JP2005021736A - Wet type crossflow electric precipitator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress occurrence of discharge to water droplets falling from dust collection electrodes in a vertical wet type crossflow electric precipitator. <P>SOLUTION: Discharge electrodes 10 and collection electrodes 11 are vertically disposed in a crossflow type in a casing 20. Water sprayers 12 are provided on the upstream side of the collection electrodes 11 for flow of air to be cleaned (flowing in from arrow 21 and discharged from arrow 22). The collection electrodes 11 and discharge electrodes 10 are mounted with a tilted angle of (α) in relation to a horizontal direction of the casing 20. Water sprayed from the sprayers and attached to the collector electrodes 11 forms droplets and flows down in the tilted direction along the collection electrodes 11, and falls down from the end parts of the electrodes 11. Thus, the fall of the water droplets into the electric field from the collector electrodes 11 can be suppressed and spark discharge occurring toward the water droplets from the discharge electrodes can be suppressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wet electrostatic precipitator having a cross flow structure, and more particularly to a cross flow wet electrostatic precipitator characterized in that a discharge electrode and a dust collecting electrode are vertically arranged in the vertical direction of the dust collector. Is.
[0002]
[Prior art]
The dust-containing gas and air containing dust, dust, water droplets, and mist that have flowed into the electric dust collector are moved up and down the dust collector, and the dust, dust, water droplets, and mist charged by the discharge electrode are collected at the dust collection electrode. As a so-called vertical gas flow type wet electrostatic precipitator, the following has been proposed (see Patent Document 1).
Dust-containing gas is introduced into a dust collection chamber formed in a long cylindrical shape from a supply port provided at the top thereof. The dust-containing gas flows down vertically in the dust collection chamber and is discharged to the outside from an outlet provided in the lower part. A dust collection unit consisting of a discharge wire as a discharge electrode, a dust collection plate as a dust collection electrode, and a spray device is installed in the dust collection chamber. The dust collection plate follows the flow of dust-containing gas. The discharge lines are suspended and arranged between the dust collecting plates. The spray device is attached to the upper part of the dust collecting plate toward the dust collecting plate and the discharge line. A dust-containing gas is introduced into the dust-collecting chamber, and a high-voltage current is applied to the discharge line to allow dust and dust in the dust-containing gas to adhere to the dust collecting plate. When the dust or the like has sufficiently adhered to the dust collecting plate, the introduction of the dust-containing gas is stopped, and the spray water is ejected by the spray device to wash away the adhering dust / dust. The trough is inclined at the lower part of the dust collecting plate, and the washed-off dust, dust and the like flow down along the trough together with the cleaning water and are discharged to the outside.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-23614
[Problems to be solved by the invention]
By the way, the conventional dust collector described above has a plurality of dust collecting electrodes and discharge electrodes arranged so as to be parallel to the flow direction of the dust-containing gas and air flowing into the dust collecting plate and the discharge line. It is a so-called parallel type.
However, although a parallel type vertical gas flow type wet electrostatic precipitator has been disclosed, a so-called cross, in which a plurality of dust collecting electrodes and discharge electrodes are arranged so as to be orthogonal to the flow direction of the flowing air. A flow type vertical gas flow type wet electrostatic precipitator has not been proposed, and its development has been awaited.
[0005]
Therefore, the inventors of the present application have developed a cross-flow type vertical gas flow type wet electrostatic precipitator as shown in FIG. However, this cross flow type vertical gas flow type wet electrostatic precipitator has the following problems.
[0006]
As shown in FIG. 8, the discharge electrode 10 and the dust collection electrode 11 are arranged at a predetermined interval in the casing 20 as the main body of the electric dust collector so as to be parallel to the horizontal direction of the casing 20. Yes. Dust-containing gas or air containing dust, dust, water droplets, and mist flows in the direction of arrow 21 to arrow 22, and a sprayer 12 is provided on the upstream side of the flow, that is, on the lower side of the casing 20. If the amount of water droplets or mist is large, a water spray device is not necessary. When water is sprayed from the sprayer 12 in this state and then the electric dust collector is turned on, the water adheres to the dust collection electrode 11 and the discharge electrode 10. When the adhering moisture increases, the water droplets become large and fall downward from the dust collection electrode 11 and the discharge electrode 10 (water droplets a and b shown in FIG. 8). At this time, since an electric field exists between the discharge electrode 10 and the dust collecting electrode 11, when the falling water drops a and b enter the electric field, a spark discharge is generated toward the water drops a and b. In particular, since the water droplet a falling from the dust collecting electrode 11 is a large water droplet, the frequency of occurrence of spark discharge is high, and a continuous spark discharge may be generated.
