JP6317558B2 - Electric dust collector - Google Patents

Description

  The present invention relates to an electrostatic precipitator that charges and collects particles such as fine dust and mist in dust-containing air by corona discharge generated by application of a high voltage.

  Conventionally, an industrial electrostatic precipitator has been used to perform air purification in a factory by sucking dust-containing air generated from a processing machine such as a machining center. The electrostatic precipitator has a charging unit that charges particles such as fine dust and mist in the dust-containing air by corona discharge generated by applying a high voltage, and a dust collecting unit that collects particles charged by the charging unit. Is provided.

  As a conventional electrostatic precipitator of this type, for example, as disclosed in Patent Document 1, a plurality of support substrates on which a large number of discharge needle electrodes are arranged side by side in a vertically spaced manner are arranged in parallel. Or a protruding discharge electrode for applying a high voltage, as disclosed in Patent Document 2, or the like. Further, there are known ones configured by alternately arranging grounding plates connected to the ground.

JP 2007-222717 A JP 2008-207168 A

  However, in the electric dust collector disclosed in Patent Document 1 or 2 described above, as the fine dust and mist in the dust-containing air are sucked, the fine dust and mist are gradually deposited on the ground electrode plate, and the amount of the accumulated dust is constant. If the distance between the ground electrode and the discharge needle electrode is reduced when the amount reaches, the abnormal discharge may occur and the operation may be stopped, or the temperature may rise to cause the worst fire, Alternatively, there is a problem that deposits on the ground plate re-scatter.

  In addition, since a plurality of ground electrode plates are provided, it takes time to clean and remove fine dust and mist adhering to and deposited on the ground electrode plate, and it is difficult to improve usability.

  Furthermore, in the electric dust collector of Patent Document 1 described above, in order to widen the charging region, a configuration in which the discharge needle electrodes are obliquely arranged with respect to the flow direction of the dust-containing air has also been proposed. Even when the configuration is adopted, due to the structure in which the discharge needle electrode and the grounding electrode plate are arranged in parallel to the dust-containing air, there is inevitably an area where the discharge is weak, and all fine dust in the dust-containing air In addition, since the mist cannot be charged, it is difficult to increase the charging efficiency, resulting in a decrease in the collection efficiency.

  Furthermore, since the ground electrode plates are provided in parallel so as to follow the flow direction of the dust-containing air, it is difficult to shorten the length of the electrode device in the longitudinal direction (flow direction of the dust-containing air). Therefore, the electric dust collector described in Patent Document 1 or 2 has a problem that it is difficult to reduce the size of the product. Furthermore, in the electric dust collector of patent document 1, since a charge part and a dust collection part are comprised by the separate frame body, there also exists a problem that a number of parts increases and it is difficult to aim at size reduction of a product.

  The present invention has been made to solve the above-described problems, and suppresses the occurrence of abnormal discharge by reducing the amount of particles such as fine dust and mist adhering to the ground electrode plate as much as possible to make it difficult to get dirty. By reducing the number of ground plates, the cost can be reduced, maintainability can be improved, and the size of the product can be reduced, and particles such as fine dust and mist in the dust-containing air can be charged reliably. An object of the present invention is to provide an electrostatic precipitator that is excellent in charging efficiency.

  In order to solve the above-described problems, the first electrostatic precipitator of the present invention is an electrostatic precipitator that charges and collects particles such as fine dust and mist in dust-containing air by corona discharge generated by application of a high voltage. A ground electrode plate that is arranged in a direction that blocks the flow of dust-containing air and that has a large number of openings that allow the passage of dust-containing air, and each of the openings on the downstream side in the flow direction of the dust-containing air from the ground electrode plate. And a support for supporting the base end portion of the discharge needle electrode so that a predetermined distance is maintained between the distal end portion of the discharge needle electrode and the peripheral portion of the opening portion. A substrate, a plurality of dust collecting plates arranged in parallel in the flow direction of the dust-containing air from the discharge needle electrode, and a high voltage electrode plate disposed between the dust collecting plates so as to face the dust collecting plate And.

  According to the first electrostatic precipitator of the present invention, the discharge needle electrode has each opening of the ground electrode plate such that the tip of the discharge needle electrode and the peripheral edge of the opening maintain a predetermined distance. Therefore, the dust-containing air that passes through the opening always passes through the charging area, and the discharge needle electrode does not discharge abnormally. Particles can be charged and charging efficiency can be increased. In addition, since the ground electrode plate is disposed in a direction that blocks the flow of the dust-containing air, the length of the dust-containing air in the flow direction can be shortened, and downsizing can be realized. Furthermore, particles such as fine dust and mist charged by the discharge needle electrode are reliably moved to the dust collecting plate side by the repulsive action of the high voltage electrode plate provided on the dust-containing air downstream side. Particles can be collected.

  In the second electric dust collector of the present invention, the dust collecting plate is formed to extend to the upstream side in the flow direction to a position where the dust collecting plate wraps with the support substrate.

  According to the second electrostatic precipitator of the present invention, the repulsive force due to the applied voltage acts at the place where the dust collecting plate wraps with the support substrate, and the fine dust or mist charged by the discharge needle electrode. Since particles such as are immediately collected by the dust collecting plate, the collection efficiency can be improved.

  In the third electrostatic precipitator of the present invention, the distance from the tip of the discharge needle electrode to the peripheral edge of the opening corresponding to the discharge needle electrode is the closest to the discharge needle electrode of the dust collector plate. It is provided so that it may become shorter than the distance to an edge part.

  According to the third electrostatic precipitator of the present invention, a discharge area can be reliably generated between the discharge needle electrode and the ground electrode plate. Moreover, since the area of the dust collecting plate is large enough to prevent abnormal discharge and more charged particles can be collected, the collection efficiency of charged particles can be improved.

  In the fourth electric dust collector of the present invention, the first dust collecting plate is disposed so as to extend upstream in the flow direction to a position where the dust collecting plate wraps with the supporting substrate at an intermediate position between the adjacent supporting substrates. A dust collecting plate, and a second dust collecting plate disposed on the downstream extension line of the supporting substrate in the flow direction and spaced from the supporting substrate, wherein the high-voltage plate is the first collecting plate. It is arranged at an intermediate position between the dust plate and the second dust collecting plate, respectively.

  According to the fourth electric dust collector of the present invention, by providing the first dust collecting plate and the second dust collecting plate, the area of the dust collecting plate can be increased. It has excellent collection efficiency, can cope with suction of high concentration particles, and can extend the maintenance cycle.

  In the fifth electrostatic precipitator of the present invention, the high-voltage electrode plate is located at a position where the entire peripheral edge portion of the high-voltage electrode plate is inside the entire peripheral edge portion of the second dust collector plate when viewed from a direction orthogonal to the flow direction. It is characterized by being formed smaller than the second dust collecting plate.

