.

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

Moreover, the voltage drop which arises in the resistor part 122 in the counter electrode 12 generate | occur | produces in the horizontal direction at the paper surface of FIG. Therefore, the electric field generated in the transverse direction on the surface of the resistor portion 122 is smaller than the electric field generated in the thickness direction of the resistor portion 122 when the insulator portion 125 is not formed. Therefore, 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 be stopped by the 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, the discharge resumes. Thereafter, the discharge may be stopped again due to the voltage drop of the resistor portion 122 of the counter electrode 12. In this manner, the discharge is stopped and resumed. That is, although the high voltage generation circuit 40 supplies a DC voltage between the high voltage electrode 11 and the counter electrode 12, discharge can be stopped and resumed AC by AC.

On the other hand, when charge gradually accumulates in the resistor portion 122, the discharge gradually weakens, and the discharge finally stops. Therefore, it is necessary to flow the current I from the resistor portion 122 to the conductor portion 121 so that electric 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. Next, 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 in which the conductor portion 121 and the resistor portion 122 are in electrical contact is referred to as the electrostatic precipitator 1 of the eleventh embodiment. The electrostatic precipitator 1 having the counter electrode 12 which 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. FIG.

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

As shown in FIG. 38A, when the conductor portion 121 and the resistor portion 122 are brought into contact with each other in the contact region 126 at the end of the counter electrode 12, ions are generated at a time point of about 2.4 s. Onset, and then on, generation of ions was observed.

This is because the conductor portion 121 and the resistor portion 122 are in electrical contact with each other, so that electric charges do 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 is continued.

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 contacted, ions start to be generated at a time of about 2.8 s, but after about 8 s The number of ions decreases, and ions do not appear after about 28 s.

This is due to the accumulation of electric charges in the resistor portion 122 because the conductor portion 121 and the resistor portion 122 are not in electrical contact with each other. That is, the voltage acting on the space between the high voltage electrode 11 and the counter electrode 12 decreases, and the discharge stops.

(Example 12)

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

As shown in FIG. 39A, in the electrification part 10 in the electrostatic precipitator 1 of Example 12, the high voltage electrode 11 is comprised by the wire 114. As shown in FIG. The conductor portion 121 of the counter electrode 12 is a plate-shaped member (punching metal) made of a conductive material in which a plurality of openings 124 are formed in a zigzag. The insulator portion 125 and the resistor portion 122 are sequentially formed on the surface of the conductor portion 121. On the other hand, a portion of the conductor portion 121 is provided with a contact region 126 which makes the conductor portion 121 and the resistor portion 122 contact with each other without forming the insulator portion 125. In addition, a conductor exposed region 123 exposing the conductor portion 121 is formed at an end portion 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 the site | part which produces electric field concentration.

Here, the wire 114 which is the high voltage electrode 11 was comprised with SUS of 0.2 mm in diameter.

On the other hand, in the counter electrode 12, the conductor part 121 is made into the aluminum plate of 30 mm in width, and the circular opening 124 whose planar shape is 3 mm in inner diameter is arranged in zigzag. The aluminum of the conductor portion 121 was anodized (armite treatment) to form an insulator portion 125 made of aluminum oxide on the surface. The resistor portion 122 was formed by covering 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 by the conductor exposed region 123 on which the conductor portion 121 is exposed so as to be electrically connected to the case 30 (conducting). In this way, the case 30 is suppressed from being charged by static electricity.

(Example 13)

40A and 40B are views for explaining the charging section 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 sectional view of a part of the counter electrode 12. As shown in FIG.

As shown in FIG. 40A, in the electrification part 10 in the electrostatic precipitator 1 of Example 13, the high voltage electrode 11 is comprised by the wire 114 similarly to Example 11. As shown in FIG.

The conductor portion 121 of the counter electrode 12 is a wire mesh (mesh) made of a conductive material. In this case, the counter electrode 12 is a wire mesh of square SUS304 having an outer shape of the conductor portion 121 of 100 mm on one side.

Incidentally, a cross-sectional view of a part of the counter electrode 12 illustrated in FIG. 40B illustrates 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 coated to cover the conductor portion 121 was used as the insulator portion 125, and the acrylic resin coated so as to cover the insulator portion 125 was used as the resistor portion 122.

A portion of the counter electrode 12 is caulked to serve as an electrical contact 127. The electrical contact 127 is connected to the cathode 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 broken, and the resistor portion 122 is electrically connected to the conductor portion 121. In addition to the conduction, a part of the conductor portion 121 is exposed. That is, in the twelfth embodiment, the contact region 126 and the conductor exposed region 123 shown in FIGS. 39A and 39B are collectively formed by caulking.

