JPH11239738A - Electric precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric precipitator which can stabilize corona discharge by a discharge electrode and control the vibration generated during corona discharge. SOLUTION: An electric precipitator is equipped with discharge electrodes 18 for charging fine particles to specified polarity, counter electrodes 16 facing the discharge electrodes 18, and dust collecting electrodes 22 for collecting the fine particles charged by the discharge electrodes 18. The discharge electrodes 18 are slender plate-shaped electrodes, the thickness of which is tapered, and corona discharge is emitted from the tapered ends toward the counter electrodes 16.

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 DC voltage is applied to the discharge electrodes, and the counter electrodes are grounded. In the dust collecting unit, 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]

In this known electrostatic precipitator, the discharge electrode of the charging section is constituted by a wire-like electrode, and there are the following problems related to this. That is, when a wire-like electrode is used as the discharge electrode, the discharge electrode is easily vibrated by corona discharge generated between the discharge electrode and the counter electrode. When a vibration occurs in the discharge electrode, the distance between the discharge electrode and the counter electrode fluctuates. When the vibration increases, the distance decreases, and as a result, a spark discharge occurs between the discharge electrode and the counter electrode. become. When this spark discharge occurs, a large current flows through the discharge electrode, and the heat generated by this large current causes the discharge electrode to be oxidized and degraded.

Therefore, in order to suppress the vibration of the discharge electrode which causes spark discharge, the tension of the discharge electrode may be increased, but if the applied tension is increased, the possibility of the discharge electrode being cut increases.

An object of the present invention is to provide an electric precipitator capable of stabilizing corona discharge by a discharge electrode and suppressing vibrations generated during corona discharge.

Another object of the present invention is to provide an electrostatic precipitator capable of sufficiently charging the particulate matter to be collected.

[0008]

According to the present invention, there is provided a discharge electrode for charging particulate matter to a specific polarity, and a dust collecting electrode for collecting particulate matter charged by the discharge electrode. The discharge electrode is formed of an elongated plate-like electrode, and one or both sides of the plate-like electrode have a tapered thickness gradually reduced. Device.

According to the present invention, since the discharge electrode is constituted by an elongated plate-like electrode, it has a sufficient strength.
Therefore, a large tension can be applied to the plate-shaped electrode, whereby the vibration generated at the discharge electrode can be suppressed, and the occurrence of spark discharge can be reduced. In addition, since the thickness of one or both sides of the plate-shaped electrode is gradually reduced in a tapered shape, the corona discharge from the discharge electrode is generated from the tapered side end and stably generates the corona discharge. be able to.

The present invention also provides an electrostatic precipitator comprising: a discharge electrode for charging particulate matter to a specific polarity; and a dust collection electrode for collecting particulate matter charged by the discharge electrode. Wherein the discharge electrode comprises an elongated plate-like electrode, and one or both sides of the plate-like electrode are provided with discharge protrusions protruding from both sides thereof. Device.

According to the present invention, since the discharge electrode is constituted by an elongated plate-like electrode, it has a sufficient strength.
Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. In addition, since one or both sides of the plate-shaped electrode are provided with discharge projections protruding from both sides thereof, corona discharge from the discharge electrode is generated from the discharge projection, and corona discharge is stably performed. Can be generated.

The present invention also provides an electrostatic precipitator comprising: a discharge electrode for charging particulate matter to a specific polarity; and a dust collection electrode for collecting particulate matter charged by the discharge electrode. In the above, the discharge electrode is constituted by an elongated plate-like electrode, and a plurality of substantially triangular discharge protrusions are provided on one or both sides of the plate-like electrode in the longitudinal direction of the plate electrode. It is an electric precipitator characterized by the above.

According to the present invention, since the discharge electrode is constituted by an elongated plate-like electrode, it has a sufficient strength.
Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. Further, since a plurality of substantially triangular discharge protrusions are provided on one or both sides of the plate-like electrode, corona discharge from the discharge electrode is generated from the tips of the discharge protrusions, and the plate-like electrode , A substantially uniform corona discharge can be stably generated over the longitudinal direction.

Further, according to the present invention, the tip of the plurality of discharge projections provided on one or both sides of the plate-like electrode alternately protrudes on one side and the other side of the plate-like electrode. It is characterized by having.

According to the present invention, since the tips of the plurality of discharge projections alternately project on one side and the other side of the plate-like electrode, the discharge electrode projecting on one side of the plate-like electrode. The corona discharge from the electrode is generated toward the electrode facing the one side surface, while the corona discharge from the discharge electrode portion protruding from the other side surface of the plate-like electrode is generated toward the electrode facing the other side surface. . Therefore, corona discharges generated from the discharge electrode portions adjacent to each other in the longitudinal direction of the plate-shaped electrode are less likely to interfere with each other, so that the corona discharge from the discharge electrodes can be stabilized, and the discharge electrode portions are brought close to each other. It becomes possible to provide.

Further, according to the present invention, the discharge electrode portion is provided on both sides of the plate-like electrode, and the discharge electrode portion is provided on the other side and the discharge electrode portion provided on one side of the plate electrode. The discharge electrode part is shifted in the longitudinal direction.

According to the present invention, the discharge electrode portion provided on one side of the plate-like electrode and the discharge electrode portion provided on the other side are displaced in the longitudinal direction. Mutual interference between the corona discharge from the discharge electrode portion and the corona discharge from the other side portion is reduced, and the corona discharge from the discharge electrode can be stabilized.

Further, according to the present invention, the thickness of the plate-like electrode on the upstream side in the flow direction of the particulate matter is gradually reduced in a tapered shape, and the flow of the particulate matter in the plate-like electrode is reduced. On the downstream side when viewed in the direction,
A plurality of the discharge protrusions are provided.

According to the present invention, the thickness of the upstream side portion of the plate-shaped electrode is gradually reduced in a tapered shape, so that the pressure loss due to the plate-shaped electrode can be reduced. Further, since the corona discharge is generated from the tapered side end, the corona discharge can be stabilized. Further, since a plurality of discharge electrodes are provided on the downstream side of the plate-like electrode, corona discharge from the discharge electrode can be stabilized.

Further, according to the present invention, the discharge electrode is provided on a charging portion, and the charging portion is provided with a counter electrode facing the discharge electrode, and the dust collecting electrode is provided in a flow direction of the particulate matter. Seen in the drawing, it is provided in a dust collecting part disposed downstream of the charging part.

According to the present invention, since the discharge electrode is provided on the charging section and the dust collecting electrode is provided on the dust collecting section, the charging section and the dust collecting section are provided at intervals in the flow direction of the particulate material. The present invention can be advantageously applied to a two-stage electric precipitator.

[0022]

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.
An inflow opening 4 is provided at one end (the left end in FIG. 1), and an outflow opening 6 is provided at the other end (the right end in FIG. 1). 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 four opposing electrodes 16 spaced apart in the vertical direction.
Discharge electrodes 18 are provided between the respective electrodes 6. The discharge electrodes 18 are arranged substantially at the center in the vertical direction between the opposing electrodes 16 located on both sides, and the interval between the discharge electrodes 18 and the upper opposing electrode 16 is set to be equal to the distance between the discharge electrode 18 and the lower opposing electrode 16. The interval is set to be equal to 16. The counter electrode 16 is composed of, for example, a rectangular plate-like electrode having a relatively wide width, and extends in a direction perpendicular to the plane of FIG. These counter electrodes 16 are arranged substantially parallel to each other and extend in the flow direction indicated by the arrow 8. The discharge electrode 18 is formed of an elongated plate-like electrode, is disposed substantially parallel to the counter electrode 16, and extends in a direction perpendicular to the plane of FIG. The width of these discharge electrodes 18 is smaller than the width of the counter electrode 16, and corona discharge from the discharge electrode 18 is generated toward the surface of the counter electrode 16. The discharge electrode 18 will be described in further detail later.

In this embodiment, as shown in FIG. 1, for example, a negative (minus) DC voltage is applied to the discharge electrode 16 and the counter electrode 16 facing the discharge electrode 16.
Is grounded. Therefore, when a high DC voltage is applied from the DC power supply 20, a negative corona discharge is generated from the discharge electrode 16 toward the counter electrode 16, and the particulate matter flowing through the charging unit 12 is negatively charged due to the negative corona discharge. Is charged. For example, -11 to-
A DC voltage of about 13 kV can be applied. The counter electrode 16 may be applied with a positive DC voltage instead of being grounded. Further, instead of the above-described configuration, a positive DC voltage may be applied to the discharge electrode 18 and a negative DC voltage may be applied to the counter electrode 16 or grounded.
The particulate matter is positively charged.

