JPH11262680A - Electric dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the configuration of a power source of a discharge electrode and also to enhance the availability of a dust collecting electrode. SOLUTION: This dust collector is provided with an electrifying part 12 for electrifying particulate material and a dust collecting part 12 for collecting the particulate material electrified in the electrifying part 12. In the electrifying part 12, plural discharge areas 16 and 18 are installed spaced in the flow direction of the particulate material. The plural discharge areas 16, 18 contains the first discharge area 16 in which by applying voltage from an AC power source 30, positive corona discharge and negative corona discharge are alternately formed and the second discharge area 18 in which by applying voltage from the AC power source 30, corona discharge whose polarity is reverse to that of the first discharge area 16 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric precipitator for electrically collecting and collecting particulate matter to be collected.

[0002]

2. Description of the Related Art As an example of an electric dust collector, for example,
One disclosed in Japanese Patent Application Laid-Open No. Sho 60-209273 is known. This known electric dust collector includes a charging unit and a dust collecting unit which are arranged at intervals in the flow direction of the particulate matter to be collected. A plurality of discharge electrodes and counter electrodes are alternately arranged on the charging unit. For example, a negative (minus) DC voltage is applied to the discharge electrodes, and the counter electrodes are grounded. In the dust collecting section, for example, a plurality of positively (plus) applied dust collecting electrodes and a grounded dust collecting electrode are alternately arranged.

In such an electrostatic precipitator, a negative corona discharge is generated from the discharge electrode toward the counter electrode, and the particulate matter to be collected is negatively charged in the charging section by the negative corona discharge. . The negatively charged particulate matter flows to the dust collecting section, where it is electrostatically attracted to the dust collecting electrode to which a positive DC voltage is applied, and thus the particulate matter is required for the dust collecting electrode. Dust is collected as follows.

[0004]

This known electric precipitator requires a DC power supply for applying a DC voltage to the discharge electrode of the charging section. In order to obtain a high-voltage DC power supply from a commercial power supply, the commercial power supply must be stepped up and then rectified, which complicates the configuration of the power supply of the charging unit and increases the manufacturing cost.

Further, when the particulate matter is negatively (or positively) charged in the charging unit, the particulate matter is collected only in the positively (or negatively) applied dust collection electrode in the dust collection unit, There is a problem that the use efficiency of the dust collection electrode is low.

An object of the present invention is to provide an electric precipitator capable of simplifying the structure of a power supply for applying a voltage to a discharge electrode and improving the use efficiency of a precipitating electrode. is there.

[0007]

According to the present invention, there is provided an electric dust collecting apparatus comprising: a charging section for charging particulate matter; and a dust collecting section for collecting particulate matter charged in the charging section. In the apparatus, the charging unit is provided with a plurality of discharge areas at intervals in the flow direction of the particulate matter, and the plurality of discharge areas are provided with a positive corona discharge by applying a voltage from an AC power supply. A first discharge region in which negative corona discharges are alternately generated, and a voltage from an AC power supply is applied to generate a corona discharge having a polarity opposite to that of the first discharge region. An electric precipitator including a discharge area.

According to the present invention, the charging section includes a first discharge area and a second discharge area. In the first discharge area, a positive corona discharge and a negative corona discharge are performed by applying an AC voltage. Are alternately generated, and in the second discharge region, the alternating voltage generates a corona discharge having a polarity opposite to that of the corona discharge in the first discharge region, that is, a negative corona discharge and a positive corona discharge alternately. Therefore, the charging section charges the particulate matter to be collected using the AC voltage,
The voltage may be boosted using a commercial AC power supply, and the power supply can be simplified as compared with the case where a DC voltage is used. In addition, since the particulate matter is positively and negatively charged, in the dust collection electrode, the positively charged particulate matter is collected by some of the dust collection electrodes, and the negatively charged particulate matter remains in the remaining dust collection electrode. Since the dust is collected by the dust collecting electrode, the utilization efficiency of the dust collecting electrode can be increased, and the particulate matter can be efficiently collected.

Further, according to the present invention, in each of the plurality of discharge areas, a discharge electrode and a counter electrode are provided alternately, respectively.
In the first discharge region, a positive corona discharge and a negative corona discharge are alternately generated from the discharge electrode toward the counter electrode, and in the second discharge region, A negative corona discharge and a positive corona discharge are alternately generated toward the counter electrode.

According to the present invention, in each discharge region, the discharge electrode and the counter electrode are provided alternately, so that the positive and negative corona discharges from the discharge electrode toward the counter electrode in the first discharge region. Alternatingly generated, negative and positive corona discharges are generated from the discharge electrode toward the counter electrode in the second discharge region.

Further, the present invention is characterized in that the counter electrode in the second discharge region is provided corresponding to the discharge electrode in the first discharge region, and the counter electrode in the first discharge region corresponds to the counter electrode in the first discharge region. And the discharge electrode in the second discharge area is provided.

According to the present invention, the counter electrode of the second discharge region is provided corresponding to the discharge electrode of the first discharge region, and the second electrode corresponding to the counter electrode of the first discharge region. Since the discharge electrodes in the discharge area are provided, it is possible to suppress the mutual interference of corona discharge in the first and second discharge areas while making the charging unit relatively compact.

