Patent Application
20230173506
This application is based on and claims the benefits of priority from Japanese Patent Application No. 2021-199120 filed on Dec. 8, 2021, which is incorporated by reference in its entirety.
This invention relates to a brush device which charges particles such as dust in dust-containing air and mist in oily smoke by corona discharge generated by applying voltage, a brush device of a static eliminator which eliminates static electricity of charged particles, an electrostatic precipitator including the brush device, and an air cleaner including the brush device.
Generally, a device that charges airborne particles by corona discharge has been known.
For example,
However, in the invention disclosed in the above-mentioned Patent Document 1, the claw-shaped projection provided in one metal plate is not provided at all of the intervals of the carbon fiber bundles, and in
In addition, in the invention disclosed in the above-mentioned Patent Document 2, it is structurally difficult for all brushes to improve and equalize the brush pullout strength and to prevent the brush from shifting from the predetermined position.
Furthermore, in the inventions disclosed in Patent Documents 1 and 2, when dirt adhering to the discharge brushes is removed by cleaning water or air blowing (blowing of compressed air) during maintenance of the discharge part, the discharge brushes bend or flex, and some wire electrodes of the discharge brush enter between the support plates or the U-shaped gap. As a result, the discharge points of the discharge brushes may decrease, resulting in a decrease in charge performance (discharge performance) and a decrease in collection performance (dust collection performance). Furthermore, if the wire electrodes of the discharge brushes enter the gap between the support plates, there is a risk that they will not be able to discharge.
The present invention is developed to solve the above problems and to provide a brush device, an electrostatic precipitator and an air cleaner capable of preventing the wire electrodes constituting the discharge brush from falling off the support board or being shifted from the predetermined position, to prevent the discharge point from decreasing and to prevent a decrease in charge performance (discharge performance) and collection performance (dust collection performance), even if pressure from cleaning water or air blowing or force in the tensile or compressive directions acts on the discharge brush when the brush device is maintained or cleaned.
In order to solve the above-mentioned problems, a first brush device of the invention is a brush device which charges airborne particles or eliminates static electricity of charged particles by corona discharge generated by applying voltage, and is characterized in that the brush device comprises: a plurality of discharge brushes formed by bundling fibrous wire electrodes; a strip-shaped support board including a first plate-shaped member and a second plate-shaped member which hold the discharge brushes from both sides; and a joining means for joining the first plate-shaped member and the second plate-shaped member, wherein the discharge brushes are disposed at intervals in a longitudinal direction of the support board with their tip end portions protruding from the support board along a width direction of the support board, and the joining means is disposed adjacent to each of the discharge brushes.
According to the first brush device of the present invention, the joining means is disposed adjacent to each discharge brush so that it becomes possible for all of the discharge brushes to improve the pullout strength and to prevent positional shift.
The second brush device of the present invention is characterized in that the joining means is disposed away from the discharge brushes on one side of each of the discharge brushes.
According to the second brush device of the present invention, it becomes possible to prevent the discharge brushes from falling off or being shifted from the support board without damaging or cutting the discharge brushes.
The third brush device of the present invention is characterized in that the joining means are disposed opposite to each other away from the discharge brushes on both sides of the discharge brushes.
According to the third brush device of the present invention, it becomes possible to enhance the effect to prevent the discharge brushes from falling off or being shifted from the support board without damaging or cutting the discharge brushes.
The fourth brush device of the present invention is characterized in that the support board is formed by joining the first plate-shaped member and the second plate-shaped member such that their fracture surfaces face each other.
According to the fourth brush device of the present invention, it becomes possible to prevent sparks (abnormal discharge) from occurring due to burrs on the fracture surfaces.
The fifth brush device of the present invention is characterized in that the support board is formed by caulking the first plate-shaped member and the second plate-shaped member.
According to the fifth brush device of the present invention, the first plate-shaped member and the second plate-shaped member can be firmly joined at a relatively low cost.
The sixth brush device of the present invention is characterized in that one of the first plate-shaped member and the second plate-shaped member is provided with a convex portion at a position where the discharge brush is disposed, and the other plate-shaped member is provided with an opening capable of being fitted into the convex portion.
