JP2020032337A - Charging apparatus and dust collector - Google Patents

Abstract

To provide a charging apparatus that can tear off dust adhering to an earth electrode by self purification.SOLUTION: A charging apparatus 10, which electrically charges dust included in dust-containing air by corona-discharge while circulating the dust-containing air, comprises a plurality of discharging electrodes 71 supported on a support body 70 and earth electrodes 60, provided, across gaps G for causing the corona discharge, between the discharging electrodes 71 respectively, which have a plurality of circulation holes H through which the dust-containing air circulated through the gaps G is passed. The earth electrode 60 includes a plurality of inclined surface parts F1 faced with the plurality of gaps G and inclined with respect to a circulating direction of the dust-containing air that enters the gaps G.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a charging device and a dust collecting device.

  A charging device that charges particles in dust-containing air by corona discharge is known.

  For example, the electrode portion of the pre-charging portion described in Patent Document 1 is connected to a plurality of projecting discharge electrodes supported by a support, a flat ground electrode having a plurality of holes, and a support. And a high-voltage power supply. The ground electrode was arranged parallel to the flow direction of the fuel exhaust gas. Further, a partition and a damper are provided on the upstream side in the flow direction of the fuel exhaust gas from the electrode unit, and the opening degree of the damper is controlled by the control unit to change the flow speed (flow amount) of the fuel exhaust gas. Was.

International Publication No. 2011/152357

  However, in the electrode portion described in Patent Literature 1, since the flat ground electrode is arranged parallel to the flow direction of the fuel exhaust gas, dust attached to the ground electrode cannot be efficiently removed by the flow of the fuel exhaust gas. There was a fear. For this reason, in the above-mentioned electrode part, in order to remove dust adhering to the ground electrode, it is necessary to control the opening of the damper to increase the flow rate of the fuel exhaust gas. That is, in the above-described electrode unit, a damper, a control unit for controlling the damper, and the like are required to remove dust attached to the ground electrode, and the structure of the electrode unit is complicated.

  SUMMARY OF THE INVENTION The present invention provides a charging device and a dust collecting device capable of removing dust attached to a ground electrode by a self-cleaning action in order to solve the above-mentioned problem.

  The first charging device of the present invention is a charging device that charges dust contained in dust-containing air by corona discharge while flowing dust-containing air, and includes a plurality of discharge electrodes supported by a support. A ground electrode provided with a gap for generating corona discharge between each of the discharge electrodes, and a ground electrode having a plurality of circulation holes through which the dust-containing air flowing through each of the gaps passes. The ground electrode includes a plurality of inclined surfaces facing the plurality of gaps and inclined with respect to a flow direction of the dust-containing air entering the gaps.

  In the first charging device of the present invention, since the inclined surface of the ground electrode is inclined with respect to the flowing direction, the dust-containing air flowing through the gap between the discharge electrode and the ground electrode collides with the inclined surface. And flows downstream from the plurality of circulation holes in the circulation direction. According to this configuration, by causing the dust-containing air to collide with the inclined surface portion, the dust adhered to the ground electrode (inclined surface portion) can be peeled off, and the separated dust is put on the airflow and flows downstream from the circulation hole. Can (self-cleansing). As a result, accumulation of dust on the ground electrode is suppressed, so that stable generation of corona discharge can be ensured, and stable charging of dust can be continued.

  According to a second charging device of the present invention, in the first charging device described above, it is preferable that the inclined surfaces adjacent to each other are arranged to face each other with the discharge electrode interposed therebetween.

  According to the second charging device of the present invention, corona discharge can be generated between the discharge electrode and the inclined surfaces on both sides thereof. Thereby, since a charged region can be generated on both sides of the discharge electrode, dust can be charged over a wide range. Further, since the inclined surface portion is arranged so as to partition adjacent discharge electrodes, electric field interference between adjacent discharge electrodes can be suppressed.

  According to a third charging device of the present invention, in the above-described first charging device, the inclined surfaces adjacent to each other are inclined in opposite directions, and are arranged line-symmetrically with the discharge electrode as a symmetric axis. Is preferred.

  According to the third charging device of the present invention, since the inclined surfaces on both sides sandwiching the discharge electrode are arranged in line symmetry, the two gaps between the discharge electrode and the inclined surfaces on both sides thereof have the same width. Can be As a result, substantially uniform charging regions can be formed on both sides of the discharge electrode, and dust can be stably charged. Further, the flow rate and the flow velocity of the dust-containing air flowing through the two gaps can be made substantially the same, so that the dust-containing air can be applied substantially uniformly to each inclined surface portion.

  The fourth charging device of the present invention is the charging device according to any one of the first to third charging devices described above, wherein the inclined surface portion is at least 20 degrees and at most 45 degrees with respect to the flow direction of the dust-containing air entering the gap. It is preferable that it is inclined within the range.

  According to the fourth charging device of the present invention, by setting the inclination angle of the inclined surface to be not less than 20 degrees and not more than 45 degrees, it is possible to peel off dust adhered to the inclined surface while applying dust-containing air to the inclined surface. it can.

  According to a fifth charging device of the present invention, in any one of the first to fourth charging devices described above, it is preferable that the ground electrode is formed in a state where the plurality of inclined surface portions are continuous.

  According to the fifth charging device of the present invention, for example, a ground electrode formed by connecting a plurality of inclined surfaces can be formed by bending a single metal mesh (sheet metal). Thus, the ground electrode can be manufactured at low cost.

  According to a sixth charging device of the present invention, in any one of the first to fifth charging devices described above, it is preferable that the discharge electrode is formed by bundling a plurality of fibrous line electrodes.

  According to the sixth charging device of the present invention, since a fibrous wire electrode is used for the discharge electrode, corona discharge can be generated at a lower applied voltage than when a thick electrode is used. Thus, the generation of sparks can be suppressed, and the generation of ozone due to the ionization of air can also be suppressed. Further, since a plurality of line electrodes are used as the discharge electrodes, even if some of the line electrodes are worn, corona discharge can continue to be generated in the remaining line electrodes.

  The seventh charging device of the present invention is the charging device according to any one of the first to sixth charging devices, wherein the plurality of discharge electrodes are arranged on the upstream side and the downstream side in the dust-containing air flow direction with the ground electrode interposed therebetween. Are preferably arranged alternately at positions shifted by a half pitch in a direction orthogonal to the distribution direction on both sides of the circumstance.

  If the discharge electrode is arranged only on the upstream side of the ground electrode, it may not be possible to form a charged region between adjacent discharge electrodes. On the other hand, according to the seventh charging device of the present invention, the plurality of discharge electrodes are arranged in a zigzag pattern on both the upstream side and the downstream side of the ground electrode. Charged areas can be formed in a staggered manner on both sides of the side. Thus, for example, a region that cannot be a charged region with the upstream discharge electrode can be supplemented with a charged region formed around the downstream discharge electrode. As a result, almost all of the dust-containing air passes through the charging region, so that substantially all of the dust contained in the dust-containing air can be charged.

  An eighth charging device according to the present invention is the charging device according to any one of the first to seventh charging devices, wherein a tip end of the discharge electrode is equidistant from the inclined surfaces adjacent to each other, and It is preferable to be arranged at a position overlapping the surface.

  According to the eighth charging device of the present invention, since the distances from the distal end portion of the discharge electrode to the inclined surfaces on both sides are equal, substantially uniform charging areas can be formed on both sides of the discharge electrode, and dust can be removed. It can be stably charged.