The dust collecting section 14 is provided with a plurality of, in this embodiment, nine, dust collecting electrodes 22 spaced apart in the vertical direction. These dust collecting electrodes 22 extend in the flow direction of the particulate matter, are arranged substantially in parallel with each other, and extend in a direction perpendicular to the paper surface of FIG. In connection with the fact that the particulate matter is negatively charged in the charging unit 12, in this embodiment,
A positive DC voltage is applied to a part of the plurality of dust collecting electrodes 14, and the remaining dust collecting electrodes 14 are grounded. Specifically, a DC power supply 24 is electrically connected to the odd-numbered collecting electrodes 22 from the lower side in FIG. 1, and a positive DC voltage is applied by the DC power supply 24. In FIG. 1, the even-numbered dust collecting electrodes 22 from the lower side are grounded. By giving a potential difference between the adjacent dust collecting electrodes 22 in this manner, the negatively charged particulate matter is electrostatically attracted to the dust collecting electrodes 22 to which a positive DC voltage is applied, and their surface is Collected electrically. For example, a DC voltage of about +4 to +6 kV can be applied to the dust collecting electrode 22.

In this embodiment, a positive DC voltage is applied to a part of the dust collecting electrode 22 and the remaining dust collecting electrode 22 is grounded, but a negative DC voltage is applied to the remaining dust collecting electrode 22. It can also be applied. When the particulate matter is positively charged, a negative DC voltage is applied to a part of the dust collecting electrode 22 and the remaining counter electrode 22 is charged.
May be applied with a positive DC voltage or be grounded.

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, a negative DC voltage from a DC power supply 20 is applied to each discharge electrode 18, and each discharge electrode 18 generates a negative corona discharge toward the opposite electrode 16,
Thus, the particulate matter flowing through the charging section 12 is negatively charged. When the particulate matter flows from the charging unit 12 to the dust collection unit 14, the particulate matter is negatively charged, so that the particulate matter is electrostatically collected by the positively charged dust collection electrode 22, As a result of the dust collection, the particulate matter is removed from the air as required, and the air from which the particulate matter has been removed is discharged from the outlet opening 6. In addition, the number of the discharge electrodes 18, the counter electrodes 16, and the dust collecting electrodes 22 in the electric dust collecting device can be appropriately set according to the size of the device housing 2, the dust collecting ability, and the like.

FIG. 2 is a view showing a part of the charging section of the electric dust collecting apparatus of FIG. On one side (the left side in FIG. 2) of the elongated plate-like electrode constituting the discharge electrode 18, a taper portion 18a is provided over substantially the entire length in the longitudinal direction. In this embodiment, the thickness of the tapered portion 18a is tapered from both sides toward the center. By providing the tapered portion 18a in this way,
On one side of the discharge electrode 18, as shown in FIG.
The corona discharge occurs from the tip of the tapered portion 18a toward the opposing electrodes 16 on both sides facing each other. Since the tip of the tapered portion 18a has a sharp shape, the generated corona discharge also becomes stable. Further, since the tapered portion 18a is provided on the above-mentioned side portion on the upstream side when viewed in the flow direction of the particulate matter indicated by the arrow 28, the resistance of the discharge electrode 18 to the flow of the particulate matter is reduced, and Pressure loss can be reduced. This plate-shaped electrode has a length in the longitudinal direction of about 500 to 1000 mm, a width (size in the flow direction of the particulate matter) of about 5 to 30 mm, and a thickness of about 0.5 to 1.0 mm. It can be set and can be formed from stainless steel, for example. By using such a plate-shaped electrode, its strength is increased, and a large tension can be applied.

Since the other end of the discharge electrode 18 has corners 18b and 18c in the vertical direction, the corners 18b and 18c are located between the upper corner 18b and the upper opposing electrode 16 facing the corner and the lower corner. Corona discharge also occurs between 18c and the opposing lower electrode 16 opposite thereto.

As described above, corona discharge is generated between the discharge electrode 18 and the counter electrode 16, so that the charging section 12
Can be charged as required.

The discharge electrode can be formed as shown in FIG. In FIG. 3, which shows a part of the charging section provided with the discharge electrode of the first modified example, the discharge electrode 42 of the first modified example is constituted by an elongated plate-like electrode, and tapered portions 42a and 42b are provided on both sides thereof. Is provided. The thickness of each of the tapered portions 42a and 42b is tapered gradually from both sides toward the center. Thus, the tapered portion 42
a, 42b, the tapered portions 42a, 4 on both sides of the discharge electrode 42 as shown in FIG.
Corona discharge occurs from the tip of 2b toward the opposing electrodes 16 on both sides facing each other, and the tip of each of the tapered portions 42a and 42b has a sharp shape, so that the generated corona discharge is also stable.

FIG. 4 shows a part of a charging section provided with a discharge electrode according to a second modification. In FIG. 4, the discharge electrode 52 of the second modification is formed of an elongated plate-like electrode, and tapered portions 52a and 52b are provided on both sides thereof. One taper portion 52a has a thickness on one side (FIG. 4).
At the upper side) to the other side (the lower side in FIG. 4).
Is smaller than the distance D2 between the tip of the tapered portion 52a and the upper counter electrode 16 (D1 <D2), and the other tapered portion 52b is
Contrary to the above, the thickness is tapered from the other surface side to the one surface side, thereby gradually decreasing the thickness.
The distance D3 between the tip of 2b and the lower opposing electrode 16 is larger than the distance D4 between the tip of the tapered portion 52a and the upper opposing electrode 16 (D3> D4).

When the discharge electrode 52 is used, as shown in FIG. 4, in the tapered portion 52a of the discharge electrode 52, the distances D1 and D2 are in the above-mentioned relationship, so that the corona discharge mainly occurs from the tip of the tapered portion 52a. The corona discharge mainly occurs from the tip of the tapered portion 52b to the upper counter electrode 52 because it is generated toward the lower counter electrode 16 and in the other tapered portion 52b, since the distances D3 and D4 are in the relationship described above. It occurs toward 16. Each taper portion 52a, 52b
Has a sharp tip, so that the tapered portions 52a, 52
The corona discharge from 2b becomes stable as described above.

FIG. 5 shows a part of a charging section having a discharge electrode according to a third modification. Referring to FIG. 5, the discharge electrode 62 of the third modification is formed of an elongated plate-like electrode, and discharge projections 64 and 66 are provided on both sides thereof. The discharge protrusion 64 protrudes from one side end (left end in FIG. 5) of the plate-shaped electrode 62 to both sides thereof, that is, toward the upper counter electrode 16 on the upper surface side in FIG. The lower surface protrudes toward the lower counter electrode 16. Similarly, the other discharge protrusion 66 protrudes from the other side (the right end in FIG. 5) of the plate-shaped electrode 62 to both sides thereof, similarly to the discharge protrusion 64 described above. The discharge projections 64 and 66 are provided over substantially the entire length of the discharge electrode 62 in the longitudinal direction.

By providing the discharge projections 64 and 66 in this way, as shown in FIG. 5, both ends of the discharge electrode 42 are directed from the tips of the discharge projections 64 and 66 to the opposing electrodes 16 on the opposite sides. Corona discharge occurs. At this time, it is desirable that the tip of each of the discharge projections 64 and 66 is formed in a sharp shape. With such a configuration, the generated corona discharge can be further stabilized.

In the third modification, the discharge projections 64 and 66 are provided on both sides of the discharge electrode 62.
A desired effect can be achieved by providing such discharge protrusions 64 and 66 only on one side or the other side of the discharge electrode 62. Also, in order to reduce the pressure loss of the discharge electrode 62, a tapered portion as shown in FIG.

