JP2001232239A - Electric dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric dust collector capable of providing a high dust collecting efficiency even if it is miniaturized. SOLUTION: Second electric discharge electrodes 8, 9 are installed in the upstream side of perforated plates 6, 7 for making the flow distribution of a dust-containing gas uniform and the perforated plates 6, 7 are provided with a function as dust collecting electrodes to cooperate with the second electric discharge electrodes 8, 9, so that the dust in the dust-containing gas can be collected by the perforated plates 6, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in an electric dust collector.

[0002]

2. Description of the Related Art In an electrostatic precipitator, dust-containing gas flowing between a discharge electrode and a collection electrode is charged by corona discharge between the discharge electrode and the collection electrode, and the charged dust is charged by electrostatic force. They are collected in a dust collection electrode. In addition,
In a wet type electrostatic precipitator, dust collected on a collecting electrode is washed away by a cleaning liquid.

[0003]

In the above-mentioned electric dust collecting apparatus, as the area of the dust collecting electrode and the discharge electrode (dust collecting area) is increased, the dust collecting performance is improved. However, the size of the dust collecting electrode and the discharge electrode may be considerably restricted due to the arrangement space, and in such a case, the required dust collecting performance cannot be obtained due to the shortage of the dust collecting area. In view of such circumstances, an object of the present invention is to provide an electric precipitator capable of obtaining high dust collection performance even when configured compact.

[0004]

The invention according to claim 1 is
The dust-containing gas whose flow distribution is made uniform by the perforated plate
And the dust in the dust-containing gas is charged by corona discharge between the first discharge electrode and the dust collecting electrode, and the charged dust is charged into the second dust collecting electrode. 1. An electrostatic precipitator that is collected on said dust collection electrode by Coulomb force generated by an electric field between said discharge electrode and said collection electrode, wherein a second discharge electrode is provided upstream of said perforated plate. The dust in the dust-containing gas is collected on the perforated plate by providing the perforated plate with a function as a dust collecting electrode in cooperation with the second discharge electrode. According to a second aspect of the present invention, the perforated plate according to the first aspect of the present invention includes a plurality of first members having a U-shaped cross section,
A belt-shaped second member fixed to the non-opening surface of the first member so as to intersect with the first member, and forming a plurality of ventilation holes together with the first members; Are disposed in such a manner as to face the opening of the first member. The invention according to claim 3 has a configuration in which an electric field concentration electrode is interposed in the opening of the first member according to claim 2. The invention according to claim 4 has a configuration in which the opening of the first member in the invention according to claim 2 is covered with a wire mesh.

[0005]

(First Embodiment) FIG. 1 is a schematic longitudinal sectional view of an electric dust collector according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. It is. 1 and 2, an inlet duct 1 is connected to one end of a casing 3 via an enlarged duct 2, and an outlet duct 4 is connected to the other end of the casing 3 via a throttle duct 5.

In the enlarged duct 2, perforated plates 6, 7 and discharge electrodes 8, 9 are arranged in a manner orthogonal to the axis of the enlarged duct 2. The perforated plates 6 and 7, as shown in FIG.
It has a lattice structure in which strip steel plates 10 and 11 are connected vertically and horizontally, and a number of air holes 12 are formed by the steel plates 10 and 11. In addition, the discharge electrodes 8 and 9 include a plurality of discharge lines 13 arranged in the vertical direction. These discharge wires 13 are respectively formed from the respective longitudinal strips 10 of the perforated plates 6 and 7 to the entrance duct 1.
Are separated from each other by a predetermined discharge distance.

In the casing 3, dust collecting portions E1 and E2 are sequentially arranged along the flow direction of the dust-containing gas. Each of the dust collecting sections E1 and E2 includes a large number of dust collecting poles 14 arranged in parallel in the width direction of the casing 3 and a large number of discharge electrodes 15 arranged in a manner facing the dust collecting poles 14. . A large number of spray nozzles 16 for spraying a cleaning liquid for cleaning the dust collection electrode 14 are disposed above the dust collection sections E1 and E2 in the casing 3. The perforated plate 6 and the discharge electrode 8, the perforated plate 7 and the discharge electrode 9, and the dust collection electrode 14
And a discharge electrode 15 are connected to a high-voltage power supply (not shown).

Hereinafter, the operation of the dust collecting apparatus according to this embodiment will be described. The dust-containing gas flows into the enlarged duct 2 via the inlet duct 1, and passes through the perforated plates 6 and 7 in sequence while decreasing the flow velocity. Since a high voltage is applied between the perforated plate 6 and the discharge electrode 8 and between the perforated plate 7 and the discharge electrode 9, respectively, as shown in FIG. 17 occurs. Therefore, in the dust-containing gas approaching the perforated plates 6 and 7, a part of the contained dust (for example, SO ₃ fine particles) is charged by the corona discharge, and the Coulomb force and porosity generated between the perforated plate 6 and the discharge electrode 8 are increased. By the Coulomb force acting between the plate 7 and the discharge electrode 9, the perforated plates 6 and 7 are collected.

