JP5254853B2 - Electric dust collector - Google Patents

Description

  The present invention relates to an electrostatic precipitator for purifying gas containing dusty bodies such as dust discharged from industrial apparatuses such as incinerators, melting furnaces, power generation boilers, and metal melting furnaces.

In industrial devices such as incinerators, melting furnaces, power generation boilers, and metal melting furnaces, high-temperature exhaust gas (hereinafter simply referred to as “gas”) containing dusty bodies such as dust accompanying combustion, heating reaction, etc. during operation. ) Occurs. The gas discharged from the industrial apparatus is cooled to a certain temperature, and then sent to a filter dust collector or an electric dust collector, where dust bodies are collected and removed by the dust collector.
Comparing filter type dust collectors and electric dust collectors, filter type dust collectors using bag filters are generally considered to be superior in terms of dust collection performance for dust-like materials dispersed in gas. However, since the bag filter becomes unusable when the gas temperature becomes high, in such a case, electrostatic dust collection that collects and removes dust-like bodies by electrostatic force (collection force). The device is used.

  As shown in FIG. 10, the electric dust collector as described above includes a hollow casing 100 in which a gas inlet 102 and a gas outlet 104 are respectively formed, and discharges disposed in the casing 100. Some include an electrode 106 and a dust collecting electrode 108, and a high voltage power source (not shown) that is connected to the discharge electrode 106 and applies a driving voltage between the discharge electrode 106 and the dust collecting electrode 108. In this electrostatic precipitator, as shown in FIG. 11, the gas G containing dust P is circulated between the discharge electrode 106 and the dust collection electrode 108, and the gas G is discharged by corona discharge from the discharge electrode 106. By applying a charge to the dusty body contained therein and charging it, the dusty body is attracted to and attracted to the dust collection electrode 108 by electrostatic force EF.

As an electric dust collector, what was described in patent document 1 is known, for example. In the electric dust collector described in Patent Document 1, a first dust collecting portion is provided in the casing along the gas flow direction on the upstream side, and a second dust collecting portion is provided on the downstream side of the first dust collecting portion. Is provided.
Here, a plurality of plate-shaped dust collecting electrodes are arranged in the first dust collecting portion, and rod-shaped discharge electrodes are arranged at a constant pitch along the longitudinal direction of the dust collecting electrodes between the pair of dust collecting electrodes. A plurality are provided over substantially the entire length. The second dust collecting unit is basically structured similarly to the first dust collecting unit, and has a plurality of dust collecting electrodes and discharge electrodes, respectively. A high-voltage power supply is connected to each of the plurality of discharge electrodes in the first and second dust collection units.

  In the electrostatic precipitator described in Patent Document 1, the dust collecting electrode is formed in an elongated mesh plate shape along the gas flow direction, and the discharge electrode extends in the vertical direction substantially orthogonal to the gas flow direction. It is formed in a rod shape and is supported so as to face the front surface portion or the back surface portion of the dust collection electrode. As a result, the contact length between the dust collection electrode and the gas can be increased along the gas flow direction, and corona discharge can be applied to the gas over the entire length of the dust collection electrode. It is said that dust collection efficiency can be improved.

  In Patent Document 1, the discharge electrode and the dust collection electrode are arranged at a high density in the downstream second dust collection portion with respect to the discharge electrode and the dust collection electrode arranged in the first dust collection portion on the upstream side. Even when dust-contaminated gas with a low concentration of dust is collected, dust that has failed to be collected by the first dust collector on the upstream side is also efficiently collected by the second dust collector on the downstream side. It is disclosed that it is possible.

JP 2004-160286 A

However, as in the electric dust collector described in Patent Document 1, in order to extend the contact length between the dust collecting electrode and the gas, the dust collecting electrode is elongated along the gas flow direction. When the two dust collecting parts are arranged in series, the dimensions of the casing along the gas flow direction are inevitably long, which may be disadvantageous due to the installation space of the apparatus.
In addition, as described in Patent Document 1, in order to efficiently collect dust from a gas having a low concentration of dust, the discharge electrode and the dust collection arranged in the first dust collecting portion on the upstream side When the discharge electrode and the dust collection electrode are arranged with high density in the second dust collection part on the downstream side of the electrode, the dust collection capacity of the upstream dust collection part is more than the dust collection capacity of the downstream dust collection part. Therefore, when collecting dust with a high dust concentration, it is difficult to maintain an appropriate load balance between the upstream dust collector and the downstream dust collector. The dust collection efficiency may be reduced and the power consumption may be increased.