  A ninth charging device of the present invention is the charging device according to any of the first to eighth charging devices, wherein the ground electrode is disposed between the inclined surfaces adjacent to each other and is orthogonal to a flowing direction of the dust-containing air. The tip portion of the discharge electrode may be disposed at a position equidistant from the inclined surface portions adjacent to each other and the facing surface portion therebetween. preferable.

  According to the ninth charging device of the present invention, in addition to the formation of the charged region between the discharge electrode and the pair of inclined surfaces, the formation of the charged region between the discharge electrode and the facing surface portion can do. This makes it possible to form charged areas in three directions in the gap by using the inclined surface portion and the facing surface portion evenly separated from the tip end portion of the discharge electrode, so that substantially all of the dust contained in the dust-containing air can be formed. Can be charged.

  The first dust collecting device of the present invention is provided with any one of the first to ninth charging devices, and provided downstream of the charging device in the flow direction of the dust-containing air, and removes the dust charged by the charging device. And a collecting device for collecting.

  According to the first dust collecting device of the present invention, the dust charged by the charging device can be collected by the collecting device.

  According to the present invention, dust adhered to the ground electrode can be peeled off by the self-cleaning action.

It is a perspective view showing the dust collection device concerning a 1st embodiment of the present invention. FIG. 2 is a perspective view illustrating a charging unit of the charging device according to the first exemplary embodiment of the present invention from an upstream side in a distribution direction. FIG. 2 is a perspective view illustrating a charging unit of the charging device according to the first embodiment of the present disclosure from a downstream side in a flow direction. FIG. 2 is a perspective view showing a ground electrode, a discharge electrode, and the like of the charging device according to the first embodiment of the present invention from an upstream side in a flow direction. FIG. 2 is a perspective view showing a ground electrode, a discharge electrode, and the like of the charging device according to the first embodiment of the present invention from a downstream side in a flow direction. FIG. 2 is a plan view showing a part of a ground electrode, a discharge electrode, and the like of the charging device according to the first embodiment of the present invention. It is a top view for explaining the dust collection operation of the dust collection device concerning a 1st embodiment of the present invention. FIG. 7 is a perspective view showing a ground electrode, a discharge electrode, and the like of a charging device according to a second embodiment of the present invention from the upstream side in the flow direction. FIG. 9 is a plan view illustrating a part of a ground electrode, a discharge electrode, and the like of a charging device according to a second embodiment of the present invention. FIG. 11 is a plan view showing a part of a ground electrode, a discharge electrode, and the like of a charging device according to a third embodiment of the present invention. FIG. 13 is a plan view illustrating a part of a ground electrode, a discharge electrode, and the like of a charging device according to a fourth embodiment of the present invention. FIG. 13 is a plan view showing a part of a ground electrode, a discharge electrode, and the like of a charging device according to a fifth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that “Fr” shown in each figure indicates “before”, “Rr” indicates “after”, “L” indicates “left”, “R” indicates “right”, and “U” indicates "D" indicates "down" and "D" indicates "down". In this specification, terms indicating directions and positions are used for convenience of description, but these terms do not limit the technical scope of the present invention.

[First Embodiment: Configuration of Dust Collector]
The dust collector 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing the dust collector 1.

  The dust collection device 1 is a device that collects dust in dust-containing air by charging it with corona discharge. For example, the dust collecting apparatus 1 is installed in a factory that performs metal processing using a plasma processing machine or a laser processing machine. In addition, for example, the dust collecting device 1 collects fine dust such as metal fume generated during metal working. In addition, the dust collecting apparatus 1 can be installed not only in a metal processing factory but also in a place where dust is generated. The dust collected by the dust collecting device 1 is not limited to the metal fume, and may be of any type as long as it is charged and can collect dust.

  The dust collection device 1 includes a charging device 10, a collection device 20, and a dust removal device 30. The charging device 10 has a function of charging dust contained in dust-containing air by corona discharge while flowing dust-containing air. The collection device 20 is provided downstream of the charging device 10 in the flow direction of the dust-containing air, and has a function of collecting dust charged by the charging device 10. The dust removing device 30 has a function of removing dust collected by the collecting device 20. In the following description, the “flow direction” indicates a direction in which dust-containing air flows. The terms "upstream" and "downstream" and similar terms refer to "upstream" and "downstream" and similar concepts in the direction of flow of dust-containing air.

[Charging device]
The charging device 10 includes a charging housing 40 having a substantially rectangular parallelepiped appearance. The charging case 40 is made of, for example, a metal material such as stainless steel, and is fixed to the left side surface of the dust collecting case 21 of the collecting device 20 described later. The internal space of the charging housing 40 is partitioned by a partition plate 41 into a lower charging chamber R3 and an upper insulator chamber R4.

  A rectangular upstream opening 42 for introducing dust-containing air into the charging chamber R3 is formed on the left side surface (upstream side) of the charging housing 40. A cylindrical intake duct 42B is connected to the upstream opening 42 via a joint 42A having a substantially truncated pyramid shape. On the right side surface (downstream side) of the charging casing 40, a circular downstream opening 43 for discharging the dust-containing air passing through the charging chamber R3 toward the dust collecting casing 21 is formed. On the front surface of the charging housing 40, a charging inspection opening 40A that opens the charging chamber R3 is formed. The charging case 40 is provided with a charging inspection door (not shown) for opening and closing the charging inspection opening 40A (the charging inspection door is removed in FIG. 1).

  Although details will be described later, two charging units 45 are provided in the charging chamber R3. Each charging unit 45 includes a plurality of discharge electrodes 71 and a ground electrode 60. A high voltage power supply (not shown) is electrically connected to each discharge electrode 71. The high-voltage power supply generates a corona discharge between the discharge electrode 71 and the ground electrode 60 by applying a DC voltage of several kV to the discharge electrode 71.

[Collection device]
The collection device 20 includes a dust collection housing 21 having a substantially rectangular parallelepiped appearance. The dust collecting casing 21 is provided with a partition plate 22 made of metal (for example, stainless steel) that divides the internal space into two in the vertical direction. The internal space of the dust collecting housing 21 is partitioned by a partition plate 22 into a lower dirty room R1 and an upper clean room R2. In FIG. 1, the upper part of the dust collecting casing 21 is shown by a virtual line (two-dot chain line) to show the inside of the clean room R2.

  In the dirty room R1, six filter units 23 are supported by being suspended from the partition plate 22. The filter unit 23 includes a pleated nonwoven fabric (made of synthetic resin fiber) with a plurality of folds. The nonwoven fabric is formed in a substantially cylindrical shape, and an opening 23 </ b> A is formed on the upper end surface of the filter unit 23. The partition plate 22 has six partition openings 22A formed in two rows in the front-rear direction and three rows in the left-right direction. The six filter units 23 are supported by the partition plate 22 corresponding to the six partition openings 22A, and the openings 23A of each filter unit 23 are exposed from the partition openings 22A to the clean room R2.

  In addition, a filter inspection opening 21A that opens the dirty room R1 is formed on the lower front side of the dust collection housing 21. Further, a filter inspection door (not shown) for opening and closing the filter inspection opening 21A is attached to the dust collection housing 21 (the filter inspection door is removed in FIG. 1). Further, a bucket 24 for storing dropped dust is provided below the dirty room R1 of the dust collecting housing 21. The dust collection housing 21 is provided with a bucket inspection door 24 </ b> D for opening and closing the bucket 24.