(Example 14)

41A and 41B are views for explaining the charging section 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 sectional view of a part of the counter electrode 12. As shown in FIG.

As shown in FIG. 41A, in the electrification part 10 in the electrostatic precipitator 1 of Example 14, the high voltage electrode 11 is comprised by the wire 114 similarly to Example 12, 13.

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. In this case, the counter electrode 12 is made of expanded metal composed of square aluminum whose outer side of the conductor portion 121 is 100 mm on one side.

Incidentally, a cross-sectional view of a part of the counter electrode 12 shown in FIG. 41B shows a cross section 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 was used as the insulator portion 125, and a polyimide resin was applied to cover the insulator portion 125 to form the resistor portion 122.

(Example 15)

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

As shown in FIG. 42A, in the charging unit 10 of the electrostatic precipitator 1 of the fifteenth embodiment, the high voltage electrode 11 is composed of a plurality of tooth rows 113 including a plurality of teeth 111. It is. Here, the tooth row 113 of the high voltage electrode 11 was made of SUS having a thickness of 0.5 mm. And each tooth 111 of the tooth row 113 was arrange | positioned in the direction orthogonal to a ventilation direction.

The counter electrode 12 is a member (punching metal) in which the conductor portion 121 is made of a plate-like conductive material in which a plurality of openings 124 are zigzag. Here, the conductor part 121 of the counter electrode 12 was comprised from the aluminum plate of 200 mm x 400 mm in planar shape by which the circular opening 124 whose planar shape is 3 mm in internal diameter is arranged in zigzag. The 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 covering the insulator portion 125 with a polyimide resin.

On the other hand, the contact region 126 which electrically connects (conducts) the conductor portion 121 and the resistor portion 122 to a portion corresponding to the rear surface side of the conductor portion 121 with respect to the high voltage electrode 11. Formed.

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

And the distance G of the high voltage electrode 11 and the counter electrode 12 was 5 mm.

FIG. 43 illustrates 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 generation (μg / h) per tooth 111. Drawing. In Fig. 43, the electrostatic precipitator 1 of the fifteenth embodiment and the counter electrode 12 of the charging portion 10 do not include the insulator portion 125 of aluminum oxide and the resistor portion 122 of the polyimide resin. The electrostatic precipitator 1 is shown by the electrostatic precipitator 1 of the comparative example 5. As shown in FIG. On the other hand, in the comparative example 5, the counter electrode 12 is comprised from the punching metal of aluminum.

As shown in FIG. 43, in Example 15, even if the electrode-to-electrode voltage was 7 kV, ozone generation amount is almost zero. On the other hand, in the comparative example 5, the amount of ozone generation increases with the increase of the voltage between electrodes.

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

The surface resistivity of the resistor portion 122 is preferably 1 G? / Cm or more when the voltage (inter-electrode voltage) applied between the high voltage electrode 11 and the counter electrode 12 is 5 kV. In this case, ozone generation amount can be suppressed to 1 microgram / h or less. On the other hand, since the surface resistivity of the resistor portion 122 varies with the inter-electrode voltage, it is shown here as the surface resistivity of the resistor portion 122 at a voltage of 5 kV between electrodes.

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

In Table 1, Example 15, Comparative Example 5, and Example 16 are shown. Example 15 and the comparative example 5 were demonstrated above. In the electrostatic precipitator 1 of the sixteenth embodiment, the conductor portion 121 of the counter electrode 12 in the charging portion 10 is made of a punching metal of aluminum, and a polyimide resin is coated on the surface of the resistor portion 122. Is an electrostatic precipitator (1). That is, it is the electrostatic precipitator 1 demonstrated in 1st Embodiment.

As shown in Table 1, the dielectric breakdown voltage of the electrification part 10 in the electrostatic precipitator 1 of Example 15 is 10 kV or more. Also in the electrostatic precipitator 1 of the sixteenth embodiment without the insulator portion 125, the dielectric breakdown voltage is 8 kV.

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

That is, the insulation breakdown voltage increases because the counter electrode 12 includes the resistor portion 122, and the insulation breakdown voltage further increases by providing the insulator portion 125.

(Example 17)

44A and 44B are views for explaining the charging section 10 in the electrostatic precipitator 1 according to the seventeenth embodiment. 44A is a perspective view of the charging unit 10, and FIG. 44B is a sectional view of a part of the counter electrode 12. As shown in FIG.

As shown in FIG. 44A, in the charging unit 10 in the electrostatic precipitator 1 of the seventeenth embodiment, the high voltage electrode 11 is provided with a plurality of teeth having a plurality of teeth 111, similarly to the fifteenth embodiment. It consists of a row 113. Therefore, detailed description is omitted.