FIG. 6 shows a part of a charging section provided with a discharge electrode according to a fourth modification. FIG. 7 shows V in FIG.
It is a figure which shows the place seen from the II-VII line. Referring to FIG. 6, discharge electrode 72 of the fourth modification is formed of an elongated plate-like electrode, and one side thereof (FIGS. 6 and 7).
In FIG. 6, the left side portion and the upstream side when viewed in the flow direction of the particulate matter indicated by the arrow 28) have substantially the longitudinal direction (the direction perpendicular to the paper surface in FIG. 6 and the vertical direction in FIG. 7). A plurality of substantially triangular discharge projections 74 are provided substantially continuously over the entire upper length. Each discharge protrusion 7
4 has substantially the same shape, and its width (the size in the vertical direction in FIG. 7) is gradually reduced in a tapered shape toward one end of the discharge electrode 72, and the tip is formed sharp.

These discharge projections 74 have a pitch P (for example, the distance between the tips of adjacent discharge projections 74) of 1 to
It can be set to about 5 mm, and the amount of protrusion H (the length from the base to the tip) can be set to about 0.1 to 5.0 mm. By setting in this manner, a desired corona discharge can be achieved. Can be generated.

By providing the discharge protrusions 74 in this manner, a corona discharge is generated at one side of the discharge electrode 72 from the tip of each discharge protrusion 74 to the opposing electrodes 16 on both sides facing each other. Since each of the discharge protrusions 74 has a substantially triangular shape, the corona discharge from each of the discharge protrusions 74 is stable, and a substantially uniform corona discharge can be generated over substantially the entire length of the discharge electrode 72. At the other side of the discharge electrode 72, a corona discharge is generated from the other side end toward the opposing electrodes 16 on both sides.

In the fourth modification, the discharge projection 74 is provided on one side of the discharge electrode 72. On the contrary, the discharge projection 74 is provided on the other side of the discharge electrode 72 in the longitudinal direction. A plurality of projections may be provided.

FIG. 8 shows a discharge electrode according to a fifth modification. Referring to FIG. 6, the discharge electrode 82 of the fifth modified embodiment is formed of an elongated plate-like electrode, and has a substantially triangular shape on both sides thereof over substantially the entire length in the longitudinal direction (vertical direction in FIG. 8). A plurality of discharge protrusions 84 and 86 are provided substantially continuously. Each discharge projection 84, 8
6 has substantially the same shape, and the discharge projection 84 on one side of the discharge electrode 82 has a width (FIG. 8) toward one end thereof.
Of the discharge electrode 82 is gradually reduced in a tapered shape toward the other side end, and their tips are sharpened. Is formed. The pitch and the amount of protrusion of the discharge projections 84 and 86 can be set in the same manner as in the modified examples of FIGS.

When the discharge projections 84 and 86 are provided on both sides of the discharge electrode 82, the discharge projections 84 and the discharge projections 86 are provided so as to be shifted in the longitudinal direction as shown in FIG. Specifically, for example, it is desirable that the tip (or valley) of the discharge projection 84 on one side corresponds to the valley (or tip) of the discharge projection 86 on the other side. With this configuration, the distance between the tip of the discharge projection 84 on one side and the tip of the discharge projection 86 on the other side is increased, thereby reducing the interference of corona discharge generated from the tips of the discharge projections 84 and 86. Accordingly, corona discharge can be further stabilized.

FIG. 9 shows a part of a charging section provided with a discharge electrode according to a sixth modification. In the sixth modification, the fourth modification shown in FIGS. 6 and 7 is modified.

Referring to FIG. 9, the discharge electrode 92 of the sixth modified embodiment is composed of an elongated plate-like electrode, and one side of the discharge electrode 92 has substantially its longitudinal direction (the direction perpendicular to the plane of FIG. 9). A substantially triangular discharge protrusion 94 over the entire upper length
a and 94b are provided substantially continuously and alternately. The distal end of each discharge protrusion 94a projects upward toward the upper counter electrode 16 in FIG.
9 protrudes downward in FIG. 9 toward the lower counter electrode 16. With such a configuration, in each of the discharge protrusions 94a, the distance D5 between the tip and the upper counter electrode 16 is determined by the distance between the tip and the lower counter electrode 16a.
(D5 <D6).
In each discharge electrode 94b, the distance D7 between the tip and the upper counter electrode 16 is set to be larger than the distance D8 between the tip and the lower counter electrode 16 (D7> D).
8).

When such a discharge electrode 92 is used, at one side of the discharge electrode 92, corona discharge from each of the discharge protrusions 94a is generated toward the upper counter electrode 16, and the tip is sharp. Therefore, a stable corona discharge can be obtained. Further, the corona discharge from each of the discharge protrusions 94b is generated toward the lower counter electrode 16, and the tip is sharply formed, so that a similarly stable corona discharge can be obtained. Further, by alternately providing the discharge protrusions 94a and 94b, the adjacent discharge protrusions 94a are provided.
The distance between the adjacent discharge protrusions 94b and the distance between adjacent discharge protrusions 94b are increased, and the mutual interference of corona discharge generated between the discharge electrode 92 and the counter electrode 16 can be reduced, thereby further stabilizing the corona discharge. Can be done.
In addition, the protrusion amount T of the discharge protrusion 94a (94b) from the upper surface (lower surface) of the discharge electrode 92 is, for example, 0.1 to 0.1.
It can be set to about 3.0 mm.

In the discharge electrode 92 of the sixth modified embodiment, it is desirable that each of the discharge projections 94a and 94b is configured such that its thickness is gradually reduced toward the tip. With this configuration, the tip of each of the discharge protrusions 94a and 94b has a sharper shape, and the corona discharge that is generated can be further stabilized.

In the sixth modification, the discharge projections 94a,
Although 94b is provided on one side of the discharge electrode 92, on the contrary, it can be provided on the other side of the discharge electrode 92,
In such a case, a similar effect is achieved.

FIG. 10 shows a part of a charging section provided with a discharge electrode according to a seventh modification. In the seventh modification, a modification similar to that shown in FIG. 9 is added to the fifth modification shown in FIG.

Referring to FIG. 10, discharge electrode 102 of the seventh modification is formed of an elongated plate-like electrode, and its one side and the other side have a longitudinal direction (in FIG. 10, perpendicular to the plane of FIG. 10). A plurality of substantially triangular discharge protrusions 104a, 104b, 106a, and 106b are provided substantially continuously and alternately over substantially the entire length (direction). The tip of each of the discharge projections 104a and 106a projects upward toward the upper counter electrode 16 in FIG.
The tips of 4b and 106b protrude downward toward the lower counter electrode 16 in FIG. With this configuration, as in the sixth embodiment, in each of the discharge protrusions 104a and 106a, the distance between the tip and the upper opposing electrode 16 is equal to the distance between the tip and the lower opposing electrode 16a. Is set smaller than the distance between the discharge electrodes 104 and
b, 106b, the tip and the upper counter electrode 1
6 is set larger than the distance between the tip and the lower counter electrode 16. In addition, each discharge protrusion 104
The shapes of a, 104b, 106a, and 106b can be formed, for example, in the same manner as in the modification of FIG.

When such a discharge electrode 102 is used,
On one side (and the other side) of the discharge electrode 102,
Corona discharge from each discharge protrusion 104a (and 106a) is generated toward the upper counter electrode 16, and corona discharge from each discharge protrusion 104b (and 106b) is directed toward the lower counter electrode 16. And the discharge electrode 10
2 can stabilize corona discharge generated from both sides. Also, by alternately providing the discharge projections 104a and 104b in the longitudinal direction and alternately providing the discharge electrodes 106a and 106ab in the longitudinal direction, the discharge protrusions 104a and 104ab are generated between the discharge electrode 102 and the counter electrode 16 as described above. Mutual interference of corona discharge can be reduced.

In this discharge electrode 102, in order to further reduce the mutual interference of the generated corona discharge, FIG.
As in the modification of the first embodiment, the discharge projections 104a and 104b
And the discharge protrusions 106a and 106b are connected to the discharge electrode 102.
Is desirably shifted in the longitudinal direction.

FIG. 11 shows a part of a charging section provided with a discharge electrode according to an eighth modification. In the eighth modification, the discharge projections of the sixth modification (see FIG. 6) are applied to the other side of the discharge electrode 18 in the first embodiment.