  According to the fifth electric dust collector of the present invention, the distance between the high-voltage plate and the second dust-collecting plate is set to a distance between the high-voltage plate and the second dust-collecting plate. Since it can take larger than a separation distance, it can prevent that abnormal discharge generate | occur | produces between the peripheral parts (edge) which is a location which is easy to discharge. Further, by making the high voltage electrode plate smaller than the second dust collecting plate, it is possible to prevent the collection area from being reduced and the maintenance cycle from being shortened.

  In the sixth electric dust collector of the present invention, a high voltage applied between the high voltage electrode plate, the first dust collector plate, and the second dust collector plate is the discharge needle electrode and the ground electrode. It is characterized in that it is controlled to be 1/2 the size of the high voltage applied to the plate.

  According to the sixth electric dust collector of the present invention, for example, in order to maintain the discharge even when the discharge needle electrode is worn due to long-term operation, the discharge needle electrode and the ground electrode plate Only the voltage of the charged part in between can be raised. At this time, if the voltage of the dust collector between the high-voltage plate and the first dust collector and the second dust collector is also raised together, the high-voltage plate and the first collector are increased. Since the distance between the dust plate and the second dust collecting plate does not change, abnormal discharge (spark) is likely to occur. When the abnormal discharge (spark) occurs, the first dust collecting plate or There is a risk that the particles collected on the second dust collecting plate will ignite and a fire may occur. However, by controlling the voltage of the charging unit and the voltage of the dust collecting unit separately, it is possible to reliably prevent the occurrence of such abnormal discharge and the occurrence of fire due to particle ignition.

  Further, by controlling the voltage of the dust collecting part to be 1/2 the magnitude of the high voltage of the charging part, the high voltage is placed at an intermediate position between the first dust collecting plate and the second dust collecting plate. Since the electrode plate can be disposed, the particles charged in the charging portion are repelled by the high voltage applied to the high voltage electrode plate, and the first dust collecting plate and the second dust collecting plate are efficiently collected. Particles are collected and the collection efficiency can be improved. Furthermore, the collected particles accumulate on the first dust collecting plate and the second dust collecting plate, but the voltage of the dust collecting unit is controlled to 1/2 of the voltage of the charging unit. Energy at the time of occurrence of abnormal discharge (spark) can be kept small, abnormal discharge (spark) due to collection and deposition of particles can be prevented, and the occurrence of fire and ignition can be prevented.

  In the seventh electric dust collector of the present invention, the opening of the ground electrode plate is formed by a round hole having an inner diameter of 13 mm, and the distance between the tip of the discharge needle electrode and the peripheral edge of the opening is 10 mm. Thus, the high voltage of −8 kV is applied between the discharge needle electrode and the ground electrode plate.

  According to the seventh electric dust collector of the present invention, since a discharge can be reliably generated between the discharge needle electrode and the ground electrode plate, a stable charged area can be generated. Moreover, the voltage applied between the discharge needle electrode and the ground electrode plate is set to a value (−8 kV) with a margin equal to or less than the abnormal discharge generation voltage, thereby suppressing the occurrence of abnormal discharge. can do. Furthermore, by setting the distance between the tip of the discharge needle electrode and the peripheral edge of the opening to 10 mm, the size of the dust-containing air in the flow direction can be made compact, and the size of the electrostatic precipitator can be reduced. Can be planned.

  The eighth electric dust collector of the present invention is arranged such that the dust collecting plate extends to the upstream side in the flow direction to a position where the dust collecting plate wraps with the support substrate at an intermediate position between the adjacent support substrates. The electrode plate is disposed at an intermediate position between the dust collecting plates, and is integrated with the support substrate on the downstream extension line of the support substrate in the flow direction.

  According to the eighth electric dust collector of the present invention, the repulsive force due to the applied voltage acts at the place where the dust collecting plate is wrapped with the support substrate, and the fine dust or mist charged by the discharge needle electrode. Since particles such as are immediately collected by the dust collecting plate, the collection efficiency can be improved. Further, by integrating the high voltage electrode plate and the support substrate, it is possible to reduce the number of parts and the cost with a simple configuration, thereby improving the economy.

  In the ninth electric dust collector of the present invention, when the high voltage plate is viewed from a direction perpendicular to the flow direction, the upstream end of the high voltage plate is in the flow direction of the dust plate. It is formed smaller than the dust collecting plate so that the peripheral edge portion of the high voltage plate excluding the upstream end portion in the flow direction is inside the peripheral edge portion of the dust collecting plate. It is characterized by that.

  According to the ninth electric dust collector of the present invention, the distance between the high voltage electrode plate and the peripheral edge (edge) of the dust collector plate is larger than the separation distance between the high voltage electrode plate and the dust collector plate. Therefore, it is possible to prevent abnormal discharge from occurring between the peripheral portions (edges) that are easily discharged. Further, by making the high voltage electrode plate smaller than the dust collecting plate, it is possible to prevent the collection area of the dust collecting plate and the maintenance cycle from being shortened. In addition, the high voltage electrode plate coincides with the upstream end of the dust collection plate in the flow direction when viewed from the direction orthogonal to the flow direction, so the dust collection plate has a voltage applied from the high voltage plate. The repulsive force acts effectively, and particles such as fine dust and mist charged by the discharge needle electrode are immediately collected on the dust collecting plate, so that the collection efficiency can be improved. The occurrence of abnormal discharge between the discharge needle electrode and the dust collecting plate can be prevented.

  In the tenth electric dust collector of the present invention, the dust collecting plate is disposed so as to extend upstream in the flow direction to a position where the dust collecting plate wraps with the supporting substrate at an intermediate position between the adjacent supporting substrates. The electrode plate is disposed at an intermediate position between the dust collecting plates, and is disposed apart from the support substrate on the downstream extension line of the support substrate in the flow direction.

  According to the tenth electric dust collector of the present invention, the voltage of the charging portion between the discharging needle electrode and the ground electrode plate and the voltage of the dust collecting portion between the high-voltage electrode plate and the dust collecting plate are respectively separated. By controlling to the above, it is possible to form a stable and uniform charging area between the discharge needle electrode and the ground electrode plate, improve the charging efficiency, generate abnormal discharge, It is possible to reliably prevent the occurrence of fire due to the ignition of.

  The eleventh electric dust collector of the present invention is characterized in that the discharge needle electrode, the support substrate and the high voltage electrode plate are integrally formed.

  According to the eleventh electric dust collector of the present invention, it is possible to reduce the number of parts and the cost with a simple configuration, and it is possible to improve the economy.