  An intake port (not shown) corresponding to the downstream opening 43 of the charging housing 40 is opened on the left side surface of the dust collecting housing 21. The inside of the charging housing 40 and the dirty room R1 communicate with each other via the air inlet and the downstream opening 43. That is, the charging casing 40 and the dust collecting casing 21 are directly connected to each other without a duct or the like, and are in a communication state. Note that the charging housing 40 and the dust collecting housing 21 may be indirectly connected via a duct or the like.

  An exhaust port 25 communicating with the clean room R2 is opened on the upper surface of the dust collecting casing 21, and an exhaust duct (not shown) is connected to the exhaust port 25. Further, an exhaust fan (not shown) for exhausting the air in the dust collecting housing 21 is provided in the exhaust duct or the clean room R2. The air may be exhausted to the outside of the dust collecting housing 21 without connecting the exhaust duct.

[Dust removal unit]
The dust removing device 30 includes a header tank 31, three blow tubes 32, and three solenoid valves 33. The dust removing device 30 has a function of blowing compressed air toward the filter unit 23 to remove dust collected by the filter unit 23 (hereinafter, also referred to as “backwashing”).

  The header tank 31 is a cylindrical pipe extending in the left-right direction in the clean room R2. The header tank 31 is arranged on the front side of the partition plate 22 so as to avoid the partition opening 22A. The right end of the header tank 31 extends outside the dust collecting casing 21 and communicates with a compressor (not shown) provided in a factory.

  The three blow tubes 32 are connected to the header tank 31 via three solenoid valves 33. The three blow tubes 32 extend rearward from the header tank 31 at positions corresponding to the partition openings 22A arranged in three rows in the left-right direction. Each blow tube 32 is arranged so as to cross two partition openings 22A (filter unit 23) arranged in the front-rear direction. On the lower surface of each blow tube 32, two blowout ports 32A for blowing out compressed air supplied from a compressor (not shown) are formed. The two outlets 32A are open at positions corresponding to (substantially the center of) the two partition openings 22A arranged in the front-rear direction.

[Configuration of Charging Device]
Next, the configuration of the charging device 10 will be described in detail with reference to FIGS. FIG. 2 is a perspective view showing the charging unit 45 from the upstream side in the distribution direction. FIG. 3 is a perspective view showing the charging unit 45 from the downstream side in the distribution direction. FIG. 4 is a perspective view showing the ground electrode 60, the discharge electrode 71, and the like from the upstream side in the flow direction. FIG. 5 is a perspective view showing the ground electrode 60, the discharge electrode 71, and the like from the downstream side in the flow direction. FIG. 6 is a plan view showing a part of the ground electrode 60, the discharge electrode 71, and the like.

  As shown in FIG. 1, the charging device 10 includes two power supply insulators 44 and two charging units 45.

<Power supply insulator>
As shown in FIG. 1, the two power supply insulators 44 are arranged in the insulator room R4 side by side in the left-right direction. Each of the power supply insulators 44 is formed in a substantially columnar shape using a material having electrical insulation such as ceramics. The lower part of each feed insulator 44 penetrates the partition plate 41 (not shown). A through-hole (not shown) through which the power supply screw 46 passes is formed in the axis of each power supply insulator 44. As shown in FIG. 2, each of the power supply insulators 44 is fixed by screwing a distal end portion of a power supply screw 46 that penetrates the through hole from above to below, to a power supply plate 47 arranged in the charging chamber R3. A high-voltage power supply (not shown) is connected to an upper portion of the feeding screw 46 via a cable.

<Charging part>
As shown in FIG. 1, the two charging units 45 are arranged in the charging chamber R3 side by side in the left-right direction (flow direction). The two charging units 45 have a structure that can be detached from the charging inspection opening 40A into the charging chamber R3. Since the two charging units 45 have the same structure, only one charging unit 45 will be described below.

  As shown in FIGS. 2 and 3, the charging unit 45 includes a frame 50, a ground electrode 60, five supports 70, and a plurality of discharge electrodes 71. The plurality of discharge electrodes 71 are supported by each support 70. The five supports 70 and the ground electrode 60 are supported by the frame 50.

<Frame>
As shown in FIGS. 2 and 3, the frame body 50 is assembled in a substantially rectangular frame shape when viewed from the side. The frame body 50 is made of, for example, a metal material such as stainless steel. The frame 50 includes a pair of side plates 51, a first upper angle member 52U, a second upper angle member 53U, a first lower angle member 52D, a second lower angle member 53D, an upper shaft 54, It includes a lower shaft 55, an upper fixed plate 56, a lower fixed plate 57, and a pair of vertical fixed plates 58.

(Side plate)
The pair of side plates 51 are formed in a substantially rectangular shape elongated in the vertical direction when viewed from the front, and are erected at positions separated from each other in the front-rear direction. The pair of side plates 51 are formed in a tray shape having an open outer surface in the front-rear direction. The side plate 51 is in contact with the charging case 40 connected to the ground, and is grounded via the charging case 40 (see FIG. 2).

(First upper angle member, second upper angle member)
Each of the first upper angle member 52U and the second upper angle member 53U is a member having a substantially L-shaped cross section. The first upper angle member 52U is provided between upper left corners (upper upstream side) of the pair of side plates 51. The second upper angle member 53U is provided between the upper right corners (upper downstream side) of the pair of side plates 51. The horizontal plate of the first upper angle member 52U and the horizontal plate of the second upper angle member 53U are separated in the left-right direction. The vertical plate of the first upper angle member 52U is formed to be longer downward than the vertical plate of the second upper angle member 53U.

(First lower angle member, second lower angle member)
Each of the first lower angle member 52D and the second lower angle member 53D is a member having a substantially L-shaped cross section. The first lower angle member 52D is provided between the lower left corners (the lower upstream side) of the pair of side plates 51. The second lower angle member 53D is provided between the lower right corners (lower downstream side) of the pair of side plates 51. The horizontal plate of the first lower angle member 52D and the horizontal plate of the second lower angle member 53D are separated in the left-right direction. The vertical plate of the first lower angle member 52D is formed to be longer upward than the vertical plate of the second lower angle member 53D.

  The vertical plate of the first upper angle member 52U and the vertical plate of the first lower angle member 52D are vertically separated from each other. In a range surrounded by the pair of side plates 51 and the vertical plates of the pair of upper and lower angle members 52U and 52D, a substantially rectangular opening having substantially the same size as the upstream opening 42 of the charging casing 40 is formed. . The size of the upstream opening 42 in the front-rear direction is set substantially equal to the size of the ground electrode 60 described later in the front-rear direction.

(Upper shaft)
The upper shaft 54 is a rod-shaped member having a circular cross section. The upper shaft 54 is provided between the upper portions of the pair of side plates 51 below the horizontal plates of the first and second upper angle members 52U and 53U. More specifically, an insulator 59 is fixed to a substantially center of each side plate 51 in the left-right direction, and both front and rear ends of the upper shaft 54 are fixed to the pair of insulators 59 with bolts. The insulator 59 is formed in a substantially columnar shape using a material having electrical insulation such as a ceramic. A holding plate 59A is interposed between the insulator 59 and the bolt. When the charging unit 45 is mounted in the charging chamber R3, the upper shaft 54 comes into contact with the power supply plate 47 (not shown).

(Lower shaft)
The lower shaft 55 is similar to the above-described upper shaft 54, and is formed in a round bar shape. The lower shaft 55 is provided above the horizontal plates of the first and second lower angle members 52D, 53D and between the lower portions of the pair of side plates 51 via an insulator 59.