Referring to FIG. 11, the discharge electrode 112 according to the eighth modification is formed of an elongated plate-like electrode, and has a tapered portion 11 whose one side gradually decreases in thickness toward one side.
4 is provided on the other side in the longitudinal direction (FIG. 11).
A plurality of substantially triangular discharge protrusions 116a and 116b are provided substantially continuously and alternately over substantially the entire length (in the direction perpendicular to the plane of the drawing). The distal end of each discharge protrusion 116a projects upward toward the upper counter electrode 16 in FIG. 11, and the distal end of each discharge electrode 116b projects downward toward the lower counter electrode 16 in FIG.

When such a discharge electrode 112 is used,
The tapered portion 114 is provided at one side of the discharge electrode 112, so that corona discharge generated from the tip of the tapered portion 114 can be stabilized, and the pressure loss due to the discharge electrode 112 can be reduced. Electrode 1
In the other side portion of 12, the corona discharge interference can be reduced to stabilize the corona discharge.

The discharge electrodes according to the first to eighth modified embodiments have been described above. These discharge electrodes can be used in place of the discharge electrode 18 in the first embodiment. 7 to 11, the discharge projections are provided substantially continuously in the longitudinal direction of the discharge electrode, but instead, a predetermined interval, for example, 5 to 30 mm is used.
It is also possible to provide them at such intervals, and the same effect can be achieved with this configuration.

In the first embodiment described above, the charging unit 12
Although the present invention is applied to the two-stage electric precipitator in which the dust collector and the dust collecting unit 14 are separated from each other, the present invention is similarly applied to the one-stage electric precipitator shown in FIG. Can be.

Referring to FIG. 12, which schematically shows a second embodiment of the electric precipitator, the electric precipitator shown has a hollow device housing 202 and the device housing 20.
The inflow opening 204 is provided at one end (the left end in FIG.
The outflow opening 206 is provided at the other end (the right end in FIG. 12). Air containing particulate matter to be collected, for example, carbon particles, tunnel dust (exhaust gas in the tunnel) flows into the apparatus housing 202 through the inflow opening 204 as shown by an arrow 208, and enters the apparatus housing 202. As will be described later, the particulate matter is removed, and the air from which the particulate matter has been removed flows out of the device housing 202 through the outlet opening 206 as shown by the arrow 210.

In the second embodiment, the device housing 20
2, five dust collecting electrodes 21 spaced apart in the vertical direction.
2 are provided, and a discharge electrode 214 is provided between the dust collecting electrodes 212. These discharge electrodes 214
Are provided at substantially equal intervals in the flow direction of the particulate matter between the adjacent dust collection electrodes 112, and the three discharge electrodes 214 are substantially parallel to the vertical direction of the adjacent dust collection electrodes 112. The distance between the discharge electrode 214 and the upper counter electrode 212 is set to be equal to the distance between the discharge electrode 212 and the lower counter electrode 214.

In the second embodiment, a DC power supply 216 is connected to the discharge electrode 214 as shown in FIG.
For example, a negative (minus) DC voltage is applied, and a counter electrode 212 facing the discharge electrode 214 has a DC power supply 2
18 are connected, and a positive DC voltage is applied, for example.
The voltage applied to the discharge electrode 214 is, for example, -11 to 11
The voltage may be about −13 kV, and the voltage applied to the dust collecting electrode 212 may be, for example, about +9 to +11 kV. Note that, contrary to the above, a positive DC voltage may be applied to the discharge electrode 214 and a negative DC voltage may be applied to the dust collection electrode 212.

The operation of the electric dust collecting apparatus will be outlined as follows. Air containing particulate matter to be collected flows into the apparatus housing 202 through the inlet opening 204. At this time, a negative DC voltage from the DC power supply 216 is applied to each discharge electrode 214, and each of the dust collection electrodes 21
2 is applied with a positive DC voltage, whereby each discharge electrode 214 generates a negative corona discharge toward the dust collection electrode 212. Thus, the discharge electrode 214 and the dust collection electrode 212
The particulate matter flowing between and is negatively charged by the generated corona discharge, and the negatively charged particulate matter is electrostatically attracted to the dust collecting electrode 212 and adheres to the surface thereof,
The particulate matter is removed from the air as required. In addition, the number of the discharge electrodes 214 and the number of the dust collection electrodes 212 in the electric dust collection device can be appropriately set according to the size of the device housing 202, the dust collection capability, and the like.

By using the discharge electrode 18 used in the first embodiment as the discharge electrode 214 in such an electrostatic precipitator, the same effects as described above can be achieved.
Further, the discharge electrodes of the first to eighth modified embodiments can be used as the discharge electrodes 214, and the same effects as described above are achieved when such discharge electrodes are used.

Example and Comparative Example As Example 1, the following experiment was performed to confirm the effect of the discharge electrode of the sixth modification shown in FIG.
A discharge electrode was arranged between a pair of opposed electrodes, and a current value flowing through the discharge electrode when a negative DC voltage was applied to the discharge electrode was measured. The size of the counter electrode is 100 mm long and 1 horizontal.
00 mm, and a pair of counter electrodes were arranged at intervals of 40 mm. In addition, a discharge electrode was a plate-shaped electrode, and was disposed at a central portion between a pair of opposed electrodes. The size of the discharge electrode (plate-like electrode) is 100 mm in length and 1 in width.
2 mm and a thickness of 0.64 mm, and one side of the discharge electrode is substantially continuously formed at a pitch of 0.25 mm.
The discharge projections were provided. The discharge projections are triangular, and their tips protrude alternately on one side and the other side,
The amount of protrusion of each discharge protrusion was 1.5 mm, and the amount of protrusion of the discharge protrusion from one side and the amount of protrusion from the other surface was 0.25 mm.

When a negative DC voltage was applied to such a discharge electrode, measurement results as shown by a solid line A in FIG. 13 were obtained. FIG. 13 shows the relationship between the applied DC voltage and the current flowing through the discharge electrode, and the current increased from around -8 kV. This is because corona discharge occurred between the discharge electrode and the counter electrode from around the vicinity.

As Comparative Example 1, the same experiment as described above was performed using a wire electrode as the discharge electrode. The discharge electrode used was a wire electrode having a length of 100 mm and a diameter of 0.5 mm. In Comparative Example 1, the measurement result as shown by the broken line B in FIG. 13 was obtained. In the comparative example, the current increased from around 10 kV, but the current value was smaller than that in Example 1, and the current values of both approximately matched around 13 to 14 kV.

From the results of Example 1 and Comparative Example 1 described above, the voltages suitable for generating corona discharge, -9 to-
In the range of 13 kV, a larger amount of current flows through the plate-shaped electrode. Therefore, when the plate-shaped electrode is used,
It has been found that the corona discharge is stronger, which makes it possible to charge the particulate matter more strongly.

As Example 2, the dust collecting effect of the electric dust collector of the embodiment shown in FIG. 1 was confirmed by the following experiment. The configuration of the charging unit and the dust collection unit in the used electrostatic precipitator,
It was as follows. In the charging section, 100m long
m, 60 mm wide opposing electrodes at 32 mm intervals
The pieces are arranged vertically. Further, one discharge electrode used in Example 1 was arranged at the center in the vertical direction between each of the pair of counter electrodes. In the dust collecting section, the height is 100 mm and the width is 1
Nine 00 mm collecting electrodes were vertically arranged at 12 mm intervals.

In the experiment of Example 2, air containing tunnel dust (containing carbon-based fine particles)
It was supplied into the apparatus housing from the introduction opening at a rate of m / s, and the removal rate of the tunnel dust was measured. The conditions of each experiment were as described in the column of experimental conditions in Table 1, and the measurement results under those experimental conditions were as shown in the column of Example 2. From the experimental results of Example 2, tunnel dust could be sufficiently removed even when the voltage applied to the discharge electrode and the voltage applied to the dust collecting electrode were changed.

[0069]

[Table 1]

As Comparative Example 2, the same experiment was performed under the same conditions as described above using three wire electrodes in place of each plate-like electrode in the electrostatic precipitator of Example 2.
These measurement results were as shown in the column of Comparative Example 2. From this measurement result, when the voltage of the discharge electrode is −11 kV, tunnel dust cannot be sufficiently collected,
Increasing the voltage of the dust collection electrode greatly reduced the dust collection effect.