  An object of the present invention is to provide an electrostatic precipitator capable of efficiently improving the dust collection capability for dusty substances contained in gas while suppressing the increase in apparatus size and power consumption in consideration of the above facts. It is in.

In order to achieve the above object, an electrostatic precipitator according to one embodiment of the present invention includes an electrostatic precipitator that collects dust-like bodies contained in a gas by electrostatic force, and the gas flows through the inside. A casing, a discharge electrode disposed in the casing and provided with a plurality of discharge lines, a casing disposed in the casing and having an exhaust port opened at one end thereof, and an internal and external space. A dust collecting electrode in which at least a part of the partitioning wall section is formed by a metal mesh filter; and a voltage applying means for applying a driving voltage between the discharge electrode and the dust collecting electrode, and the casing. The gas flow inside is controlled to flow into the dust collecting electrode through the mesh filter and then exhausted to the outside of the dust collecting electrode through the exhaust port. The opposing portion between the discharge wire in the filter, to form a concave portion curved in an arc shape so as to center of curvature of the dissipating wires, the discharge electrodes are arranged along the flow direction of the gas 3 It has a plurality of the discharge lines that are spanned between a pair of the coupling members adjacent to each other in the gas flow direction, and spanned between the pair of coupling members. The number of the discharge lines is reduced stepwise from the upstream side toward the downstream side along the gas flow direction .

  In the electric dust collector according to the first aspect, the flow of the gas in the casing is controlled to flow into the dust collecting electrode through the mesh filter and then exhausted to the outside of the dust collecting electrode through the exhaust port. As a result, the gas supplied into the casing can be discharged from the outside of the dust collecting electrode through the mesh filter having a large surface area per unit volume and then discharged to the outside of the apparatus. Even if the dimension is not increased in a specific direction, the contact area between the gas containing the dusty body charged by corona discharge from the discharge electrode and the dust collection electrode can be increased efficiently.

At this time, a concave portion that is curved in an arc shape with the discharge line as the center of curvature is formed on the surface of the mesh filter facing the discharge line, so that the discharge line and the concave portion Since a space (charged space) in which the distribution state of the electric field is substantially uniform can be formed between the dusty bodies contained in the gas in this charged space, the mesh filter can be collected more efficiently.
In addition, for example, if the mesh filter fineness (number of meshes) or weaving method is appropriately selected according to the concentration of dusty bodies and the particle size distribution in the gas, the electrostatic attraction force can be increased. In addition, the dust contained in the gas can be collected and removed by the filtering action of the mesh filter itself, improving the dust collection efficiency of the entire device when collecting dust with a high dust content. it can.

Further, in an electric precipitator in accordance with one embodiment of the present invention, discharge electrodes, three or more connecting members that are arranged along the flow direction of the gas and the pair of adjacent along the flow direction of the gas A plurality of discharge lines are provided between the connecting members, and the number of the discharge lines extended between the pair of connecting members extends from the upstream side to the downstream side along the gas flow direction. It is decreasing gradually. As a result, the distribution of charge energy can be made to correspond to the concentration distribution of dust contained in the gas, so that wasteful power consumption can be reduced, the energy efficiency of the apparatus can be improved, and the mesh filter can be formed. Since the number of concave-shaped portions to be reduced can be reduced, it becomes easy to produce a mesh filter having concave-shaped portions.

Here, in the electrostatic precipitator according to an aspect of the present invention, the dust collecting electrode includes a plurality of electrode units each provided with the exhaust port and the mesh filter stacked in the gas flow direction. It is preferable to be configured.

  According to the electric dust collector which concerns on this invention demonstrated above, the dust collection capability with respect to the dust-like body contained in gas can be improved efficiently, suppressing the increase in apparatus size and power consumption.