According to the sixth brush device of the present invention, the convex portion creates a level difference in the mounting height of the discharge brushes and adds resistance, so that the discharge brushes can be hardly fallen off and a voltage can be stably applied to all the discharge brushes.
The seventh brush device of the present invention is characterized in that the convex portion is formed in a rectangular shape.
According to the seventh brush device of the present invention, all the wire electrodes of the discharge brush can be placed on the upper surface of the rectangular-shaped convex portion, so that the discharge brushes can be hardly fallen off.
The eighth brush device of the present invention is characterized in that the discharge brushes include a holding body holding the discharge brushes from both sides such that their tip end portions protrude, the holding body is disposed on an upper surface of the convex portion, and a height of the convex portion is set such that the holding body does not protrude from the opening when the first plate-shaped member and the second plate-shaped member are joined.
According to the eighth brush device of the present invention, it becomes possible to avoid damage to the holding body and the discharge brushes held by the holding body when the support board is handled.
The ninth brush device of the present invention is characterized in that the brush device further comprises an entering prevention means covering a gap formed between the first plate-shaped member and the second plate-shaped member which hold the discharge brushes, on an end surface in the width direction of the support board.
The tenth brush device of the present invention is characterized in that the entering prevention means includes a bent portion formed in an end portion in the width direction of at least one of the first plate-shaped member and the second plate-shaped member.
The eleventh brush device of the present invention is characterized in that a protrusion is formed in an end portion in the width direction of at least one of the first plate-shaped member and the second plate-shaped member to fill a gap formed between the adjacent bent portions.
According to the ninth to eleventh brush devices of the present invention, even if the discharge brushes are bent or flexed when dirt adhering to the discharge brushes is removed by cleaning water or air blow (compressed air jet), a part of the discharge brushes is prevented from entering into the gap between the plate-shaped members. Therefore, since a decrease in the number of discharge points can be prevented, a decrease in charge performance (discharge performance) and collection performance (dust collection performance) can be prevented.
The twelfth brush device of the present invention is characterized in that the brush device further comprises a first holding body and a second holding body which hold the discharge brushes from both sides such that tip end portions of the discharge brushes protrude, the first holding body is disposed facing the first plate-shaped member, the second holding body is disposed facing the second plate-shaped member, and a voltage is applied to at least one of the first holding body and the second holding body via a conductive adhesive layer.
According to the twelfth brush device of the present invention, the discharge brushes are held between the first holding body and the second holding body, so that the work of fixing the discharge brushes can be easily performed and the structure that makes it difficult for the discharge brushes to fall off from the support board can be realized at a relatively low cost. In addition, the structure is made relatively simple. Furthermore, since the conductive adhesive layer is provided, a voltage can be stably applied to all discharge brushes.
The thirteenth brush device of the present invention is characterized in that the discharge brush is formed by bundling 10 to 200 non-magnetic stainless steel fibrous wire electrodes each having a diameter of 5 to 25 µm.
According to the thirteenth brush device of the present invention, the discharge brushes (the bundle portions) formed by bundling the wire electrodes are easily separated, so that discharge performance can be enhanced. In addition, marketability and economic efficiency can be improved, as well as durability (rust resistance) and discharge performance (charge performance).
The electrostatic precipitator of the present invention is an electrostatic precipitator including one of the brush devices described above, and is characterized in that the electrostatic precipitator comprises a dust collecting part for collecting particles charged by the brush device; and a fan for drawing dust-containing air in, wherein the brush device and the dust collecting part are integrally formed, and the brush device, the dust collecting part and the fan are arranged in series in order from an upstream side in a flow direction of the dust-containing air.
According to the electrostatic precipitator on the present invention, by arranging the brush device, the dust collecting part and the fan in series, the height dimension of the electrostatic precipitator can be kept as low as possible. In addition, by shortening the longitudinal dimension of the brush device and integrally forming the brush device and the dust collecting part, the longitudinal dimension of the electrostatic precipitator can also be reduced, which allows for downsizing of the product.