  According to the present invention, the dust-containing air that passes through the opening of the ground electrode plate always passes through the charging area, and particles such as fine dust and mist in the dust-containing air are removed without causing abnormal discharge of the discharge needle electrode. It can be charged and charging efficiency can be increased. In addition, since the ground electrode plate is disposed in a direction that blocks the flow of the dust-containing air, the length of the flow direction of the dust-containing air can be shortened, and downsizing can be realized. Furthermore, particles such as fine dust and mist charged by the discharge needle electrode move to the dust collecting plate side by the repulsive action of the high voltage electrode plate provided on the downstream side of the dust-containing air, thereby reliably capturing the particles. It is possible to obtain various excellent effects such as collection.

It is a side view which shows the inside of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the electrode apparatus of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the inside of the electrode apparatus of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is a top view which shows the electrode apparatus of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is a side view which shows the electrode apparatus of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. It is a plane sectional view which shows partially the electrode device of the electrostatic precipitator which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the electrode apparatus of the electrostatic precipitator which concerns on the 2nd Embodiment of this invention. It is a top view which shows the electrode apparatus of the electrostatic precipitator which concerns on the 2nd Embodiment of this invention. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. It is a plane sectional view which shows partially the electrode device of the electrostatic precipitator which concerns on the 2nd Embodiment of this invention. It is C arrow directional view of FIG. It is a side view which shows the modification of the electrode apparatus of the electrostatic precipitator which concerns on the 2nd Embodiment of this invention. It is a plane sectional view showing another modification of the electrode device of the electric dust collector concerning the 2nd embodiment of the present invention. It is a front view which shows another modification of the electrode apparatus of the electrostatic precipitator which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the application example which built in the electric dust collector which concerns on the 1st and 2nd embodiment of this invention in the apparatus for business use. It is a top view which shows the effect | action of the electrode apparatus of the conventional electrostatic precipitator. It is a front view which shows the effect | action of the electrode apparatus of the conventional electrostatic precipitator.

  Hereinafter, an electric dust collector according to an embodiment of the present invention will be described with reference to the drawings.

  First, an overall configuration of an electric dust collector according to a first embodiment of the present invention will be schematically described with reference to FIG. Here, FIG. 1 is a side view showing the inside of the electrostatic precipitator according to the first embodiment of the present invention. In the following description, for the sake of convenience, the directions of up, down, front, back, left and right are based on the direction seen from the direction in which the dust-containing air is sucked into the electric dust collector (the left arrow in FIG. 1).

  The electrostatic precipitator according to the first embodiment of the present invention includes a rectangular parallelepiped main body case 1. The main body case 1 has a suction port 2 opened on the front side and an exhaust port 3 opened on the rear side of the upper surface.

  In the main body case 1, an eliminator or a prefilter (not shown) disposed behind the suction port 2, an electrode device 4, and a suction fan 5 are arranged in the direction in which dust-containing air flows (arrows in FIG. 1). The motor 6 is attached to the rear surface side of the main body case 1 as a drive source for rotating the suction fan 5.

  Next, the electrode device 4 of the electrostatic precipitator according to the first embodiment of the present invention will be described in detail with reference to FIGS. 2 is a perspective view showing the electrode device 4, FIG. 3 is a perspective view showing the inside of the electrode device 4, FIG. 4 is a plan view showing the electrode device 4, and FIG. 5 is a side view showing the electrode device 4. 6 is an AA arrow view of FIG. 4, FIG. 7 is a BB arrow view of FIG. 4, and FIG. 8 is a plan sectional view showing the electrode device 4.

  As shown in FIG. 2, the electrode device 4 includes an electrode device body 10 and a high voltage power supply unit 11 that applies a high voltage to the electrode device body 10. The high voltage power supply unit 11 is configured to boost an alternating current source 12 with a high voltage transformer 13 and then convert an alternating current into direct current with a voltage doubler 14 and further boost the alternating current to generate a high voltage. It also functions as an output control unit for controlling the output of the high voltage applied to the electrode device body 10.

  The electrode device body 10 includes a frame 15 having a rectangular shape as viewed from the front side and a hollow inside, a ground electrode plate 16 attached to the front surface of the frame 15 and connected to the ground, and a rear side (including the ground electrode plate 16). A plurality of support substrates 17 arranged in a vertical posture in a direction orthogonal to the ground electrode plate 16 in the frame 15 on the downstream side of the dust air distribution direction) and on the support substrate 17 forward in the frame 15 The discharge needle electrode 18 that is cantilevered and the vertical posture in the direction perpendicular to the ground electrode plate 16 in the frame 15 behind the tip end portion 18a of the discharge needle electrode 18 (downstream in the direction in which the dust-containing air flows). And a plurality of high voltage electrode plates 20 arranged in a vertical posture so as to face the dust collection plate 19 in the frame 15.

  As shown in FIGS. 2 to 7, the frame body 15 includes left and right side plates 21 that are erected so as to face each other, and six connections that are provided in a horizontal posture between the left and right side plates 21. Shafts 22a, 22b, 23a, 23b, 24a, 24b.

  The left and right side plates 21 have a vertically long box shape in which an outer surface 25 is formed in a concave shape, and a first power supply member 26 and a second power supply member 27 connected to the high-voltage power supply unit 11 are arranged on the outer surface 25 in the front-rear direction. It is arranged.

  The first power supply member 26 has a first opposed piece 29 formed in a vertically long shape so as to face the front walls 28 of the left and right side plates 21, and a right angle forward from the first opposed piece 29 in the central portion of the first opposed piece 29. And a first end piece 31 formed by bending forward at a right angle from the first facing piece 29 at the upper and lower ends of the first facing piece 29. ing. Between the first central piece 30 and the upper and lower first end pieces 31, a first insulator 32 is interposed between the first opposing piece 29 and the front wall 28, respectively. The power supply member 26 is supported in a state of being insulated by the left and right side plates 21.

  The second feeding member 27 has a second facing piece 34 that is formed in a vertically long shape so as to face the rear walls 33 of the left and right side plates 21, and a right angle rearward from the second facing piece 34 in the central portion of the second facing piece 34. A second central piece 35 formed by bending the second opposing piece 34, a second upper end piece 36 formed by bending the second opposing piece 34 at a right angle rearward from the second opposing piece 34, and a second opposing piece 34, and a second lower end piece 37 formed by bending forward from the second opposing piece 34 at a right angle. Between the second central piece 35 and the second upper end piece 36 and the second lower end piece 37, a first insulator 39 is interposed between the second opposing piece 34 and the rear wall 33, respectively. Thus, the second power feeding member 27 is supported in a state insulated from the left and right side plates 21.