It is a perspective view which shows the structure of the electric dust collector which concerns on embodiment of this invention. It is a plane sectional view showing the composition typically of the electric dust collector shown in FIG. It is a perspective view which shows the structure of the discharge electrode in the electric dust collector shown by FIG. It is a perspective view which shows the structure of the dust collection electrode in the electric dust collector shown by FIG. It is a perspective view which shows the structure of the dust collection electrode in the electric dust collector shown by FIG. 1, and has shown the state by which the dust collection electrode was decomposed | disassembled into three electrode units. It is a top view which shows the flow path of a charging channel, a dust collection electrode, and gas in the electric dust collector shown by FIG. It is a top view which shows the relationship between the discharge line in the electric dust collector shown by FIG. 1, a mesh filter, and a dust-like body. It is a top view which shows the structure of the three electrode units and discharge line which comprise the dust collection electrode shown by FIG. (A) is a top view which shows the positional relationship of the mesh filter which has a concave shape part, and a discharge line, (B) is a top view which shows the positional relationship of the mesh filter which does not have a concave shape part, and a discharge line. . It is a top view which shows typically the structure of the conventional electrostatic precipitator. It is a top view which shows the relationship between the discharge line in the conventional electrostatic precipitator, a dust collection electrode, and a dusty body.

Hereinafter, an electric dust collector according to an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a configuration of an electrostatic precipitator according to an embodiment of the present invention. The electric dust collector 10 includes a hollow casing 12 formed in a substantially rectangular shape, and a discharge electrode 14 and a dust collecting electrode 16 disposed inside the casing 12. As shown in FIG. 1, the casing 12 is provided with a funnel-shaped hopper 18 on the bottom plate portion thereof so as to protrude downward. The hopper 18 gradually decreases in cross-sectional area from the upper end side to the lower end side, and penetrates in the height direction of the device (in the direction of arrow H).

  A flange member 19 is disposed at the lower end of the hopper 18, and a discharge device (for example, a screw conveyor or the like) for discharging the dust collected in the casing 12 to the outside of the system is provided on the flange member 19. A rotary valve is attached. Further, the hopper 18 has a gas introduction port 20 opened in a side plate portion on one end side (left side in FIG. 1) along the longitudinal direction (arrow L direction) of the apparatus. The leading end portion of the introduction duct 22 constituting the G flow path is connected.

  Here, the base end portion of the introduction duct 22 is connected to an exhaust gas port of an industrial apparatus (not shown) such as an incinerator, a melting furnace, a power generation boiler, or a metal melting furnace. The gas G discharged from the exhaust gas port normally contains a dusty substance P (see FIG. 7) such as dust and dust at a high concentration, and is sent into the casing 12 through the introduction duct 22. However, the shape and mounting position of the introduction duct 22 may change depending on the shape and arrangement of the exhaust port of the industrial device.

In addition, when the temperature of the gas G discharged from the exhaust port of the industrial device is very high, for example, the gas G is discharged from the electric dust collector 10 by a gas cooling device provided in the middle of the introduction duct 22. After cooling to below the temperature, this gas G is fed into the casing 12.
As shown in FIG. 1, the casing 12 has a gas discharge port 24 opened in the rear plate portion 12 </ b> B on the other end side (the back side in the drawing of FIG. 1) along the width direction (arrow W direction) of the apparatus. Yes. The gas discharge port 24 is open in the vicinity of the upper end of the rear plate portion 12B and in the vicinity of the end portion on the opposite side of the gas introduction port 20 along the longitudinal direction L. The gas discharge port 24 is connected to a base end portion of a discharge duct 26 that constitutes a gas G flow passage. As will be described later, the gas G that has been collected in the casing 12 passes through the discharge duct 26 and is sent to a processing device that performs other processing on the gas G as required, or into the atmosphere. Discharged.

  An induction fan (not shown) is disposed in the middle of the discharge duct 26, and this induction fan sucks the gas G from the internal space of the casing 12 through the discharge duct 26. As a result, a gas flow in which the gas G flows from the gas inlet 20 of the casing 12 toward the gas outlet 24 of the casing 12 is formed inside the casing 12 as a whole.

  The plurality (three in this embodiment) of the dust collecting electrodes 16 disposed in the casing 12 are formed in a thick plate shape and are hollow. The dust collection electrode 16 is supported by the casing 12 via a bracket (not shown) so that the thickness direction thereof coincides with the width direction W. As shown in FIG. 2, three internal flow paths 44, 46, and 48 through which gas G that has passed through a mesh filter 30 described later flows are formed inside the dust collection electrode 16. As shown in FIG. 4, three discharge ports 45, 47, and 49 are opened in the dust collecting electrode 16 on the side end surface on one end side (left side in FIG. 4) along the longitudinal direction L. The gas G flowing through the internal flow paths 44, 46, 48 is discharged into the casing 12 through the discharge ports 45, 47, 49, respectively. As shown in FIG. 2, a gas G collecting chamber 33 is formed inside the casing 12 so as to face the discharge ports 45, 47, and 49. In the collecting chamber 33, the dust collecting electrode 16 is disposed. The gas G discharged from the discharge ports 45, 47, 49 flows.