[0007]
Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a vertical gas flow type wet type electrostatic precipitator having a cross flow structure.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of the cross-flow type wet electrostatic precipitator according to claim 1 is directed to a dust-containing gas containing dust, dust, water droplets, and mist flowing through a plurality of sets of discharge electrodes and dust collection electrodes. Arranged so as to be orthogonal to the air flow direction, and provided with a sprayer for spraying moisture toward the discharge electrode and the dust collecting electrode (when the amount of moisture and mist in the gas is large, the water sprayer In the cross-flow type wet type electrostatic precipitator, the discharge electrode and the precipitator are arranged vertically in the vertical direction and attached at a predetermined angle with respect to the horizontal direction. It is characterized by.
[0009]
And according to the invention which concerns on Claim 1, the water sprayed from the sprayer is collected by the dust collecting electrode, falls as a water droplet, and falls below from the dust collecting electrode. At this time, since the dust collecting electrode is mounted at a predetermined angle in one direction with respect to the horizontal direction, the water droplets flow down along the dust collecting electrode in the inclined direction, and downward from the end of the dust collecting electrode. Fall into. Therefore, the falling water droplet does not fall into the electric field formed by the discharge electrode and the dust collecting electrode, and the spark discharge generated from the discharge electrode toward the water droplet can be suppressed.
[0010]
According to a second aspect of the invention, there is provided a cross-flow type wet electrostatic precipitator according to the first aspect of the invention, wherein the discharge electrode discharges only the dust collection electrode disposed in the downward direction. It is characterized by that.
According to the invention of claim 2, since the discharge electrode has a configuration that does not discharge to the dust collection electrode arranged in the upward direction, the occurrence of spark discharge to the water droplets falling from the dust collection electrode is further prevented. Can be suppressed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a crossflow type wet electrostatic precipitator according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a perspective view showing an embodiment of a dust collecting portion provided inside a cross-flow type wet type electrostatic precipitator, which is composed of a two-stage dust collecting portion including a first dust collecting portion and a second dust collecting portion. It is what is done. Further, both the dust collecting parts are constituted by the discharge electrode 10, the dust collecting electrodes 11, 11 and the sprayer 12. The discharge electrode 10 is composed of a plurality of thin metal plates having a sawtooth-shaped sharp edge, and the dust collection electrode 11 has a breathable shape in which a plurality of strip steels are combined in a strip shape on both sides of the discharge electrode 10. ing. An arrow 13 in the figure represents the direction in which the dust-containing gas flows, and the sprayer 12 is disposed on the upstream side of each dust collecting unit.
[0012]
As shown in FIG. 1, the cross-flow type electrostatic precipitator has a plurality of discharge electrodes 10 arranged so as to be orthogonal to the flow direction of dust-containing gas and air flowing into the precipitator. On the other hand, the dust collecting electrodes 11 are arranged on the upstream side and the downstream side in the flow direction 13 of the dust-containing gas or air. In FIG. 1, the dust collection electrodes 11 and 11 are arranged on the upstream and downstream sides of the discharge electrode 10, but there are some in which the dust collection electrode 11 is arranged only on the upstream side.
[0013]
In the discharge electrode 10 and the dust collecting electrode 11 of the crossflow type electrostatic precipitator shown in FIG. 2, dust-containing gas containing m such as dust, dust, water droplets, mist, etc. flows in from the direction of the arrow 13, Passes through the side of the dust collecting electrode 11, is charged in the discharge area 5, and m such as dust, dust, water droplets, and mist is adsorbed to the dust collecting electrode 11.
