JP2020032365A - Filter unit and dust collector - Google Patents

Abstract

To provide a filter unit which collects dust in dust-containing air by a net member and thus can suppress clogging of a filter member, and can remove the dust from the net member and the filter member at the same time.SOLUTION: A filter unit 26, which causes dust-containing air charged by corona discharge to circulate, thereby collecting dust, comprises: a net member 30 to which charged dust contained in dust-containing air are adhered; a filter member 31 which is located so as to be brought into contact with or face a circulation direction downstream side of the net member 30 with a gap interposed therebetween, and filters dust contained in the dust-containing air which has passed through the net member 30; a stationery member 32 which is fixed to the filter member 31, and has an opening 34A through which clean air, in which the dust is filtered by the filter member 31, passes. The dust collected by the net member 30 and the filter member 31 is removed by compressed-air which is blown out from a circulation direction downstream side to an upstream side through the opening 34A.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a filter unit and a dust collecting device.

  2. Description of the Related Art A dust collection device that charges and collects particles in dust-containing air by corona discharge is known.

  For example, the dust collecting device described in Patent Document 1 includes an electric dust collecting unit provided on the upstream side of the air flow path, a bag filter unit provided on the downstream side of the electric dust collecting unit, and an electric dust collecting unit. A rectifying plate arranged between the rectifying plate and the bag filter unit, and a spray port for discharging the powder adsorbent between the rectifying plate and the electric dust collecting unit were provided. The electric dust collecting section collects the dust in the dust-containing air while charging and aggregating the dust. Since the electric dust collecting portion collects 80 to 90% of the dust in the dust-containing air, the dust entering the bag filter portion can be reduced. Dust that has passed through the electrostatic precipitator is adsorbed by the powder adsorbent sprayed from the spray port, and then diffused and filtered over the entire filter filter cloth by the rectifying plate. Further, dust adhering to the filter cloth of the bag filter section is blown off by injecting compressed air from a nozzle disposed above the bag filter section.

JP-A-11-90263

  However, in the dust collector described in Patent Literature 1, a straightening plate is provided immediately before the bag filter unit, and the dust entering the bag filter unit is reduced unless the powder adsorbent is injected just before the straightening plate. Could not. In other words, it is possible to suppress the clogging of the filter cloth in the bag filter section and to reduce the cost associated with the replacement of the filter cloth, but it is necessary to add and maintain the current plate, the injection port, the powder adsorbent, and the like. Cost was incurred.

  Further, in the dust collecting device described in Patent Document 1, although the electric dust collecting portion arranged on the upstream side of the bag filter collects 80 to 90% of the dust in the dust-containing air, this electric dust collecting device is not used. It has not been sufficiently considered to remove dust adhering to the dust part.

  In order to solve the above-mentioned problems, the present invention can collect dust in dust-containing air with a mesh member to suppress clogging of the filter member, and can simultaneously remove dust from the mesh member and the filter member. Provided are a filter unit and a dust collecting device that can be used in the present invention.

  A first filter unit of the present invention is a filter unit for collecting dust by flowing dust-containing air containing dust charged by corona discharge, and attaching the charged dust contained in the dust-containing air. A filter member that is disposed opposite to or in contact with the downstream side in the flow direction of the mesh member with a gap therebetween, and that filters dust contained in the dust-containing air that has passed through the mesh member; A fixing member having an opening through which clean air obtained by filtering the dust through the member is provided, and the dust collected by the mesh member and the filtering member is moved from the downstream in the distribution direction to the upstream through the opening. Dust is removed by the blown compressed air.

  According to the first filter unit of the present invention, the charged dust in the dust-containing air can be roughly collected by the net member, so that the dust in the dust-containing air passing through the net member can be reduced. it can. Accordingly, dust to be filtered by the filtering member is reduced, and thus clogging of the filtering member can be suppressed. Further, since the dust collected on the mesh member is aggregated and coarsened, the dust which is coarsened and accumulated on the mesh member by continuous suction of the dust-containing air collapses, passes through the mesh member, and passes through the mesh member. Even if it adheres to the surface, it is difficult for the coarse dust to enter the inside of the filter member. For this reason, clogging of the filtering member can be suppressed as compared with the case where there is no net member. In addition, by blowing compressed air from the opening for discharging clean air into the filter unit, the backflowed air passes through the filter member and the mesh member, and removes dust attached to the filter member and the mesh member. be able to. That is, dust removal (backwashing) between the mesh member and the filtering member can be performed at the same time.