As shown in FIG. 4, the dust collecting electrode 16 has a support frame 34 disposed at one end on the discharge ports 45, 47, and 49 side along the longitudinal direction L, and a closing plate 36 at the other end. Has been placed. The support frame 34 is made of steel and is formed in a rectangular frame shape. The closing plate 36 is formed elongated in the height direction H, and closes the other end of the dust collecting electrode 16.
The dust collection electrode 16 is provided between an upper closing plate 38 spanned between the upper end portion of the support frame 34 and the upper end portion of the closing plate 36, and between the lower end portion of the support frame 34 and the lower end portion of the closing plate 36. A lower closing plate 40 is provided. The dust collecting electrode 16 is provided with an upper partition wall portion 42 and a lower partition wall portion 43 that divide the internal space into three internal flow paths 44, 46 and 48.

  The dust collecting electrode 16 is formed by a mesh filter 30 having air permeability between the support frame 34 and the closing plate 36. The mesh filter 30 is configured by knitting a fibrous material, a wire-like material, or the like made of a conductive metal into a net-like body. The mesh filter 30 is configured by a plurality of divided pieces each formed in a planar shape, and these divided pieces are attached to frame members (not shown) formed in a frame shape by shape steels, respectively. It is attached to the support frame 34 and the closing plate 36 via a frame member. The top surface portion and the bottom surface portion of the dust collection electrode 16 are in a closed state in which the gas G is not vented by the upper closing plate 38 and the lower closing plate 40, respectively.

  Regarding the fineness (number of meshes) of the mesh filter 30, the amount of gas G per unit time, the number of dust bodies P contained in the gas G (see FIG. 7) per unit volume, the dust bodies P The average particle size and the particle size distribution are appropriately set. Here, the mesh filter 30 usually has a finer mesh (the larger the number of meshes), the higher the dust collection efficiency with respect to the dusty body P. However, the mesh filter 30 is likely to be clogged, and the time until the clogging occurs is also long. Therefore, it is necessary to set the number of meshes appropriately in consideration of these balances.

  Further, regarding the weaving method of the mesh filter 30, usually, when the number of meshes is constant, a three-dimensional weaving method such as a tatami weaving has a higher dust collection efficiency than the ordinary plain weaving. Although the cost increases, the cost of parts increases and the removal work of the dust-like body P becomes complicated. Therefore, it is necessary to appropriately set the weaving method of the mesh filter 30 in consideration of these balances. In addition, about the mesh filter 30, you may use the thing of the same number of meshes, or the thing of the laminated structure on which different things were piled up.

  As shown in FIG. 2, a plurality (three) of dust collecting electrodes 16 are arranged at an equal pitch along the width direction W, and the width direction W is between a pair of dust collecting electrodes 16 adjacent to each other. And a space penetrating along the height direction H is formed. This space serves as a charging flow path 58 for applying a charge to the dust-like body P in the gas G by the discharge electrode 14 described later. A charging channel 58 is also formed between the dust collecting electrode 16 and the front plate portion 12F of the casing 12 and between the dust collecting electrode 16 and the rear plate portion 12B of the casing 12.

  As shown in FIG. 2, in the casing 12, between the pair of dust collecting electrodes 16 adjacent to each other along the width direction W, between the dust collecting electrode 16 and the front plate portion 12 </ b> F, and between the dust collecting electrode 16 and the rear. Discharge electrodes 14 are respectively disposed between the plate portions 12B. As shown in FIG. 3, the discharge electrode 14 has a ladder-like structure as a whole (so-called ladder structure), and is disposed so as to face the mesh filter 30 of the dust collection electrode 16.