Further, in the present invention, a plurality of plate-shaped electrodes are provided on the charging section, and the plurality of plate-shaped electrodes are provided with discharge protrusions at an upstream end in a flow direction of the particulate matter. A first plate-shaped electrode, and a second plate-shaped electrode provided with a discharge electrode at an end on the downstream side in the flow direction of the particulate matter, wherein the first plate-shaped electrode and the second plate-shaped electrode are provided. The plate-like electrodes are alternately arranged, and a positive corona discharge and a negative corona discharge are alternately generated from the discharge projections of the first plate-like electrode toward the second plate-like electrode, A negative corona discharge and a positive corona discharge are alternately generated from the discharge protrusions of the second plate-shaped electrode toward the first plate-shaped electrode.

According to the present invention, the charging section is composed of first and second plate-like electrodes arranged alternately, and the first plate-like electrode has a first plate-like electrode between the discharge projection and the second plate-like electrode. , And a portion between the discharge protrusion of the second plate-like electrode and the first plate-like electrode acts as a second discharge region. Therefore, the first configuration has a relatively simple configuration.
And the second discharge zone can be provided as required,
The particulate matter flowing through the charging section can be charged as required.

The present invention further comprises a discharge electrode for charging the particulate matter, and a dust collection electrode for collecting the charged particulate matter, wherein the discharge electrode faces the dust collection electrode. In the arranged electrostatic precipitator, a plurality of the discharge electrodes are provided at intervals in a flow direction of the particulate matter, and a positive corona discharge and a negative corona discharge are generated by applying a voltage from an AC power supply. By applying a voltage from an AC power supply and a first discharge electrode disposed in a first discharge region that is generated alternately, a corona discharge having a polarity opposite to that of the first discharge region is generated. And a second discharge electrode disposed in a second discharge area.

According to the present invention, the discharge electrodes disposed opposite to the dust collecting electrode are disposed in the first discharge area and the second discharge area. A second discharge electrode, wherein a positive corona discharge and a negative corona discharge are alternately generated from the first discharge electrode by applying an AC voltage in the first discharge region, and in the second discharge region, By the AC voltage, a corona discharge having a polarity opposite to that of the corona discharge in the first discharge region, that is, a negative corona discharge and a positive corona discharge are alternately generated from the second discharge electrode. Therefore, even in such a single-stage electric precipitator, since the particulate matter to be collected is charged using an AC voltage, the voltage may be increased using a commercial AC power supply, and the DC voltage may be increased. The power supply can be simplified as compared with the case of using. Also, since the particulate matter is positively and negatively charged,
At the dust collection electrode, the positively charged particulate matter is collected by some of the collection electrodes, and the negatively charged particulate matter is collected by the remaining collection electrodes. The use efficiency of the electrode can be increased, and the particulate matter can be collected efficiently.

Further, according to the present invention, the distance (L) between the corona discharge generating portion in the first discharge region and the corona discharge generating portion in the second discharge region is as follows: L = V / (2 × f) V: The flow rate of the particulate matter (m / s) f: The frequency is set to the AC frequency (Hz) of the applied AC power supply.

According to the present invention, since the corona generation site in the first discharge zone and the corona generation site in the second discharge zone are maintained in the above-mentioned predetermined relationship, the positive (or the positive) in the first discharge zone. The negatively charged particulate matter is
When flowing into the second discharge region, the second discharge region is positively (or negatively) charged, whereby the particulate matter can be strongly charged.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electric precipitator according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view schematically showing a first embodiment of an electric precipitator according to the present invention.

Referring to FIG. 1, the illustrated electrostatic precipitator is
A hollow device housing 2 is provided.
The inflow opening 4 is provided at one end (the left end in FIG. 1), and the outflow opening 6 is provided at the other end (the right end in FIG. 4). Particulate matter to be collected, such as carbon particles, tunnel dust (exhaust gas in tunnels)
Flows into the device housing 2 through the inflow opening 4 as shown by the arrow 8, and the device housing 2
As described later, the particulate matter is removed therein, and the air from which the particulate matter has been removed flows out of the device housing 2 from the outlet opening 6 as shown by the arrow 10.

The charging section 1 is located on the upstream side (left side in FIG. 1) of the apparatus housing 2 when viewed in the flow direction of the particulate matter.
2 is provided, and a downstream side of the device housing 2 (FIG. 1)
The right side of the drawing) is provided with a dust collecting section 14. In this embodiment, the charging unit 12 is provided with a first discharge area 16 and a second discharge area 18, and the first discharge area 16 is
Is arranged on the upstream side of the discharge region 18 of the first embodiment. The first discharge region 16 includes four opposing electrodes 20 spaced apart in the vertical direction.
Are provided, and a discharge electrode 22 is provided between these opposed electrodes 20. In the second discharge region 18, four discharge electrodes 24 are provided at intervals in the up-down direction.
Is provided. In this embodiment, the opposing electrodes 20,
Reference numeral 26 denotes a plate-like electrode, and the discharge electrode 2
The counter electrodes 20, 26 and the discharge electrodes 22, 24 extend in a direction perpendicular to the plane of FIG.