  The six connecting shafts 22a, 22b, 23a, 23b, 24a, 24b have upper and lower first connecting shafts 22a, 22b whose both ends are fastened to the left and right first end pieces 31, and second left and right second ends. The upper and lower second connection shafts 23a and 23b fastened to the upper end piece 36 and the second lower end piece 37, and the upper and lower third connection shafts 24a and 24b fastened to the left and right side plates 21 at both ends. Yes. In the side view, the first connection shafts 22a and 22b are arranged on the same vertical line, the second connection shafts 23a and 23b are arranged at diagonal positions between the upper rear side and the lower center side, and the third connection shafts 24a and 24b. Is arranged diagonally outside the second connecting shafts 23a, 23b. In addition, circular escape holes 47 (see FIG. 5) are formed on the upper and lower sides of the left and right side plates 21 at positions corresponding to the second connection shafts 23a and 23b. The connecting shafts 23a and 23b and a second spacer 48 described later are prevented from interfering with each other.

  As shown in FIG. 2, the ground electrode plate 16 is formed in a flat plate shape by a single rectangular conductive metal (iron in the embodiment) in which a large number of round hole-shaped openings 41 are formed. It is detachably attached to the front surface of the frame 15 in a direction that blocks the flow of the dust-containing air by a detachable means such as a detachable rivet (direction perpendicular to the flow direction of the dust-containing air). The openings 41 are arranged at regular intervals so as to be aligned vertically and horizontally like a grid. In the present embodiment, a total of 132 openings 41 are provided across the upper and lower 12 steps and the left and right 11 rows, and the inner diameter of the opening 41 is set to 13 mm.

  As shown in FIG. 3, the support substrate 17 is formed of a plate material made of a metal (aluminum in the embodiment) having a vertically long strip shape and having conductivity, and the upper and lower end portions thereof are connected to the first connecting shafts 22a and 22b. And the support substrates 17 are held in parallel at equal intervals by the first spacers 42 attached to the first connecting shafts 22a and 22b. In the present embodiment, eleven support substrates 17 are provided corresponding to the arrangement of the openings 41 and are arranged so as to pass through the vicinity of the middle of the openings 41 in a front view.

  As shown in FIGS. 3 to 8, the crimping portions 9 are formed on one support substrate 17 by the number of stages corresponding to the number of openings 41 (12 in this embodiment) corresponding to one row. A base end portion 18b of one discharge needle electrode 18 is cantilevered at each crimping portion 9 of each stage. The discharge needle electrode 18 is held in a horizontal posture with its tip 18a facing forward. The discharge needle electrode 18 is made of a titanium alloy called 64 titanium, specifically, a JIS 60 type alloy (6% Al + 4% V + 90% Ti), for example, a thin wire having a diameter of φ0.5 mm to 0.6 mm. It is formed in a shape or a needle shape, and the tip is polished.

  The discharge needle electrode 18 is held in a horizontal posture with the tip end portion 18a facing forward from the crimping portion 9, and the tip end portion 18a of the discharge needle electrode 18 is center line CL (see FIG. 8)). Thereby, the front-end | tip part 18a of the needle electrode 18 for discharge and the peripheral part of the opening part 41 maintain a fixed space | interval. In the present embodiment, the distance (see FIG. 8L1) between the distal end portion 18a of the discharge needle electrode 18 and the peripheral portion of the opening 41 is set to 10 mm in order to achieve compactness.

  By configuring the discharge needle electrode 18 in this manner, the amount of ozone generated can be significantly reduced, the workability is excellent, and stable discharge is possible, and the wear amount of the discharge needle electrode 18 is suppressed, Long life can be achieved. Further, since the discharge needle electrode 18 made of 64 titanium is excellent in toughness, it is difficult to break when caulking and bending can be performed, and durability can be improved.

  As shown in FIGS. 2 to 8, the dust collecting plate 19 is connected to the ground, and the first dust collecting plate 43 disposed at an intermediate position of the support substrate 17 and the rear extension of the support substrate 17. Second dust collecting plates 44 arranged on the line, and the first dust collecting plates 43 and the second dust collecting plates 44 are alternately arranged. The third connecting shafts 24a and 24b penetrate through the upper rear portion and the lower front portion of the first dust collecting plate 43 and the second dust collecting plate 44, respectively, and are attached to the third connecting shafts 24a and 24b. 3 spacers 45 (see FIG. 3) hold the first dust collecting plate 43 and the second dust collecting plate 44 in parallel at equal intervals. In the present embodiment, ten first dust collecting plates 43 and eleven second dust collecting plates 44 are alternately arranged.

  As well shown in FIG. 8, the first dust collecting plate 43 is formed to extend forward to a position where the front end portion 43 a coincides with the front end portion 17 a of the support substrate 17. At this time, the distance L1 from the distal end portion 18a of the discharge needle electrode 18 to the peripheral edge portion of the opening 41 corresponding to the discharge needle electrode 18 is the closest to the first dust collecting plate 43 of the discharge needle electrode 18. It is set to be shorter than the distance L2 to the front end portion 43a. In this embodiment, L1 is set to 10 mm and L2 is set to 13 mm.

  Cutouts 46 (see FIG. 7) are formed in the upper and lower ends of the front portion of the first dust collecting plate 43, whereby the first connecting shafts 22a, 22b and The first spacer 42 does not interfere. In addition, circular escape holes 47 (see FIG. 7) are formed above and below the first dust collecting plate 43 at positions corresponding to the second connecting shafts 23a and 23b. The second connection shafts 23a and 23b and a second spacer (not shown) described later do not interfere with the dust plate 43.

  The front end portion 44a of the second dust collecting plate 44 is disposed at a predetermined distance rearward from the rear end portion 18b of the discharge needle electrode 18, and the front end portion 44a of the second dust collecting plate 44 in a side view. The upper and lower peripheral edges excluding are arranged so as to coincide with the upper and lower peripheral edges of the first dust collecting plate 43. In addition, circular escape holes 47 (see FIG. 6) are formed above and below the second dust collecting plate 44 in the same manner as the first dust collecting plate 43, whereby the second dust collecting plate 44 is prevented from interfering with the second connecting shafts 23a, 23b and a second spacer (not shown) described later.

  The high voltage electrode plate 20 is disposed at an intermediate position between the first dust collecting plate 43 and the second dust collecting plate 44 so as to sandwich the first dust collecting plate 43 or the second dust collecting plate 44 from both sides. Is provided. The second connecting shafts 23a and 23b penetrate through the upper rear portion and the lower front portion of the high voltage electrode plate 20, respectively, and each high voltage electrode plate 20 is provided by the second spacer attached to the second connection shafts 23a and 23b. The gap is held in parallel at equal intervals. In this embodiment, 22 high voltage electrode plates 20 are arranged.