  The second filter unit of the present invention is the above-mentioned first filter unit, wherein the filter member is formed in a pleat shape with a plurality of folds, and the fold is located on the upstream side in the flow direction of the filter member. Is preferably opposed to the mesh member with a gap therebetween.

  According to the second filter unit of the present invention, since the filter member is formed in a pleated shape, the surface area (filtration area) can be increased as compared with a case where the filter member is a plate without folds. Thereby, the filter member can continuously filter the dust for a long time (the life of the filter member can be extended). Further, since a gap is formed between the mesh member and the fold of (the mountain fold on the upstream side in the flow direction of the filter member), the fold of the filter member expands to the upstream side in the flow direction at the time of backwashing. Contact with a member can be suppressed.

  In the third filter unit of the present invention, in the above-described first or second filter unit, one end portions of the mesh member and the filter member are fixed to the fixing member, and the mesh member, the filter member, Is preferably fixed to the mounting member.

  According to the third filter unit of the present invention, the mesh member and the filtration member can be unitized using the fixing member and the attachment member. Thereby, since the net member and the filtering member can be collectively attached to and detached from the dust collecting device, the attaching and detaching work is easily performed as compared with a case where the net member and the filtering member are detachably attached to the dust collecting device 1 separately. be able to.

  In a fourth filter unit of the present invention, in any one of the first to third filter units described above, the mesh member and the filter member are formed in a cylindrical shape extending in an axial direction, and the mesh member is Preferably, the filter member covers the outer peripheral surface of the filter member and is arranged on the same axis as the filter member.

  According to the fourth filter unit of the present invention, since the mesh member is disposed so as to surround the outer periphery of the filter member, the mesh member collects dust in the dust-containing air from the outer side to the inner side in the circumferential direction. be able to. Accordingly, the occurrence of uneven clogging in the filter member is suppressed, and the load increase and wear of the filter member can be made substantially uniform in the circumferential direction.

  The fifth filter unit of the present invention is the above-described fourth filter unit, wherein one end of the net member and the filter member is fixed to the fixing member, and the other end of the net member and the filter member is provided. Preferably, the portion is fixed to a mounting member, and the mesh member is shaped so as to gradually expand radially outward from both ends in the axial direction toward the center.

  According to the fifth filter unit of the present invention, since the mesh member has a shape swelling at the axial center, it can be allowed to bulge outward at the axial center of the filtering member during backwashing. Thereby, it can control that the axial direction center part of the filtration member which swells outward easily contacts a mesh member.

  In a sixth filter unit of the present invention, in any one of the first to third filter units described above, a pair of the filter members are disposed so as to face each other with a gap therebetween, and the mesh member is a pair of the filter members. It is preferable that a pair of filter members be disposed so as to face each other with the filter member interposed therebetween, and the openings of the fixing member be formed to correspond to gaps between the pair of filter members.

  According to the sixth filter unit of the present invention, since the pair of filter members is disposed between the pair of net members, the net member allows dust-containing air after collecting dust to pass through the filter members. Can be filtered. Thereby, dust in the dust-containing air that has passed through the mesh member can be reduced, and clogging of the filter member can be suppressed. Also, by blowing compressed air from the opening for discharging clean air into the filter unit, the air that has flowed back passes through the pair of filter members and the pair of net members, and removes dust adhering to these at the same time. Can be paid off.

  In a seventh filter unit of the present invention, in any one of the second to sixth filter units described above, the filter member is formed in a pleated shape, and the mesh member extends from a side surface to a lower end of the filter member. Is preferably formed in a substantially L-shaped section.

  According to the seventh filter unit of the present invention, since the dust removed by the backwash falls from the lower end of the mesh member, it is possible to suppress the dust removed from reattaching to the filter member. As a result, clogging of the filtering member can be suppressed.

  In an eighth filter unit of the present invention, in any one of the first to seventh filter units described above, it is preferable that the mesh member is formed of a conductive material.

