JPH1128385A - Electrostatic precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the concentration of dust on the outlet side of an electrostatic precipitator. SOLUTION: The electrostatic precipitator is provided with moving electrodes 47 equipping electrode plates which are freely travelably provided between the upper rollers and the lower rollers, with electrodes 48 provided oppositely to the electrode plates and with discharge electrodes 49 provided in the front steps of the moving electrodes 47. In this case, charging parts are formed of the discharge electrodes 49 and dust contained in gas to be treated is charged to negative polarity in the charging parts. Therefore, not only collection speed of dust is remarkably enhanced, but also the dust collection area of the electrode plates is made <=1/2. Accordingly, the electrostatic precipitator is drastically miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric dust collecting device.
It concerns the device.

[0002]

2. Description of the Related Art Conventionally, in an electric precipitator, after a gas containing dust passes through an inlet flue, a flow velocity distribution is made uniform by a flow straightening plate, and then a gap between the discharge electrode and the precipitating electrode is formed. Is introduced into the electric field formed at the end. Dust in the gas to be treated introduced into the electric field is sucked by the dust collecting electrode and collected by the electric force of the electric field. And
Dust is hammered by a hammer for dust collection electrodes, and the dust adhering to the dust collection electrodes is separated from the collection electrodes by the impact force of the hammer for dust collection electrodes and is separated from the hopper. After being dropped, it is discharged.

However, in a gas to be treated, such as exhaust gas discharged from a heavy oil boiler, the electric resistivity of dust in the gas to be treated is low, so that it is not only difficult to collect dust electrically, In addition, when the dust attached to the dust collecting electrode is separated by the hammer for the dust collecting electrode, the dust is easily scattered again. Further, when treating a gas to be treated such as exhaust gas discharged from a heavy oil boiler, a chimney is directly connected to the downstream side of the electric dust collector. Therefore, the re-scattered dust is immediately discharged from the chimney.

Therefore, in order to prevent the performance of the electrostatic precipitator from deteriorating due to the re-dispersion of dust, the inside of the electric precipitator is divided into a plurality of charged sections, and each of the charged sections is provided with an inlet and an outlet. A section damper is provided, and the section damper is opened and closed for each charged section to perform hammering.
FIG. 2 is a conceptual diagram of a first conventional electric dust collector.

[0005] In the drawing, reference numeral 11 denotes an electric precipitator for treating a gas to be treated containing dust, 12 denotes a plurality of partitioning plates disposed in the electric precipitator 11, 13 denotes an inlet flue, 1
4 is an outlet flue, 15 is a section damper disposed between the inlet flue 13 and the electrostatic precipitator 11, that is, an upstream damper, 16 is a section damper between the electric precipitator 11 and the outlet flue 14. The partition damper disposed therebetween, that is, the downstream damper.

The gas to be treated passes through the inlet flue 13 in the direction of arrow A, and after the flow velocity distribution is made uniform by a rectifying plate (not shown), the gas enters the electrostatic precipitator 11 and is connected to a discharge electrode (not shown). It is introduced into the electric field formed between the dust collecting electrode. Dust in the gas to be treated introduced into the electric field is sucked by the dust collecting electrode and collected by the electric force of the electric field.
Then, hammering is performed by a dust collecting electrode hammer (not shown), and the dust adhered to the dust collecting electrode is separated from the dust collecting electrode by an impact force of the dust collecting electrode hammer and is transferred to a hopper (not shown). After being dropped, it is discharged from the electrostatic precipitator 11.

By the way, in order to prevent the performance of the electrostatic precipitator 11 from deteriorating due to re-dispersion of dust,
The interior of the electrostatic precipitator 11 is divided into the respective charging sections AR1 to AR4 by the respective partitioning plates 12, and the respective charging sections AR1 to AR4.
An upstream damper 15 is provided at the inlet of R4, and a downstream damper 16 is provided at the outlet of R4.
Are arranged, and the upstream damper 15 and the downstream damper 16 are opened and closed for each of the charging sections AR1 to AR4 to perform hammering.

However, since dust is not collected in the charged section where hammering is performed, not only is the load on the other three charged sections increased, but also the upstream damper 15 is not used.
In addition, since a space for disposing the downstream damper 16 is required, the size of the electric precipitator 11 increases accordingly. In addition, the cost of the electric precipitator 11 increases. Therefore, there has been provided an electrostatic precipitator in which a moving electrode is used and dust attached to the moving electrode is brushed off by a brush.