(Upper fixing plate, lower fixing plate)
The upper fixed plate 56 and the lower fixed plate 57 are formed in a substantially plate shape having a substantially horizontal posture. The upper fixed plate 56 and the lower fixed plate 57 are formed in a substantially plate shape having substantially the same width as the left and right widths of the side plate 51. The upper fixed plate 56 and the lower fixed plate 57 are the same component, and the lower fixed plate 57 is fixed with the up-down direction reversed. The upper fixed plate 56 and the lower fixed plate 57 are fixed to a vertical fixed plate 58 described later. The upper fixed plate 56 is provided between the upper portions of the pair of side plates 51 below the upper shaft 54, and the lower fixed plate 57 is provided between the lower portions of the pair of side plates 51 above the lower shaft 55. I have. The upper fixed plate 56 is provided above the lower end of the vertical plate of the first upper angle member 52U, and the lower fixed plate 57 is provided below the upper end of the vertical plate of the first lower angle member 52D. I have.

  The upper fixing plate 56 has three notches 56A (see FIG. 2) cut out from the upstream end to the downstream in a substantially U-shape, and a notch in the substantially U-shape from the downstream end to the upstream. Two cut-out portions 56A (see FIG. 3) are formed. The upstream cut-out portion 56A and the downstream cut-out portion 56A are cut out to the extent that they slightly overlap at the center in the left-right direction of the upper fixing plate 56. The three notches 56A on the upstream side and the two notches 56A on the downstream side are alternately formed at positions shifted by a half pitch in the front-rear direction. That is, the five cutout portions 56A are formed in a staggered shape when viewed from a plane. The left and right ends of the upper fixed plate 56 without the notch 56A are bent upward to form receiving pieces 56B. The three receiving pieces 56B formed at the left end (upstream side) of the upper fixed plate 56 abut on the back surface of the vertical plate of the first upper angle member 52U, and suppress the deformation of the vertical plate of the first upper angle member 52U. (See FIG. 2).

  Similarly to the above-described upper fixing plate 56, the lower fixing plate 57 has three notches 57A (see FIG. 2) cut out in a substantially U-shape from the upstream end to the downstream, and Two notches 57A (see FIG. 3) cut out in a substantially U shape toward the upstream are formed. The left and right ends of the lower fixing plate 57 without the notch 57A are bent downward to form receiving pieces 57B. The three receiving pieces 57B formed at the left end (upstream side) of the lower fixing plate 57 abut against the back surface of the vertical plate of the first lower angle member 52D, and are formed on the vertical plate of the first lower angle member 52D. Deformation is suppressed (see FIG. 2). The upper fixed plate 56 and the lower fixed plate 57 are electrically grounded. Three notches 56A on the upstream side of the upper fixing plate 56 and two notches 56A on the downstream side, and three notches 57A on the upstream side of the lower fixing plate 57 and two notches on the downstream side. 57A is spaced apart from a support 70 to which a high voltage described later is applied so as not to discharge.

(Vertical fixing plate)
As shown in FIG. 3, each vertical fixing plate 58 is formed in a substantially plate shape that is parallel to the side plate 51 and has a substantially vertical posture. Each vertical fixing plate 58 is formed narrower than the left and right width of the side plate 51. The pair of vertical fixing plates 58 are fixed to the downstream side of the pair of side plates 51, and are connected to both ends of the upper fixing plate 56 and the lower fixing plate 57.

<Ground electrode>
As shown in FIGS. 2 and 3, the ground electrode 60 is formed in a wavy shape in which the shape uneven in the flow direction is repeated in the front-rear direction. The ground electrode 60 is disposed between the upper fixed plate 56 and the lower fixed plate 57. Upper and lower ends of the ground electrode 60 are fixed to the upper fixed plate 56 and the lower fixed plate 57 via two sets of upper and lower connecting pieces P1 and P2. More specifically, the upper connection piece P1 is fixed to the upper fixing plate 56 with the upper end of the ground electrode 60 sandwiched from both left and right sides. The lower connecting piece P2 is fixed to the lower fixing plate 57 with the lower end of the ground electrode 60 sandwiched from both left and right sides. The front and rear ends of the connecting pieces P1 and P2 are fixed to a pair of vertical fixing plates 58.

  As shown in FIGS. 4 and 5, the ground electrode 60 has a plurality of flow holes H (mesh) through which dust-containing air that has flowed through a gap G with a discharge electrode 71 described later passes. The ground electrode 60 is formed in a wave shape by bending a single metal net made of metal such as stainless steel (SUS304), for example. The wire diameter of the ground electrode 60 can be set, for example, in the range of 0.1 to 1.0 mm, and the aperture (mesh opening diameter) of the ground electrode 60 can be set, for example, in the range of 1 to 5 mm. The opening ratio of the ground electrode 60 can be set, for example, in a range of 50 to 70%. In the attached drawings, a part of the mesh of the ground electrode 60 is illustrated.

  The ground electrode 60 includes six inclined surface portions F1 inclined with respect to the flow direction and five facing surface portions F2 extending between the adjacent inclined surface portions F1 in a direction (front-back direction) orthogonal to the flow direction. And The inclined surfaces F1 adjacent to each other are inclined in different directions. The six inclined surface portions F1 and the five facing surface portions F2 are alternately provided in the front-rear direction. The two facing surfaces F2 are connected to the upstream end of the inclined surface F1, and the three facing surfaces F2 are connected to the downstream end of the inclined surface F1.

  As shown in FIGS. 4 to 6, the ground electrode 60 is formed in a state where six inclined surface portions F1 are continuous via five facing surface portions F2 (in FIG. 6, five inclined surface portions F1 are illustrated). Is shown). A substantially trapezoidal concave portion D1 is formed between the adjacent inclined surface portions F1. Three concave portions D1 are formed on the upstream side of the ground electrode 60, and two concave portions D1 are formed on the downstream side of the ground electrode 60. The three concave portions D1 on the upstream side and the two concave portions D1 on the downstream side are alternately arranged in the front-rear direction. Note that a pair of fixing pieces 60A are formed on both front and rear end portions of the ground electrode 60 on substantially the same plane as the upstream facing surface portion F2. The pair of fixing pieces 60A are fixed to a pair of vertical fixing plates 58 (see FIG. 3). In a state where the ground electrode 60 is fixed to the frame body 50, the five notches 56A and 57A formed in the upper and lower fixing plates 56 and 57 are provided at positions corresponding to the five recesses D1. (See FIGS. 2 and 3).

<Support>
As shown in FIGS. 4 to 6, the five supports 70 are arranged on the upstream side and the downstream side in the flow direction with the ground electrode 60 interposed therebetween, and oppose the concave portion D1 on the upstream side and the concave portion D1 on the downstream side. (Four support members 70 are shown in FIG. 6). The three support members 70 on the upstream side and the two support members 70 on the downstream side are alternately arranged (in a staggered shape when viewed from a plane) at positions shifted by half a pitch in the front-rear direction (see FIG. 6).

  Each support 70 is formed in a substantially plate shape that is parallel to the side plate 51 and substantially vertical. Each support 70 is formed narrower than the left and right width of the side plate 51. The upper and lower sides of the three upstream supports 70 are bent to the downstream side (right side), and the upper and lower sides of the two downstream support bodies 70 are bent to the upstream side (left side). A substantially U-shaped engaging recess 70A is formed at both upper and lower ends of each support 70. The upper and lower sides of each support 70 penetrate the notches 56A and 57A of the upper and lower fixing plates 56 and 57 (see FIGS. 2 and 3), and the engaging recesses 70A at the upper and lower ends of each support 70. Are engaged with engagement grooves 54A, 55A formed in the upper and lower shafts 54, 55 (see FIGS. 4 and 5). Thus, the five support members 70 are bridged between the upper and lower shafts 54, 55 in a non-contact state with the upper and lower fixing plates 56, 57 (see FIGS. 2 and 3).