  The discharge electrode 14 is provided with a plurality of (three in this embodiment) discharge line support portions 50 along the height direction H. The discharge line support portion 50 is provided with a pair of upper and lower connecting members 52 and a plurality of discharge lines 60 spanned between the pair of connecting members 52. The discharge line 60 is formed in a strip shape from a conductive metal material, and the upper end portion and the lower end portion thereof are respectively connected to a connecting member 52 made of steel pipe. In the discharge electrode 14, a high-voltage current flows through the connecting member 52 to the discharge line 60 in the discharge line support 50.

  The connecting member 52 extends in parallel with the longitudinal direction L, and the discharge line 60 extends in parallel with the height direction H. As shown in FIG. 7, a large number of discharge protrusions 61 are radially formed on the outer periphery of the discharge line 60. Thus, corona discharge is likely to occur from the tip of the discharge protrusion 61 when a voltage is applied. As shown in FIG. 7, the discharge protrusions of the discharge line 60 do not necessarily have to dispose the needle-like members radially with respect to the core material, and the protrusions with sharpened tips protrude in an arbitrary direction. The tip of the protrusion does not necessarily have to protrude from the surface of the core material.

  As shown in FIG. 1, a box-shaped storage portion 28 is formed in the central portion in the longitudinal direction L of the top plate portion of the casing 12, and a drive voltage power source (not shown) is provided in the storage portion 28. A conducting member (not shown) for conducting the battery to the discharge electrode 14 and an insulator (not shown) for insulating the conducting member and the casing 12 are housed. On the other hand, as shown in FIG. 3, a suspension tube 54 made of a conductive material is coupled to the central portion in the longitudinal direction L of the uppermost coupling member 52 in the discharge electrode 14. The suspension tube 54 is connected to a power supply member (not shown) disposed in the storage portion 28 via a power supply cable 55, and the power supply member discharges through the high-voltage cable 55, the suspension tube 54 and the connecting member 52. Power is supplied to the electrode 14.

  In the discharge line support portion 50, the discharge lines 60 are arranged at equal intervals along the longitudinal direction L. In the discharge electrode 14, the number of discharge lines 60 arranged in each of the plurality of stages of discharge line support units 50 is gradually increased from the discharge line support unit 50 positioned on the lower side toward the discharge line support unit 50 positioned on the upper side. is decreasing. Specifically, in the present embodiment, the discharge electrode 14 is provided with three stages of discharge line support portions 50, the lower discharge line support portion 50 is provided with twelve discharge lines 60, and the middle stage. Eight discharge lines 60 are arranged on the discharge line support part 50, and five discharge lines 60 are arranged on the upper discharge line support part 50. However, the number of discharge line support portions 50 provided in the discharge electrode 14 and the number of discharge lines 60 disposed in each discharge line support portion 50 are not limited to those of the present embodiment.

  As shown in FIGS. 4 and 5, the dust collection electrode 16 includes a plurality (three in this embodiment) of electrode units 62, 64, and 66. The three electrode units 62, 64, 66 are integrally assembled in a state of being stacked along the height direction, and one dust collection electrode 16 is configured in this assembled state. Further, the three electrode units 62, 64, 66 are connected by a fastening member (not shown) such as a bolt and assembled as a dust collection electrode 16. Therefore, the dust collecting electrode 16 can be disassembled into three electrode units 62, 64, 66 by releasing the connection state by the fastening member.

  Here, the height direction (arrow H direction) substantially coincides with the flow direction of the gas G in the charging channel 58. The three electrode units 62, 64, 66 are arranged at substantially the same position as the three-stage discharge line support portion 50 in the discharge electrode 14 along the height direction H and the longitudinal direction L, respectively. As a result, the mesh filter 30 of the lower electrode unit 62 faces the lower discharge line support portion 50, the mesh filter 30 of the middle electrode unit 64 faces the middle discharge line support portion 50, and the upper electrode unit 66 The mesh filter 30 directly faces the upper discharge line support portion 50.

  A plurality of concave portions 68 are formed in the mesh filter 30 in the electrode units 62, 64, and 66, respectively. Here, as shown in FIG. 8C, the mesh filter 30 of the lower electrode unit 62 has a concave portion 68 at a portion facing each of the plurality of discharge lines 60 in the lower discharge line support portion 50. Is formed. As shown in FIG. 8B, the mesh filter 30 of the middle-stage electrode unit 64 is formed with concave-shaped portions 68 at portions facing the plurality of discharge lines 60 in the middle-stage discharge line support section 50, respectively. Has been. Further, as shown in FIG. 8A, the mesh filter 30 of the upper electrode unit 66 is formed with a concave portion 68 at a portion of the upper discharge line support portion 50 that faces each of the plurality of discharge lines 60. Has been.