  According to the eighth filter unit of the present invention, by forming the mesh member from a conductive material, an electrostatic force (Coulomb force) generated by a potential difference between the charged dust and the mesh member can be applied. Dust charged on the net member can be collected. Further, since the mesh member attracts and attaches the dust due to the electrostatic force, the mesh member can be set to have a larger opening than the inertial dust collection which collides the dust and collects the dust. Thereby, clogging of the mesh member can be suppressed.

  The first dust collecting device of the present invention includes a charging unit that charges dust contained in dust-containing air by corona discharge while flowing dust-containing air, and a charging unit that is provided downstream of the charging unit in the flow direction. A dust collection unit including any one of the first to eighth filter units, and a dust removal unit that blows compressed air toward the filter unit to remove dust collected by the filter unit.

  According to the first dust collecting apparatus of the present invention, dust can be collected by the net member first, so that clogging of the filtering member that filters dust later can be suppressed. As a result, the frequency of replacing the filter unit can be reduced. In addition, by blowing out compressed air from the opening for discharging clean air into the filter unit, dust attached to the filtering member and the net member can be removed at the same time.

  According to a second dust collector of the present invention, in the first dust collector described above, it is preferable that the mesh member is electrically connected to a ground provided in the dust collector.

  According to the second dust collecting apparatus of the present invention, since the electric charge accumulated in the net member can be removed by collecting the charged dust, a stable potential difference is generated between the charged dust and the net member. Thus, the electrostatic force (Coulomb force) can be stably applied.

  A third dust collector according to the present invention, in the above second dust collector, electrically connects the mesh member and the ground when the dust removing unit is stopped, and operates the dust removing unit. It is preferable that the apparatus further comprises a grounding control unit that releases the connection between the mesh member and the ground when the grounding is performed.

  According to the third dust collecting device of the present invention, the mesh member can stably collect the charged dust by grounding the mesh member when the dust removing unit is stopped. On the other hand, by canceling the grounding of the mesh member when the dust removing unit is operating, the potential difference between the charged dust and the mesh member can be made unstable to weaken the electrostatic force. Thereby, dust adhering to the net member can be easily removed by the backflowing air (compressed air). That is, the dust removing effect of the dust removing unit can be improved.

  A fourth dust collector according to the present invention, in the above third dust collector, wherein the ground control unit is provided at a position facing the opening, and is electrically connected to the ground. The filter unit is provided so as to protrude inside the opening, and when the dust removing unit is stopped, the dust is pushed out by the clean air filtered by the filter unit and rotates in one direction to contact the ground plate. A rotating plate that is pushed out by the compressed air when the dust removing section is operating, rotates to the other side, and separates from the ground plate.

  In the fourth dust collecting apparatus of the present invention, the rotating plate is rotatably provided in an area where the clean air and the compressed air flow, and the rotating plate is swung by the flow of the clean air and the compressed air. did. According to this configuration, when the clean air or the compressed air passes through the opening, the turning plate is grounded via the ground plate, and the turning plate is separated from the ground plate and released from the ground. Can be switched. Thus, for example, there is no need to separately provide a power or control circuit for switching the contact state of the rotating plate, and the ground state of the net member can be switched with a simple structure.

  ADVANTAGE OF THE INVENTION According to this invention, the dust in dust-containing air can be collect | recovered by a net member, and clogging of a filtration member can be suppressed. In addition, the backwash between the mesh member and the filter member can be performed at the same time.

It is a perspective view showing the dust collection device concerning a 1st embodiment of the present invention. It is a block diagram showing a control system of a dust collector concerning a 1st embodiment of the present invention. It is a sectional view showing a filter unit and a dust removal part concerning a 1st embodiment of the present invention. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. It is a sectional view (at the time of back washing) showing a filter unit and a dust removal part concerning a 1st embodiment of the present invention. It is a perspective view showing a filter unit concerning a 1st modification of a 1st embodiment of the present invention. It is a side view showing the filter unit concerning the 2nd modification of a 1st embodiment of the present invention. It is sectional drawing which shows the filter unit which concerns on the 4th modification of 1st Embodiment of this invention, a dust removal part, and a grounding control part. It is sectional drawing (at the time of backwashing) which shows the filter unit which concerns on the 4th modification of 1st Embodiment of this invention, a dust removal part, and a grounding control part. It is a perspective view showing a dust collection device concerning a 2nd embodiment of the present invention. It is a side view which shows the dust collector which concerns on 2nd Embodiment of this invention. It is a perspective view showing a filter unit concerning a 2nd embodiment of the present invention. It is XIII-XIII sectional drawing of FIG. It is sectional drawing (at the time of backwashing) which shows the filter unit which concerns on 2nd Embodiment of this invention. It is a perspective view showing a filter unit concerning a modification of a 2nd embodiment of the present invention.