The air cleaner of the present invention is an air cleaner including one of the brush devices described above, and is characterized in that the air cleaner comprises an air intake port; an exhaust port; a fan; and a dust collecting part, wherein dust and fine particles contained in air drawn in through the intake port by the fan are charged by the brush device, then adsorbed by the dust collecting part, and then clean air is discharged through the exhaust port.
According to the air cleaner of the present invention, particles including airborne dust and fine particles can be reliably charged and collected, and the dust collection efficiency can be improved.
According to the present invention, even if pressure from cleaning water or air blow or force in a tensile or compressive direction acts on the discharge brushes during maintenance or cleaning of the brush device, it becomes possible to prevent the wire electrodes constituting the discharge brushes from falling off the support board or being displaced from the predetermined position, and to prevent the discharge point from decreasing. Therefore, it becomes possible to prevent a decrease in the charge performance (discharge performance) and collection performance (dust collection performance), and various other excellent effects can be obtained.
Hereinafter, with reference to the drawings, the embodiment of the invention will be described.
[Entire Configuration of Electrostatic Precipitator] First, with reference to
As shown in
Inside the main body case 2, a pre-filter 5, a charging and dust collecting part 6 and a fan 7 (see
As shown in
The charging part (the brush device) 10 includes a plurality of discharge brushes 12, a plurality of support boards 13 supporting the discharge brushes 12, and a plurality of charging ground plates 14 (the ground electrodes) arranged parallel to the support boards 13 so as to face the support boards 13. An air flow path is formed between the support board 13 and the charging ground plate 14. The charging part (the brush device) 10 will be described later in detail.
The dust collecting part 11 is provided on the downstream side of the support boards 13 and the charging ground plates 14 in the air flow direction, and includes a plurality of dust collecting plates 15 arranged in parallel orientation to the support boards 13 and the charging ground plates 14, and a plurality of dust collecting voltage electrode plates 16 arranged in parallel so as to face the dust collecting plates 15.
The frame 8 includes end plates 17 provided facing each other, and ten coupling shafts 18 passed between the end plates 17 in a horizontal posture. Two coupling shafts 18 among the ten coupling shafts 18 support both the upper and lower end portions of the support boards 13, another four coupling shafts 18 support the upper, lower, left and right end portions of the dust collecting plates 15, and the remaining four coupling shafts 18 support the upper, lower, left and right end portions of the dust collecting voltage electrode plates 16.
To the coupling shaft 18 of the support board 13 and the coupling shaft 18 of the dust collecting voltage electrode plate 16, a power supply member 20 is mounted. The power supply member 20 of the support board 13 is fixed to a stay 19 provided on the end plate 17 via an insulator 29. The power supply member 20 of the dust collecting voltage electrode plate 16 is fixed to the frame 8 via the insulator 29. To the power supply members 20, a voltage supply part 21 (see
As shown in
[Charging Part (Brush Device)] Next, with reference to
<Discharge Brush> As described above, the charging part (the brush device) 10 includes the plurality of discharge brushes 12. Each discharge brush 12 has a bundle portion formed by bundling fibrous wire electrodes into a brush-shape. The wire electrode is made of non-magnetic stainless steel fiber having a diameter of 14 µm. As the stainless steel, SUS316 made of 18% Cr and 12% Ni added with molybdenum (Mo) and excellent in marketability, economic efficiency and corrosion resistance is used. The wire electrode may be made of other non-magnetic stainless steel, for example, SUS304 containing 18% Cr and 8% Ni.
By making the wire electrode of the discharge brush 12 with the non-magnetic stainless steel, the wire electrodes may be easily separated from the bundle portion of the discharge brush 12, thereby enhancing discharge performance. If the wire electrode is made of magnetic ferrite fiber, since it may be difficult for the wire electrode to separate from the bundle portion of the discharge brush 12, the effect of electric field interference with the discharge brush may be significant. Therefore, it is difficult to generate corona discharge with a strong electric field.