From the results of Example 2 and Comparative Example 2, it was confirmed that when the plate-shaped electrode was used as the discharge electrode, the dust collecting effect could be enhanced as compared with the case where the wire-shaped electrode was used. This is considered to be due to the fact that when a plate-like electrode is used, the corona discharge current becomes large, whereby the tunnel dust can be more strongly charged.

As Example 3, the dust collecting effect of the electric precipitator of the form shown in FIG. 12 was confirmed by the following experiment. The configuration of the electric precipitator used was as follows. Five plate electrodes having a length of 100 mm and a width of 100 mm were vertically arranged at intervals of 24 mm as dust collecting electrodes. In addition, three discharge electrodes used in Example 1 were arranged at the center in the vertical direction between each of the pair of dust collecting electrodes, at intervals of 20 mm in the flow direction of the particulate matter. In the experiment of Example 3, the air containing the tunnel dust was 3 m.
/ S into the device housing from the inlet opening,
The removal ratio of tunnel dust was measured. The conditions of each experiment were as described in the column of experimental conditions in Table 2, and the measurement results under each experimental condition were as shown in the column of Example 3. From the experimental results of Example 3, the voltage applied to the discharge electrode was 9.0 kV even in the single-stage electrostatic precipitator.
It has been found that the above makes it possible to sufficiently remove tunnel dust.

[0073]

[Table 2]

[0074]

According to the electrostatic precipitator of the first aspect of the present invention, the discharge electrode has a sufficient strength because the discharge electrode is constituted by an elongated plate-like electrode. Therefore, a large tension can be applied to the plate-shaped electrode, whereby the vibration generated at the discharge electrode can be suppressed, and the occurrence of spark discharge can be reduced. In addition, since the thickness of one or both sides of the plate-shaped electrode is gradually reduced in a tapered shape, the corona discharge from the discharge electrode is generated from the tapered side end and stably generates the corona discharge. be able to.

Further, according to the electrostatic precipitator of the second aspect of the present invention, the discharge electrode has a sufficient strength because the discharge electrode is constituted by an elongated plate-like electrode. Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. In addition, since one or both sides of the plate-shaped electrode are provided with discharge projections protruding from both sides thereof, corona discharge from the discharge electrode is generated from the discharge projection, and corona discharge is stably performed. Can be generated.

According to the third embodiment of the present invention, since the discharge electrode is constituted by the elongated plate-shaped electrode, it has a sufficient strength. Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. Further, since a plurality of substantially triangular discharge protrusions are provided on one or both sides of the plate-like electrode, corona discharge from the discharge electrode is generated from the tips of the discharge protrusions, and the plate-like electrode , A substantially uniform corona discharge can be stably generated over the longitudinal direction.

According to the fourth aspect of the present invention, since the tips of the plurality of discharge protrusions alternately protrude on one side and the other side of the plate-like electrode, the plate-like shape is formed. Corona discharge from the discharge electrode part protruding on one side of the electrode occurs toward the electrode facing this one side,
On the other hand, corona discharge from the discharge electrode portion projecting to the other side surface of the plate-like electrode is generated toward the electrode facing the other side surface. Therefore, corona discharges generated from the discharge electrode portions adjacent to each other in the longitudinal direction of the plate-shaped electrode are less likely to interfere with each other, so that the corona discharge from the discharge electrodes can be stabilized, and the discharge electrode portions are brought close to each other. It becomes possible to provide.

According to the fifth aspect of the present invention, the discharge electrode portion provided on one side of the plate-like electrode and the discharge electrode portion provided on the other side of the plate-like electrode extend in the longitudinal direction. Because of the deviation, the mutual interference between the corona discharge from the one side discharge electrode portion and the corona discharge from the other side portion is reduced, and the corona discharge from the discharge electrode can be stabilized.

According to the electrostatic precipitator of the sixth aspect of the present invention, the thickness of the upstream side of the plate-shaped electrode is gradually reduced in a tapered shape, so that the pressure loss due to the plate-shaped electrode is reduced. can do. Further, since the corona discharge is generated from the tapered side end, the corona discharge can be stabilized. Further, since a plurality of discharge electrodes are provided on the downstream side of the plate-like electrode, corona discharge from the discharge electrode can be stabilized.

Further, according to the seventh aspect of the present invention, the discharge electrode is provided on the charging portion and the dust collection electrode is provided on the dust collecting portion. The present invention can be conveniently applied to a two-stage electric dust collector provided with a charging unit and a dust collecting unit.

[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 illustrating a part of a charging unit including a discharge electrode according to a first modification.

FIG. 4 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to a second modification.

FIG. 5 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to a third modification.

FIG. 6 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to a fourth modification.

FIG. 7 is a plan view as viewed from line VII-VII in FIG. 6;

FIG. 8 is a plan view showing a part of a discharge electrode according to a fifth modification.

FIG. 9 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to a sixth modification.

FIG. 10 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to a seventh modification.

FIG. 11 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to an eighth modification.

FIG. 12 is a cross-sectional view schematically showing a second embodiment of the electric precipitator according to the present invention.

FIG. 13 is a diagram showing a relationship between a voltage applied to a discharge electrode and a current flowing therethrough.

[Explanation of symbols]

2,202 Device housing 12 Charging part 14 Dust collecting part 16 Counter electrode 18,42,52,62,72,82,92,102,
112, 214 Discharge electrode 18a, 42a, 42b, 52a, 52b, 114 Tapered portion 22, 212 Dust collection electrode 74, 84, 86, 92a, 92b, 104a, 104
b, 106a, 106b, 114a, 114b Discharge projection

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 5, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Electric dust collector

[Claims]

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 DC voltage is applied to the discharge electrodes, and the counter electrodes are grounded. In the dust collecting unit, 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]

In this known electrostatic precipitator, the discharge electrode of the charging section is constituted by a wire-like electrode, and there are the following problems related to this. That is, when a wire-like electrode is used as the discharge electrode, the discharge electrode is easily vibrated by corona discharge generated between the discharge electrode and the counter electrode. When a vibration occurs in the discharge electrode, the distance between the discharge electrode and the counter electrode fluctuates. When the vibration increases, the distance decreases, and as a result, a spark discharge occurs between the discharge electrode and the counter electrode. become. When the spark discharge occurs, a large current flows through the discharge electrode, and the heat generated by the large current causes the oxidation and deterioration of the discharge electrode.

Therefore, in order to suppress the vibration of the discharge electrode which causes spark discharge, the tension of the discharge electrode may be increased, but if the applied tension is increased, the possibility of the discharge electrode being cut increases.

An object of the present invention is to provide an electric precipitator capable of stabilizing corona discharge by a discharge electrode and suppressing vibrations generated during corona discharge.

Another object of the present invention is to provide an electrostatic precipitator capable of sufficiently charging the particulate matter to be collected.

[0008]

According to the present invention, there is provided a discharge electrode for charging particulate matter to a specific polarity, and a dust collecting electrode for collecting particulate matter charged by the discharge electrode. In the electrostatic precipitator, the discharge electrode is formed of an elongated plate-like electrode, and the thickness of the plate-like electrode on the upstream side in the flow direction of the particulate matter is gradually reduced in a tapered shape. A plurality of substantially triangular discharge protrusions are provided in a longitudinal direction of the plate-like electrode on a downstream side of the plate-like electrode in the flow direction of the particulate matter. It is a dust device.

According to the present invention, since the discharge electrode is constituted by an elongated plate-like electrode, it has a sufficient strength.
Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. Also, since a plurality of substantially triangular discharge protrusions are provided on the downstream side of the plate-like electrode,
Corona discharge from the discharge electrode is generated from the tips of the discharge projections, and can generate stably a substantially uniform corona discharge over the longitudinal direction of the plate-shaped electrode. A substantially triangular discharge projection may also be formed on the upstream side of the plate-like electrode.

Further, according to the present invention, the thickness of the upstream side portion of the plate-shaped electrode is gradually reduced in a tapered shape, so that the pressure loss due to the plate-shaped electrode can be reduced. Further, since the corona discharge is generated from the tapered side end, the corona discharge can be stabilized. Further, since a plurality of discharge electrodes are provided on the downstream side of the plate-like electrode, corona discharge from the discharge electrode can be stabilized.