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

[First Embodiment]
The dust collector 1 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing the dust collector 1. FIG. 2 is a block diagram showing a control system of the dust collecting apparatus 1. FIG. 3 is a cross-sectional view illustrating the filter unit 26 and the dust removing unit 12. FIG. 4 is a sectional view taken along line IV-IV of FIG.

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

  As shown in FIGS. 1 and 2, the dust collecting device 1 includes a charging unit 10, a dust collecting unit 11, and a dust removing unit 12. The charging unit 10 has a function of charging dust contained in the dust-containing air by corona discharge while flowing the dust-containing air. The dust collection unit 11 has a function of collecting charged dust. The dust removing unit 12 has a function of removing dust collected by the dust collecting unit 11. In the following description, the “flow direction” indicates a direction in which dust-containing air flows. The terms "upstream" and "downstream" and similar terms refer to "upstream" and "downstream" and similar concepts in the direction of flow of dust-containing air.

[Charging part]
As shown in FIG. 2, the charging unit 10 includes a charge electrode 13 including a discharge electrode and a ground electrode, and a high-voltage power supply 14 connected to the charge electrode 13. When the high voltage power supply 14 applies a DC voltage of several kV to several tens kV to the load electrode 13 (between the discharge electrode and the ground electrode), corona discharge occurs between the discharge electrode and the ground electrode. As shown in FIG. 1, a first intake duct 15 for introducing dust-containing air is connected to the upstream side of the charging unit 10. A second intake duct 16 that communicates with the dust collection unit 11 is connected to the downstream side of the charging unit 10. In order to stably generate corona discharge, it is desirable that the ground electrode of the charge electrode 13 be grounded (earthed). The ground electrode may be directly connected to the ground, or may be electrically connected to the housing 17 when the housing 17 of the dust collection unit 11 described later is connected to the ground.

[Dust collection unit]
As shown in FIG. 1, the dust collecting unit 11 includes a housing 17 having a substantially rectangular parallelepiped appearance. The housing 17 is provided with a partition plate 18 made of metal (for example, stainless steel) that divides the internal space into two in the vertical direction. The internal space of the housing 17 is partitioned by a partition plate 18 into a lower dirty room R1 and an upper clean room R2. In FIG. 1, the upper part of the housing 17 is shown by a virtual line (two-dot chain line) to show the inside of the clean room R2.

  The partition plate 18 is formed with six circular partition openings 18A. The six partition openings 18A are arranged in two rows in the front-rear direction and three rows in the left-right direction so as to correspond to six filter units 26 described later. On the lower surface of the partition plate 18, three pairs of guide rails (not shown) are provided so as to correspond to the three rows of partition openings 18A in the left-right direction.

  A filter inspection opening 17 </ b> A that opens the dirty room R <b> 1 is formed on the lower front side of the housing 17. A filter inspection door (not shown) for opening and closing the filter inspection opening 17A is attached to the housing 17 (the filter inspection door is removed in FIG. 1). Below the dirty room R1 of the housing 17, a bucket 19 for storing the dropped dust is provided. The housing 17 is provided with a bucket inspection door 19D for opening and closing the bucket 19. In addition, the housing | casing 17 is earthed | grounded (grounded) by embedding the metal rod or the electric wire electrically connected to this in the earth.

  An intake port 20 communicating with the dirty room R1 is opened on the left side surface of the housing 17, and the charging section 10 is connected to the intake port 20 via a second intake duct 16. An exhaust port 21 communicating with the clean room R2 is opened on the upper surface of the housing 17, and an exhaust duct (not shown) is connected to the exhaust port 21. An exhaust fan 22 (see FIG. 2) for forming an airflow from the intake port 20 to the exhaust port 21 is provided in the exhaust duct or the clean room R2.

  As shown in FIG. 2, the dust collecting unit 11 includes a control unit 23, an operation input unit 23A, a display / input unit 23B, a clock / timer 23C, an external input / output unit 23D, a differential pressure gauge 23E, And two dust collecting filter sections 24 (see FIG. 1).