The concave portions 68 in each of the electrode units 62, 64, 66 are formed elongated along the height direction H, and the pitch in the longitudinal direction L is substantially equal to the pitch of the discharge lines 60 in the discharge line support 50. I'm doing it. The concave portion 68 has a dimension along the height direction H substantially equal to the length of the discharge line 60.
The concave portion 68 is formed by bending a part of the mesh filter 30 into a concave shape by pressing or the like. Here, as shown in FIG. 9A, the concave portion 68 is curved in an arc shape so that one discharge line 60 at the opposite position is the central axis (curvature center line). In the concave portion 68, the distance (curvature radius R) from the arbitrary portion (small region) to one discharge line 60 at the opposite position is constant. The concave portion 68 is most preferably curved with the discharge line 60 as the center line of curvature, but may be a polygonal shape bent at a plurality of locations along such a curved surface.

Next, the dust collection process with respect to the gas G by the electric dust collector 10 comprised as mentioned above is demonstrated.
When operating an industrial apparatus such as an incinerator, a melting furnace, a power generation boiler, or a metal melting furnace, the electrostatic precipitator 10 operates an attracting fan (not shown) disposed in the middle of the discharge duct 26. As a result, the upstream side of the introduction duct 22, the casing 12, and the discharge duct 26, which is the space on the industrial device side with respect to the induction fan, is in a negative pressure state, and the gas G including the dust bodies P generated by the industrial device is generated. The air is sucked into the casing 12 through the introduction duct 22.

  Here, the inner part of the hopper 18 in the space in the casing 12 is a distribution chamber 90 for the gas G flowing into the casing 12 from the gas inlet 20 as shown in FIG. The gas G flowing into the chamber 90 is distributed and flows into a plurality of (four in this embodiment) charging flow paths 58.

  The gas G flowing into the charging channel 58 flows from the lower end (opening end) to the upper end (closing end) of the charging channel 58 as a whole by the action of the negative pressure generated by the attracting fan. However, the gas G also has a velocity component that moves from the inlet of the charging channel 58 to the back side due to the inertial action. At this time, the discharge electrode 14 is disposed in the charging channel 58, and a driving voltage is applied to the discharge line 60 of the discharge electrode 14 by a high voltage power source (not shown). As a result, an ion flow IJ (see FIG. 6) that flows from the discharge line 60 to the mesh filter 30 side of the dust collection electrode 16 is formed in the charging channel 58 due to the influence of corona discharge generated by the discharge line 60. At the same time, as shown in FIG. 7, a charge C is applied to the dust-like body P included in the gas G to be charged with a predetermined polarity. For this reason, the gas G and dust P flowing in the charging flow path 58 are attracted to the mesh filter 30 by the electrostatic force EF while flowing in the charging flow path 58. Thereby, the dust body P passes through the inside of the mesh filter 30 and flows into the internal flow paths 44, 46 and 48.

  Here, since the mesh filter 30 electrostatically applies an attracting force to the dusty body P charged to a predetermined polarity, when the gas G passes through the mesh filter 30, the dust in the gas G The shaped body P is adsorbed on the outer surface of the mesh filter 30 and is also trapped in a minute gap (inner surface) inside the mesh filter 30 when passing through the mesh filter 30. Therefore, when the gas G passes through the mesh filter 30, the dust body P contained in the gas G can be efficiently removed by the mesh filter 30, and the dust body P is removed from the mesh filter 30 and cleaned. The gas G is fed into the internal flow paths 44, 46 and 48.

  As shown in FIG. 2, the gas G fed into the internal flow paths 44, 46, 48 flows into the collecting chamber 33 through the discharge ports 45, 47, 49 (see FIG. 4) of the dust collecting electrode 16. . Since the gas discharge port 24 is opened at the upper end of the collective chamber 33, the gas G flowing into the collective chamber 33 is discharged to the exhaust duct 26 through the gas exhaust port 24, and is necessary from the exhaust duct 26. In response to this, the gas G is sent to a device that performs other processing, or is released into the atmosphere without performing other processing.