[0014]
The positional relationship between the discharge electrode 10 and the dust collection electrode 11 shown in FIG. 2 is arranged such that the discharge electrode 10 and the dust collection electrodes 11 and 11 overlap with the direction in which the dust-containing gas flows (the direction of the arrow 13). However, the present invention is not limited to this form, and the form shown in FIG. 3 may be used. That is, the dust collecting electrodes 11 and 11 disposed on the upstream side of the discharge electrode 10 and the dust collecting electrodes 11 and 11 disposed on the downstream side are respectively positioned so as to overlap with the direction in which the dust-containing gas flows. The discharge electrode 10 may be disposed at an intermediate position between the dust collection electrodes 11 and 11 in the direction in which the dust-containing gas flows (so-called staggered arrangement).
[0015]
In such a configuration, as shown in FIG. 4, the corona discharge from the edge 4 of the discharge electrode 10 flies toward the two dust collecting electrodes 11, 11 on both the upstream side and the downstream side, and the discharge area 5 zigzags. It will be in the state which crossed the flow path of dust-containing gas. Accordingly, the weakly charged portion 6 is substantially surrounded by the discharge area 5, so that dust, dust, water droplets, mist, etc. in the dust-containing gas are almost charged and adsorbed by the dust collecting electrode 11. Thereby, the efficiency of air purification improves. Note that the edges 4 formed on both sides of the discharge electrode 10 have the same configuration as that shown in FIG.
[0016]
The cross-flow type wet electrostatic precipitator according to the present invention has a dust collecting portion having the above-described configuration provided vertically in the main body of the electrostatic precipitator (hereinafter also referred to as a casing). FIG. 5 shows one form thereof. FIG. 5 corresponds to a case where the dust collection portion shown in FIG. 1 is installed in the casing when the dust collection portion is viewed from the direction of the arrow 15 in FIG.
[0017]
The casing 20 serving as the main body of the cross-flow type wet electrostatic precipitator has a cylindrical or prismatic appearance. A space portion is formed in the casing 20, and the discharge electrode 10 and the dust collection electrode 11 are arranged in the space portion at a predetermined interval in the vertical direction in FIG. 5, that is, in the vertical direction of the casing 20. Has been. The dust-containing gas flows in the direction of the arrow 21 from the lower side of the casing 20, passes through the dust collection portion, and is discharged from the upper side of the casing 20 in the direction of the arrow 22. There is also an embodiment in which dust-containing gas enters and exits from above.
[0018]
As in the case of the above-described embodiment, saw blade-shaped sharp edges 4 are formed on both sides of the discharge electrode 10. On the upper and lower sides of the discharge electrode 10, that is, on the upstream side and the downstream side with respect to the direction in which the dust-containing gas flows, dust collection electrodes 11 are arranged to face the discharge electrode 10. In each discharge electrode 10 and dust collection electrode 11, a plurality of discharge electrodes 10 and dust collection electrodes 11 having the same shape are arranged in the back direction of the casing 20 (back direction in FIG. 5). A sprayer 12 for spraying moisture toward the discharge electrode 10 and the dust collection electrode 11 is provided below the casing 20, that is, upstream of the flow of the dust-containing gas. (However, the water sprayer is not necessary when the water droplets or mist amount in the gas is contained in large quantities.) When the electric dust collection system is turned on, water is first sprayed from the sprayer 12, and then the discharge electrode 10 is discharged. A discharge area 5 having a strong charge is generated between the dust collecting electrodes 11. When the electric dust collector is turned on, a highly charged discharge area 5 is generated between the discharge electrode 10 and the dust collection electrode 11, and moisture is sprayed from the sprayer 12.
[0019]
The width W ′ of the dust collecting electrode 11 is formed to be narrower than the width W of the casing 20. The dust collection electrode 11 is disposed in the casing 20 so as to be inclined so as to have a predetermined angle α with respect to the horizontal direction of the casing. Each of the dust collection electrodes 11 is inclined in one direction, and one end portion of these dust collection electrodes 11 is attached to a support base 23 formed with an inclination angle α in the casing 20.