The bundle portion of one discharge brush 12 is formed, for example, by bundling about hundred (100) wire electrodes.
The discharge brush 12 may be formed by bundling ten (10) to two hundred (200) wire electrodes having a diameter of 5 to 25 µm. By forming the discharge brush 12 in this way, marketability and economic efficiency can be improved, and durability (rust resistance) and static elimination performance (charge performance) can be also improved.
Each discharge brush 12 is provided in a state extending from the support board 13 along the width direction of the support board 13 toward both the upstream and downstream sides of the air flow direction. This allows the number of discharge brush 12 to be increased and the number of the area where the corona discharge is generated to be increased, compared with a case where the discharge brush 12 is provided on one side of the support board 13 in the air flow direction. Therefore, it becomes possible to charge the airborne particles efficiently. As described below, the discharge brushes 12 may be arranged from the support board 13 only on the upstream side in the air flow direction, or may be arranged from the support board 13 only on the downstream side in the air flow direction.
The discharge brushes 12 are all formed to have almost the same length, and the tips of the discharge brushes 12 are aligned approximately. The protruding length of the discharge brush 12 (the length from the edge of the support board 13 to the tip of the discharge brush 12) is set to about 5 mm. The protruding length of the discharge brush 12 is preferably set in the range of 3 to 7 mm because the separable length is 3 mm or more and the self-standing length is 7 mm or less.
The discharge brushes 12 are provided intermittently at predetermined pitches along the longitudinal direction of the support board 13. The pitch between the adjacent discharge brushes 12 is preferably in the range of 5 to 10 mm. This allows the device to be downsized (high-density layout), and also improves dust collection performance (collection performance).
The voltage applied to the discharge brush 12 is in the range of 4 to 8 kV (in this embodiment, 8 kV). A negative voltage is applied to the discharge brush 12 by direct current. By adopting the direct current method, the configuration can be made relatively simple compared with other methods (AC, pulse). Also, by adopting the negative charging method, more discharge current can be applied to the discharge brush 12 in the same space (gap) compared with the positive charge method, and the discharge stability (property of being difficult to occur abnormal discharge) can also be improved.
<Holding Body> The plurality of discharge brushes 12 are held by a holding body 34 such that both the tip end portions of the discharge brushes 12 protrude. As shown in
As the holding body 34, an aluminum tape-type brush that is widely available on the market as a member for static eliminating purposes may be used. In this case, since it is not necessary to prepare a manufacturing equipment for supplying the discharge brush 12 in the manufacturing process, the holding body 34 can be manufactured more easily and inexpensively, and the initial cost of the holding body 34 can be reduced. In addition, since the manufacturing process of the discharge brush 12 can be simplified, the manufacturing cost of the discharge brush 12 can also be reduced.
<Support Board> As described above, the charging part (the brush device) 10 includes the plurality of support boards 13. In this embodiment, the support boards 13 are provided in seven rows in an orientation parallel to the air flow direction. The support board 13 is formed by joining a base plate 40 which is the first plate-shaped member and a press plate 41 which is the second plate-shaped member. Between the base plate 40 and the press plate 41, the plurality of discharge brushes 12 held by the holding body 34 is fixed. Both the base plate 40 and the press plate 41 are made of conductive metal formed in an elongated strip.
The base plate 40 is made of aluminum which has excellent workability, and has an elongated shape. The base plate 40 is subjected to a press punching process such that the side facing the press plate 41 is a fracture surface. With the fracture surface outside in this manner, it is possible to prevent sparks (abnormal electrical discharge) from occurring due to burrs on the fracture surface.