  As shown well in FIG. 6, the high voltage electrode plate 20 has a second side so that the entire peripheral edge portion of the high voltage electrode plate 20 is inside the entire peripheral edge portion of the second dust collecting plate 44 in a side view. The dust collecting plate 44 is smaller than the dust collecting plate 44 (in this embodiment, about 6 mm). Further, a notch 49 (see FIG. 6) is formed in the upper rear portion and the lower front portion of the high voltage electrode plate 20, respectively, whereby the third connecting shafts 24a and 24b and the first connection shafts 24a, 24b and the 3 so as not to interfere with the spacer 45 (see FIG. 3). As shown well in FIG. 7, the high voltage electrode plate 20 includes the first collector plate such that the upper and lower peripheral edges are inside the upper and lower peripheral edges of the first dust collecting plate 43 in a side view. It is formed slightly smaller than the dust plate 43. Further, as described above, the front end portion 43 a of the first dust collecting plate 43 is formed to extend forward to a position that coincides with the front end portion 17 a of the support substrate 17. It is formed larger than the peripheral part by one or more forwards.

  Next, the operation of the electrostatic precipitator according to the first embodiment of the present invention will be described.

  As shown by arrows in FIGS. 1 and 2, dust-containing air generated from a processing machine such as a machining center is sucked into the main body case 1 from the suction port 2 by suction of a suction fan 5 that is rotated by driving of a motor 6. Inhaled. The dust-containing air that has flowed into the main body case 1 is filtered by the eliminator (or the prefilter) and then sucked into the electrode device 4.

  In the electrode device 4, a high voltage HV is applied to the discharge needle electrode 18 from the high voltage power supply unit 11 through the first power supply member 26, and the tip 18 a of the discharge needle electrode 18 is generated by corona discharge generated thereby. And a clean parabolic conical charging area EA is formed between the peripheral edge of the opening 41 of the ground electrode plate 16. On the other hand, a high voltage LV is applied to the high voltage electrode plate 20 from the high voltage power supply unit 11 via the second power feeding member 27.

  In the case of the present embodiment, in order to reduce the size, the distance between the distal end portion 18a of the discharge needle electrode 18 and the entire peripheral edge portion of the opening 41 is set to 10 mm, so that the start voltage of corona discharge is about 6 mm. It will be about 5kV. Therefore, the high voltage HV applied between the distal end portion 18a of the discharge needle electrode 18 and the entire peripheral edge portion of the opening 41 is set to −8 kV with some allowance added to the discharge start voltage. Yes. On the other hand, the high voltage LV applied to the high voltage plate 20 is set to -4 KV which is 1/2 of the high voltage HV.

  As shown in FIG. 8, when the dust-containing air passes through the charging area EA formed in this way, particles such as fine dust and mist in the dust-containing air are charged, and the charged particles have a high voltage. By being repelled by the high voltage LV applied to the electrode plate 20, it is collected by the first dust collecting plate 43 and the second dust collecting plate 44. As a result, the dust-containing air becomes clean air and is discharged from the exhaust port 3 to the outside of the main body case 1 as indicated by an arrow shown on the upper right side of FIG.

  As described above, according to the electric dust collector according to the first embodiment of the present invention having the above-described configuration, the distal end portion 18a of the discharge needle electrode 18 and the peripheral portion of the opening 41 of the ground electrode plate 16 are predetermined. Since the discharge needle electrode 18 is arranged corresponding to each opening 41 of the ground electrode plate 16 so as to maintain the distance, the dust-containing air that passes through the opening 41 always passes through the charging area EA and discharges. Without abnormal discharge of the needle electrode 18, particles such as fine dust and mist in the dust-containing air can be charged, and charging efficiency can be increased. Further, since the ground electrode plate 16 is arranged in a direction that blocks the flow of the dust-containing air, the length of the dust-containing air in the flow direction can be shortened, and downsizing can be realized. Furthermore, particles such as fine dust and mist charged by the discharge needle electrode 18 are caused by the repulsive action of the high voltage electrode plate 20 provided on the downstream side of the dust-containing air, and the first dust collecting plate 43 side and the second dust collecting plate 43 side. By moving to the dust collecting plate 44 side, the particles can be reliably collected.

  Further, since the first dust collecting plate 43 extends to the upstream side in the flow direction of the dust-containing air up to a position where the first dust collecting plate 43 wraps with the support substrate 17, the first dust collecting plate 43 is connected to the support substrate 17. Since the repulsive force due to the applied voltage acts at the lapping location, particles such as fine dust and mist charged by the discharge needle electrode 18 are immediately collected by the first dust collecting plate 43, The collection efficiency can be improved.

  Further, the distance L1 from the tip end portion 18a of the discharge needle electrode 18 to the peripheral edge portion of the opening 41 corresponding to the discharge needle electrode 18 is the end portion of the first dust collecting plate 43 closest to the discharge needle electrode 18. Therefore, the discharge area can be reliably generated between the discharge needle electrode 18 and the ground electrode plate 16. In addition, since the area of the first dust collecting plate 43 can be formed large enough to prevent abnormal discharge and more charged particles can be collected, the collection efficiency of charged particles can be further improved. .

  Further, since the dust collecting plate 19 includes the first dust collecting plate 43 and the second dust collecting plate 44 and the area of the dust collecting plate 19 can be increased, the collection efficiency of the charged particles is increased. In addition to being able to cope with the suction of high-concentration particles, a maintenance cycle such as cleaning of the dust collecting plate 19 can be extended.

  Further, by forming the high voltage electrode plate 20 smaller than the second dust collecting plate 44 in a side view, the distance between the high voltage electrode plate 20 and the peripheral edge (edge) of the second dust collecting plate 44 is set to a high voltage. Since the distance between the electrode plate 20 and the second dust collecting plate 44 can be set larger than that, it is possible to prevent abnormal discharge from occurring between the peripheral portions (edges) that are easily discharged. Further, by making the high voltage electrode plate 20 smaller than the second dust collecting plate 44, it is possible to prevent the collection area from being reduced and the maintenance cycle from being shortened.

  Further, the high voltage LV applied between the high voltage electrode plate 20 and the dust collecting plate 19 is controlled to be 1/2 the size of the high voltage HV applied between the discharge needle electrode 18 and the ground electrode plate 16. Thus, for example, even when the discharge needle electrode is worn due to long-term operation, only the voltage HV between the discharge needle electrode 18 and the ground electrode plate 16 can be increased in order to maintain the discharge. . At this time, if the voltage LV between the high voltage electrode plate 20 and the dust collecting plate 19 is also increased, the distance between the high voltage electrode plate 20 and the dust collecting plate 19 does not change. When (spark) easily occurs and abnormal discharge (spark) occurs, the particles collected on the dust collecting plate 19 are ignited and there is a risk of fire. However, by separately controlling the voltage HV between the discharge needle electrode 18 and the ground electrode plate 16 and the voltage LV between the high-voltage electrode plate 20 and the dust collecting plate 19, the occurrence of such abnormal discharge, It is possible to reliably prevent the occurrence of fire due to the ignition of particles.