<Discharge electrode>
As shown in FIGS. 4 and 5, eleven discharge electrodes 71 are fixed to one support 70 at substantially equal intervals in the vertical direction. The plurality of discharge electrodes 71 are supported by five support members 70 and are arranged in a staggered manner when viewed from above (see FIG. 6). In detail, the plurality of discharge electrodes 71 are alternately arranged at positions shifted by a half pitch in the front-rear direction (the direction orthogonal to the flow direction of dust-containing air) on both the upstream side and the downstream side in the flow direction with the ground electrode 60 interposed therebetween. Are located in The discharge electrode 71 supported by the support 70 on the upstream side extends downstream in the flow direction. For this reason, the discharge electrode 71 supported by the support 70 on the upstream side has a configuration in which the dust in the dust-containing air hardly comes into contact with the tip. On the other hand, the discharge electrode 71 supported by the downstream support 70 extends upstream in the flow direction (see FIG. 6). That is, the discharge electrode 71 is provided in a posture along the flow direction.

  Each discharge electrode 71 is formed in a brush shape by bundling a plurality of fibrous line electrodes. The wire electrode is formed of, for example, a stainless steel fibrous material having a diameter of 12 μm. As the material of the wire electrode, non-magnetic stainless steel or the like can be used. For example, it is preferable to use austenitic stainless steel (SUS304, SUS316, etc.) having excellent corrosion resistance. Each discharge electrode 71 (line electrode) is fixed to the support 70 by a processing method such as pressure bonding, adhesion, or flocking.

[Position relationship between ground electrode and discharge electrode]
As shown in FIGS. 4 and 5, the above-described ground electrode 60 is provided with a gap G for generating a corona discharge between each of the discharge electrodes 71. Further, the six inclined surface portions F1 of the ground electrode 60 are formed facing the gap G, respectively. As shown in FIG. 6, the six inclined surface portions F1 are inclined with respect to the direction of flow of the dust-containing air entering the gap G. In the first embodiment, as an example, the angle θ formed between the direction of flow of the dust-containing air and the inclined surface portion F1 is set to about 30 degrees. The inclined surfaces F1 adjacent to each other are inclined at the same angle in opposite directions, and are arranged line-symmetrically with respect to the discharge electrode 71 provided with the gap G interposed therebetween. The fact that the inclined surfaces F1 adjacent to each other are inclined at the same angle in the opposite direction does not require that they be exactly the same, but means that a manufacturing error is allowed.

  In addition, as shown in FIG. 6, the five facing surfaces F2 of the ground electrode 60 are each formed to face the gap G (the concave portion D1). The five facing surface portions F2 are orthogonal to the flow direction of the dust-containing air entering the gap G.

  The distal end of the discharge electrode 71 is disposed at a position overlapping the inclined surface F1 (when viewed from a plane). That is, the tip of the discharge electrode 71 enters the recess D1. In addition, the shortest distance L1 of the gap G from the tip of the discharge electrode 71 to the one inclined surface F1 is the same as the shortest distance L2 of the gap G from the tip of the discharge electrode 71 to the other inclined surface F1. (L1 = L2). Further, the shortest distance L3 of the gap G from the tip of the discharge electrode 71 to the facing surface F2 is set to be the same as the shortest distance L1 (or L2) of the gap G (L3 = L1 = L2). . The fact that the tip of the discharge electrode 71 is equidistant from the inclined surface portion F1 and the facing surface portion F2 does not require that they be exactly the same. This is an acceptable meaning.

  The shortest distances L1 to L3 of the gaps G between the distal end portion of the discharge electrode 71 and each of the surface portions F1 and F2 are set to distances that can generate an appropriate corona discharge in relation to the applied voltage. For example, when the applied voltage is 1 to 9 kV (preferably 4 to 6 kV), the shortest distances L1 to L3 of the gap G are set to 10 to 19 mm.

[Dust collection operation]
Next, the dust collecting operation of the dust collecting device 1 will be described with reference to FIGS. 1, 2, 6, and 7. FIG. FIG. 7 is a plan view for explaining the dust collecting action of the dust collecting device 1.

  First, the operator performs a predetermined operation to activate the charging device 10 and the collection device 20 (to prepare for the operation start). A control unit (not shown) of the dust collector 1 controls a high-voltage power supply (not shown) to generate a high voltage. The high voltage generated by the high-voltage power supply is applied to each discharge electrode 71 via the power supply screw 46, the power supply plate 47, the upper shaft 54, and each support 70 (see FIG. 2). Then, as shown in FIG. 6, a corona discharge is generated between each discharge electrode 71 and the inclined surface portion F1 (gap G), and a substantially conical charging area EA is formed. Corona discharge also occurs between each discharge electrode 71 and the facing surface portion F2 to form a substantially conical charging area EA. That is, the charged area EA is formed in three directions from the tip of the discharge electrode 71. Further, since the distal end of the discharge electrode 71 is disposed at a position equidistant from the inclined surface F1 adjacent to each other and the facing surface F2 therebetween, the tip of the discharge electrode 71 is located between the plurality of surfaces F1 and F2. Can be made substantially uniform.

  Further, the control unit rotates the exhaust fan of the collection device 20. Then, an airflow from the intake port to the exhaust port 25 is formed, so that dust-containing air passes through the intake duct 42B from the outside and is taken into the charging casing 40 (see the thick arrow in FIG. 1). Then, as shown in FIG. 7, the dust in the dust-containing air is charged while passing through a plurality of charging areas EA formed between each of the discharge electrodes 71 on the upstream side and the plurality of surface portions F1 and F2. Then, they are attracted to each other, aggregate and coarsen (they are coarsened by a factor of 20 or more). The coarse dust passes through the flow hole H of the ground electrode 60 and flows downstream.

  In addition, the dust in the dust-containing air passes through the circulation hole H of the ground electrode 60, and a plurality of charged particles formed between each of the downstream discharge electrodes 71 and the plurality of surface portions F1 and F2. It is charged and coarsened while passing through the area EA.

  By the way, most of the coarsened dust passes through the flow hole H of the ground electrode 60 and flows to the downstream side, but a part of the coarsened dust is distributed to the ground electrode 60 (the inclined surface portion F1 and the facing surface portion F2). On the upstream side of Dust adhered to the ground electrode 60 has the same potential (earth potential) as the ground electrode 60. When the force exerted by the airflow on the dust on the ground electrode 60 becomes larger than the adhesive force between the ground electrode 60 and the dust, the dust on the ground electrode 60 is peeled off from the ground electrode 60 and passes through the circulation hole H. It flows downstream.

  The dust that has flowed from the upstream adheres to the dust on the ground electrode 60 and is in a bead-like state (see the dust indicated by broken lines in FIG. 7). Dust that has been enlarged in a bead shape on the ground electrode 60 is more likely to receive a force from an air current, and is thus more easily separated from the ground electrode 60 than dust that has not been enlarged (see the thin arrow in FIG. 7).

  Further, since the inclined surface portion F1 of the ground electrode 60 is inclined with respect to the flowing direction and the facing surface portion F2 is orthogonal to the flowing direction, the airflow collides with the inclined surface portion F1 and the facing surface portion F2, and It flows downstream from the plurality of circulation holes H in the circulation direction. Dust adhering to the upstream side of the inclined surface portion F1 and the facing surface portion F2 is peeled off from the surface portions F1 and F2 by receiving a force from an airflow that collides with the surface portions F1 and F2.