In this embodiment, the discharge electrodes 24 of the second discharge region 18 correspond to the counter electrodes 20 of the first discharge region 16.
Are provided, and each discharge electrode 24 is provided downstream of each counter electrode 20.
Is arranged. Further, counter electrodes 26 in the second discharge region 18 are arranged corresponding to the discharge electrodes 22 in the first discharge region 16, and each counter electrode 26 is arranged downstream of each discharge electrode 22. By arranging the discharge electrodes 22, 24 and the counter electrodes 20, 26 in the first and second discharge regions 16, 18 in this manner, the length of the charging section 12 in the flow direction of the particulate matter can be made relatively short. And at the same time, suppress the mutual interference of corona discharges generated in the first and second discharge regions 16, 18, and
18, a stable corona discharge can be obtained.
The discharge electrodes 22 (or 24) are disposed substantially at the center in the vertical direction between the opposing electrodes 20 (or 26) located on both sides, and the discharge electrodes 22 (or 24) and the upper opposing electrode 20 (or 26) are arranged. ) Is the distance between the discharge electrodes 2
2 (or 24) and lower counter electrode 20 (or 26)
Is set to be equal to the interval. The counter electrodes 20 (or 26) are arranged substantially parallel to each other and extend in the flow direction indicated by arrow 8. Further, the discharge electrode 22 (or 2)
4) is substantially parallel to the counter electrode 20 (or 26) in FIG.
In the direction perpendicular to the plane of the drawing.

Referring to FIG. 2 together with FIG. 1, in this embodiment, the discharge electrode 22 in the first discharge region 16 and the counter electrode 26 in the second discharge region 18 are connected to one of the single-phase AC power sources 30. The output section is electrically connected to the counter electrode 20 and the second discharge area 18 in the first discharge area 16.
The other output section of the single-phase AC power supply 30 is electrically connected to the discharge electrode 26 at. When a positive (or negative) voltage is applied from one output unit of the AC power supply 30, a negative (or positive) voltage is applied from the other output unit of the AC power supply 30. A positive (or negative) high voltage is applied to the discharge electrode 22 of the first discharge region 16 and the counter electrode 26 of the second discharge region 18, and the counter electrode 20 and the second When a negative (or positive) high voltage is applied to the discharge electrode 24 in the discharge region 18, the first discharge region 16
In, a positive (or negative) corona discharge is generated from the discharge electrode 22 toward the counter electrode 20, and the particulate matter flowing therethrough is positively (or negatively) charged. Also, the second
In the discharge region 18 of FIG.
A negative (or positive) corona discharge is generated toward 6, and the particulate matter flowing therethrough is negatively (or positively) charged.

As described above, when the corona discharge generated in the first discharge region 16 and the corona discharge generated in the second discharge region 18 are configured to have opposite polarities,
The distance L (FIG. 2) between the corona generating portion in the first discharge region 16, ie, the portion where the discharge electrode 22 is provided, and the corona generating portion in the second discharge region 18, ie, the portion where the discharge electrode 24 is provided. It is desirable to set L = V / (2 × f) (V: the speed at which the particulate matter flows, f: the AC frequency of the applied AC power supply). By setting such an interval L, when the particulate matter positively (or negatively) charged in the first discharge region 16 flows downstream to the second discharge region 18, an alternating current is generated during the flow. The voltage from the power supply 30 is switched, and the positive (or negative) is also applied to the second discharge area 18.
And therefore the first and second discharge areas 16,
At 18, the particulate matter is charged to the same polarity, and the particulate matter becomes strongly charged. As the AC power supply 30, a power supply of, for example, 10 to 15 kV can be used.

In this embodiment, one first discharge region 16 and one second discharge region 18 are provided, but a plurality of these can be provided. In such a case, the first discharge region 16 and the second discharge region 18 are provided. And the second discharge region 18 are alternately arranged in the flow direction of the particulate matter.

Next, the structure of the dust collecting section 14 will be described.
In this embodiment, nine dust collecting electrodes 32 are provided. These dust collecting electrodes 32 extend in the flow direction of the particulate matter, are arranged substantially parallel to each other, and extend in a direction perpendicular to the paper surface of FIG. In this embodiment, a positive DC voltage is applied to some of the plurality of dust collecting electrodes 32, and a negative DC voltage is applied to the remaining dust collecting electrodes 32. Specifically, in FIG. 1, a positive (plus) output portion of a DC power supply 34 is electrically connected to the odd-numbered dust collecting electrodes 32 from the lower side, and a positive DC voltage is applied by the DC power supply 34. You. Also, in FIG.
A negative (minus) output portion of a DC power supply 34 is electrically connected to 2, and a negative DC voltage is applied by the DC power supply 34. By giving a potential difference between the adjacent dust collecting electrodes 32 in this way, the particulate matter negatively charged while flowing through the charging unit 12 is electrostatically charged to the dust collecting electrodes 32 to which a positive DC voltage is applied. The particulate matter that is electrically collected on the surface thereof and is positively charged while flowing through the charging unit 12 is electrostatically attracted to the dust collection electrode 32 to which a negative DC voltage is applied. And collected on their surface. A DC voltage of, for example, about +4 to +6 kV can be applied to the dust collecting electrode 32 to which a positive DC voltage is applied, and, for example, −4 to −− to the dust collecting electrode 32 to which a negative DC voltage is applied. A DC voltage of about 6 kV can be applied.

In this embodiment, a positive DC voltage is applied to some of the dust collecting electrodes 32, and a negative DC voltage is applied to the remaining dust collecting electrodes 32. A positive DC voltage may be applied to the dust collecting electrode of the portion, and the remaining dust collecting electrode 32 may be grounded. In this case, the negatively charged particulate matter is collected by the positive DC voltage applied to the dust collecting electrode 32. The particulate matter collected by the dust electrode 32 and positively charged is collected by the grounded dust collection electrode 32. Further, instead of the above-described configuration, a negative DC voltage may be applied to some of the dust collection electrodes and the remaining dust collection electrodes 32 may be grounded. In this case, the positively charged particulate matter Is collected on the dust collection electrode 32 to which a negative DC voltage is applied, and the negatively charged particulate matter is collected on the grounded collection electrode 32.