  Further, the voltage LV between the high voltage electrode plate 20 and the dust collecting plate 19 is controlled to be ½ of the voltage HV between the discharge needle electrode 18 and the ground electrode plate 16, thereby allowing the first collector. Since the high voltage electrode plate 20 can be disposed at an intermediate position between the dust plate 43 and the second dust collecting plate 44, the particles charged by the high voltage LV applied to the high voltage electrode plate 20 repel, Particles are efficiently collected on the first dust collecting plate 43 and the second dust collecting plate 44, and the collection efficiency can be improved. Further, the collected particles are deposited on the first dust collecting plate 43 and the second dust collecting plate 44, and the voltage LV between the high voltage electrode plate 20 and the dust collecting plate 19 is used as the discharge needle electrode 18. And the voltage HV between the ground electrode plate 16 and the ground electrode plate 16 is controlled to be 1/2, so that the energy at the occurrence of abnormal discharge (spark) can be kept small, and abnormal discharge due to particle collection and deposition ( (Spark) can be prevented, and the occurrence of fire and ignition can be prevented.

  In addition, by setting the voltage HV applied between the discharge needle electrode 18 and the ground electrode plate 16 to a value (−8 kV) with a margin equal to or less than the abnormal discharge generation voltage, the occurrence of abnormal discharge is prevented. Can be suppressed. Furthermore, by setting the distance between the distal end portion 18a of the discharge needle electrode 18 and the peripheral edge portion of the opening 41 to 10 mm, the dimension in the flow direction of the dust-containing air can be made compact, and the electric dust collector can be downsized. Can be achieved.

  Further, the ground electrode plate 16 is arranged in a direction orthogonal to the flow direction of the dust-containing air, and a large number of openings 41 are formed in the ground electrode plate 16. Since it has the function of a ground plate and the function of rectifying dust-containing air, it is not necessary to provide a separate rectifying plate, and the cost can be reduced accordingly.

  In addition, since the ground electrode plate 16 is detachably provided on the frame 15 and is composed of only one sheet metal, when the ground electrode plate 16 is contaminated by the deposition of fine dust or mist, In particular, dirt accumulated on the back surface side of the ground electrode plate 16 (downstream in the direction of the flow of dust-containing air) can be easily cleaned, improving maintainability and reducing the number of parts, resulting in cost reduction. Can be reduced. Further, by forming the ground electrode plate 16 with a single sheet metal disposed in an orthogonal direction that blocks the flow of dust-containing air, the size of the electrode device 4 in the longitudinal direction (the flow direction of the dust-containing air) is shortened. And the size of the electrostatic precipitator itself in the longitudinal direction can be reduced, so that the product can be downsized.

  Next, the electrode device 50 of the electrostatic precipitator according to the second embodiment of the present invention will be described in detail with reference to FIGS. Here, FIG. 9 is a perspective view showing an electrode device 50 of an electric dust collector according to the second embodiment of the present invention, FIG. 10 is a plan view showing the electrode device 50, and FIG. 11 is a view taken along arrows AA in FIG. FIG. 12, FIG. 12 is a BB arrow view of FIG. 10, FIG. 13 is a plane sectional view showing the electrode device 50, and FIG. 14 is a C arrow view of FIG. In the following description, for simplification of description, the same reference numerals as those in FIGS. 1 to 8 are given to the same components as those of the electrode device 4 in the first embodiment. Detailed description thereof will be omitted.

  As shown in FIG. 9, the electrode device 50 includes an electrode device main body 51 and a high voltage power supply unit 11 that applies a high voltage to the electrode device main body 51.

  As shown in FIGS. 9 to 14, the electrode device main body 51 includes a rectangular frame 52 as viewed from the front side and a hollow inside, and a ground attached to the front surface of the frame 52 and connected to the ground. The electrode plate 16 and a plurality of high-voltage electrode plates 53 arranged in parallel in a vertical posture in a direction orthogonal to the ground electrode plate 16 in a frame 52 behind the ground electrode plate 16 (downstream in the direction in which dust-containing air flows). And the discharge needle electrode 18 that is cantilevered and supported by the high-voltage electrode plate 53 toward the front in the frame 52, and a plurality of dust collectors arranged in parallel at a vertical position at an intermediate position between the high-voltage electrode plates 53. And a plate 54.

  The frame 52 includes left and right side plates 55 erected so as to face each other, and four connection shafts 56 a, 56 b, 57 a, 57 b that are provided in a horizontal posture between the left and right side plates 55. It is configured.

  The left and right side plates 55 have a vertically long box shape formed in a concave shape, and the left and right side plates 55 are respectively provided with circular escape holes 58 at the upper rear and the lower front, respectively. A support member 59 is attached.

  The four connecting shafts 56a, 56b, 57a, 57b have upper and lower first connecting shafts 56a, 56b whose both ends are fastened to the left and right lever support members 59, and upper rear corners of the left and right side plates 55. And upper and lower second connecting shafts 57a and 57b fastened to the lower front corner. In a side view, the first connecting shafts 56 a and 56 b are arranged at diagonal positions between the upper rear side and the lower front side, and pass through the escape hole 58. The second connection shafts 57a and 57b are arranged at diagonal positions on the outer side of the first connection shafts 56a and 56b.

  The high voltage electrode plate 53 is formed of a conductive metal (iron in the embodiment) plate material. The first connecting shafts 56a and 56b pass through the upper rear portion and the lower front portion of the high voltage electrode plate 53, respectively, and each height is increased by a first spacer (not shown) attached to the first connecting shafts 56a and 56b. The voltage plate 53 is held in parallel at equal intervals. In the present embodiment, 14 high-voltage plates 53 are provided corresponding to the arrangement of the openings 41 and are arranged so as to pass near the center of the openings 41 in a front view. In the present embodiment, a total of 168 openings 41 of the ground electrode plate 16 are provided across the upper and lower 12 stages and the left and right 14 rows.

  As shown well in FIG. 12, the high voltage electrode plate 53 is configured to collect dust so that the upper and lower peripheral edges excluding the front end 53 a are inward of the upper and lower peripheral edges of the dust collector 54 in a side view. It is smaller than the plate 54 (in this embodiment, about 9 mm). Cutout portions 60 are formed in the upper rear portion and the lower front portion of the high voltage electrode plate 53, respectively, whereby the second connection shafts 57a and 57b and a second spacer 61 (described later) are formed on the high voltage electrode plate 53. 9)). Insulators 62 are interposed between the high-voltage electrode plate 53 and the insulator support member 59 on the left and right end portions, respectively, so that the high-voltage electrode plate 53 is insulated from the left and right side plates 55. It is supported in the state that was done.

  The high-voltage electrode plate 53 also has a function as a support substrate, and the front end portion 53a has a number of caulking portions (not shown) of openings 41 corresponding to one row (in this embodiment, 12). The base end portion 18b of one discharge needle electrode 18 is cantilevered at the crimping portion of each step.