  Note that if the speed of the airflow in the charging housing 40 is low (for example, less than 10 m / s), dust easily adheres to the ground electrode 60, and thus the control unit sets the airflow speed to a range of 10 to 20 m / s. The exhaust fan is controlled to be as follows.

  Dust-containing air containing charged and coarsened dust passes through the downstream opening 43 from inside the charging device 10 and is taken into the dirty room R1 of the collection device 20 (see FIG. 1). The coarse dust is mainly collected on the surface side of the filter unit 23 (nonwoven fabric) (see FIG. 7). The dust-containing air is filtered through the dust while passing through each filter unit 23 to become clean air.

  The clean air is exhausted from the opening 23A of the filter unit 23 into the clean room R2, and is exhausted from the exhaust port 25 to the outside through the clean room R2 (see FIG. 1).

  As described above, by charging and coarsening the dust by the charging device 10, the dust is suppressed from entering deep into the filter unit 23 (nonwoven fabric), and the dust can be collected on the surface side of the nonwoven fabric. Thereby, clogging of the filter unit 23 can be suppressed. Note that dust that has fallen without being collected by the filter unit 23 accumulates in the bucket 24 (see FIG. 1).

[Dust removal operation]
Next, the dust removing operation (backwashing operation) of the dust collecting device 1 will be described with reference to FIG.

  The control unit executes the dust removal operation when it determines that the detected value of the differential pressure gauge (not shown) that detects the differential pressure between the dirty room R1 and the clean room R2 exceeds a threshold. Further, the control unit performs the dust removing operation on the two filter units 23 arranged in three rows in order one by one. The execution timing of the dust removal operation is not limited to the above. For example, the dust removal operation may be performed when the dust collector 1 is stopped, or the dust removal operation may be performed at a timing set in advance by a timer. The operator sets the threshold value of the differential pressure, the time (interval) of the timer, and the like in advance.

  The dust removal operation is performed without stopping the exhaust fan and continuing to suction the dust-containing air. Alternatively, the dust removal operation may be performed in a state where the rotation speed of the exhaust fan is lower than normal (during the dust collection operation). As described above, the dust removal operation is preferably performed in a state where the suction of the dust-containing air is continued without stopping the exhaust fan. However, the present invention is not limited thereto, and the dust removal operation may be performed in a state where the exhaust fan is stopped.

  When the collection device 20 is started, the solenoid valve 33 is controlled by the control unit and closed. Then, compressed air is stored in the header tank 31 connected to the compressor. The pressure of the compressed air is set to, for example, 0.4 to 0.7 MPa.

  When the control unit determines that the detected value has exceeded the threshold value, the solenoid valve 33 is controlled and opened by the control unit. Then, the compressed air stored in the header tank 31 is blown out from the two outlets 32A toward the openings 23A of the two filter units 23 through the blow tube 32.

  The compressed air flows backward from the radial center of the filter unit 23 toward the outside, and removes dust collected by the filter unit 23 (nonwoven fabric). Since the dust is collected on the surface side of the nonwoven fabric, the dust is easily removed by the backflow of the compressed air. The dust that has been blown off falls into a bucket 24 provided at the lower part of the collection device 20, and the accumulated dust is appropriately discarded.

  Further, the compressed air that has passed through the filter unit 23 flows from the dust collecting housing 21 into the charging housing 40 through the downstream opening 43 to remove dust adhering to the ground electrode 60.

  Note that the control unit performs control to close the electromagnetic valve 33 after a lapse of a predetermined time (after several tens to several hundreds of ms) from the start of compressed air injection (the opening of the electromagnetic valve 33). Thereby, compressed air is stored in the header tank 31 again.

  In the charging device 10 according to the first embodiment described above, the inclined surface F1 of the ground electrode 60 is inclined with respect to the flowing direction, and the facing surface F2 is orthogonal to the flowing direction. The dust-containing air that has flowed through the gap G between the discharge electrode 71 and the ground electrode 60 collides with the inclined surface portion F1 and the facing surface portion F2, and flows downstream from the plurality of flow holes H in the flow direction. According to this configuration, dust adhering to the upstream side of the inclined surface portion F1 and the facing surface portion F2 can be peeled off by colliding the dust-containing air with the inclined surface portion F1 and the facing surface portion F2, and the separated dust can be removed. The air can flow on the air flow and flow downstream from the circulation hole H (self-cleaning action). As a result, accumulation of dust on the ground electrode 60 is suppressed, so that stable generation of corona discharge can be ensured, and stable charging of dust can be continued.

  Further, according to the charging device 10 of the first embodiment, since the inclined surfaces F1 on both sides of the discharge electrode 71 are arranged in line symmetry, the distance between the discharge electrode 71 and the inclined surfaces F1 on both sides thereof is increased. Can have the same width (the same shortest distance L1 = L2). Thereby, substantially uniform charging areas EA can be formed on both sides of the discharge electrode 71, and dust can be stably charged. Further, the flow rate and the flow rate of the dust-containing air flowing through the two gaps G can be made substantially the same, and the dust-containing air can be applied to each inclined surface portion F1 almost uniformly. Further, since the inclined surface portion F1 is disposed so as to partition the adjacent discharge electrodes 71, electric field interference between the adjacent discharge electrodes 71 can be suppressed.

  In addition, according to the charging device 10 according to the first embodiment, the ground electrode 60 in which the plurality of inclined surface portions F1 and the plurality of facing surface portions F2 are connected can be formed by bending one wire net. . Thereby, the ground electrode 60 can be manufactured at low cost. In addition, since the ground electrode 60 is a single component, the replacement (detachment) of the ground electrode 60 can be performed more easily than when the ground electrode 60 is composed of a plurality of components.

  Further, according to the charging device 10 according to the first embodiment, since a fibrous wire electrode is used as the discharge electrode 71, corona discharge is generated at a lower applied voltage than when a thick electrode is used. be able to. Thus, it is possible to suppress the generation of sparks (sparks) due to the abnormal discharge and also to suppress the generation of ozone due to the ionization of air. In addition, since a plurality of line electrodes are used as the discharge electrodes 71, even if some of the line electrodes are worn, the remaining line electrodes can continue to generate corona discharge. Further, since the discharge electrode 71 is disposed between the pair of inclined surface portions F1, electric field interference between the adjacent discharge electrodes 71 can be suppressed.

  In the charging device 10 according to the first embodiment, the plurality of discharge electrodes 71 are arranged in a zigzag pattern on both the upstream side and the downstream side of the ground electrode 60. If the discharge electrode 71 is arranged only on the upstream side of the ground electrode 60, the charging area EA may not be formed between the discharge electrodes 71 (support 70) adjacent in the front-rear direction. On the other hand, according to the charging device 10 described above, since the plurality of discharge electrodes 71 are arranged in a staggered manner on both sides of the ground electrode 60, the discharge electrodes 71 are arranged in the front-rear direction on both the upstream side and the downstream side of the ground electrode 60. The charged areas EA can be alternately formed (in a zigzag pattern when viewed from a plane) at positions shifted by a half pitch. Accordingly, for example, a region where the charging region EA cannot be formed by the upstream discharge electrode 71 can be supplemented by the charging region EA formed around the downstream discharge electrode 71. As a result, almost all of the dust-containing air passes through the charging area EA, so that substantially all of the dust contained in the dust-containing air can be charged.