Further, according to the present invention, the tip of the plurality of discharge projections provided on one side of the plate-like electrode may be:
The plate-like electrode is characterized by alternately protruding on one side and the other side.

Further, according to the present invention, the tip of the plurality of discharge projections provided on both side portions of the plate-like electrode may include:
The plate-like electrode is characterized by alternately protruding on one side and the other side.

According to the present invention, the tips of the plurality of discharge projections alternately project on one side and the other side of the plate-like electrode, so that the discharge electrode projecting on one side of the plate-like electrode. The corona discharge from the electrode is generated toward the electrode facing the one side surface, while the corona discharge from the discharge electrode portion protruding from the other side surface of the plate-like electrode is generated toward the electrode facing the other side surface. . Therefore, corona discharges generated from the discharge electrode portions adjacent to each other in the longitudinal direction of the plate-shaped electrode are less likely to interfere with each other, so that the corona discharge from the discharge electrodes can be stabilized, and the discharge electrode portions are brought close to each other. It becomes possible to provide.

Further, the present invention is characterized in that the discharge projections provided on one side of the plate-shaped electrode and the discharge projections provided on the other side are displaced in the longitudinal direction. I do.

According to the present invention, the discharge electrode portion provided on one side of the plate-shaped electrode and the discharge electrode portion provided on the other side are displaced in the longitudinal direction. Mutual interference between the corona discharge from the discharge electrode portion and the corona discharge from the other side portion is reduced, and the corona discharge from the discharge electrode can be stabilized.

Further, according to the present invention, the discharge electrode is provided on a charging section, and the charging section is provided with a counter electrode facing the discharge electrode, and the dust collecting electrode is provided in a flow direction of the particulate matter. Seen in the drawing, it is provided in a dust collecting part disposed downstream of the charging part.

According to the present invention, since the discharge electrode is provided on the charging unit and the dust collecting electrode is provided on the dust collecting unit, the charging unit and the dust collecting unit are provided at intervals in the flow direction of the particulate material. The present invention can be advantageously applied to a two-stage electric precipitator.

[0018]

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 cross-sectional view schematically showing a prerequisite configuration 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.
An inflow opening 4 is provided at one end (the left end in FIG. 1), and an outflow opening 6 is provided at the other end (the right end in FIG. 1). 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 four opposing electrodes 16 spaced apart in the vertical direction.
Discharge electrodes 18 are provided between the respective electrodes 6. The discharge electrodes 18 are arranged substantially at the center in the vertical direction between the opposing electrodes 16 located on both sides, and the interval between the discharge electrodes 18 and the upper opposing electrode 16 is set to be equal to the distance between the discharge electrode 18 and the lower opposing electrode 16. The interval is set to be equal to 16. The counter electrode 16 is composed of, for example, a rectangular plate-like electrode having a relatively wide width, and extends in a direction perpendicular to the plane of FIG. These counter electrodes 16 are arranged substantially parallel to each other and extend in the flow direction indicated by the arrow 8. The discharge electrode 18 is composed of an elongated plate-like electrode, is disposed substantially parallel to the counter electrode 16, and extends in a direction perpendicular to the plane of FIG. The width of these discharge electrodes 18 is smaller than the width of the counter electrode 16, and corona discharge from the discharge electrode 18 is generated toward the surface of the counter electrode 16.

In this configuration, as shown in FIG. 1, for example, a negative (minus) DC voltage is applied to the discharge electrode 16, and the counter electrode 16 facing the discharge electrode 16 is grounded. Accordingly, when a high DC voltage is applied from the DC power supply 20, the discharge electrode 16
, A negative corona discharge is generated, and the particulate matter flowing through the charging unit 12 is negatively charged by the negative corona discharge. The discharge electrodes 18 include, for example, -11 to -13
A DC voltage of about kV can be applied. The counter electrode 16 may be applied with a positive DC voltage instead of being grounded. In addition, instead of applying the above-described configuration, while applying a positive DC voltage to the discharge electrode 18,
A negative DC voltage may be applied to the counter electrode 16 or grounded. In such a case, the particulate matter is positively charged.

The dust collecting section 14 is provided with a plurality of, in this configuration, nine dust collecting electrodes 22 at intervals in the vertical direction. These dust collecting electrodes 22 extend in the flow direction of the particulate matter, are arranged substantially in parallel with each other, and extend in a direction perpendicular to the paper surface of FIG. In connection with the fact that the particulate matter is negatively charged in the charging unit 12, in this embodiment, a positive DC voltage is applied to a part of the plurality of dust collecting electrodes 14,
The remaining dust collecting electrodes 14 are grounded. Specifically, a DC power supply 24 is electrically connected to the odd-numbered collecting electrodes 22 from the lower side in FIG. 1, and a positive DC voltage is applied by the DC power supply 24. In FIG. 1, the even-numbered dust collecting electrodes 22 from the lower side are grounded. By giving a potential difference between the adjacent dust collecting electrodes 22 in this manner, the negatively charged particulate matter is electrostatically attracted to the dust collecting electrodes 22 to which a positive DC voltage is applied, and their surface is Collected electrically. For example, a DC voltage of about +4 to +6 kV can be applied to the dust collecting electrode 22.

In this configuration, a positive DC voltage is applied to a part of the dust collecting electrode 22 and the remaining dust collecting electrode 22 is grounded, but a negative DC voltage is applied to the remaining dust collecting electrode 22. It can also be done. When the particulate matter is positively charged, a negative DC voltage is applied to a part of the dust collecting electrode 22 and a positive DC voltage is applied to the remaining counter electrode 22 or grounded. Can be

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, a negative DC voltage from a DC power supply 20 is applied to each discharge electrode 18, and each discharge electrode 18 generates a negative corona discharge toward the opposite electrode 16,
Thus, the particulate matter flowing through the charging section 12 is negatively charged. When the particulate matter flows from the charging unit 12 to the dust collection unit 14, the particulate matter is negatively charged, so that the particulate matter is electrostatically collected by the positively charged dust collection electrode 22, As a result of the dust collection, the particulate matter is removed from the air as required, and the air from which the particulate matter has been removed is discharged from the outlet opening 6. In addition, the number of the discharge electrodes 18, the counter electrodes 16, and the dust collecting electrodes 22 in the electric dust collecting device can be appropriately set according to the size of the device housing 2, the dust collecting ability, and the like.

FIG. 2 shows a part of a charging section provided with a discharge electrode as another premise of the present invention. FIG. 3 is a diagram showing a portion viewed from line VII-VII in FIG.
Referring to FIG. 2, a discharge electrode 72 in place of discharge electrode 18 is formed of an elongated plate-like electrode, and one side thereof (the left side in FIGS. A substantially triangular discharge projection 74 is provided substantially over the entire length in the longitudinal direction (the direction perpendicular to the paper surface in FIG. 2 and the vertical direction in FIG. 3) on the upstream side in the flow direction. A plurality is provided continuously above. Each of the discharge protrusions 74 has substantially the same shape, and has a width (a vertical size in FIG. 3) toward one end of the discharge electrode 72.
Is tapered, and the tip is sharply formed.

These discharge projections 74 have a pitch P (eg, a distance between the tips of adjacent discharge projections 74) of 1 to 1.
It can be set to about 5 mm, and the protruding amount H (the length from the base to the tip) can be set to about 0.1 to 5.0 mm. Can be generated.

By providing the discharge protrusions 74 in this manner, a corona discharge is generated at one side of the discharge electrode 72 from the tip of each discharge protrusion 74 toward the opposing electrodes 16 on both sides facing each other. Since each of the discharge protrusions 74 has a substantially triangular shape, the corona discharge from each of the discharge protrusions 74 is stable, and a substantially uniform corona discharge can be generated over substantially the entire length of the discharge electrode 72. At the other side of the discharge electrode 72, a corona discharge is generated from the other side end toward the opposing electrodes 16 on both sides.

In this configuration, the discharge projection 74 is provided on one side of the discharge electrode 72. On the contrary,
A plurality of discharge protrusions may be provided on the other side of the discharge electrode 72 in the longitudinal direction.