  The dust collecting plate 54 is grounded, and the second connecting shafts 57a and 57b penetrate through the upper rear portion and the lower front portion of the dust collecting plate 54, respectively, and are attached to the second connecting shafts 57a and 57b. The second spacer 61 (see FIG. 9) holds the dust collecting plates 54 in parallel at equal intervals. In this embodiment, thirteen dust collecting plates 54 are provided.

  As well shown in FIG. 13, the dust collecting plate 54 is formed to extend forward to a position where the front end portion 54 a coincides with the front end portion 53 a of the high voltage electrode plate 53. At this time, the distance L1 from the distal end portion 18a of the discharge needle electrode 18 to the peripheral edge portion of the opening 41 corresponding to the discharge needle electrode 18 is the front end portion 54a of the dust collecting plate 54 closest to the discharge needle electrode 18. Is set to be shorter than the distance L2.

  Next, the operation of the electrode device 50 for an electrostatic precipitator according to the second embodiment of the present invention will be described.

  As shown in FIG. 13, the high voltage HV is applied to the high voltage electrode plate 53 and the discharge needle electrode 18 from the high voltage power supply unit 11 through the first connecting shaft 56b on the lower side. Due to the corona discharge, a clean parabolic conical charging area EA is formed between the distal end portion 18 a of the discharge needle electrode 18 and the entire peripheral end portion of the opening 41 of the ground electrode plate 16. In this embodiment, the high voltage HV is set to -8 kV, but may be set to a positive high voltage +8 kV.

  When the dust-containing air sucked into the electrode device 50 passes through the charging area EA formed in this way, particles such as fine dust and mist in the dust-containing air are charged, and the charged particles are the high-voltage electrode plate. By being repelled by the high voltage HV applied to 53, it is collected by the dust collecting plate 54. Thereby, the dust-containing air becomes clean air and is discharged to the outside.

Thus, according to the electric dust collector according to the second embodiment of the present invention having the above-described configuration,
The high voltage electrode plate 53 is integrated with the support substrate, and the dust collecting plate 54 is arranged to extend to the upstream side in the flow direction of the dust-containing air to a position where it is wrapped with the front end portion 53a of the high voltage electrode plate 53. Has been. For this reason, a repulsive force due to the applied voltage acts on the lapped portion, and the charged particles are immediately collected by the dust collecting plate 54, so that the collection efficiency can be improved. Further, by integrating the high-voltage electrode plate 53 and the support substrate, the number of parts and the cost can be reduced with a simple configuration, and the economy can be improved.

  Further, the front end portion 53a of the high voltage electrode plate 53 coincides with the front end portion 54a of the dust collector plate 54 in a side view, and the upper and lower peripheral edges of the high voltage electrode plate 53 excluding the front end portion 53a are the peripheral edges of the dust collector plate 54. Since the high voltage electrode plate 53 is formed to be smaller than the dust collecting plate 54 so as to be inside the portion, the distance between the high voltage electrode plate 53 and the peripheral edge (edge) of the dust collecting plate 54 is set to the high voltage electrode plate 53. And the separation distance between the dust collecting plates 54 can be larger. For this reason, it is possible to prevent abnormal discharge from occurring between the peripheral portions (edges) that are easily discharged. Further, by making the high voltage electrode plate 53 smaller than the dust collecting plate 54, it is possible to prevent the collection area from being reduced and the maintenance cycle from being shortened.

  In the above-described second embodiment, the discharge needle electrode 18 and the high voltage electrode plate 53 are configured separately, but as shown in FIG. 15, the discharge needle electrode 61 and the high voltage electrode The plate 62 and the sheet metal may be integrally formed, and the discharge needle electrode 61 may be tapered to have a triangular projection shape. In this case, the number of parts can be reduced, and the cost can be reduced.

  In the second embodiment described above, the high voltage electrode plate 53 is formed integrally with the support substrate. However, as shown in FIG. 16, the high voltage electrode plate 53 is separated from the support substrate 71. May be.

  In this case, the voltage HV between the discharge needle electrode 18 and the ground electrode plate 16 and the voltage HV between the high voltage electrode plate 53 and the dust collecting plate 54 can be controlled separately. Therefore, a stable and uniform charging area can be formed between the discharge needle electrode 18 and the ground electrode plate 16, and the charging efficiency can be improved. In addition, an abnormal discharge or a fire due to particle ignition can be achieved. Can be reliably prevented. The voltage HV between the discharge needle electrode 18 and the ground electrode plate 16 and the voltage HV between the high-voltage electrode plate 53 and the dust collecting plate 54 may be the same value or different values.

  In addition, as shown in FIG. 17, the opening 91 of the ground electrode plate may be formed in a rectangular shape and the four corners of the opening 91 may be curved. Thus, when the opening 91 of the ground electrode plate 90 has a rectangular shape, a larger opening area can be ensured than when the opening 91 has a round hole shape. Is particularly effective. Furthermore, by making the four corners of the opening 91 R-shaped, it is possible to suppress a decrease in the discharge amount in the charging area EA at the four corners, and it is also possible to suppress the accumulation of fine dust and mist at the four corners.

  Next, the charging area EA of the electrode device will be described by comparing the conventional electrode device and the electrode devices 4 and 50 of the present invention with reference to FIGS. 8, 13, 14, 19 and 20. FIG.

  In FIG. 19, a support substrate 102 is disposed between the ground electrode plates 101 arranged side by side, and the discharge needle electrode 103 is supported along the flow direction of the dust-containing air so as to be parallel to the ground electrode plate 101. FIG. 20 is a plan view showing an electrode device 100 of a conventional electrostatic precipitator supported by 102, and FIG. 20 is a front view thereof, and each shows a charging area EA by a one-dot chain line. In this case, as shown by the dashed ellipse in FIG. 20, there is a weakly charged area WA between the discharge needle electrodes 103. In order to reduce this weakly charged area WA, it has also been proposed to attach the discharge needle electrode 103 so as to be inclined in the vertical direction (see FIGS. 4 to 6 in Patent Document 1). It is difficult to cover all weak areas WA. Therefore, the conventional electrode device 100 has a problem that it is difficult to improve the charging efficiency.

  On the other hand, in the electrode devices 4 and 50 of the electrostatic precipitator according to the first and second embodiments of the present invention described above, the opening of the ground electrode plate 16 is provided as shown in FIGS. A charging area EA can be formed between the entire periphery of the portion 41 and, particularly when the opening 41 has a round hole shape, a conical charging in which a clean parabola is drawn in the opening 41. Area EA can be formed. Therefore, the dust-containing air always passes through the opening 41, and particles such as fine dust and mist in the dust-containing air can be reliably and uniformly charged, and air ions and fine dust generated by high-voltage corona discharge can be obtained. In addition, since the efficiency of collision (contact) with mist can be increased, efficient charging can be performed.