As described above, in the electric precipitator according to this embodiment, since the perforated plates 6 and 7 have a function as a precipitating electrode, a part of the dust contained in the gas flowing through them is removed. It is collected by the perforated plates 6 and 7. The dust collected by the perforated plates 6 and 7 is removed by a hammering means or a cleaning liquid spraying means (not shown).

The dust-containing gas from which a part of dust has been removed by the perforated plates 6 and 7 passes through the dust collecting sections E1 and E2 sequentially after the flow is made uniform by the perforated plates 6 and 7. Since a high voltage is applied between the dust collecting electrode 14 and the discharge electrode 15 of the dust collecting sections E1 and E2, corona discharge occurs between them. Therefore, the residual dust of the dust-containing gas flowing between the dust collecting electrode 14 and the discharge electrode 15 is charged by the corona discharge, and then collected by the Coulomb force generated by the electric field between the dust collecting electrode 14 and the discharge electrode 15. The dust is collected by the dust pole 14.
The dust collected by the dust collecting electrode 8 is washed by the washing liquid sprayed from the spray nozzle 16. Then, the cleaning liquid flowing down the dust collecting electrode 8 is stored at the bottom of the housing 3 and then returned to a cleaning liquid storage tank (not shown).

According to the electric dust collecting apparatus according to the first embodiment, dust is collected not only by the collecting electrodes 14 of the dust collecting portions E1 and E2 but also by the perforated plates 6 and 7, that is,
Since the substantial dust collecting area is enlarged, the dust collecting portions E1, E2
The dust collection efficiency is significantly improved as compared with the case where only the dust is collected. Note that the clean gas that has passed through the dust collection units E1 and E2 is discharged to the outlet duct 4 via the throttle duct 5.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
It is a schematic cross section of the electric precipitator concerning an embodiment.
This electric dust collector differs from the electric dust collector of the first embodiment in that porous plates 20 and 21 as shown in FIG. 6 are provided instead of the porous plates 6 and 7 shown in FIG. The configuration is different.

The perforated plates 20 and 21 use a steel material 22 having a U-shaped cross section instead of the longitudinally strip steel plate 10 of the perforated plates 6 and 10 shown in FIG. Each steel material 22 has its opening 2
2a is disposed so as to face the discharge wire 13 of the corresponding discharge electrode 8, 9, and the lateral strip steel plate 11 is fixed to the non-opening side surface thereof. And each steel material 22 has formed many ventilation holes 23 with each strip | belt-shaped board 11. As shown in FIG.

Between perforated plate 20 and discharge electrode 8 and perforated plate 21
Since a high voltage is applied between the discharge electrode 9 and the discharge electrode 9, as shown in FIG.
Occurs. Therefore, part of the dust contained in the dust-containing gas approaching the perforated plates 20 and 21 is charged by the corona discharge 25. Then, the charged dust is collected on the perforated plates 20 and 21 by Coulomb force. In the electric dust collecting apparatus according to the second embodiment, since dust is collected on the inner surface of the steel material 22 having a U-shaped cross section, re-scattering of the dust is suppressed, and the dust collecting area is reduced. As the size increases, the dust collection efficiency is further improved.

(Third Embodiment) FIG. 8 shows a third embodiment of the present invention.
It is a schematic cross section of the electric precipitator concerning an embodiment.
This electric dust collector differs from the electric dust collector of the second embodiment in that perforated plates 30 and 31 as shown in FIG. 9 are provided instead of the perforated plates 20 and 21 shown in FIG. The configuration is different.

The perforated plates 30 and 31 have a configuration in which an electric field concentration electrode 32 is provided along the longitudinal direction of the steel material 2 at the center of the opening of the steel material 22 having a U-shaped cross section shown in FIG. The electric field concentration electrode 32 is supported by a support plate 22c protruding from the inner surface of the steel material 22 on the non-opening side.

Between the perforated plate 30 and the discharge electrode 8 and the perforated plate 31
Since a high voltage is applied between the discharge electrode 9 and the discharge electrode 9, as shown in FIG. Corona discharge 35 occurs between the wire 13 and the electric wire 13. Therefore, in the dust-containing gas approaching the perforated plates 30 and 31, a part of the dust contained in the gas contains the corona discharge 35.
, And are collected on the perforated plates 30 and 31 by Coulomb force.

According to the electrostatic precipitator according to the third embodiment, the steel material 22
The charging efficiency of dust in front of the opening 22a is improved, and the Coulomb force for inducing the charged dust into the U-shaped space of the steel material 22 is increased, so that the dust collecting efficiency is further improved.

(Fourth Embodiment) FIG. 11 is a schematic cross-sectional view of an electric precipitator according to a fourth embodiment of the present invention. This electrostatic precipitator is provided with the perforated plates 20 and 2 shown in FIG.
The configuration is different from that of the electric dust collector of the second embodiment in that perforated plates 40 and 41 as shown in FIG.