The counter electrode 12 is a wire mesh (mesh) in which the conductor portion 121 is made of a conductive material. Here, the counter electrode 12 was made of a wire mesh of square SUS304 having an outer shape of the conductor portion 121 of 100 mm in the same way as in the thirteenth embodiment. Therefore, detailed description is omitted.

(Example 18)

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

As shown in FIG. 45A, in the charging unit 10 of the electrostatic precipitator 1 of the eighteenth embodiment, the high voltage electrode 11 is provided with a plurality of teeth having a plurality of teeth 111, similarly to the fifteenth embodiment. It consists of a row 113. Here, the tooth row 113 of the high voltage electrode 11 was made of SUS having a thickness of 0.5 mm. And the teeth 111 of each tooth row 113 were arrange | positioned in the direction orthogonal to a ventilation direction.

The counter electrode 12 is comprised from the member (punching board) of the plate-shaped resin material in which the resistor part 122 was formed in the several opening 124 in zigzag form. Here, the resistor portion 122 of the counter electrode 12 was a plate of acrylic resin having a planar shape of 200 mm x 400 mm and a thickness of 2 mm. A circular opening 124 having an inner diameter of 3 mm in a planar shape is arranged in a zigzag pattern in the acrylic resin plate that is the resistor portion 122 of the counter electrode 12. And the electroconductive film which has a 20-micrometer-thick adhesive layer and the conductive layer which consisted of an electrically conductive material on the back surface side of the acrylic resin plate which is the resistor part 122 of the counter electrode 12 was adhere | attached. .

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

Here, the resistor part 122 is an example of a base material, the insulator part 125 is an example of a 1st member, and the conductor part 121 is an example of a 2nd member.

On the other hand, in the conductive film, an opening having a diameter (for example, 3.5 mm) larger 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 pressure-sensitive adhesive layer and the conductive layer of the conductive film do not protrude from the opening formed in the acrylic resin as viewed from the high voltage electrode 11 side.

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

(Example 19)

46A and 46B are views for explaining the charging section 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 in the XLVIB-XLVIB line in FIG. 46A.

As shown in FIG. 46A, in the charging unit 10 in the electrostatic precipitator 1 of the nineteenth embodiment, the high voltage electrode 11 is provided with a plurality of teeth having a plurality of teeth 111, similarly to the fifteenth embodiment. It consists of a row 113. Here, the tooth row 113 of the high voltage electrode 11 was made of SUS having a thickness of 0.5 mm. And the teeth 111 of each tooth row 113 were arrange | positioned in the direction orthogonal to a ventilation direction.

The counter electrode 12 is a member (punching board) in which the insulator portion 125 is formed of the plate-like insulating material in which a plurality of openings 124 are zigzag. Here, the insulator portion 125 of the counter electrode 12 is a ceramic plate having a planar shape of 200 mm x 400 mm and a thickness of 2 mm. In the ceramic plate, which is 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.

Moreover, the conductor part 121 comprised from the electroconductive material of the copper plate was adhere | attached on the back surface side with respect to the high voltage electrode 11 of the ceramic plate which is the insulator part 125 of the counter electrode 12. As shown in FIG. On the other hand, in the copper plate which is the conductor part 121, the opening was formed corresponding to the opening 124 formed in the ceramic plate which is the insulator part 125. FIG.

And the circumference | surroundings of the ceramic plate which is the insulator part 125 were covered with the polyimide resin, and the resistor part 122 was formed. On the other hand, the resistor portion 122 of the polyimide resin is formed so as to cover the copper plate and the opening 124 which are the conductor portions 121. 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 of the polyimide resin.

Here, the insulator part 125 is an example of a base material, the resistor part 122 is an example of a 1st member, and the conductor part 121 is an example of a 2nd member.

As described above, one of the conductor portion 121, the insulator portion 125, and the resistor portion 122 is a hard member (base member), and the other is a film or a film (layer) adhered to the base member. ) May be. In addition, a plurality of conductor parts 121, insulator parts 125, and resistor parts 122 are hard members (base members), and these may be laminated.

The conductor portion 121 may be made of a conductive material, that is, a good conductor. The insulator portion 125 may be configured to suppress the flow of electrons (current) in the resistor portion 122 so as not to directly face the conductor portion 121. In addition, the resistor unit 122 may be any one capable of suppressing ozone generation by limiting the discharge current.

[Seventh Embodiment]

In the first to sixth embodiments, in the charging unit 10 of the electrostatic precipitator 1, the high pressure electrode 11 is disposed upstream and the counter electrode 12 is disposed downstream of the ventilation direction. there was.