The operation of the electric precipitator will be outlined as follows. Air containing particulate matter to be collected flows into the device housing 2 through the inlet opening 4,
The air thus introduced flows through the charging unit 12 and the dust collection unit 14. In the charging section 12, first, an AC voltage from an AC power supply 30 is applied to each discharge electrode 22 in the first discharge area 16.
, And each discharge electrode 22 generates an AC corona discharge toward the counter electrode 20. For example, when a positive (or negative) voltage is applied from the AC power supply 30, a positive (or negative) corona discharge is generated from the discharge electrode 22, and the particulate matter flowing through the first discharge region 16 is positive (or negative). Negative). When the charged particulate matter then flows into the second discharge region 18, each discharge electrode 24 generates an AC corona discharge toward the counter electrode 26 by the AC voltage applied from the AC power supply 30. For example, the first discharge area 16
When the particulate matter positively (or negatively) flows into the second discharge region 18, a positive (or negative) voltage from the AC power supply 30 is applied to the discharge electrode 24, As a result, a positive (or negative) corona discharge is generated from the discharge electrode 24, and the particulate matter flowing through the second discharge region 18 is again charged positively (or negatively). Thus, since the AC voltage is applied to the discharge electrodes 22 and 24, the charging unit 1
The particulate matter flowing through 2 is charged positively and negatively alternately.

When the particulate matter thus charged flows into the dust collecting portion 14, the positively charged particulate matter is electrostatically attracted to the dust collecting electrode 32 to which a negative DC voltage is applied, and Further, the negatively charged particulate matter is electrostatically attracted to the dust collecting electrode 32 to which a positive DC voltage is applied, and thus the particulate matter to be collected is collected by the dust collecting electrode 32 as required. Is done. At this time, the particulate matter is collected by the dust collecting electrode 32.
Of the dust collecting electrode 32.
Use efficiency is increased.

In the embodiment shown in FIGS. 1 and 2, the electrodes in the charging section 12 are connected to the discharge electrodes 22, 2 of wire-like electrodes.
Although it is composed of a combination of the electrode 4 and the counter electrodes 20 and 26 of the plate-shaped electrode, it can be configured as shown in FIG. 3 instead.

Referring to FIG. 3, charging section 1 of this modified embodiment
2a includes a first plate-shaped electrode 42 and a second plate-shaped electrode 44 arranged at intervals, and the first and second plate-shaped electrodes 42, 44 are alternately arranged. . In FIG. 3, a first plate-like electrode 42 is disposed at an even-numbered number from the lower side, and the first plate-like electrode 4
2 is provided with a discharge projection 46 at the side end on the upstream side when viewed in the flow direction of the particulate matter. In FIG. 3, odd-numbered second plate-shaped electrodes 44 are provided, and the second plate-shaped electrodes 44 have downstream end portions in the flow direction of the particulate matter. Is provided with a discharge projection 48. First and second plate-like electrodes 42, 4
4 have substantially the same shape, and the first plate-shaped electrode 4
2, the discharge projection 46 is disposed on the upstream side, and the second plate-shaped electrode 44 has the discharge electrode 48.
Are disposed on the downstream side, and the first plate-shaped electrode 42 is disposed displaced downstream from the second plate-shaped electrode 44 in the flow direction of the particulate matter. With this arrangement, as shown in FIG. 3, the plate portion of the second plate-shaped electrode 44 is located opposite to the discharge projection 46 of the first plate-shaped electrode 42, The plate portion of the first plate-shaped electrode 42 is located to face the discharge projection 48 of the electrode 44.

In this embodiment, the discharge projections 46 of the first plate-like electrode 42 are arranged on both sides from one end (upstream side end), that is, the second upper protrusion on the upper surface side in FIG. In addition to protruding toward the plate-shaped electrode 44, it protrudes toward the lower second plate-shaped electrode 44 on the lower surface side in FIG. The discharge projection 48 of the second plate-like electrode 44 has one end (downstream end).
3, that is, on the upper side in FIG.
Projecting toward the plate-like electrode 42 of
In FIG. 3, the lower first plate-like electrode 42 is provided on the lower surface side.
(Note that the first plate-shaped electrode 42 does not exist outside the lowermost and uppermost second plate-shaped electrodes 44).

In this modification, one output of a single-phase AC power supply 50 is electrically connected to the first plate-like electrode 42, and the single-phase AC power supply 50 is connected to the second plate-like electrode 44. Are electrically connected to each other. Accordingly, a positive (or negative) voltage is applied to the first plate-shaped electrode 42 from one output portion of the AC power supply 50, and a negative (or positive) voltage is applied to the first output electrode 42 from the other output portion of the AC power supply 50. When the voltage is applied to the second plate-shaped electrode 44, a positive (or negative) corona discharge is generated from the discharge protrusion 46 of the first plate-shaped electrode 42 toward the opposing second plate-shaped electrode 44. A negative (or positive) corona discharge is generated from the discharge protrusion 48 toward the opposing first plate-shaped electrode 42 in the generated second plate-shaped electrode 44. Thus, the region from the discharge protrusion 46 of the first plate-shaped electrode 42 toward the second plate-shaped electrode 44 acts as the first discharge region 52, and the particulate matter flowing therethrough becomes positive (or negative). Be charged. Further, the discharge protrusions 4 of the second plate-shaped electrode 44 are formed.
8 to the first plate-shaped electrode 42 is the second region.
The particulate matter flowing through this region is positively (or negatively) charged.