Since the discharge electrode 10 is provided opposite to the dust collection electrode 11, that is, in parallel with the dust collection electrode 11, the discharge electrode 10 is also inclined with respect to the horizontal direction of the casing 20 by an angle α. Will be.
[0020]
As shown in FIG. 5, when the dust collection electrode 11 and the discharge electrode 10 are attached with an inclination angle with respect to the horizontal direction of the casing 20, the moisture and mist in the gas and the sprayer 12 are sprayed to the dust collection electrode 11. The adhering water becomes a large water droplet and flows down the dust collecting electrode 11 in the inclined direction. And it will fall from the edge part of the dust collection electrode 11. FIG. The drop of the water droplet from the dust collection electrode 11 into the electric field formed by the discharge electrode and the dust collection electrode is suppressed, and the spark discharge generated from the discharge electrode toward the water droplet is suppressed. The dropped water droplets are stored in a water droplet storage space portion 26 formed in the casing 20 and appropriately discharged from the discharge port 27 to the outside of the casing 20. Further, the water adhering to the discharge electrode 10 also becomes water droplets and flows down in the inclined direction through the discharge electrode 10, but since the discharge electrode 10 has a structure having sharp edges 4 on both sides thereof, most of the edges are each edge. Since it falls as a small water droplet from 4, the occurrence frequency of spark discharge is low and it does not become a malfunction.
[0021]
As the predetermined angle α, the frequency of occurrence of spark discharge could be suppressed by setting α to 5 ° to 18 ° as a result of experiments and measurements.
[0022]
In FIG. 5, two discharge electrodes 10 and three dust collection electrodes 11 facing them are arranged in the vertical direction of the casing 20, and a sprayer 12 is provided on the downstream side thereof (one combination is obtained by this combination). The configuration of the dust unit) is shown, but the number of dust collection units installed in the electrostatic precipitator is suitable for the degree of dusty gas contamination and the required dust collection rate. Can be set to
[0023]
In the form shown in FIG. 6, the edge 4 is provided only on one side of the discharge electrode. In the case of a so-called single-blade discharge electrode 10 'having such characteristics, the side of the single-blade discharge electrode 10' where the edge 4 is formed (flow of dust-containing gas) with respect to one single-blade discharge electrode 10 '. One dust collecting electrode 11 is arranged opposite to the downstream side to form a one-stage dust collecting portion. And this dust collection part is arrange | positioned two steps in the up-down direction of the casing 20, and the dust collector 12 is comprised by the combination which provided the sprayer 12 in the downstream.
[0024]
The dust-containing gas flows in the direction of the arrow 21 from the lower side of the casing 20, passes through the dust collection portion, and is discharged from the upper side of the casing 20 in the direction of the arrow 22. When the electric dust collection system is powered on, first, water is sprayed from the sprayer 12. Since a highly charged discharge area 5 is generated between the discharge electrode 10 ′ and the dust collection electrode 11, dust, dust, water droplets, mist and the like in the dust-containing gas are collected on the dust collection electrode 11.
[0025]
Also in this embodiment, the single-edged discharge electrode 10 ′ and the dust collecting electrode 11 are attached to be inclined at a predetermined angle α with respect to the horizontal direction of the casing 20, and the water adhering to the dust collecting electrode 11 is water droplets. It flows down in the inclination direction of the dust collecting electrode 11 and falls from the end of the dust collecting electrode 11. Therefore, the same operational effects as the above-described embodiment of FIG. 5 can be obtained.
[0026]
In the embodiment described above, the discharge electrode 10 is made of a plurality of thin metal plates having a saw-toothed sharp edge, and the dust collecting electrode 11 is a ventilation in which a plurality of strip steels are combined in a strip shape on both sides of the discharge electrode 10. However, the present invention is not limited to this configuration, and the configuration of the dust collection electrode that reliably guides the water droplets attached to the dust collection electrode to the water droplet storage space 26 is illustrated in FIG. 7 can be mentioned.
FIG. 7 is a cross flow type electrostatic precipitator of the form shown in FIG. 6 and is characterized in that a groove for guiding water droplets adhering to the dust collecting electrode is formed.