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

Here, the high voltage electrode 11 and the counter electrode 12 in the charging part 10 of the electrostatic precipitator 1 shown in FIG. 1 are arrange | positioned in reverse with respect to a ventilation direction. That is, with respect to the ventilation direction, the counter electrode 12 is arrange | positioned upstream and the high voltage electrode 11 is arrange | positioned downstream.

Since the other structure is the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

And even if the high voltage electrode 11 and the counter electrode 12 in the charging part 10 are arrange | positioned in this way, the electrostatic precipitator 1 operates similarly to having demonstrated in 1st Embodiment.

[Eighth Embodiment]

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

For example, in 1st Embodiment shown in FIG. 1, the high voltage electrode 11 provided with the tooth | gear 111 in the upstream of the ventilation direction, and the counter electrode 12 were formed in the downstream side.

On the other hand, in the electrostatic precipitator 1 of 8th Embodiment, in the charging part 10, the high voltage electrode 11 and the counter electrode 12 are arrange | positioned so that it may cross | intersect with the ventilation direction.

Moreover, the high voltage electrode 11 is equipped with the main high voltage electrode 11A and the vertical high voltage electrode 11B.

48 is a diagram illustrating an example of the electric dust collector 1 to which the 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 vertical high voltage electrodes 11B. In addition, the counter electrode 12 includes a plurality of sub counter electrodes 12A. And the high voltage electrode 11 and the counter electrode 12 are arrange | positioned so that it may cross | intersect (orthogonally in FIG. 48) in a ventilation direction.

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

In addition, the electrostatic precipitator 1 is not limited to the arrangement | positioning shown in FIG. 48, and may be arrange | positioned in any direction as long as ventilation is ensured.

The main high pressure electrode 11A in the high voltage electrode 11 is provided with a plurality of teeth 111, for example, as shown in FIG. In addition, 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 provided with the wire 114, for example, as shown in FIG.

Although the sub counter electrode 12A of each of the counter electrodes 12 is not shown, for example, the counter electrode 12 of the electrification part 10 in the electrostatic precipitator 1 to which the sixth embodiment is applied, 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, the insulator portion and the resistor portion are formed on the surface of the conductor portion in this order. The sub counter electrode 12A has a plate shape.

As shown in FIG. 48, the counter electrodes 12 are formed side by side in a direction intersecting (orthogonal in FIG. 48) in the ventilation direction such that the plurality of sub counter electrodes 12A are along the ventilation direction. . On the other hand, the surface of the counter electrode 12 may not be parallel with respect to the ventilation direction, and may be inclined with respect to the ventilation direction as long as predetermined ventilation can be obtained.

The main high pressure electrode 11A in the high voltage electrode 11 is disposed between two adjacent sub counter electrodes 12A, and is arranged between the main high voltage electrode 11A and the sub counter electrode 12A. A longitudinal high voltage electrode 11B is disposed.

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

The teeth 111 of the main high voltage electrode 11A are disposed so that the tip thereof faces the ventilation direction (toward the downstream side in the ventilation direction).

And the wire 114 which is the longitudinal high voltage electrode 11B is formed so that the tooth row 113 which the teeth 111 in 11 A of main high voltage electrodes comprise may be formed. On the other hand, the wire 114 which is the longitudinal 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 unit 10, two main high voltage electrodes 11A of the high voltage electrode 11 and the vertical high voltage electrode 11B are provided. Although the case where there are four sub counter electrodes 12A of four and the counter electrode 12 is shown, it 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. FIG. FIG. 49A is Example 20, FIG. 49B is Comparative Example 6, and FIG. 49C is Comparative Example 7. FIG.

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

The electrostatic precipitator 1 which concerns on Example 20 is the electrostatic precipitator 1 to which 8th Embodiment is applied, as shown to FIG. 49A. In Example 20, the vertical high voltage electrode 11B is provided between the sub counter electrode 12A and the main high voltage electrode 11A.

And as mentioned above, the main high voltage electrode 11A is equipped with the tooth row 113 comprised by the tooth | gear 111 connected to the connection part 112. As shown in FIG. The tip of the tooth 111 is arranged to face the downstream side of the ventilation direction.

On the other hand, the longitudinal 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.

The sub counter electrode 12A is a laminate 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 set to 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.

The electrostatic precipitator 1 which concerns on the comparative example 6 is a structure remove | excluding the vertical high voltage electrode 11B in Example 20 as shown in FIG. 49B. That is, it is the structure which makes the saw tooth row 113 into the main high pressure electrode 11A (high voltage electrode 11). Also in this case, the distance between the main high pressure electrode 11A (high voltage electrode 11) and the sub counter electrode 12A was set to 20 mm.