Thus, even in the modification shown in FIG.
Also, similarly to the embodiment shown in FIG. 2, the particulate matter flowing through the charging section 12a can be alternately charged positively and negatively, and the above-described effects can be achieved with a relatively simple configuration. Also in this modified embodiment, in order to further increase the charging of the particulate matter, the corona discharge generating portion in the first discharge region 52, that is, the portion where the discharge protrusion 46 of the first plate-shaped electrode 42 is disposed, 2 discharge area 54
, Ie, the distance L1 between the corona discharge generating portion, that is, the portion where the discharge projection 48 of the second plate-shaped electrode 44 is disposed,
It is desirable to set L1 = V / (2 × f) (V: the speed at which the particulate matter flows, f: the AC frequency of the applied AC power supply). By setting such an interval L1,
When the particulate matter positively (or negatively) charged in the first discharge region 52 flows downstream to the second discharge region 54, the voltage from the AC power supply 50 is switched during this flow, and The positive (or negative) charge is also obtained in the second discharge region 54.

The charging section may be configured as shown in FIG. Referring to FIG. 4 showing a charging section of another modification, a charging section 12b of this modification includes a first plate-like electrode 62 and a second plate-like electrode 64 arranged at intervals. A first and a second plate-shaped electrode 6
2, 64 are arranged alternately. In FIG. 4, a first plate-like electrode 62 is provided at an even-numbered position from the lower side,
The first plate-shaped electrode 62 is provided with a discharge projection 66 at an end on the upstream side when viewed in the flow direction of the fine particulate matter. In FIG. 4, an odd-numbered second plate-like electrode 64 is disposed from the lower side, and the second plate-like electrode 64 is provided at the downstream end when viewed in the flow direction of the particulate matter. Discharge projections 68 are provided (see also FIG. 5).
The first and second plate-like electrodes 62 and 64 have substantially the same shape. In the first plate-like electrode 62, the discharge projection 66 is disposed on the upstream side, and the second plate-like electrode In the plate-like electrode 64, the discharge electrode 68 is disposed on the downstream side, and the first plate-like electrode 62 is located on the downstream side of the second plate-like electrode 64 when viewed in the flow direction of the particulate matter. It is arranged. With this arrangement, as shown in FIG. 4, the plate portion of the second plate-shaped electrode 64 is located opposite to the discharge projection 66 of the first plate-shaped electrode 62, and The plate portion of the first plate-shaped electrode 62 is located facing the discharge projection 68 of the electrode 64.

In this embodiment, as shown in FIG. 5, the second (or first) plate-like electrode 64 (or 62)
4 and 5, on the right side (or left side) in FIG. 4 and on the downstream side (or downstream side) when viewed in the flow direction of the particulate matter, its longitudinal direction, FIG. In FIG. 5, a plurality of substantially triangular discharge protrusions 68 (or 66) are provided substantially continuously over substantially the entire length in the direction perpendicular to the paper surface and in the vertical direction in FIG. Each discharge protrusion 68
(Or 66) have substantially the same shape, the width thereof is gradually reduced in a tapered shape toward one end of the plate-shaped electrode 64 (or 62), and the tip is sharply formed. The pitch P of these discharge protrusions 68 (or 66), that is, the distance between the tips of adjacent discharge protrusions 68 (or 66) can be set to about 1 to 5 mm, and the protrusion amount H, that is, the distance from the base to the tip Length to 0.1 to 5.0
mm.

Also in this modification, one output of a single-phase AC power supply 70 is electrically connected to the first plate-shaped electrode 62, and the single-phase AC power supply 70 is connected to the second plate-shaped electrode 64. Are electrically connected to each other. Accordingly, a positive (or negative) voltage is applied to the first plate-shaped electrode 62 from one output portion of the AC power supply 70, and a negative (or positive) voltage is applied to the first output electrode 62 from the other output portion of the AC power supply 70. When applied to the second plate-shaped electrode 64, a positive (or negative) corona discharge is applied to the first plate-shaped electrode 62 from the discharge protrusion 66 toward the opposing second plate-shaped electrode 64. In the generated second plate-shaped electrode 64, a negative (or positive) corona discharge is generated from the discharge projection 68 toward the opposing first plate-shaped electrode 62. Thus, the region from the discharge projection 66 of the first plate-shaped electrode 62 toward the second plate-shaped electrode 64 acts as the first discharge region 72, and the particulate matter flowing therethrough becomes positive (or negative). Be charged. Further, the discharge protrusion 6 of the second plate-shaped electrode 64 is formed.
8 to the first plate-like electrode 62 is the second region.
And the particulate matter flowing through this region is negatively (or positively) charged.

Thus, in the modification shown in FIGS. 4 and 5, similarly to the embodiment shown in FIGS. 1 and 2, the particulate matter flowing through the charging section 12b can be charged alternately positively and negatively. The effects described above can be achieved with a relatively simple configuration. Further, in this modified embodiment, since the tips of the discharge projections 66, 68 of the first and second plate-like electrodes 62, 64 are formed sharp, a stable AC corona discharge is generated from the discharge projections 66, 68. Is done.