FIG. 4 shows a discharge electrode as yet another premise of the present invention. Referring to FIG. 4, discharge electrode 82 instead of discharge electrode 72 is formed of an elongated plate-like electrode, and has a substantially triangular shape on both sides thereof over substantially the entire length in the longitudinal direction (vertical direction in FIG. 4). Discharge projection 8
4, 86 are provided substantially continuously. The discharge projections 84 and 86 have substantially the same shape, and the discharge projection 84 on one side of the discharge electrode 82 has a width (a size in the vertical direction in FIG. 4) toward one end thereof. Is gradually reduced to a tapered shape, and the discharge protrusion 8 on the other side of the discharge electrode 82 is formed.
6 has a tapered shape whose width is gradually reduced toward the other side end, and their tips are sharply formed. The pitch and the amount of protrusion of the discharge projections 84 and 86 can be set in the same manner as in the configurations of FIGS.

When the discharge projections 84 and 86 are provided on both sides of the discharge electrode 82, as shown in FIG. 4, the discharge projections 84 and the discharge projections 86 are provided so as to be shifted in the longitudinal direction. Specifically, for example, it is desirable that the tip (or valley) of the discharge projection 84 on one side corresponds to the valley (or tip) of the discharge projection 86 on the other side. With this configuration, the distance between the tip of the discharge projection 84 on one side and the tip of the discharge projection 86 on the other side is increased, thereby reducing the interference of corona discharge generated from the tips of the discharge projections 84 and 86. Accordingly, corona discharge can be further stabilized.

FIG. 5 shows a part of a charging section provided with a discharge electrode as another premise of the present invention. In this configuration, the configurations shown in FIGS. 2 and 3 are modified.

Referring to FIG. 5, a discharge electrode 92 in place of the above-mentioned discharge electrode 72 is constituted by an elongated plate-like electrode.
On one side, a plurality of substantially triangular discharge protrusions 94a and 94b are provided substantially continuously alternately over substantially the entire length in the longitudinal direction (the direction perpendicular to the paper surface in FIG. 5). The tip of each discharge projection 94a projects upward in FIG. 5 toward the upper counter electrode 16, and the tip of each discharge electrode 94b projects downward in FIG.
It protrudes toward 6. With such a configuration, in each of the discharge protrusions 94a, the distance D5 between the tip and the upper counter electrode 16 is set smaller than the distance D6 between the tip and the lower counter electrode 16. (D5 <D
6). In each discharge electrode 94b, the distance D7 between the tip and the upper counter electrode 16 is set to be larger than the distance D8 between the tip and the lower counter electrode 16 (D
7> D8).

When such a discharge electrode 92 is used, at one side of the discharge electrode 92, a corona discharge from each of the discharge protrusions 94a is generated toward the upper counter electrode 16, and the tip is sharp. Therefore, a stable corona discharge can be obtained. Further, the corona discharge from each of the discharge protrusions 94b is generated toward the lower counter electrode 16, and the tip is sharply formed, so that a similarly stable corona discharge can be obtained. Further, by alternately providing the discharge protrusions 94a and 94b, the adjacent discharge protrusions 94a are provided.
The distance between the adjacent discharge protrusions 94b and the distance between adjacent discharge protrusions 94b are increased, and the mutual interference of corona discharge generated between the discharge electrode 92 and the counter electrode 16 can be reduced, thereby further stabilizing the corona discharge. Can be done.
In addition, the protrusion amount T of the discharge protrusion 94a (94b) from the upper surface (lower surface) of the discharge electrode 92 is, for example, 0.1 to 0.1.
It can be set to about 3.0 mm.

In the discharge electrode 92 as well, each discharge protrusion 9
4a and 94b are configured such that their thickness gradually decreases toward the tip. With this configuration, the tip of each of the discharge protrusions 94a and 94b has a sharper shape, and the corona discharge that is generated can be further stabilized.

The discharge projections 94a and 94b are connected to the discharge electrodes 92.
However, on the other hand, it can be provided on the other side downstream of the discharge electrode 92, and the same effect can be achieved in such a case.

FIG. 6 shows a part of a charging section provided with a discharge electrode 102 according to an embodiment of the present invention. In this embodiment, a modification similar to that shown in FIG. 5 is added to the configuration shown in FIG.

Referring to FIG. 6, discharge electrode 102 is formed of an elongated plate-like electrode, and one side of the upstream side and the other side of the downstream side have a longitudinal direction (in FIG. 6, a direction perpendicular to the plane of FIG. 6). A plurality of substantially triangular discharge protrusions 104a, 104b, 106a, and 106b are provided substantially continuously and alternately over substantially the entire length (direction). The tip of each of the discharge projections 104a and 106a protrudes upward toward the upper counter electrode 16 in FIG.
6 and 106b project downward toward the lower counter electrode 16 in FIG. With this configuration, the discharge projections 104a, 104a,
6a, the interval between the tip and the upper opposing electrode 16 is set smaller than the interval between the tip and the lower opposing electrode 16, and in each of the discharge electrodes 104b and 106b, the tip and the upper opposing electrode 16 are set. The interval between the counter electrode 16 and the counter electrode 16 is set larger than the interval between the tip and the lower counter electrode 16. Each of the discharge protrusions 104a, 104b, 106a,
The shape of 106b can be formed in the same manner as that of FIG.

When such a discharge electrode 102 is used,
On one side (and the other side) of the discharge electrode 102,
Corona discharge from each discharge protrusion 104a (and 106a) is generated toward the upper counter electrode 16, and corona discharge from each discharge protrusion 104b (and 106b) is directed toward the lower counter electrode 16. And the discharge electrode 10
2 can stabilize corona discharge generated from both sides. Also, by alternately providing the discharge projections 104a and 104b in the longitudinal direction and alternately providing the discharge electrodes 106a and 106ab in the longitudinal direction, the discharge protrusions 104a and 104ab are generated between the discharge electrode 102 and the counter electrode 16 as described above. Mutual interference of corona discharge can be reduced.

In this discharge electrode 102, in order to further reduce the mutual interference of the generated corona discharge, FIG.
Similarly, the respective discharge protrusions 104a and 104b and the respective discharge protrusions 106a and 106b are shifted in the longitudinal direction of the discharge electrode 102.

FIG. 7 shows a discharge electrode 1 according to another embodiment of the present invention.
12 shows a part of the charging unit provided with the reference numeral 12. In this configuration, the discharge projections 106a and 106b of FIG. 6 are applied to the other side downstream of the discharge electrode 18 of FIG.

Referring to FIG. 7, discharge electrode 112 is formed of an elongated plate-like electrode, and a tapered portion 114 whose thickness is gradually reduced toward one end is provided on one upstream side thereof. On the other side on the downstream side, a plurality of substantially triangular discharge protrusions 114a and 114b are provided substantially continuously alternately over substantially the entire length in the longitudinal direction (the direction perpendicular to the paper surface in FIG. 7). Have been. The distal end of each discharge projection 114a projects upward toward the upper counter electrode 16 in FIG. 7, and the distal end of each discharge electrode 114b projects downward toward the lower counter electrode 16 in FIG.

When such a discharge electrode 112 is used,
Since the tapered portion 114 is provided at one side of the upstream side of the discharge electrode 112, the corona discharge generated from the tip can be stabilized, and the pressure loss due to the discharge electrode 112 can be reduced. On the other side of the downstream side of the discharge electrode 112, the interference of the corona discharge can be reduced and the corona discharge can be stabilized.

Each of these discharge electrodes 102 and 112 can be used in place of the discharge electrode 18 in FIG. Further, in the modified examples shown in FIGS. 3 to 7, the discharge protrusions are provided substantially continuously in the longitudinal direction of the discharge electrode. However, instead of this, a predetermined interval, for example, 5 to 30 mm is used.
It is also possible to provide them at such intervals, and the same effect can be achieved with this configuration.

In the above-described embodiment, the charging unit 1 shown in FIG.
Although the present invention is applied to the two-stage electric precipitator in which the dust collecting unit 14 and the dust collecting unit 14 are separated from each other, the present invention is similarly applied to the one-stage electric precipitator shown in FIG. be able to.

Referring to FIG. 8, which schematically shows still another embodiment of the electric precipitator, the electric precipitator has a hollow device housing 202, and this device housing 202
An inflow opening 204 is provided at one end (the left end in FIG. 8), and an outflow opening 206 is provided at the other end (the right end in FIG. 8). Air containing particulate matter to be collected, for example, carbon particles, tunnel dust (exhaust gas in the tunnel) flows into the apparatus housing 202 through the inflow opening 204 as shown by an arrow 208,
The particulate matter is removed in the device housing 202 as described later, and the air from which the particulate material has been removed flows out of the device housing 202 through the outlet opening 206 as shown by an arrow 210.