The base plate 40 is subjected to a press punching process such that a U-shaped groove 42 is formed at one end portion (the lower end portion) and a semicircular groove 43 is formed at the other end portion (the upper end portion). The U-shaped groove 42 and the semicircular groove 43 are each formed so as to engage with the coupling shaft 18. On the coupling shaft 18 with which the U-shaped groove 42 is engaged, grooves engageable with the U-shaped groove 42 are worked in parallel at equal intervals. On the coupling shaft 18 with which the semicircular groove 43 is engaged, a plurality of spacers 44 (see
By this configuration, when the support board 13 is slid by weakening the clamping force of one coupling shaft 18, the semicircular groove 43 is disengaged from the coupling shaft 18. Then, by turning the support board 13 and separating it from the coupling shaft 18, the support board 13 can be detached from the charging and dust collecting part 6 easily. In addition, by forming one groove 42 of the base plate 40 in a U-shape having a greater groove depth than the other groove 43, when it is necessary to replace the support board 13, it becomes possible to detach and attach the support board 13 easily. When attaching the support board 13 to the charging and dust collecting part 6, the procedures can be performed in the reverse order of the procedures described above.
As well shown in
The first convex portions 45 and the second convex portions 46 are both formed by a half-punching process. The first convex portions 45 are formed at predetermined intervals along the longitudinal centerline of the base plate 40. The second convex portions 46 are formed at predetermined intervals in the longitudinal direction on both end sides in the width direction of the base plate 40, and are disposed at positions corresponding to the intervals of the first convex portions 45 and at positions corresponding outside the outermost first convex portions 45 in the longitudinal direction. The height of the first convex portions 45 and the second convex portions 46 is set such that the holding body 34 disposed on the upper surfaces of the first convex portions 45 does not protrude upward from the support board 13 when the base plate 40 is joined to the press plate 41.
The concave portion 47 is a center punch for positioning the holding body 34, and is formed outside the outermost first convex portions 45 in the longitudinal direction (between the outermost second convex portions 46 in the longitudinal direction). The round hole 48 is a hole for positioning the base plate 40 and the press plate 41, and is formed outside the outermost concave portions 47 in the longitudinal direction, and is configured to be engaged with a pin of a manufacturing jig.
The protrusions 50 are formed at predetermined intervals in the longitudinal direction on both the end surfaces in the width direction of the base plate 40, and are disposed at positions corresponding to the first convex portions 45. Thereby, grooves 51 are formed between the protrusion 50 on both the end surfaces in the width direction of the base plate 40, and the grooves 51 are disposed at the positions corresponding to the second convex portions 46.
The press plate 41 is made of stainless steel excellent in strength, and has an elongated shape. As well shown in
The first openings 52 are formed at predetermined intervals along the longitudinal centerline of the press plate 41. The first opening 52 has a dimension one size larger than the first convex portion 45 of the base plate 40 so that the first convex portion 45 can be fitted inside.
The second openings 53 are formed at predetermined intervals in the longitudinal direction at both the end sides in the width direction of the press plate 41. The second opening 53 has a dimension one size larger than the second convex portion 46 of the base plate 40 so as to be appropriately caulked with the second convex portion 46 to form a caulked portion 49 as the coupling means.
The round hole 54 is a hole for positioning the base plate 40 and the press plate 41, and is formed at a position corresponding to the round hole 48 of the base plate 40 at both the end portions in the longitudinal direction of the press plate 41, and is configured to be engaged with the pin of the manufacturing jig.
The bent portions 55 are formed at predetermined intervals in the longitudinal direction on both the end surfaces in the width direction of the press plate 41. The bent portions 55 are bent toward the facing base plate 40, and are fitted into the grooves 51 of the base plate 40 when the base plate 40 is joined to the press plate 41 such that the tip end portions of the bent portions 55 form the same surface as a non-joined surface of the base plate 40 or dent slightly from the non-joined surface of the base plate 40 so as not to protrude from the non-joined surface (see
By forming the bent portion 55 in this manner, bending relief portions 56 are formed between the bent portions 55 on both the end surfaces in the width direction of the press plate 41. As shown in
As shown in
However, as described above, since the charging part (the brush device) 10 according to the embodiment of the present invention has the bent portions 55, the above problem is prevented from occurring. Furthermore, the base plate 40 is provided with the protrusions 50 in order to fill the gaps between the bent portions 55 of the press plate 41, and the protrusions 50 prevent some of the wire electrodes of the discharge brush 12 from entering into the gap between the base plate 40 and the press plate 41 (the shaded area in
The bent portion 55 may be provided on one end surface in the width direction of the base plate 40 and the other surface in the width direction of the press plate 41, or be provided alternately on both the end surfaces in the width direction of the base plate 40 and the press plate 41.