  The control unit 23 includes an arithmetic processing unit, a storage device, and the like (not shown). An operation input unit 23A, a display / input unit 23B, a clock / timer 23C, an external input / output unit 23D, a differential pressure gauge 23E, and an exhaust fan 22 (motor) are electrically connected to an interface (not shown) of the control unit 23. Have been. Further, the interface of the control unit 23 is also electrically connected to the high-voltage power supply 14 of the charging unit 10, a solenoid valve 43 of the dust removing unit 12, which will be described later, and the like.

  The operation input unit 23 </ b> A has an ON / OFF button for switching between starting and stopping the dust collector 1. The display / input unit 23B includes a touch panel and the like, and has a function of inputting and displaying various settings. The content input by the display / input unit 23B is stored in the storage device of the control unit 23, and is appropriately used for operation control of the dust collecting device 1. The clock / timer 23C has a function of displaying the current time on the display / input unit 23B and measuring a set time. The external input / output unit 23D has a function of inputting / outputting a signal for interlocking with a laser processing machine or the like. The differential pressure gauge 23E has a function of detecting a pressure difference between the dirty room R1 and the clean room R2. By detecting this pressure difference, the pressure loss of each filter unit 26 can be measured.

<Dust collection filter section>
As shown in FIG. 1, the three dust collection filter sections 24 are arranged side by side in the dirty room R1 of the housing 17 in the left-right direction. Since the three dust collection filters 24 have the same structure, only one dust collection filter 24 will be described below.

  The dust collection filter unit 24 includes a filter plate 25 and two filter units 26. Each filter unit 26 is provided downstream of the charging unit 10 in the flow direction, and has a function of flowing dust-containing air containing dust charged by corona discharge and collecting dust. Since the two filter units 26 have the same structure, only one filter unit 26 will be described below.

<Filter plate>
As shown in FIG. 1, the filter plate 25 is formed of, for example, a metal material such as stainless steel and has a substantially rectangular plate shape that is long in the front-rear direction. The filter plate 25 has two insertion holes 25A (see FIG. 3) formed side by side in the front-rear direction. The left and right ends of the filter plate 25 are bent downward to form a pair of guide pieces 25B. The front end of the filter plate 25 is bent upward to form a contact piece 25C. In addition, a hole (not shown) through which the wing bolt B1 (see FIG. 3) passes is formed on the front side of the filter plate 25.

<Filter unit>
As shown in FIGS. 1, 3, and 4, the filter unit 26 includes a mesh member 30, a filtering member 31, a fixing member 32, and a mounting member 33. The net member 30 has a function of adhering charged dust contained in the dust-containing air. The filtering member 31 is disposed inside the mesh member 30 and has a function of filtering dust contained in the dust-containing air passing through the mesh member 30. The fixing member 32 and the attachment member 33 are attached to both end surfaces of the mesh member 30 and the filtering member 31, and have a function of uniting the mesh member 30 and the filtering member 31.

(Mesh member)
As shown in FIGS. 1 and 3, the mesh member 30 is formed in a substantially cylindrical shape extending in the vertical direction (axial direction). The mesh member 30 has an outer diameter that can be inserted into the insertion hole 25A of the filter plate 25. The mesh member 30 is formed to have substantially the same diameter from the upper part to the lower part. The net member 30 is a metal net made of metal such as stainless steel (SUS304) having excellent corrosion resistance. In the attached drawings, a part of the mesh of the mesh member 30 is illustrated.

  As the mesh member 30, a plain-woven wire mesh having a wire diameter of 1 mm or less and about several meshes to several tens of meshes is used. Specifically, the wire diameter of the mesh member 30 can be set in a range of 0.1 to 0.9 mm, but is preferably set in a range of 0.3 to 0.8 mm, More preferably, it is set in the range of 0.7 mm. The number of meshes (the number of meshes per inch) of the mesh member 30 can be set in the range of 1 to 20 meshes, but is preferably set in the range of 3 to 10 meshes, and is preferably 6 to 7 meshes. Is more preferably set in the range. Further, the mesh (opening diameter) of the mesh member 30 can be set in the range of 1 to 10 mm, but is preferably set in the range of 2 to 5 mm, and more preferably in the range of 3 to 4 mm. .