In addition, it described with "(laminated body)" on the sub counter electrode 12A in FIG. 49A, 49B.

As shown in FIG. 49C, the electrostatic precipitator 1 according to the comparative example 7 has a tooth row 113 which is the main high voltage electrode 11A (high pressure electrode 11) in the comparative example 6 of FIG. 49B. The wire 114 is used. The sub counter electrode 12A is a conductor portion that does not include an insulator portion and a resistor portion. On the other hand, the conductor part is made Al. Therefore, "(Al)" was written on the sub counter electrode 12A.

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

It is a figure explaining the dust collection efficiency calculated | required for every ozone density | concentration and particle diameter in the electrostatic precipitator 1 which concerns on Example 20, Comparative Examples 6 and 7. FIG. In addition, in FIG. 50, in Example 20 and the comparative example 6, the sub counter electrode 12A was described as "(laminated body)."

In Comparative Example 7, the sub counter electrode 12A was designated as "Al".

Here, the electrostatic precipitator 1 was installed in the test wind tunnel, the wind speed was set to 1 m / s by the fan, and the wind passed through the dust collector 20 from the charging section 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 nano particle diameter distribution meter (SMPS) through the sampling port. did.

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

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

The ozone concentration was 9.2 ppb even when 300 μA was flowed through the main high pressure electrode 11A. In this case, dust collection efficiency was 97% or more in 20 nm of particle diameters, and 99% or more in other particle diameters (50 nm, 100 nm, 300 nm).

In Comparative Example 6, except for the vertical high voltage electrode 11B from Example 20, when 300 µA was flowed into the main high pressure electrode 11A as in Example 20, the ozone concentration was 22.9 ppb. In addition, dust collection efficiency was 76% in 20 nm of particle diameters, and 80% in other particle diameters (50 nm, 100 nm, 300 nm).

That is, when the vertical high voltage electrode 11B is not used (comparative example 6), ozone concentration becomes large and dust collection efficiency falls. In particular, the dust collection efficiency of the ultrafine particle of small particle diameter falls.

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

As described above, by using the vertical high voltage electrode 11B as a laminate in which the sub counter electrode 12A is formed on the surface of the conductor portion in this order, the ozone concentration is kept low and The dust collection efficiency of the ultrafine particle of 0.1 micrometer or less of particle diameters can be improved.

FIG. 51 is a diagram illustrating an operation of the vertical high voltage electrode 11B. Here, the positions of the voltage on the vertical axis and the main high voltage electrode 11A, the vertical high voltage electrode 11B, and the sub counter electrode 12A are schematically illustrated 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 caused to the floating high voltage electrode 11B. As a result, the potential gradient from the main high pressure electrode 11A toward the sub counter electrode 12A becomes two steps without becoming uniform. That is, a high potential gradient region α having a potential difference from the main high voltage electrode 11A to the longitudinal high voltage electrode 11B of 5.7 kV to 6.2 kV and sub-opposed from the longitudinal high voltage electrode 11B. A low potential gradient region β having a potential difference of 1.8 kV to 2.5 kV toward the electrode 12A is generated.

The reason why the ultrafine particles having a particle diameter of 0.1 µm or less is effectively charged is because the discharge space is enlarged (extended) by generating discharge step by step through the longitudinal high-voltage electrode 11B. That is, the potential gradient in the high potential gradient region α is larger than the potential gradient (potential gradient indicated by broken lines as Comparative Example 6) when the longitudinal high voltage electrode 11B is not used. As a result, discharge is likely to be initiated. This discharge causes a discharge between the vertical high voltage electrode 11B and the sub counter electrode 12A. In this way, the discharge space is expanded (expanded) by causing the discharge in stages.

The reason why the ozone concentration can be suppressed is estimated to be that the resistance (space resistance) of the discharge space is high and that the electric field concentration on the sub counter electrode 12A (the counter electrode 12) is relaxed. That is, when the sub counter electrode 12A is a laminate in which the insulator portion and the resistor portion are formed on the surface of the conductor portion in this order, the surface resistance is increased and the resistance (space resistance) of the discharge space is increased. In addition, by forming the vertical high voltage electrode 11B, electric field concentration between the vertical high voltage electrode 11B and the sub counter electrode 12A (the counter electrode 12) is alleviated. It is thought that the ratio which balances supply and annihilation of electric charge by ionization increased by this, and the generation amount of the electron which becomes the origin of ozone generation was suppressed.

As described above, the high-voltage electrode 11B is formed, and the dust collection efficiency of the ultrafine particles is improved by forming regions (regions α and β in FIG. 51) having different potential gradients. Therefore, the main high pressure electrode 11A may have a needle portion instead of the sawtooth portion, and may have other shapes such as a wire shape or a brush shape. Similarly, the longitudinal high voltage electrode 11B is not limited to the wire 114, and may be an electrode provided with a serrated portion or a needle-shaped portion.