  Further, according to the charging device 10 of the first embodiment, in addition to the formation of the charging area EA between the discharge electrode 71 and the pair of inclined surfaces F1, the discharge electrode 71 and the facing surface F2 are formed. To form a charged area EA. This makes it possible to form the charged area EA in the gap G (the concave portion D1) in three directions by using the inclined surface portion F1 and the facing surface portion F2 which are evenly separated from the distal end portion of the discharge electrode 71. Almost all of the dust contained in the dust air can be charged.

  Further, according to the dust collection device 1 according to the first embodiment, the dust charged by the charging device 10 can be collected by the collection device 20. Further, since the charging device 10 is directly fixed to the collection device 20 (the dust collecting housing 21) and communicates with the charging device via the downstream opening 43, the compressed air at the time of back washing is charged into the charging housing 40. Can be reversed. Thus, the dust of the ground electrode 60 can be removed at the same time as the dust of the filter unit 23 is removed.

  In the dust collecting apparatus 1 according to the first embodiment, since the ground electrode 60 is formed by a single wire net, the plurality of flow holes H (mesh) have substantially the same size over the entire area. However, the present invention is not limited to this. Since the inclined surface portion F1 is inclined with respect to the flow direction, the projected area of the flow hole H of the inclined surface portion F1 is smaller than that of the flow hole H of the facing surface portion F2 when viewed from the flow direction. Therefore, for example, the flow hole H formed in the facing surface portion F2 may be formed smaller than the flow hole H formed in the inclined surface portion F1 (not shown). Thereby, the projected areas of the flow hole H of the inclined surface portion F1 and the flow hole H of the facing surface portion F2 can be made substantially the same. As a result, the flow rate of the dust-containing air passing through the flow hole H of the inclined surface portion F1 and the flow hole H of the facing surface portion F2 can be made substantially uniform. Further, by reducing the flow hole H in the facing surface portion F2, the amount of dust passing through the flow hole H in the facing surface portion F2 can be reduced, and the discharge electrode 71 facing the downstream side of the facing surface portion F2 can be reduced. Can be prevented from adhering to the dust.

  Further, in the charging device 10 according to the first embodiment, the inclined surface portion F1 is inclined by about 30 degrees with respect to the flow direction of the dust-containing air, but the present invention is not limited to this. The inclined surface portion F1 only needs to be inclined in a range of 20 degrees or more and 45 degrees or less with respect to the flow direction of the dust-containing air entering the gap G. According to this configuration, by setting the inclination angle of the inclined surface portion F1 to the above range, dust adhering to the inclined surface portion F1 can be peeled off while dust-containing air is applied to the inclined surface portion F1.

  Further, in the charging device 10 according to the first embodiment, the ground electrode 60 is formed in a wave shape in which substantially trapezoidal irregularities are continuous, but the present invention is not limited to this. The ground electrode 60 may be formed in, for example, a wave shape in which curved irregularities are continuous (not shown).

[Second embodiment]
Next, a charging device 11 (ground electrode 61) according to the second embodiment will be described with reference to FIGS. FIG. 8 is a perspective view showing the ground electrode 61 and the discharge electrode 71 of the charging device 11 from the upstream side in the flow direction. FIG. 9 is a plan view showing a part of the ground electrode 61, the discharge electrode 71, and the like. In the following description, the same components as those of the charging device 10 according to the above-described first embodiment are denoted by the same reference numerals, and the same description will be omitted.

  In the charging device 11 according to the second embodiment, the ground electrode 61 is formed in a triangular wave shape in which irregularities in a substantially triangular shape are repeated. In the ground electrode 61, the facing surface portion F2 is omitted, and the ground electrode 61 is formed in a state where six inclined surface portions F1 inclined with respect to the flow direction are continuous. The inclined surfaces F1 adjacent to each other are inclined at the same angle in different directions, and a substantially triangular concave portion D2 is formed between the adjacent inclined surfaces F1. The six inclined surface portions F1 are continuously provided in the front-rear direction. The three concave portions D2 on the upstream side and the two concave portions D2 on the downstream side are alternately arranged in the front-rear direction.

  The five supports 70 are arranged on the upstream side and the downstream side in the flow direction with the ground electrode 61 interposed therebetween, and face the concave portion D2 on the upstream side and the concave portion D2 on the downstream side. The plurality of discharge electrodes 71 are supported by five support members 70 and extend into the concave portion D2. The plurality of discharge electrodes 71 (five support members 70) are arranged in a staggered manner when viewed from a plane. The discharge electrode 71 is arranged on the center line between the adjacent inclined surface portions F1. The shortest distances L1, L2 of the gap G from the tip of the discharge electrode 71 to the inclined surfaces F1 on both sides are set to be substantially the same (L1 = L2). The distance L30 from the tip of the discharge electrode 71 to the intersection (bend) of the pair of inclined surfaces F1 is set to be about twice the shortest distance L1 (or L2) of the gap G (L30). = L1 × 2 = L2 × 2).

  In the charging device 11 according to the second embodiment described above, a corona discharge is generated between each discharge electrode 71 and the inclined surface portions F1 on both sides thereof to form a charged region EA. That is, the charged area EA is formed in two directions from the tip of the discharge electrode 71. According to this configuration, the same operation and effect as those of the charging device 10 (the ground electrode 60) according to the first embodiment can be obtained.

[Third embodiment]
Next, a charging device 12 according to a third embodiment will be described with reference to FIG. FIG. 10 is a plan view showing a part of the ground electrode 61 and the discharge electrode 71 of the charging device 12. In the following description, the same components as those of the charging devices 10 and 11 according to the above-described first and second embodiments are denoted by the same reference numerals, and the same description will be omitted.

  In the charging device 11 according to the second embodiment, the plurality of discharge electrodes 71 are arranged on the upstream side and the downstream side in the flow direction with the ground electrode 61 interposed therebetween. However, in the charging device 12 according to the third embodiment, The difference is that a plurality of discharge electrodes 71 are arranged on the upstream side in the flow direction of the ground electrode 61.

  The three supports 70 are arranged facing three recesses D2 on the upstream side in the flow direction of the ground electrode 61. The plurality of discharge electrodes 71 are supported by the three supports 70 and extend into the recess D2 (downstream side). The plurality of discharge electrodes 71 (three support members 70) are linearly arranged at substantially equal intervals when viewed from a plane.

  A flow prevention member 72 that closes the flow hole H is fixed to a valley (a bent portion of the pair of inclined surfaces F1) of the concave portion D2 on the downstream side. The flow preventing member 72 is made of, for example, a synthetic resin or a metal, and is formed in a substantially triangular prism shape in accordance with the valley of the concave portion D2. The flow preventing member 72 is provided in a region where the charging region EA cannot be formed by the upstream discharge electrode 71, and prevents passage of dust-containing air in this region.

  According to the charging device 12 according to the third embodiment described above, the same operations and effects as those of the charging devices 10 and 11 according to the first and second embodiments can be obtained.

[Fourth embodiment]
Next, a charging device 13 (ground electrode 62) according to a fourth embodiment will be described with reference to FIG. FIG. 11 is a plan view showing a part of the ground electrode 62 and the discharge electrode 71 of the charging device 13. In the following description, the same components as those of the charging devices 10 to 12 according to the above-described first to third embodiments are denoted by the same reference numerals, and the same description will be omitted.

  In the charging devices 10 to 12 according to the first to third embodiments, the ground electrode 60 is formed by bending a single wire net, but in the charging device 13 according to the fourth embodiment, the ground electrode 62 is divided. It is different in that it is composed of four ground plates 62A (wire mesh).