  In addition, since the above description of the embodiment of the present invention describes a preferred embodiment of the electric dust collector according to the present invention, there may be various technically preferable limitations. The technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

  The technology of the present invention is expected to be used in an electric dust collector that sucks and collects dust and oil mist generated in a processing factory. Further, as shown in FIG. 18, it is expected that the electrostatic precipitator 90 of the present invention is built in and used in the business equipment 91.

  18 has a vertically long rectangular parallelepiped shape, an oil tank 92 disposed in the lower part of the interior, an electric dust collector 90 disposed in the upper part of the interior, a suction port 93 opened in the front center, An operation portion 94 penetrating in the upper part of the front surface and an exhaust port 95 opened in the upper part of the rear surface are provided. The electric dust collector 90 has a push-in type fan 96, and the air that flows into the inside through the suction port 93 by the driving of the fan 96 includes the smoke generated from the oil tank 92 as shown by the arrows in FIG. After that, it is cleaned by passing through the electrostatic precipitator 90 and discharged to the outside through the exhaust port 95.

16 Ground electrode plate 17 Support substrate 18 Discharge needle electrode 18a (tip of discharge needle electrode) 19 Dust collector plate 20 High voltage electrode plate 41 Opening portion 43 First dust collector plate 44 Second dust collector plate 53 High Voltage electrode plate 54 Dust collector plate 61 Discharge needle electrode 62 High voltage electrode plate 71 Support substrate 91 Opening

Claims (7)

In an electrostatic precipitator that charges and collects fine dust and mist particles in dust-containing air by corona discharge generated by the application of high voltage.
A grounding electrode plate that is arranged in a direction that blocks the flow of dusty air and that has a large number of openings that allow the dusty air to pass through;
On the downstream side in the direction of flow of dust-containing air from the ground electrode plate, a discharge needle electrode disposed corresponding to each opening,
A support substrate that supports the base end of the discharge needle electrode such that the distal end of the discharge needle electrode and the peripheral edge of the opening maintain a predetermined distance;
A plurality of dust collecting plates arranged in parallel on the downstream side in the flow direction of the dust-containing air from the tip of the discharge needle electrode;
A high voltage electrode plate disposed between the dust collector plates and facing the dust collector plates;
With
The dust collecting plate is disposed so as to extend upstream in the flow direction to a position that coincides with an upstream end of the support substrate in the flow direction of dust-containing air at an intermediate position between the adjacent support substrates. 1 dust collecting plate and a second dust collecting plate arranged on the extension line on the downstream side in the flow direction of the support substrate and spaced from the support substrate, and the high voltage electrode plate The first and second dust collecting plates are respectively disposed at intermediate positions, and the entire peripheral edge portion of the high-voltage plate is viewed from the direction orthogonal to the flow direction. An electric dust collector, wherein the electric dust collector is formed smaller than the second dust collecting plate so as to be inside the entire peripheral edge of the dust plate.   The distance from the tip of the discharge needle electrode to the peripheral edge of the opening corresponding to the discharge needle electrode is shorter than the distance from the discharge needle electrode to the end of the dust collecting plate closest to the discharge needle electrode. The electrostatic precipitator according to claim 1, wherein the electrostatic precipitator is provided.   The high voltage applied between the high voltage electrode plate and the first dust collector plate and the second dust collector plate is a high voltage applied between the discharge needle electrode and the ground electrode plate. 3. The electrostatic precipitator according to claim 1, wherein the electrostatic precipitator is controlled to be half the size of the electric dust collector.   The opening of the ground electrode plate is formed by a round hole having an inner diameter of 13 mm, and the tip of the discharge needle electrode is disposed at the center of the opening so that the distance from the peripheral edge of the opening is 10 mm. The electrostatic precipitator according to any one of claims 1 to 3, wherein a high voltage of -8 kV is applied between the discharge needle electrode and the ground electrode plate. In an electrostatic precipitator that charges and collects fine dust and mist particles in dust-containing air by corona discharge generated by the application of high voltage.
A grounding electrode plate that is arranged in a direction that blocks the flow of dusty air and that has a large number of openings that allow the dusty air to pass through;
On the downstream side in the direction of flow of dust-containing air from the ground electrode plate, a discharge needle electrode disposed corresponding to each opening,
A plurality of dust collecting plates arranged in parallel on the downstream side in the flow direction of the dust-containing air from the tip of the discharge needle electrode;
A high voltage electrode plate disposed between the dust collector plates and facing the dust collector plates;
With
The dust collecting plate, so that the high voltage extending in the flow direction upstream to a position which coincides with the end of the flow direction upstream side of the dust-containing air of the high voltage electrode plate at an intermediate position of the electrode plate adjacent The high-voltage plate is disposed as a support substrate that supports a base end portion of the discharge needle electrode so that a distal end portion of the discharge needle electrode and a peripheral edge portion of the opening are maintained at a predetermined interval. It also has a function,
The high voltage electrode plate has a peripheral portion of the high voltage electrode plate excluding an end on the upstream side in the flow direction as viewed from a direction perpendicular to the flow direction of the dust-containing air, become such, electrical dust collector you characterized in that it is smaller than the dust collecting plate. In an electrostatic precipitator that charges and collects fine dust and mist particles in dust-containing air by corona discharge generated by the application of high voltage.
A grounding electrode plate that is arranged in a direction that blocks the flow of dusty air and that has a large number of openings that allow the dusty air to pass through;
On the downstream side in the direction of flow of dust-containing air from the ground electrode plate, a discharge needle electrode disposed corresponding to each opening,
A support substrate that supports the base end of the discharge needle electrode such that the distal end of the discharge needle electrode and the peripheral edge of the opening maintain a predetermined distance;
A plurality of dust collecting plates arranged in parallel on the downstream side in the flow direction of the dust-containing air from the tip of the discharge needle electrode;
A high voltage electrode plate disposed between the dust collector plates and facing the dust collector plates;
With
The dust collecting plate is disposed so as to extend upstream in the flow direction to a position that coincides with an end of the support substrate on the upstream side in the flow direction of dust-containing air at an intermediate position between the adjacent support substrates, The high voltage electrode plate is disposed at an intermediate position of each dust collecting plate, and is disposed apart from the support substrate on the extension line on the downstream side in the flow direction of the support substrate,
The high voltage electrode plate, when viewed from the direction perpendicular to the flow direction of the dust-containing air, as the peripheral portion of the high-voltage electrode plates becomes inside the periphery of the dust collecting plate, less than the dust collecting plate An electric dust collector characterized by being formed. Electrostatic precipitator of claim 5, wherein the discharge needle electrode and before Symbol high voltage electrode plate characterized in that it is formed integrally.

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