In the electrostatic precipitator 10 according to the present embodiment, the gas G flowing into the distribution chamber 90 in the casing 12 is distributed to the plurality of charging channels 58, and the mesh filter 30 of the dust collecting electrode 16 from each charging channel 58. After flowing into the internal flow paths 44, 46, and 48 through the exhaust ports 45, 47 and 49, they are discharged into the collecting chamber 33.
As a result, the gas G flowing into the casing 12 can be discharged outside the apparatus after passing through the mesh filter 30 having a very large surface area per unit volume, so that the dimensions of the dust collecting electrode 16 and the casing 12 are set in a specific direction. Even if it is not long, the contact area between the gas G containing the charged dust P and the dust collecting electrode 16 (mesh filter 30) can be increased efficiently.

  Further, for example, if the number of meshes of the mesh filter 30 and the weaving method of the mesh are appropriately selected according to the concentration and particle size of the dust bodies P in the gas G, in addition to the electrostatic adsorption force, The dust-like body P contained in the gas G can be removed also by the filtering action by the mesh filter 30 itself. Therefore, when collecting the gas G having a high content of the dust-like body P, the dust collection efficiency of the entire apparatus is improved. It can be improved.

  In the electric dust collector 10, the gas G sent from the distribution chamber 90 of the casing 12 into the charging flow path 58 moves to the mesh filter 30, passes through the mesh filter 30, and passes through the internal flow paths 44, 46, 48. Flow into. At this time, since the direction of the electrostatic force acting on the dust body P and the direction of the flow of the gas G substantially coincide, dust collection by the mesh filter 30 can be performed reliably and efficiently.

In the electrostatic precipitator 10, the concave portions curved in an arc shape so that the discharge line 60 is centered on the curvature of the mesh filter 30 in the three electrode units 62, 64, and 66 are opposed to the discharge line 60. A shape portion 68 is formed. As a result, as shown in FIG. 9A, the distance from the discharge line 60 to an arbitrary part in the concave portion 68 is constant (= curvature radius R), and between the discharge line 60 and the concave portion 68. since distribution of electric field ED can substantially form a uniform and become space (charging space SC), in the in the charging space SC _a can charge the dust-like material P contained in the gas G efficiently.

As a result, it is possible to improve the charging efficiency for the dust body P as the whole of the electrostatic precipitator 10, so that the dust collection ability for the dust body P contained in the gas G is suppressed while suppressing the increase in the size and power consumption of the apparatus. It can be improved efficiently.
On the other hand, as shown in FIG. 9B, when the concave portion 68 is not formed in the facing portion of the mesh filter 30 facing the discharge line 60, the distance from the discharging line 60 to the facing portion of the mesh filter 30 is as follows. It changes according to the position in the longitudinal direction L. As a result, the distribution state of the electric field ED in the space between the discharge line 60 and the facing part of the mesh filter 30 changes according to the change in the distance from the discharging line 60 to the facing part of the mesh filter 30. Compared to the space SC, the charging of the dust-like body P contained in the gas G becomes non-uniform, and the collection efficiency by the dust collection electrode 16 decreases.

  In the electrostatic precipitator 10, the discharge electrode 14 having a plurality of stages (three stages) of discharge line support portions 50 is disposed in the charging flow path 58, and the discharge lines disposed on the plurality of stages of discharge line support portions 50, respectively. The number of 60 is gradually reduced from the lower end side toward the upper end side. As a result, the amount of corona discharge generated by the discharge line 60 increases on the lower end side of the charging flow path 58 and gradually decreases toward the upper end side. Therefore, the charge energy distribution in the charging flow path 58 is changed to the charge energy distribution. Can be made higher at the lower end side and gradually lower toward the upper end side. On the other hand, the gas G as a whole flows from the lower end side toward the upper end side in the charging flow path 58, and the dust bodies P contained in the gas G are gradually adsorbed and removed by the mesh filter 30. The content rate of the dust-like body P of this falls gradually.

As a result, the charge energy distribution along the height direction H in the charging channel 58 can correspond to the content rate of the dust bodies P contained in the gas G, so that the area where the content rate of the dust bodies P is low. Therefore, it is possible to prevent excessive corona discharge and wasteful power consumption, thereby improving the power energy use efficiency.
Further, the number of discharge lines 60 in the entire discharge electrode 14 can be reduced without reducing the dust collection efficiency, and the number of concave portions 68 in the entire dust collection electrode 16 can be reduced.
Fabrication of the mesh filter 30 having the concave portion 68 is also facilitated.