FIG. 3 is a schematic view of a moving electrode in the second conventional electrostatic precipitator, and FIG. 4 is a sectional view of the moving electrode in the second conventional precipitator. In this case, a fixed electrode portion is formed on the upstream side in the flow direction of the gas to be treated in the electrostatic precipitator, and a plurality of fixed electrodes (not shown) are provided on the fixed electrode portion. Is provided with a discharge electrode (not shown). Then, an electric field is formed between the discharge electrode and the fixed electrode, and when the gas to be treated is introduced into the electric field, dust in the gas to be treated is attracted to and adhered to the fixed electrode by the electric force of the electric field. Let me do. The gas to be processed after the dust has been sucked is supplied to a moving electrode unit (not shown) formed on the downstream side in the flow direction of the gas to be processed.

A dust collecting hammer (not shown) is provided adjacent to the fixed electrode. Dust adhered to the fixed electrode is separated from the fixed electrode by the impact force of the dust collecting hammer. After being dropped by a hopper (not shown). The dust re-scattered when the hammering is performed is supplied to the moving electrode unit together with the gas to be processed.

In the moving electrode section, a plurality of moving electrodes 21 are arranged at a predetermined interval from each other.
A grid-shaped discharge electrode 33 inside and between each movable electrode 21
Is arranged. Each of the moving electrodes 21 has a pair of upper rollers 23 fixed to the drive shaft 22 at the upper side, a pair of lower rollers 25 fixed to the driven shaft 24 at the lower side, and the upper rollers 23 and the lower rollers 25. And a plurality of plate-like electrode plates 27 extending in the horizontal direction and connecting the chains 26 to each other.

Therefore, when driving means (not shown) is driven to rotate the drive shaft 22 in the direction of arrow B,
The chain 26 is moved in the direction of arrow C, and the electrode plate 27 is moved with the movement of the chain 26.
When the chains 26 reach the upper roller 23 and the lower roller 25 and bend, the electrode plate 27
Is the upper roller 23 and the lower roller 2 together with the chain 26.
5 so that each electrode plate 27 can move around
Is fixed to the chain 26 by fixing means 31 at the center of both edges.

When an electric field is formed between the discharge electrode 33 and the electrode plate 27 and the gas to be treated is introduced into the electric field in the direction of arrow F, the dust in the gas to be treated is reduced by the electric field of the electric field. It is sucked and attached to the electrode plate 27 by the electric force. Further, a pair of rotating brushes 32 are disposed at predetermined positions below the moving electrodes 21 with the electrode plate 27 interposed therebetween from both sides. The rotating brush 32 is connected to driving means (not shown), and is rotated in the directions of arrows D and E so that the tip moves in a direction opposite to the moving direction of the electrode plate 27. Therefore, dust adhering to the electrode plate 27 is blown off by the impact force of the rotating brush 32, peeled off from the electrode plate 27, dropped into a hopper (not shown), and then discharged.

[0014]

However, in the above-mentioned conventional electric precipitator, a part of the dust separated from the electrode plate 27 is treated by mechanical shock generated when the rotating brush 32 is rotated. Re-scattered in the gas,
The dust concentration on the outlet side of the electrostatic precipitator increases.

Therefore, it is difficult to reduce the concentration of dust in the gas to be treated discharged from a chimney (not shown) to an invisible level (5 to 10 [mg / Nm ³ ] or less) in which dust is invisible. SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric precipitator capable of solving the problems of the conventional electric precipitator and reducing the dust concentration at the outlet side.

[0016]

For this purpose, in the electric dust collecting apparatus of the present invention, a moving electrode provided with an electrode plate movably disposed between an upper roller and a lower roller; The movable electrode has an electrode disposed opposite thereto and a discharge electrode disposed in front of the movable electrode. In another electrostatic precipitator of the present invention, further, a fixed electrode portion is formed on the upstream side in the flow direction of the gas to be treated, and a moving electrode portion is formed on the downstream side, respectively. It is arranged on the moving electrode unit.

In still another aspect of the present invention, there is further provided a suction device disposed below the moving electrode for sucking dust adhered to the electrode plate. In still another electrostatic precipitator of the present invention, a separating unit for separating dust adhered to the electrode plate is provided near the suction unit.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a conceptual diagram of a moving electrode of an electric precipitator according to an embodiment of the present invention,
FIG. 5 is a conceptual diagram of the electric precipitator according to the embodiment of the present invention, FIG. 6 is a schematic diagram of a fixed electrode of the electric precipitator according to the embodiment of the present invention, and FIG. FIG. 8 is a schematic view of a moving electrode of the dust collector, FIG. 8 is a cross-sectional view of a main part of the moving electrode of the electric dust collector according to the embodiment of the present invention,
FIG. 9 is an operation explanatory view of the suction pipe according to the embodiment of the present invention.