Also in this modified embodiment, in order to further enhance the charging of the particulate matter, a corona discharge generating portion in the first discharge region 72, that is, the first plate electrode 6
The distance L2 between the tip of the second discharge projection 66 and the location of the corona discharge in the second discharge region 74, that is, the tip of the discharge projection 68 of the second plate-shaped electrode 64 is L2.
= V / (2 × f) (V: flow rate of the particulate matter,
f: AC frequency of the applied AC power supply). By setting such an interval L1, similarly to the above, when the particulate matter positively (or negatively) charged in the first discharge region 72 flows to the second discharge region 74 downstream. In the second discharge region 74, the charge is negatively (or positively).

The charging section may be configured as shown in FIG. Referring to FIG. 6 showing a charging section of still another modification, a charging section 12c of this modification includes a first plate-like electrode 82 and a second plate-like electrode 84 which are arranged at intervals. , And the first and second plate-like electrodes 82 and 84 are alternately arranged. As can be easily understood by comparing FIGS. 4 and 6, in this modification, the first and second plate-like electrodes 82 and 84 are provided.
Are substantially the same as those shown in FIG.
In the plate-like electrode 82, the substantially triangular discharge protrusions 86 are alternately bent upward and downward, and the tips of the discharge protrusions 86 protrude alternately on the upper surface side and the lower surface side.
In the second plate-shaped electrode 84, the substantially triangular discharge protrusions 88 are alternately bent upward and downward, and the tips of the discharge protrusions 88 protrude alternately on the upper surface side and the lower surface side. .

Also in this modification, one output of a single-phase AC power supply 90 is electrically connected to the first plate-like electrode 82, and the single-phase AC power supply 90 is connected to the second plate-like electrode 84. Are electrically connected to each other. Therefore, a positive (or negative) voltage is applied to the first plate-shaped electrode 82 from one output unit of the AC power supply 90, and a negative (or positive) voltage is applied to the first output terminal of the AC power supply 90 from the other output unit. When applied to the second plate-shaped electrode 84, a positive (or negative) corona discharge is applied to the first plate-shaped electrode 82 from the discharge protrusion 86 toward the opposing second plate-shaped electrode 84. The generated AC corona discharge from the upwardly bent discharge protrusion 86 is generated toward the upper second plate-shaped electrode 84, and the AC corona discharge from the downwardly bent discharge protrusion 86 is generated in the lower side. It is generated toward the second plate-like electrode 84), and the second plate-like electrode 84 is negative (or positive) from the discharge projection 88 toward the opposing first plate-like electrode 82. Of corona discharge (The AC corona discharge from the upwardly bent discharge projection 88 is generated toward the upper first plate-shaped electrode 82, and the AC corona discharge from the downwardly bent discharge projection 88 is generated in the lower side. Generated toward the first plate-shaped electrode 82). Thus, as described above, the region from the discharge projection 86 of the first plate-like electrode 82 toward the second plate-like electrode 84 acts as the first discharge region 92, and the particulate matter flowing therethrough is It is positively (or negatively) charged. A region from the discharge projection 88 of the second plate-shaped electrode 84 toward the first plate-shaped electrode 82 acts as a second discharge region 94, and the particulate matter flowing in this region is negative (or positive). Is charged. In order to more strongly charge the particulate matter, the distance L2 between the corona discharge generation site in the first discharge region 92 and the corona discharge generation site in the second discharge region 94 is set as follows.
It is desirable to set the relationship described above.

Thus, even in the modification shown in FIG.
Also, similarly to the embodiment shown in FIG. 2, the particulate matter flowing through the charging section 12c can be charged alternately positively and negatively, and the above-described effects can be achieved with a relatively simple configuration. Further, in this modification, the discharge projections 86, 88 of the first and second plate-like electrodes 82, 84 are provided.
Are formed sharply in the width direction and the thickness direction of the projections 86, 88, and therefore, these discharge projections 66, 68 are formed.
, A more stable AC corona discharge is generated.

In the first embodiment described above, the present invention is applied to the two-stage type electric dust collector in which the charging unit and the dust collecting unit are separated from each other. The present invention can be similarly applied to an electric dust collector of a type.

Referring to FIG. 7, which schematically shows a second embodiment of the electric precipitator, the electric precipitator shown has a hollow device housing 102, and this device housing 102
Has an inflow opening 104 at one end (the left end in FIG. 7) and an outflow opening 106 at the other end (the right end in FIG. 7). Air containing particulate matter to be collected, for example, tunnel dust, passes through the inlet opening 104 and through the device housing 102 as shown by arrow 108.
The particulate matter is removed as described later in the apparatus housing 102, and the air from which the particulate matter has been removed is discharged into the outlet 106 as shown by an arrow 110.
From the device housing 102.

In the second embodiment, the device housing 10
2 are spaced apart from each other in the flow direction of the particulate matter.
And a second discharge region 114 are provided. In the first discharge area 112, five dust collecting electrodes 116 are provided at intervals in the vertical direction.
The wire-shaped discharge electrodes 118 are disposed between the respective electrodes 6. Further, in the second discharge region 114, five wire-like discharge electrodes 120 are provided at intervals in the vertical direction, and the dust collection electrodes 12 are provided between the discharge electrodes 120, respectively.
2 are provided.