<Supporting Method of Discharge Brush by Support Board> Next, with reference to
First, as shown in
Next, as shown in
Note that prior to the processes shown in
Next, as shown in
Next, as shown in
Also, from
When joining the base plate 40 and the press plate 41 in this manner, it is preferable that one of the base plate 40 and the press plate 41 is more easily deformed than the other. For example, by making the base plate 40 thicker and stronger while making the press plate 41 thinner and easier to be flexed, when joining the base plate 40 and the press plate 41, the press plate 41 comes into tightly contact with the base plate 40, so that the gap between the base plate 40 and the press plate 41 can be kept as small as possible.
In the embodiment of the present invention, the holding body 34 is disposed at a position where it does not interfere with the joining area between the base plate 40 and the press plate 41 (the caulked portion 49), so that the holding body 34 is not caulked together when the base plate 40 is joined to the press plate 41, and there is no risk of occurrence of joint defects.
As the joining method to join the base plate 40 and the press plate 41, there are various methods, such as welding (spot welding or the like), ultrasonic welding, screwing and adhering. However, the joining method by caulking, as in the embodiment of the present invention, is suitable because the base plate 40 and the press plate 41 can be firmly joined at low-cost. In the embodiment of the present invention, the shape of the caulked portion 49 is round, but it may be other shapes such as oval, rectangular, square, polygonal and the like.
In order to increase the tightness of the discharge brush 12, it is effective to increase the length of the discharge brush 12 that rides on the first convex portion 45. Therefore, the shape of the first convex portion 45 may be preferably a rectangle in which the length of the discharge brush 12 riding on the first convex portion 45 does not change even outside the center, rather than a round shape in which the length of the discharge brush 12 riding on the first convex portion 45 is shortened outside the center.
[Action of Electrostatic Precipitator] Next, with reference to
Dust-containing air flowing into the main body case 2 through the intake port 3 by driving the fan 7 is filtered by the pre-filter 5, and then flows into the charging part (the brush device) 10.
In the charging part (the brush device) 10, a voltage is applied to the discharge brushes 12 via the support board 13 and the holding body 34. The dust-containing air passes through the charging area formed between the discharge brushes 12 supported by the support board 13 and the charging ground plate 14 so that particles such as fine dust or mist and minute viruses in the dust-containing air are uniformly charged.
The charged particles, fine viruses and the others are then collected on the dust collecting plates 15 in the dust collecting part 11, filtered to become clean air, and then discharged through the exhaust port 4 to the outside of the electrostatic precipitator 1.
[Modified Examples of the Charging Part (Brush Device)] Next, with reference to
In the modified examples shown in
In the modified examples shown in
In the embodiments of the invention described above, the electrostatic precipitator equipped with a so-called one-stage charging and dust collecting part 6 in which the charging part (the brush device) 10 and the dust collecting part 11 are integrated, but it goes without saying that the invention can also be applied to a two-stage type electrostatic precipitator in which the charging part 10 and the dust collecting part 11 are separately provided. It is also possible to use the present invention for the charging part of an air cleaner.
In the above description of the embodiments of the present invention, various technically preferable limitations may be attached, but the technical scope of the present invention is not limited to these aspects unless otherwise stated that limit the present invention. In other words, the components in the above embodiments of the invention can be replaced with existing components, etc., as appropriate, and various variations including combinations with other existing components are possible, and the description of the above embodiments of the invention does not limit the content of the invention described in the claims. The above description of the embodiments of the invention does not limit the content of the invention described in the claims.
The technology of the present invention is expected to be used in a brush device of a static eliminator that eliminates static electricity of charged particles, an electrostatic precipitator that draws in dust and oil mist generated in processing plants and then collect them, and an air cleaner for home and commercial use.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-199120 | Dec 2021 | JP | national |