In this embodiment, the device housing 20
2, five dust collecting electrodes 21 spaced apart in the vertical direction.
2 are provided, and a discharge electrode 214 is provided between the dust collecting electrodes 212. These discharge electrodes 214
Are provided at substantially equal intervals in the flow direction of the particulate matter between the adjacent dust collection electrodes 112, and the three discharge electrodes 214 are substantially parallel to the vertical direction of the adjacent dust collection electrodes 112. The distance between the discharge electrode 214 and the upper counter electrode 212 is set to be equal to the distance between the discharge electrode 212 and the lower counter electrode 214.

In this embodiment, as shown in FIG. 8, a DC power supply 216 is connected to the discharge electrode 214, for example, a negative (minus) DC voltage is applied.
A direct-current power supply 218 is connected to the counter electrode 212 facing the counter 14, and a positive direct-current voltage is applied, for example. The voltage applied to the discharge electrode 214 is, for example, -11 to -13 k
V, and the voltage applied to the dust collection electrode 212 may be, for example, about +9 to +11 kV. Contrary to the above, a positive DC voltage may be applied to the discharge electrode 214 and a negative DC voltage may be applied to the dust collection electrode 212.

The operation of this electric precipitator will be outlined as follows. Air containing particulate matter to be collected flows into the apparatus housing 202 through the inlet opening 204. At this time, a negative DC voltage from the DC power supply 216 is applied to each discharge electrode 214, and each of the dust collection electrodes 21
2 is applied with a positive DC voltage, whereby each discharge electrode 214 generates a negative corona discharge toward the dust collection electrode 212. Thus, the discharge electrode 214 and the dust collection electrode 212
The particulate matter flowing between and is negatively charged by the generated corona discharge, and the negatively charged particulate matter is electrostatically attracted to the dust collecting electrode 212 and adheres to the surface thereof,
The particulate matter is removed from the air as required. Discharge electrode 214 and dust collection electrode 21 in electric dust collector
The number 2 can be set as appropriate according to the size of the device housing 202, the dust collecting capacity, and the like.

By using the discharge electrode 102 of FIG. 6 as the discharge electrode 214 in such an electrostatic precipitator, the same effects as described above can be achieved. The discharge electrode 112 shown in FIG. 7 can be used as the discharge electrode 214, and the same effects as described above can be achieved when such discharge electrodes 102 and 112 are used.

[0050]

According to the electrostatic precipitator of the first aspect of the present invention, the discharge electrode has a sufficient strength because the discharge electrode is constituted by an elongated plate-like electrode. Therefore, a large tension can be applied to the plate-shaped electrode, thereby suppressing vibration generated in the discharge electrode. Further, since a plurality of substantially triangular discharge protrusions are provided on one or both sides of the plate-like electrode, corona discharge from the discharge electrode is generated from the tips of the discharge protrusions, and the plate-like electrode , It is possible to stably generate a substantially uniform corona discharge over the longitudinal direction.

Further, according to the electrostatic precipitator of the present invention, the thickness of the upstream side of the plate-shaped electrode is gradually reduced in a tapered shape, so that pressure loss due to the plate-shaped electrode can be reduced. . Further, since the corona discharge is generated from the tapered side end, the corona discharge can be stabilized. Further, since a plurality of discharge electrodes are provided on the downstream side of the plate-like electrode, corona discharge from the discharge electrode can be stabilized.

According to the electrostatic precipitator of the second and third aspects of the present invention, the tips of the plurality of discharge projections project alternately on one side and the other side of the plate-like electrode. Corona discharge from the discharge electrode portion protruding to one side of the plate-like electrode is generated toward the electrode facing this one side, while corona discharge from the discharge electrode portion protruding to the other side of the plate-like electrode is This is generated toward the electrode facing the other side surface. Therefore, corona discharges generated from the discharge electrode portions adjacent to each other in the longitudinal direction of the plate-shaped electrode are less likely to interfere with each other, so that the corona discharge from the discharge electrodes can be stabilized, and the discharge electrode portions are brought close to each other. It becomes possible to provide.

According to the fourth embodiment of the present invention, the discharge electrode provided on one side of the plate-shaped electrode and the discharge electrode provided on the other side have the same length. Since they are displaced in the directions, the mutual interference between the corona discharge from the discharge electrode on one side and the corona discharge from the other side is reduced, and the corona discharge from the discharge electrode can be stabilized.

According to the fifth aspect of the present invention, the discharge electrode is provided on the charging portion and the dust collection electrode is provided on the dust collecting portion. The present invention can be conveniently applied to a two-stage electric dust collector provided with a charging unit and a dust collecting unit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a prerequisite configuration of an electric precipitator according to the present invention.

FIG. 2 is a partial cross-sectional view showing a part of a charging unit including a discharge electrode 72 which is another premise of the present invention.

FIG. 3 is a plan view as viewed from line VII-VII in FIG. 2;

FIG. 4 is a plan view showing a part of a discharge electrode 82 which is another premise of the present invention.

FIG. 5 is a partial cross-sectional view showing a part of a charging unit including a discharge electrode 92 which is another premise of the present invention.

FIG. 6 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode according to an embodiment of the present invention.

FIG. 7 is a partial cross-sectional view illustrating a part of a charging unit including a discharge electrode 112 according to another embodiment of the present invention.

FIG. 8 is a sectional view schematically showing a second embodiment of the electric precipitator according to the present invention.

DESCRIPTION OF SYMBOLS 2,202 Device housing 12 Charging part 14 Dust collecting part 16 Counter electrode 18, 72, 82, 92, 102, 112, 214 Discharge electrode 114 Taper part 22, 212 Dust collecting electrode 74, 84, 86, 94a, 94b, 104a, 104
b, 106a, 106b, 114a, 114b Discharge projection

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

Claims (7)

[Claims] 1. An electrostatic precipitator comprising: a discharge electrode for charging particulate matter to a specific polarity; and a dust collection electrode for collecting particulate matter charged by the discharge electrode. The electrostatic precipitator according to claim 1, wherein the discharge electrode comprises an elongated plate-like electrode, and one or both sides of the plate-like electrode have a tapered thickness. 2. An electrostatic precipitator comprising: a discharge electrode for charging particulate matter to a specific polarity; and a dust collection electrode for collecting particulate matter charged by the discharge electrode. An electrostatic precipitator, wherein the discharge electrode comprises an elongated plate-like electrode, and one or both side portions of the plate-like electrode are provided with discharge projections projecting from both sides thereof. 3. An electrostatic precipitator comprising: a discharge electrode for charging particulate matter to a specific polarity; and a dust collection electrode for collecting particulate matter charged by the discharge electrode. The discharge electrode is composed of an elongated plate-like electrode, and a plurality of substantially triangular discharge protrusions are provided on one or both sides of the plate-like electrode in the longitudinal direction of the plate electrode. Electric dust collector. 4. A tip of the plurality of discharge projections provided on one or both sides of the plate-like electrode,
The electrostatic precipitator according to claim 3, wherein the plate-like electrode is alternately projected on one side and the other side. 5. The discharge electrode section is provided on both sides of the plate-shaped electrode, and the discharge electrode section provided on one side of the plate electrode and the discharge electrodes provided on the other side. The electrostatic precipitator according to claim 3 or 4, wherein the electrode part is displaced in a longitudinal direction thereof. 6. The thickness of the side of the plate-like electrode on the upstream side as viewed in the flow direction of the particulate matter is gradually reduced in a tapered shape, and the thickness of the plate-like electrode is reduced in the flow direction of the particulate matter in the plate-like electrode. The electrostatic precipitator according to claim 3 or 4, wherein a plurality of the discharge projections are provided on a downstream side. 7. The discharge electrode is provided on a charging portion, the charging portion is provided with a counter electrode facing the discharge electrode, and the dust collection electrode is provided in the flow direction of the particulate matter. The electric dust collector according to any one of claims 1 to 6, wherein the dust collector is provided in a dust collector disposed downstream of the charging unit.