In the second embodiment, as shown in FIG. 7, the dust collecting electrode 116 in the first discharge region 112 and the discharge electrode 120 in the second discharge region 114 are connected to one of the single-phase AC power sources 24. The output part is electrically connected to the first part.
The other output portion of the single-phase AC power supply 124 is electrically connected to the discharge electrode 118 in the discharge region 112 and the dust collecting electrode 122 in the second discharge region 114. When a positive (or negative) voltage is applied from one output unit of the AC power supply 124, a negative (or positive) voltage is applied from the other output unit of the AC power supply 124. First discharge area 112
When a positive (or negative) high voltage is applied to the negative discharge electrodes 118, a positive (or negative) corona discharge is generated from the discharge electrodes 118 in the first discharge region 112 toward the dust collecting electrode 116. The particulate matter flowing through the dust collecting electrode 1 is charged positively (or negatively), and the particulate matter charged positively (or negatively) is in a state where a negative (or positive) voltage is applied.
The dust is electrostatically attracted to the dust 16 and collected. At this time, a negative (or positive) high voltage is applied to the discharge electrode 120 in the second discharge region 114, and the negative (or positive) voltage is applied from the discharge electrode 120 in the second discharge region 114 to the dust collection electrode 122. )
Is generated, the particulate matter flowing therethrough is negatively (or positively) charged, and the negatively (or positively) charged particulate matter is in a state where a positive (or negative) voltage is applied. The dust is collected by being electrostatically attracted to the dust collecting electrode 122. As described above, the same effect is achieved even when applied to a single-stage electric precipitator. In the single-stage dust collector, positive and negative voltages are alternately applied to the dust collecting electrodes 116 and 122.
A substance having relatively small electric insulation, for example, 1.0 × 10Ω
-It is desirable that the carbon-based fine particles are adjusted to about cm.

Also in this single-stage type electrostatic precipitator, the corona discharge generating site in the first discharge region 112, that is, the arrangement of the discharge electrodes 118, is strengthened in order to strengthen the charging of the particulate matter and enhance the dust collecting effect. The distance L3 between the location and the location where the corona discharge occurs in the second discharge region 114, that is, the location where the discharge electrode 120 is provided, is L3 = V / (2 ×
It is desirable to set f) (V: speed at which the particulate matter flows, f: AC frequency of the applied AC power supply).

Example As an example, the charging unit having the form shown in FIG. 3 was applied to the electric dust collecting apparatus shown in FIG. 1 to confirm the dust collecting effect. The configuration of the charging unit and the dust collecting unit in the used electrostatic precipitator was as follows. In the charging section, the height is 100 mm,
Nine plate electrodes having a width of 13 mm were vertically arranged at intervals of 15 mm. The distance between the discharge protrusion of the first plate-like electrode and the discharge protrusion of the second plate-like electrode is 1
It was set to 6.7 mm. Also, in the dust collecting section,
Eleven dust collecting electrodes having a size of 00 mm and a width of 100 mm were vertically arranged at intervals of 10 mm.

In this experiment, air containing tunnel dust (mainly composed of combustion ash) was supplied into the apparatus housing at a rate of 3 m / s from the introduction opening, and the charging section was supplied with a voltage of 15 kV from an AC power supply and a frequency of 60 Hz. , A DC voltage of 8 kV was applied to the odd-numbered dust collecting electrodes, and a ground potential (0 V) was applied to the even-numbered dust collecting electrodes.

In such a dust collection experiment, the tunnel dust contained in the air can be sufficiently removed, and the dust collection efficiency is 90%. No significant reduction in the dust collection effect was observed.

[0051]

According to the first aspect of the present invention, the charging unit includes the first discharge area and the second discharge area, and applies an AC voltage in the first discharge area. As a result, a positive corona discharge and a negative corona discharge are generated alternately. In the second discharge region, a corona discharge having a polarity opposite to that of the corona discharge in the first discharge region, that is, a negative corona discharge is generated by an AC voltage. An alternating positive corona discharge is generated. Therefore, the charging unit uses an AC voltage to charge the particulate matter to be collected, so that the voltage may be increased using a commercial AC power supply, and the power supply may be increased as compared with the case of using a DC voltage. It can be simplified. In addition, since the particulate matter is positively and negatively charged, in the dust collection electrode, the positively charged particulate matter is collected by some of the dust collection electrodes, and the negatively charged particulate matter remains in the remaining dust collection electrode. Since the dust is collected by the dust collecting electrode, the utilization efficiency of the dust collecting electrode can be increased, and the particulate matter can be efficiently collected.

According to the second aspect of the present invention, since the discharge electrodes and the counter electrodes are alternately provided in each discharge area, the discharge electrodes and the counter electrodes are provided in the first discharge area. , Positive and negative corona discharges are generated alternately, and in the second discharge region, negative and positive corona discharges are generated from the discharge electrode toward the counter electrode.

According to the third aspect of the present invention, the counter electrode of the second discharge area is provided corresponding to the discharge electrode of the first discharge area. Since the discharge electrodes in the second discharge region are provided corresponding to the opposite electrodes, the mutual interference of corona discharge in the first and second discharge regions can be suppressed while the charging unit is relatively compact. .

According to the electrostatic precipitator of the present invention, the charging section is composed of the first and second plate-like electrodes alternately arranged, and the discharge projection of the first plate-like electrode and the first plate-like electrode are arranged alternately. The space between the two plate electrodes acts as a first discharge region, and the space between the discharge protrusions of the second plate electrode and the first plate electrode acts as a second discharge region. Therefore,
The first and second discharge regions can be provided as required with a relatively simple configuration, and the particulate matter flowing through the charging section can be charged as required.