On the other hand, the region in which the electric potential gradient is different is not limited to two as shown in FIG. For example, another vertical high voltage electrode may be formed between the main high voltage electrode 11A and the vertical high voltage electrode 11B, and three or more regions having different potential gradients may be used.

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

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

52 is a diagram showing a modification 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 pressure electrode of the charging unit 10 was directed downstream of the ventilation direction. In the electrostatic precipitator 1 shown as a modification 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 unit 10 is directed upstream of 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 eighth embodiment described above is applied, as described in Example 20, the vertical high voltage electrode 11B was placed in a floating state without applying a voltage.

However, a voltage may be applied to the vertical high voltage electrode 11B. In this case, the ozone concentration may be suppressed to 1/2 or less of the voltage applied to the main high pressure electrode 11A. In other words, the voltage applied to the main high voltage electrode 11A may be twice or more the voltage applied to the vertical high voltage electrode 11B. On the other hand, the voltage applied to the main high voltage electrode 11A is more preferably two times or more and five times or less the voltage applied to the vertical high voltage electrode 11B.

When a voltage is applied to the vertical high voltage electrode 11B, the discharge can be made more stable as compared with the case where the floating state is set.

[Ninth Embodiment]

53 is a diagram illustrating an example of the electric dust collector 1 to which the ninth embodiment is applied.

The high voltage electrode 11 in the charging unit 10 includes a plurality of teeth 111 (sawtooth-shaped portions), for example. Each of the plurality of teeth 111 is connected to the connecting portion 112, and constitutes a plurality of tooth rows 113. In addition, since the high voltage electrode 11 is comprised by the tooth row 113, it denotes 11 (113) in FIG.

The counter electrode 12 is provided with the some sub counter electrode 12A similarly to 8th Embodiment. The sub counter electrode 12A has a flat plate shape and is made of a conductive material.

The tooth 111 (sawtooth part) of the high voltage electrode 11 is formed to be parallel to the plane of the sub counter electrode 12A. The teeth 111 (sawtoothed portion) of the high voltage electrode 11 and the sub counter electrode 12A are arranged in a direction crossing (orthogonal in Fig. 53) in the ventilation direction.

In addition, the tip of the tooth 111 faces the upstream side in the ventilation direction. The tip of the tooth 111 is located downstream from the upstream end in the ventilation direction of the plate-shaped sub counter electrode 12A. In addition, the sub counter electrode 12A is formed over at least the length (distance) from the tip of the saw tooth 111 (sawtooth part) to the connection portion 112.

The dust collector 20 is similar to the electric dust collector 1 to which the first to eighth embodiments are applied. Therefore, 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 at a predetermined separation distance downstream from the end of the member closest to the dust collecting unit in the ventilation direction. In this case, the predetermined 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 secured.

In addition, the charging unit 10 includes an inductor Ls shown in the fourth embodiment or the fifth embodiment, and a pulse current in discharge generated between the high voltage electrode 11 and the counter electrode 12. The current limiting circuit 16 may be provided to lower the potential of the high voltage electrode 11.

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, two tooth rows 113 of the high voltage electrode 11 and three sub counter electrodes 12A of the counter electrode 12 are 3. Although an individual case is shown, it is not limited to this number.

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

54 is a cross-sectional view of the ventilation direction of the main part of the charging unit 10 and the dust collecting unit 20 in the electrostatic precipitator 1 according to the twenty-first embodiment.

In the electrostatic precipitator 1 according to the twenty-first embodiment, the charging unit 10 includes a counter electrode 22 having a high voltage electrode 11 and a plurality of sub counter electrodes 12A made of a plate-like conductive material. . The high voltage electrode 11 is provided with the tooth row 113 provided with the some teeth 111 with which the tip was directed in the upstream of the ventilation direction.

The tooth row 113 of the high voltage electrode 11 is 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 from the tip of the tooth 111 to the connection part 112 in the high voltage electrode 11 is 3 mm. The tip of the tooth 111 is located 2 mm downstream from the end on the upstream side of the sub counter electrode 12A in the ventilation direction (distance indicated by T1 in FIG. 54). Moreover, it is 5 mm from the front-end | tip of the tooth | tip 111 to the edge part of the downstream side of the ventilation direction of 12 A of sub opposing electrodes (distance shown by T2 in FIG. 54).