[0027]
FIG. 7 corresponds to a cross-sectional view taken along line EE in FIG. A dust collection electrode 11 ′ having a groove 31 is disposed opposite to the single-blade discharge electrode 10 ′ to constitute a one-stage dust collection portion. Further, the dust collecting section is arranged in two stages, and a sprayer 12 is provided on the downstream side thereof to constitute one dust collecting unit. In FIG. 7, two dust collection units are arranged. Further, a plurality of single-blade discharge electrodes 10 ′ and dust collecting electrodes 11 ′ are arranged at predetermined intervals in the left-right direction in FIG.
[0028]
Since the single-edged discharge electrode 10 ′ and the dust collecting electrode 11 ′ are attached with a predetermined angle α with respect to the horizontal direction of the casing 20, the water adhering to the dust collecting electrode 11 ′ becomes water droplets. It flows down in the inclination direction of the dust collecting electrode 11. At this time, the water droplet is guided to the groove 31 formed in each dust collecting electrode 11 ′, flows down to the end portion of the dust collecting electrode 11 ′, and falls from the end portion to the water droplet storing space portion 26. In addition, the other effect can obtain the effect similar to the form of FIG. 5 and FIG. 6 mentioned above.
[0029]
【The invention's effect】
According to the crossflow type electrostatic precipitator according to claim 1 of the present application, the water droplets collected by the dust collecting electrode are caused to flow down in the inclined direction along the dust collecting electrode, and downward from the end of the dust collecting electrode. Can be dropped. Therefore, it is possible to prevent the water droplet from falling into the electric field formed by the discharge electrode and the dust collecting electrode, suppress the spark discharge generated from the discharge electrode toward the water droplet, and stabilize the charge state between the electrodes. And the dust collection performance can be improved. Moreover, since it can be used as a vertical type, it can be employed, for example, in the interior of a chimney having a vertical type and the upper part of a wet flue gas desulfurization device, and the usage can be expanded.
[0030]
Further, according to the cross-flow type electrostatic precipitator according to claim 2 of the present application, the discharge electrode has a configuration that discharges only to the dust collection electrode arranged in the downward direction, and thus falls from the dust collection electrode. It is possible to further suppress the occurrence of spark discharge in the incoming water droplets, stabilize the charging state between the electrodes, and improve the dust collection performance.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of a dust collecting part of a cross-flow type wet electrostatic precipitator according to the present invention.
FIG. 2 is a diagram showing one form of discharge between a discharge electrode and a dust collecting electrode.
FIG. 3 is a diagram showing an embodiment of the arrangement of discharge electrodes and dust collection electrodes.
4 is a view showing a state of discharge between the discharge electrode and the dust collecting electrode shown in FIG. 4;
FIG. 5 is a diagram showing an embodiment of a cross-flow type wet electrostatic precipitator according to the present invention.
FIG. 6 is a diagram showing another embodiment of a cross-flow type wet electrostatic precipitator according to the present invention.
FIG. 7 is a view showing another embodiment of a cross-flow type wet electrostatic precipitator according to the present invention.
FIG. 8 is a view showing another embodiment for comparison with the cross-flow type wet electrostatic precipitator according to the present invention.
[Explanation of symbols]
4 Edge 5 Discharge area 10 Discharge electrode 10 'Single-blade discharge electrode 11, 11' Dust collecting electrode 12 Sprayer 20 Casing

Claims (2)

Place multiple sets of discharge electrodes and dust collection electrodes so as to be perpendicular to the flow direction of dust-containing gas and air containing dust, dust, water droplets, and mist, and face the discharge electrodes and dust collection electrodes. In a cross-flow type wet electrostatic precipitator equipped with a sprayer for spraying moisture,
A cross-flow type wet electrostatic precipitator, wherein the discharge electrode and the dust collecting electrode are vertically arranged in the vertical direction and are attached at a predetermined angle with respect to the horizontal direction. The cross-flow-type wet electrostatic precipitator according to claim 1, wherein the discharge electrode is provided so as to discharge only to the dust collection electrode arranged in the downward direction.

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