  Each ground plate 62A is formed in a substantially flat plate shape. The four grounding plates 62A are arranged at substantially equal intervals in the front-rear direction, and are fixed to the fixing plates 56 to 58. The four grounding plates 62A are inclined in the same direction with respect to the flow direction. Each ground plate 62A is rotated clockwise with respect to the flow direction when viewed from a plane, and is inclined forward from the upstream side to the downstream side in the flow direction. A space S is formed between the adjacent ground plates 62A, and a gap G is formed between the ground plate 62A and the discharge electrode 71. The ground plate 62A forms an inclined surface portion F1 facing the gap G. In addition, each ground plate 62A (inclined surface portion F1) may be inclined in a direction opposite to FIG.

  Each of the three supports 70 is disposed in the space S between the adjacent ground plates 62A. Each support 70 enters from the upstream side in the flow direction to the vicinity of the center. The plurality of discharge electrodes 71 are supported by three supports 70 and extend in the space S (downstream in the flow direction). The inclined surfaces F1 adjacent to each other are arranged to face each other with the discharge electrode 71 interposed therebetween. The plurality of discharge electrodes 71 (three supports 70) are arranged side by side at substantially equal intervals in the front-rear direction when viewed from a plane. The shortest distances L1 and L2 of the gap G between the tip of the discharge electrode 71 and the ground plates 62A on both sides are set to be substantially the same (L1 = L2).

  According to the charging device 13 according to the fourth embodiment described above, the same operation and effect as those of the charging devices 10 to 12 (ground electrodes 60 and 61) according to the first to third embodiments can be obtained. That is, corona discharge can be generated between the discharge electrode 71 and the inclined surfaces F1 on both sides thereof. Thereby, since the charged area EA can be generated on both sides of the discharge electrode 71, dust can be charged over a wide range. Further, since the inclined surface portion F1 is disposed so as to partition the adjacent discharge electrodes 71, electric field interference between the adjacent discharge electrodes 71 can be suppressed.

[Fifth Embodiment]
Next, a charging device 14 (ground electrode 63) according to a fifth embodiment will be described with reference to FIG. FIG. 12 is a plan view showing a part of the ground electrode 63 and the discharge electrode 71 of the charging device 14. In the following description, the same components as those of the charging devices 10 to 13 according to the above-described first to fourth embodiments are denoted by the same reference numerals, and the same description will be omitted.

  In the charging device 13 according to the fourth embodiment, a region (non-charged region) where the charged region EA cannot be formed exists near the center of the flow direction of the ground plate 62A (gap G) (see FIG. 11). Therefore, in the charging device 14 according to the fifth embodiment, the ground electrode 63 is arranged to be inclined with respect to the flow direction. More specifically, the four ground plates 62A arranged in parallel in the front-rear direction are provided in a state in which the four ground plates 62A are inclined in the direction opposite to the inclination direction of the individual ground plates 62A. Specifically, the entire four grounding plates 62A are rotated clockwise with respect to the flow direction when viewed from above, and are inclined rearward from the upstream side to the downstream side in the flow direction. The inclination directions of the four ground plates 62A as a whole are changed according to the inclination directions of the individual ground plates 62A.

  According to the charging device 14 according to the fifth embodiment described above, the charging area EA can be formed also near the center of the flow direction of the ground plate 62A (gap G), and the area where the charging area EA cannot be formed is reduced. be able to.

  In the charging devices 10 to 14 according to the first to fifth embodiments, the two charging units 45 are mounted in the charging chamber R3, but the present invention is not limited to this. It is sufficient that one or more charging units 45 are mounted in the charging chamber R3.

  In the charging devices 10 to 14 according to the first to fifth embodiments, the wire mesh is used as the ground electrodes 60 to 63, but the present invention is not limited to this. For example, the ground electrode may be one in which a plurality of circulation holes H are opened in a metal plate such as a punching metal (not shown). Further, the ground electrode may have a plurality of cut-and-raised portions formed in one metal plate to open a plurality of circulation holes H (not shown).

  In the charging devices 10 to 12 according to the first to third embodiments, six inclined surface portions F1 of the ground electrodes 60 and 61 are formed, and in the charging devices 13 and 14 according to the fourth and fifth embodiments, the inclined surfaces F1 are inclined. Although four ground plates 62A constituting the surface portion F1 are provided, the present invention is not limited to this. For example, two or more inclined surface portions F1 and the ground plate 62A may be provided so as to sandwich the discharge electrode 71.

  Further, in the charging devices 10 to 14 according to the first to fifth embodiments, the (discharge end) of the discharge electrode 71 enters between the adjacent inclined surface portions F1, but the present invention is not limited to this. . For example, when the adjacent discharge electrodes 71 are arranged at intervals that do not cause electric field interference, or the like, the discharge electrodes 71 (tips thereof) are inclined without entering between the adjacent inclined surface portions F1. You may arrange | position at the position which does not overlap with the surface part F1.

  It should be noted that the description of the above embodiment shows one mode of the charging device and the dust collecting device according to the present invention, and the technical scope of the present invention is not limited to the above embodiment.

  The technology of the present invention can be used for a charging device that charges fine particles generated from a processing machine such as a metal or a resin. Further, the present invention can be used for a dust collection device that collects charged fine particles.

1-5 Dust collection device 10-14 Charging device 20 Collection device 60-63 Ground electrode 70 Support body 71 Discharge electrode F1 Inclined surface portion F2 Facing surface portion G Gap H Flow hole

Claims (10)

A charging device for charging dust contained in dust-containing air by corona discharge while flowing dust-containing air,
A plurality of discharge electrodes supported by the support,
A ground electrode provided with a gap for generating corona discharge between each of the discharge electrodes, and a ground electrode having a plurality of flow holes through which the dust-containing air flowing through each of the gaps passes.
The charging device, wherein the ground electrode includes a plurality of inclined surfaces facing the plurality of gaps and inclined with respect to a flow direction of the dust-containing air entering the gaps.   The charging device according to claim 1, wherein the inclined surfaces adjacent to each other are arranged to face each other with the discharge electrode interposed therebetween.   2. The charging device according to claim 1, wherein the inclined surfaces adjacent to each other are inclined in opposite directions, and are arranged line-symmetrically with the discharge electrode as a symmetric axis. 3.   4. The charging device according to claim 1, wherein the inclined surface portion is inclined in a range of 20 degrees or more and 45 degrees or less with respect to a flow direction of the dust-containing air entering the gap. 5. .   The charging device according to claim 1, wherein the ground electrode is formed such that the plurality of inclined surface portions are continuous.   The charging device according to any one of claims 1 to 5, wherein the discharge electrode is formed by bundling a plurality of fibrous line electrodes.   The plurality of discharge electrodes are alternately arranged at positions shifted by a half pitch in a direction orthogonal to the flow direction on both the upstream side and the downstream side of the flow direction of the dust-containing air with the ground electrode interposed therebetween. The charging device according to any one of claims 1 to 6, wherein   The tip part of the discharge electrode is equidistant with respect to the mutually adjacent said inclined surface part, and is arrange | positioned in the position which overlaps with the said inclined surface part, The Claim 1 characterized by the above-mentioned. Charging device. The ground electrode includes a facing surface portion extending in a direction perpendicular to the flow direction of the dust-containing air between the inclined surface portions adjacent to each other,
9. The tip of the discharge electrode is arranged at a position equidistant from the inclined surface portion adjacent to each other and the facing surface portion therebetween. 3. The charging device according to claim 1. A charging device according to any one of claims 1 to 9,
A dust collecting device, which is provided downstream of the charging device in the direction of flow of the dust-containing air and collects dust charged by the charging device.

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