Each of the perforated plates 40 and 41 has a structure in which an opening 22a of a steel material 22 having a U-shaped cross section shown in FIG. The wire mesh 43 has both ends fixed to each bent end portion 22b of the steel material 22 by welding or the like. Since a high voltage is applied between the perforated plate 40 and the discharge electrode 8 and between the perforated plate 41 and the discharge electrode 9, respectively, as shown in FIG. 13 and between the wire netting 43 and the discharge wire 13. Therefore, the dust-containing gas approaching the perforated plates 40 and 41 is partially charged by the corona discharge 45 and collected by the perforated plates 40 and 41 by Coulomb force.

According to the electric precipitator according to the fourth embodiment, corona discharge is generated by the wire mesh 43 over the entire area of the opening 22a of the steel material 22. That is, the discharge area is widened. Therefore, a large amount of dust is transferred to the perforated plates 40 and 41.
And the dust collection efficiency can be further improved.

The electrostatic precipitator according to each of the above embodiments is of a wet type in which the dust collected on the precipitating poles 14 of the precipitators E1 and E2 is washed away by spraying a cleaning liquid. The present invention can also be applied to a dry-type electric dust collecting device that removes the collected dust with a hammer or the like.

[0023]

According to the present invention, a second discharge electrode is disposed on the upstream side of the perforated plate for making the distribution of the flow of the dust-containing gas uniform, and the second discharge electrode is provided on the perforated plate. It has a function as a dust collection electrode in cooperation with the discharge electrode. Therefore, the dust contained in the dust-containing gas is also collected by the perforated plate, and the dust collection efficiency is greatly improved. Although the dust collection efficiency increases as the area of the dust collecting plate increases, the area of the dust collecting electrode cannot be unnecessarily increased in consideration of the installation space. According to the present invention, since the perforated plate has a function as a dust collecting electrode, the perforated plate substantially increases the dust collection area. Therefore, it is possible to improve the dust collection efficiency without increasing the area of the dust collection electrode of the dust collection part, that is, without increasing the size.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged perspective view showing a configuration of a perforated plate provided in the dust collector of FIG. 1;

FIG. 4 is a schematic diagram showing an aspect of discharge between the perforated plate and the discharge electrode of FIG. 3;

FIG. 5 is a schematic cross-sectional view showing a second embodiment of the electric precipitator according to the present invention.

FIG. 6 is a partially enlarged perspective view showing a configuration of a perforated plate provided in the dust collector of FIG.

FIG. 7 is a schematic diagram showing a mode of discharge between the perforated plate and the discharge electrode of FIG. 6;

FIG. 8 is a schematic cross-sectional view showing a third embodiment of the electric precipitator according to the present invention.

FIG. 9 is a partially enlarged perspective view showing the configuration of a perforated plate provided in the dust collecting apparatus of FIG.

FIG. 10 is a schematic diagram showing a mode of discharge between the perforated plate and the discharge electrode of FIG. 9;

FIG. 11 is a schematic cross-sectional view showing a fourth embodiment of the electric precipitator according to the present invention.

FIG. 12 is a partially enlarged perspective view showing a configuration of a perforated plate provided in the dust collector of FIG. 11;

FIG. 13 is a schematic diagram showing a mode of discharge between the perforated plate and the discharge electrode of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inlet duct 2 Enlarged duct 3 Casing 4 Outlet duct 5 Restriction duct 6,7,20,21,30,31,40,41 Perforated plate 8,9,15 Discharge electrode 10,11 Strip steel plate 12,23, vent hole 11 , 20a to 20f Electromagnetic on-off valve 13 Discharge wire 14 Collector electrode 22 Steel 22a Opening 25, 35, 45 Corona discharge 32 Electrode for concentration of electric field 43 Wire mesh E1, E2 Dust collector

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B03C 3/47 B03C 3/47 (72) Inventor Yasutoshi Ueda 2-1-1 Shinama, Araimachi, Takasago-shi, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory F-term (reference) 4D054 AA01 BA01 BA08 BA14 BB02 BB13 BB21 BB24 BC01 BC02 EA16

Claims (4)

[Claims] 1. A dust-containing gas whose flow distribution is uniformized by a perforated plate is caused to flow between a first discharge electrode and a dust collection electrode, and a dust-containing gas is supplied between the first discharge electrode and the dust collection electrode. The dust in the dust-containing gas is charged by corona discharge, and the charged dust is collected on the dust collecting electrode by Coulomb force generated by an electric field between the first discharge electrode and the dust collecting electrode. A second discharge electrode is disposed upstream of the perforated plate, and the perforated plate has a function as a dust collection electrode cooperating with the second discharge electrode. The dust in the dust-containing gas is collected by the perforated plate. 2. A method according to claim 1, wherein the perforated plate is fixed to a plurality of first members having a U-shaped cross section, and to a surface on a non-opening side of the first members so as to intersect with the first members. A strip-shaped second member forming a large number of air holes together with each of the first members, wherein the second discharge electrode is disposed in a manner to face the opening of the first member. The electric precipitator according to claim 1. 3. The electrostatic precipitator according to claim 2, wherein an electric field concentration electrode is interposed in the opening of the first member. 4. The electrostatic precipitator according to claim 2, wherein the opening of the first member is covered with a wire mesh.