(Filter member)
As shown in FIGS. 3 and 4, the filtering member 31 is formed in a substantially cylindrical shape extending in the vertical direction (axial direction). The filtering member 31 is formed to have substantially the same length in the axial direction as the mesh member 30 and has an outer diameter smaller than that of the mesh member 30. The filtering member 31 is formed to have substantially the same diameter from the upper part to the lower part. The filtering member 31 is, for example, a nonwoven fabric formed of resin fibers such as polypropylene or polyester. Note that the filtering member 31 may be formed of a resin fiber (so-called electret) holding static electricity. The filtering member 31 is formed in a pleated shape in which a plurality of folds are formed by repeating mountain folds and valley folds on the nonwoven fabric. The fold of the filtering member 31 extends in the axial direction (vertical direction).

  The filtering member 31 is opposed to the inner peripheral surface (downstream in the distribution direction) of the mesh member 30 with a gap therebetween while being inserted into the mesh member 30. Specifically, the fold 31 </ b> A located on the upstream side in the flow direction of the filtering member 31 is opposed to the mesh member 30 with a gap (several mm) therebetween. The mesh member 30 covers the outer peripheral surface of the filter member 31 and is arranged on the same axis (concentric circle) as the filter member 31. In the present specification, “on the same axis (on a concentric circle)” does not require complete identity, but means that an error of about several millimeters in manufacturing is allowed.

(Fixing member)
As shown in FIGS. 1 and 3, upper ends (one ends) of the net member 30 and the filtering member 31 are fixed to a fixing member 32. The fixing member 32 has a circular opening 34A that allows the filtering member 31 to pass clean air obtained by filtering dust. Specifically, the fixing member 32 includes a flange portion 34 and a Venturi tube 35. The flange portion 34 and the venturi tube 35 are formed integrally.

  The flange portion 34 is formed in a flange shape extending outward from the opening 34A (the upper end portion of the venturi tube 35) when viewed from a plane. That is, the flange portion 34 is formed in an annular shape when viewed from a plane. The outer diameter of the flange portion 34 is formed larger than the diameter of the insertion hole 25A of the filter plate 25. The diameter of the opening 34 </ b> A is formed slightly smaller than the inner diameter of the filtering member 31.

  As shown in FIG. 3, the venturi tube 35 extends downward from the edge of the opening 34 </ b> A of the flange 34. The venturi tube 35 is a tube having a through hole continuous with the opening 34A. The venturi tube 35 is arranged on the same axis as the flange portion 34 (opening 34A), and has an outer diameter that can be inserted into the filtering member 31. The venturi tube 35 is formed in a substantially cylindrical shape confined at a central portion rather than upper and lower ends. The venturi pipe 35 has a function of increasing the flow rate of air (clean air or compressed air) flowing from the downstream side to the upstream side in the flow direction.

  An annular recess for fitting the upper ends of the mesh member 30 and the filtering member 31 is formed on the lower surface of the flange portion 34. The upper ends of the mesh member 30 and the filter member 31 are fixed via an adhesive in a state of being fitted into the recesses of the flange portion 34. In this state, the venturi tube 35 is inserted into the filtering member 31 and is arranged to face the inner peripheral surface of the filtering member 31 (a fold 31A located on the downstream side in the flow direction) with a gap therebetween. Further, the lower end of the venturi tube 35 is disposed above the vertical center of the filtering member 31.

(Mounting member)
As shown in FIG. 3, the lower ends (the other ends) of the net member 30 and the filtering member 31 are fixed to the mounting member 33. The attachment member 33 has a plate portion 36 and an internal support 37. The plate portion 36 and the internal support 37 are formed integrally.

  The plate portion 36 is formed in an annular shape when viewed from the bottom surface, and the internal support 37 is formed in a substantially dome shape bulging upward from the plate portion 36. The outer diameter of the plate portion 36 is formed smaller than the diameter of the insertion hole 25A of the filter plate 25 and slightly larger than the outer diameter of the mesh member 30. The internal support 37 is arranged on the same axis as the plate 36 and has an outer diameter that can be inserted into the filter member 31. The internal support 37 is formed so as to gradually decrease the outer diameter from below to above.