In the figure, reference numeral 41 denotes an electric precipitator,
A fixed electrode part AR5 is formed on the upstream side in the flow direction (the direction of the arrow in FIG. 5) of the gas containing dust in the electrostatic precipitator 41, and a plurality of fixed electrodes 43 are arranged on the fixed electrode part AR5. A discharge electrode 44 is provided between the fixed electrodes 43. The fixed electrode 43 and the discharge electrode 44 constitute a two-stage electric dust collector in which the charging unit AR7 and the dust collection unit AR8 are integrated. And
An electric field is formed between the fixed electrode 43 and the discharge electrode 44 by a continuous charging method or a pulse charging method, and the gas to be treated having a high dust concentration (5 to 30 [g / Nm ³ ]) is applied to the electric field in the direction of arrow G. Then, the dust in the gas to be treated is sucked and adhered to the fixed electrode 43 by the electric force of the electric field. Further, the gas to be treated whose dust concentration is reduced to about 100 [mg / Nm ³ ] or less is supplied to the moving electrode part AR6 formed on the downstream side in the flow direction of the gas to be treated.

In the fixed electrode part AR5, a charging method is selected according to the electric resistance value of the dust.
For example, when it is desired to collect dust having a high electrical resistance of 10 ¹¹ [Ω · cm] or more, it is preferable to adopt a pulse charging method. Further, the fixed electrode 4
A dust collecting electrode hammering device 45 is provided adjacent to 3, and the dust attached to the fixed electrode 43 is separated from the fixed electrode 43 by the impact force of the dust collecting electrode hammering device 45 and is not shown. After being dropped by the hopper, it is discharged. And
The dust re-scattered when hammering is performed by the hammering device 45 for the dust collecting electrode includes the moving electrode unit AR together with the gas to be processed.
Sent to 6.

In the moving electrode part AR6, a plurality of moving electrodes 47 are arranged at a predetermined interval from each other, and each of the grid-shaped electrodes 48 is provided in each of the moving electrodes 47 and between the moving electrodes 47. The dust collecting part AR8 is provided so as to face the electrode plate 27, and is formed between the electrode plate 27 and the electrode. Further, a rod-shaped discharge electrode 49 is disposed upstream of each electrode 48 in the flow direction of the gas to be treated, that is, at a stage preceding the electrode 48 at a distance from each electrode 48.
A charging part AR7 is formed between the discharge electrode 7 and the discharge electrode 49. Therefore, the movable electrode 47, the electrode 48, and the discharge electrode 49 constitute a two-stage electric dust collector in which the charging unit AR7 and the dust collecting unit AR8 are separated.

Each of the moving electrodes 47 is connected to a pair of upper rollers 2 fixed to the drive shaft 22 above.
3, a pair of lower rollers 25 fixed to the driven shaft 24 below, chains 26 stretched between the upper rollers 23 and the lower rollers 25, respectively, It has a plurality of plate-like electrode plates 27 extending in the direction.

Accordingly, when the drive shaft (not shown) is driven to rotate the drive shaft 22 in the direction of arrow B,
The chain 26 is moved in the direction of arrow C, and the electrode plate 27 is moved with the movement of the chain 26.
When the chains 26 reach the upper roller 23 and the lower roller 25 and bend, the electrode plate 27
Is the upper roller 23 and the lower roller 2 together with the chain 26.
5 so that each electrode plate 27 can move around
Is fixed to the chain 26 by fixing means 31 at the center of both edges.

Then, as shown in FIG.
And a negative polarity voltage is applied to the discharge electrode 49 and the electrode plate 2
7, a voltage having a positive polarity is applied, and an electric field is formed between the electrode 48 and the discharge electrode 49 and the electrode plate 27. When a gas to be treated is introduced into the electric field in the direction of arrow F, the Dust in the gas is charged by the charging unit AR7, and the dust collection unit AR
At 8, it is sucked and attached to the electrode plate 27 by the electric force of the electric field.

Since the gas to be treated having a reduced dust concentration is supplied to the moving electrode part AR6, the dust in the gas to be treated is effectively and sufficiently negatively charged in the charging part AR7. Charge of the polarity. As a result, the charged dust is effectively sucked and attached by the electrode plate 27. Further, a pair of suction pipes 51 as suction means are provided at predetermined positions below the moving electrodes 47 across the electrode plate 27 from both sides in the width direction of the moving electrodes 47. 51
Is connected to a negative pressure source (not shown) via an air collecting pipe 52. The suction pipe 51 has a plurality of suction ports (not shown) formed at a portion facing the electrode plate 27. Then, a brush 53 as a peeling means is fixed to the upper part of the suction pipe 51 so that dust adhered to the electrode plate 27 is easily peeled, and the tip of the brush 53 is attached to the electrode plate 27 near the suction pipe 51. Pressed. Therefore, when the chain 26 is run and the electrode plate 27 is moved in the direction of arrow C, dust attached to the electrode plate 27 is separated from the electrode plate 27 by the impact force of the brush 53 and is sucked into the suction pipe 51. After being discharged.
As a result, the sucked dust does not re-scatter in the gas to be processed.