  Next, the case where the electric dust collector 10 which concerns on this embodiment is maintained is demonstrated. In the electrostatic precipitator 10, the dust collecting electrode 16 is beaten at predetermined intervals, so that the dust bodies P collected by the dust collecting electrode 16 are removed and the inside of the casing 12 is periodically cleaned. There is a need. Further, when the dust collecting electrode 16 is damaged due to corrosion, aging deterioration, or the like, it is necessary to repair or replace the dust collecting electrode 16.

In the electrostatic precipitator 10, a plurality of (in this embodiment, three) electrode units 62, 64, 66 are integrally assembled and the plurality of electrode units 62, 64, 66 are arranged. It can be disassembled.
Accordingly, when the dust collecting electrode 16 is repaired or replaced, or when the inside of the casing 12 is cleaned, the dust collecting electrode 16 is disassembled into a plurality of electrode units 62, 64, 66 inside the casing 12. Since each of the electrode units 62, 64, 66 can be taken out from the casing 12, the dust collecting electrode 16 can be taken out from the casing 12 as compared with the case where the dust collecting electrode 16 is taken out from the casing 12 without being disassembled. It is possible to reduce the work load of the worker when taking out 16 and to reduce the work load when assembling the dust collecting electrode 16 in the casing 12.

As a result, as in the case of the electrostatic precipitator 10 of the present embodiment, even if a dust collector electrode 16 having a box structure that is relatively bulky and tends to increase in weight is used, Since handling and assembling work can be performed by dividing the electrode units 62, 64, and 66, the maintainability of the electrostatic precipitator 10 can be made very good.
In the electrostatic precipitator 10 of the present embodiment, the dust collecting electrode 16 has a three-divided structure composed of the electrode units 62, 64, 66. However, the dust collecting electrode can be divided into two or more than four. It is also possible to use.

DESCRIPTION OF SYMBOLS 10 Electric dust collector 12 Casing 12B Rear plate part 12F Front plate part 14 Discharge electrode 16 Dust collection electrode 18 Hopper 19 Flange member 20 Gas introduction port 22 Introduction duct 24 Gas exhaust port 26 Exhaust duct 28 Storage part 30 Mesh filter 33 Collecting chamber 34 Support Frame 36 Blocking Plate 38 Upper Blocking Plate 40 Lower Blocking Plate 42 Upper Bulkhead Part 43 Lower Bulkhead Part 44, 46, 48 Internal Channel 45, 47, 49 Discharge Port 50 Discharge Line Support Part 52 Connecting Material 54 Suspended Tube 55 High voltage cable 58 Charging flow path 60 Discharge wire 61 Discharge protrusion 62, 64, 66 Electrode unit 68 Concave portion 90 Distribution chamber 100 Casing 102 Gas inlet 104 Gas outlet 106 Discharge electrode 108 Dust collection electrode C Charge G Gas IJ Ion current P Dust body SC _A charged space SC _B charged space

Claims (2)

In an electrostatic precipitator that collects dust contained in gas by electrostatic force,
A casing through which gas flows;
A discharge electrode disposed in the casing and provided with a plurality of discharge lines;
A dust collecting electrode disposed in the casing, formed in a box shape having an exhaust port opened at one end thereof, and at least a part of a partition wall partitioning the inner and outer space formed by a metal mesh filter;
Voltage application means for applying a drive voltage between the discharge electrode and the dust collection electrode,
The flow of gas in the casing is controlled to be exhausted to the outside of the dust collecting electrode through the exhaust port after flowing into the dust collecting electrode through the mesh filter,
Forming a concave-shaped part curved in an arc shape so that the discharge line is the center of curvature at the part of the mesh filter facing the discharge line ,
The discharge electrode includes three or more connecting members arranged along the gas flow direction and a plurality of the discharge members spanned between a pair of adjacent connecting members along the gas flow direction. Have electric wires,
The electrostatic precipitator according to claim 1, wherein the number of the discharge lines stretched between the pair of connecting members is gradually reduced from the upstream side toward the downstream side along the gas flow direction. 2. The electrostatic dust collection device according to claim 1 , wherein the dust collection electrode is configured by stacking a plurality of electrode units each provided with the exhaust port and the mesh filter along a flow direction of the gas. apparatus.

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