Further, a plurality of gratings (grills) 31 of the case 30 made of a resin material are placed at a position (distance indicated by T3 in FIG. 54) of the sub counter electrode 12A on the upstream side of the ventilation direction. The provided case 30 is formed. When the grating (grill) 31 is disposed at a position facing the teeth 111 and the sub counter electrode 12A of the high voltage electrode 11 with respect to the up-down direction shown in FIG. 54, the user is charged with the charging unit 10. Since contact to is suppressed, it is preferable.

On the other hand, the dust collector 20 has a structure in which a high voltage electrode 21 made of a nonconductive material and an opposing electrode 22 made of a conductive material are alternately stacked.

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. FIG. 55A is Example 21 and FIG. 55B is Comparative Example 7. FIG. On the other hand, the comparative example 7 is the same as the electrostatic precipitator 1 which concerns on the comparative example 7 demonstrated by 8th Embodiment (refer FIG. 49C). That is, the electrostatic precipitator 1 according to the comparative example 7 shown in FIG. 55B has the tooth row 113 which is the high voltage electrode 11 in the electrostatic precipitator 1 which concerns on Example 21 of FIG. The wire 114 of tungsten (W) is used.

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

In addition, in FIG. 55A, the arrangement | positioning of the tooth row 113 of the high voltage electrode 11 and the sub counter electrode 12A of the counter electrode 12 in FIG. 53, FIG. 54 is shown by rotating 90 degrees. In addition, in FIG. 55B, arrangement | positioning of the

wire

114 and 12 A of sub counter electrodes in FIG. 49C is shown by rotating 90 degrees.

56 is a diagram illustrating dust collection efficiency obtained for each ozone concentration and particle diameter in the electrostatic precipitator 1 according to Example 21 and Comparative Example 7. FIG.

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

Dust collection efficiency was computed by forming the sampling port in the upstream and downstream of a test wind tunnel, and measuring the number of suspended particles by particle diameter with the scanning nanoparticle diameter distribution analyzer (SMPS) through a sampling port.

In Comparative Example 7 in FIG. 56, the current of the high voltage electrode 11 (the main high voltage electrode) of Comparative Example 7 in FIG. 50 is 440 µA and 5000 µA.

As shown in FIG. 56, compared with the comparative example 7, in the electrostatic precipitator 1 which concerns on Example 21, while ozone concentration is suppressed to 3.0 ppb, dust collection efficiency improves to 90% or more regardless of particle diameter.

The factor of the improved dust collection efficiency is to direct the tip of the tooth 111 to the upstream side of the ventilation direction and optimize the position of the tip of the tooth 111 and the sub counter electrode 12A so that the ions generated from the tip of the tooth 111 are high pressure. It is thought to be due to the easy diffusion of the electrode 11 (tooth rows 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.

Further, the factor in which the ozone concentration is suppressed is that the space resistance at the time of discharge is increased by taking the distance between the tooth 111 and the sub counter electrode 12A while increasing the electric field concentration by using the high voltage electrode 11 as the tooth 111. This is considered to be attributable to the fact that the amount of electrons which is the starting point of ozone generation is suppressed even in the discharge conditions in which the increase in the generation of high-density ions is obtained.

On the other hand, also in the comparative example 7, when current (discharge current) is made large (for example, 5000 microamperes), dust collection efficiency can be made high regardless of a particle diameter. However, the ozone concentration is 60 times or more as compared with Example 21. That is, in the electrostatic precipitator 1 according to Comparative Example 7, which uses the wire 114 for the high voltage electrode 11, when the ion density is increased (when the current is increased) to charge the small particles having the particle diameter, the ozone concentration increases. do.

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

In addition, in the electrostatic precipitator 1 to which the ninth embodiment is applied, it is not necessary to cover the counter electrode 12 (sub counter electrode 12A) with an insulator portion, and therefore, there are advantages in terms of cost and productivity. There is.

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

In addition, various combinations and modifications may be made unless it contradicts the spirit of the present invention.

Claims

A high voltage electrode supplied with a high voltage from a high voltage generator circuit, and a counter electrode formed opposite the high voltage electrode and supplied with a reference voltage from the high voltage generator circuit, and floating by generating a discharge between the high voltage electrode and the counter electrode. A charging unit for charging the fine particles; And

An electrostatic precipitator including a dust collector disposed on a downstream side of the charging direction of the charging unit and collecting the suspended fine particles charged by the charging unit.
The method of claim 1,

The counter electrode covers a conductor portion made of a conductive material and a surface of at least the side of the conductor portion opposite to the high voltage electrode, and has a volume resistivity of 10 14 Pa · which limits the discharge current between the high voltage electrode and the counter electrode. An electrostatic precipitator comprising a resistor unit portion of at least cm and less than 10 18 Pa · cm.
The method of claim 1,