As described above, dust adhering to the electrode plate 27 is sucked into the suction pipe 51 without being blown off, so that it is not necessary to arrange a hopper below the moving electrode part AR6. Therefore, the size of the electric precipitator 41 can be reduced. In the moving electrode part AR6, a two-stage electric precipitator in which the charging part AR7 and the dust collecting part AR8 are integrated is provided, so that the dust collecting speed can be remarkably improved. As a result, the dust collection area by the electrode plate 27 can be reduced to 以下 or less as compared with the conventional single-stage electric dust collector, and the electric dust collector 41 can be greatly reduced in size.

In the present embodiment, the brush 53 is fixed to the upper part of the suction pipe 51. However, a brush may be provided at the lower part of the suction pipe 51. In that case, when the brush is broken, the fragments of the brush fall to the bottom of the electrostatic precipitator 41, and the suction pipe 5
Since it is not sucked into the dust, it does not mix with the collected dust as foreign matter. Therefore, dust
For example, when reused as coal ash, the quality of dust can be improved.

The present invention is not limited to the above embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0029]

As described above in detail, according to the present invention, in the electrostatic precipitator, a moving electrode including an electrode plate movably disposed between an upper roller and a lower roller; An electrode disposed opposite to the electrode plate; and a discharge electrode disposed in front of the movable electrode.

In this case, a charging portion is formed by the discharge electrode, and the dust in the gas to be processed is charged to a negative polarity in the charging portion. Therefore, not only can the dust collection speed be remarkably improved, but also the dust collection area of the electrode plate can be reduced to 以下 or less, so that the electric dust collector can be significantly reduced in size. In another electrostatic precipitator of the present invention, further, a fixed electrode portion is formed on the upstream side in the flow direction of the gas to be treated, and a moving electrode portion is formed on the downstream side, respectively. It is arranged on the moving electrode unit.

In this case, the gas to be treated having a reduced dust concentration is supplied to the moving electrode portion.
Dust in the gas to be treated is effectively and sufficiently charged to a negative polarity in the charging section. As a result, the charged dust is effectively sucked and deposited by the electrode plate. In still another electric dust collector of the present invention, the electric dust collector further includes a suction unit disposed below the moving electrode and suctioning dust attached to the electrode plate.

In this case, when the moving electrode is run, dust adhering to the electrode plate of the moving electrode is separated, and is sucked and discharged by the suction means, so that the sucked dust re-scatters in the gas to be processed. Will not be done. As described above, dust adhering to the electrode plate is sucked by the suction means without being washed off, so that there is no need to dispose a hopper below the moving electrode. Therefore,
The electric dust collector can be miniaturized.

[0033] In still another electrostatic precipitator of the present invention, a separating means for separating dust adhering to the electrode plate is provided near the suction means. In this case, dust adhering to the electrode plate of the moving electrode is separated from the moving electrode by the separating means.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a moving electrode of an electric precipitator according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a first conventional electric dust collector.

FIG. 3 is a schematic view of a moving electrode in a second conventional electrostatic precipitator.

FIG. 4 is a cross-sectional view of a moving electrode in a second conventional electrostatic precipitator.

FIG. 5 is a conceptual diagram of an electric precipitator according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a fixed electrode of the electric precipitator according to the embodiment of the present invention.

FIG. 7 is a schematic diagram of a moving electrode of the electric precipitator according to the embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a moving electrode of the electric precipitator according to the embodiment of the present invention.

FIG. 9 is an operation explanatory view of the suction pipe in the embodiment of the present invention.

[Explanation of symbols]

 23 upper roller 25 lower roller 27 electrode plate 41 electric dust collector 47 moving electrode 48 electrode 49 discharge electrode 51 suction pipe 53 brush AR5 fixed electrode part AR6 moving electrode part AR7 charging part AR8 dust collecting part

Claims (4)

[Claims] (A) a moving electrode including an electrode plate movably disposed between an upper roller and a lower roller;
(B) an electrode disposed to face the electrode plate;
(C) An electrostatic precipitator, comprising: a discharge electrode disposed in front of the movable electrode. 2. A fixed electrode portion is formed on the upstream side in the flow direction of the gas to be treated, and a moving electrode portion is formed on the downstream side. (B) The moving electrode, the electrode and the discharge electrode are formed by the moving electrode portion. The electric precipitator according to claim 1, which is disposed in the electric dust collector. 3. A suction device disposed below the moving electrode and suctioning dust attached to the electrode plate.
An electric precipitator according to claim 1. 4. The electrostatic precipitator according to claim 3, wherein a separating means for separating dust attached to the electrode plate is provided near the suction means.