According to the fifth aspect of the present invention, the discharge electrode provided opposite to the dust collection electrode is the first type.
And a second discharge electrode disposed in a second discharge region, wherein a positive corona discharge is generated by applying an AC voltage in the first discharge region. And a negative corona discharge are alternately generated from the first discharge electrode. In the second discharge region, the alternating voltage applies a corona discharge having a polarity opposite to that of the corona discharge in the first discharge region, that is, a negative corona discharge and a positive corona discharge. Are alternately generated from the second discharge electrode. Therefore, even in such a single-stage electric precipitator, since the particulate matter to be collected is charged using an AC voltage, the voltage may be increased using a commercial AC power supply, and the DC voltage may be increased. The power supply can be simplified as compared with the case of using. In addition, since the particulate matter is positively and negatively charged, in the dust collection electrode, the positively charged particulate matter is collected by some of the dust collection electrodes, and the negatively charged particulate matter is remaining in the dust collection electrode. Since the dust is collected by the dust collecting electrode, the utilization efficiency of the dust collecting electrode can be increased, and the particulate matter can be efficiently collected.

Further, according to the electrostatic precipitator of the present invention, the distance (L) between the corona discharge generating portion in the first discharge region and the corona discharge generating portion in the second discharge region.
Is set to L = V / (2 × f), so that the particulate matter positively (or negatively) charged in the first discharge region flows into the second discharge region when the second particulate matter flows into the second discharge region. In the discharge region, the particles are positively (or negatively) charged, whereby the particulate matter can be strongly charged.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a first embodiment of an electric precipitator according to the present invention.

FIG. 2 is a partial cross-sectional view showing a part of a charging unit of the electrostatic precipitator of FIG.

FIG. 3 is a partial cross-sectional view showing a part of a modification of a charging unit.

FIG. 4 is a partial cross-sectional view showing a part of another modification of the charging unit.

FIG. 5 is a partial plan view as viewed from line VV in FIG. 4;

FIG. 6 is a partial sectional view showing a part of still another modification of the charging unit.

FIG. 7 is a sectional view schematically showing a second embodiment of the electric precipitator according to the present invention.

[Explanation of symbols]

 2,102 Device housing 12,12a, 12b, 12c Charging part 14 Dust collecting part 16,52,72,92,112 First discharge area 18,54,74,94,114 Second discharge area 20,26 Electrode 22, 24, 118, 120 Discharge electrode 30, 50, 70, 90, 124 AC power supply 32, 116, 122 Dust collection electrode 34 DC power supply 42, 62, 82 First plate electrode 44, 64, 84 Second Plate-shaped electrodes 46, 48, 66, 68, 86, 88 Discharge protrusions

Claims (6)

[Claims] 1. A charging unit for charging a particulate matter,
An electrostatic precipitator comprising: a dust collection unit for collecting particulate matter charged in the charging unit; wherein the charging unit has a plurality of discharge areas spaced apart in a flow direction of the particulate matter. A plurality of discharge areas, a first discharge area in which a positive corona discharge and a negative corona discharge are alternately generated by applying a voltage from an AC power supply;
An electrostatic precipitator comprising: a first discharge region and a second discharge region in which a corona discharge having an opposite polarity is generated by application of a voltage from an AC power supply. 2. In each of the plurality of discharge areas, a discharge electrode and a counter electrode are provided alternately, and in the first discharge area, a positive corona is provided from the discharge electrode to the counter electrode. Discharge and negative corona discharge are generated alternately, and in the second discharge region, negative corona discharge and positive corona discharge are generated alternately from the discharge electrode toward the counter electrode. The electric precipitator according to claim 1, characterized in that: 3. The counter electrode in the second discharge region corresponding to the discharge electrode in the first discharge region, and the counter electrode in the first discharge region corresponding to the counter electrode in the first discharge region. The electrostatic precipitator according to claim 2, wherein the discharge electrode in the second discharge area is provided. 4. A plurality of plate-shaped electrodes are disposed on the charging section, and the plurality of plate-shaped electrodes are provided with discharge protrusions at an upstream end in a flow direction of the particulate matter. And a second plate-like electrode provided with a discharge electrode at an end on the downstream side in the flow direction of the particulate matter, wherein the first plate-like electrode and the second plate-like electrode Are disposed alternately, and a positive corona discharge and a negative corona discharge are alternately generated from the discharge protrusions of the first plate-shaped electrode toward the second plate-shaped electrode. The electrostatic precipitator according to claim 1, wherein a negative corona discharge and a positive corona discharge are alternately generated from the discharge protrusions of the plate-shaped electrode toward the first plate-shaped electrode. 5. A discharge electrode for charging fine particulate matter, and a dust collecting electrode for collecting charged fine particulate matter, wherein the discharge electrode is arranged to face the dust collecting electrode. In the electrostatic precipitator, a plurality of the discharge electrodes are provided at intervals in a flow direction of the particulate matter, and a positive corona discharge and a negative corona discharge are alternately generated by applying a voltage from an AC power supply. A first discharge electrode disposed in the first discharge region to be applied and a voltage from an AC power supply are applied to generate a corona discharge having a polarity opposite to that of the first discharge region.
An electrostatic precipitator, comprising: a second discharge electrode disposed in the discharge area. 6. An interval (L) between a corona discharge generation site in the first discharge region and a corona discharge generation site in the second discharge region is as follows: L = V / (2 × f) V: particulate matter The electrostatic precipitator according to claim 1 or 5, wherein the flow rate is set to: f (m / s) f: AC frequency (Hz) of an applied AC power supply.