The high pressure electrode is an electric precipitator having a wire shape or a brush shape.
The method of claim 1,

The high voltage electrode is an electrostatic precipitator having a sawtooth-shaped portion having a pointed tip or a needle-shaped portion having a pointed tip.
The method of claim 4, wherein

A plurality of the serrated portions or a plurality of the needle-like portions intersect with the ventilation direction, 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 electric dust collector which is arrange | positioned so that the front-end | tip of may be mutually offset or oppose to each other in the column direction between adjacent rows.
The method of claim 1,

And said high voltage electrode comprises a main high voltage electrode and a longitudinal high voltage electrode.
The method of claim 6,

The said high voltage electrode WHEREIN: The said main high voltage electrode is provided with the sawtooth-shaped part or the needle-shaped part, and the said longitudinal high voltage electrode is a wire-shaped dust collector characterized by the above-mentioned.
The method of claim 1,

The conductor portion of the counter electrode in the electrification portion is composed of a plurality of flat plates arranged at intervals to ensure ventilation, a mesh having an opening, a punching metal having an opening, or an expanded metal having an opening. Electric dust collector.
The method of claim 1,

The counter electrode in the charging unit is disposed on an upstream side of the ventilation direction with respect to the high voltage electrode in the charging unit.
The method of claim 1,

And a case configured to contain the charging unit, wherein the counter electrode in the charging unit covers a conductor portion made of a conductive material and a surface of the conductor portion that faces at least the high voltage electrode. With a resistor body,

The case for accommodating the charging unit has an electrical dust collector having electrical contact with the conductor portion of the counter electrode of the charging unit.
The method of claim 1,

The counter electrode further includes a conductor portion made of a conductive material, 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,

And the counter electrode has a contact region in which the second member is in electrical contact with the conductor portion.
The method of claim 1,

The counter electrode has an electrostatic precipitator including a substrate for setting the shape of the counter electrode, a first member formed on a surface of the substrate that does not face the high voltage electrode, and a conductive second member formed on the substrate.
The method of 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 that opposes the high voltage electrode, and a conductive second member formed on a surface of the substrate that does not oppose the high voltage electrode of the substrate. Electrostatic precipitator having a.
The method of claim 1,

The high voltage electrode has a serrated portion or a needle shaped portion, the counter electrode has a flat sub counter electrode made of a conductive material, and the plurality of serrated portions or the needle shaped portion and the sub counter electrode of the high voltage electrode The electrostatic precipitator is disposed in a direction crossing with the ventilation direction, and the sawtooth-shaped portion or the needle-like portion of the high voltage electrode is disposed parallel to the surface of the planar sub counter electrode.
The method of claim 14,

The tip of the sawtooth-shaped portion or the tip of the needle-like portion of the high-voltage electrode is directed to the upstream side of the ventilation direction, the electrostatic precipitator is located downstream from the upstream end of the ventilation direction of the plate-shaped sub counter electrode.
The method of claim 14,

And said sub counter electrode is disposed at least over the length of the sawtooth portion or the needle-like portion on the downstream side of the ventilation direction from the tip of the sawtooth portion or the tip of the needle-shaped portion of the high pressure electrode.
The method of claim 1,

And the counter electrode comprises 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 located between the conductor portion and the resistor portion.
And a high voltage electrode supplied with a high voltage from a high voltage generation circuit, and a counter electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit, to generate a discharge between the high voltage electrode and the counter electrode to generate floating fine particles. Charging unit for charging; And

Another high voltage electrode disposed on a downstream side of the ventilation direction of the charging unit and supplied with a high voltage from another high voltage generator circuit, and another counter electrode formed to face the other high voltage electrode and supplied with a reference voltage from the other high voltage generator circuit; And a dust collecting unit collecting the suspended fine particles charged by the charging unit.

And said other high voltage electrode of said dust collector is arranged with a predetermined separation distance downstream from the end of the member which is closest to said dust collector to the said dust collection part among the members which comprise the said electrification part.
A discharge generated between the high voltage electrode and the counter electrode, including a high voltage electrode supplied with a high voltage from a high voltage generation circuit, a counter electrode formed to face the high voltage electrode and supplied with a reference voltage from the high voltage generation circuit, and an inductor; A charging section that has a current limiting circuit for lowering the potential of the high voltage electrode by a pulse current in the cell, and generates a discharge between the high voltage electrode and the counter electrode to charge floating fine particles; And

And a dust collecting unit disposed on a downstream side of the charging direction of the charging unit and collecting the suspended fine particles charged by the charging unit.
The method of claim 19,

And said current limiting circuit comprises a parallel circuit of said inductor and diode.