  As shown in FIGS. 3 and 4, a plurality of connection arms 37 </ b> A extend radially outward on the upper part of the internal support 37. The plurality of connection arms 37A are arranged at substantially equal intervals in the circumferential direction of the internal support 37. An annular connection band 37B is connected to the distal end of each connection arm 37A. A plurality of grooves are formed on the surface of the connection band 37B.

  As shown in FIG. 3, an annular recess for fitting the lower ends of the mesh member 30 and the filtering member 31 is formed on the upper surface of the plate portion 36. The lower ends of the mesh member 30 and the filtering member 31 are fixed via an adhesive in a state of being fitted in the recesses of the plate portion 36. Further, the internal support 37 is inserted into the filter member 31, and the connection band 37B is formed on the inner peripheral surface of the filter member 31 (the fold 31A located on the downstream side in the flow direction) via the adhesive applied to the groove on the surface. Fixed. In this state, the internal support body 37 is arranged to face the inner peripheral surface of the filter member 31 (the fold 31A located on the downstream side in the flow direction) with a gap therebetween. More specifically, since the upper portion of the inner support 37 is tapered, the distance between the outer peripheral surface of the inner support 37 and the inner peripheral surface of the filter member 31 gradually increases (becomes wider) from below to above. Become. The upper end of the internal support 37 is disposed near the center of the filter member 31 in the vertical direction. Therefore, the upper end of the internal support 37 is separated downward from the lower end of the Venturi tube 35 to form a space between the inner support 37 and the lower end of the Venturi tube 35.

[Assembly of dust filter unit]
Next, an assembling procedure of the dust collecting filter unit 24 will be described with reference to FIG. The dust collection filter unit 24 is configured by supporting two filter units 26 on the filter plate 25.

  Specifically, each filter unit 26 is inserted into the insertion hole 25A from the upper surface of the filter plate 25. Each filter unit 26 is supported by being hung on the filter plate 25 by the flange 34 of each filter unit 26 abutting on the periphery of the insertion hole 25A. Thus, the assembling work of the dust collecting filter unit 24 is completed.

[Mounting of dust collection filter]
Next, a procedure for attaching the dust collection filter unit 24 to the housing 17 will be described with reference to FIGS. Since the mounting procedure of the three dust collecting filter sections 24 is the same, the mounting procedure of one dust collecting filter section 24 will be described below.

  The dust collection filter unit 24 is disposed in the dirty room R1 from the filter inspection opening 17A of the housing 17 (see FIG. 1). Specifically, the worker pushes the dust collecting filter unit 24 into the dirty room R1 with the pair of guide pieces 25B of the filter plate 25 placed on the guide rail pair of the partition plate 18. Then, as shown in FIG. 3, the openings 34A of each filter unit 26 are arranged corresponding to the partition openings 18A of the partition plate 18. Next, the operator inserts the wing bolt B1 into a hole opened on the front side of the filter plate 25, and screws the tip of the wing bolt B1 into a female screw (not shown) formed on the partition plate 18. As the wing bolt B1 is screwed, the dust collecting filter portion 24 is slightly lifted up, and the peripheral portion of the opening 34A of the filter unit 26 comes into close contact with the peripheral portion of the partition opening 18A while crushing the seal member S.

  As described above, the dust collection filter unit 24 is fixed to a predetermined position in the dirty room R1 and is supported by being suspended from the partition plate 18. In this state, the opening 34A of each filter unit 26 is exposed to the clean room R2 via the partition opening 18A of the partition plate 18 (see FIG. 1).

[Dust removal unit]
As shown in FIGS. 1 to 3, the dust removing unit 12 includes a header tank 41, three blow tubes 42, and three solenoid valves 43. The dust removing unit 12 has a function of blowing compressed air toward the filter unit 26 to remove dust collected by the filter unit 26 (hereinafter, also referred to as “backwashing”).

  As shown in FIG. 1, the header tank 41 is a cylindrical pipe extending in the left-right direction in the clean room R2. The header tank 41 is arranged on the front side of the partition plate 18 so as to avoid the partition opening 18A. The right end of the header tank 41 extends outside the housing 17 and communicates with a compressor (not shown) provided in a factory.

  The three blow tubes 42 are connected to the header tank 41 via three solenoid valves 43. The three blow tubes 42 extend rearward from the header tank 41 at positions corresponding to the partition openings 18A arranged in three rows in the left-right direction. Each blow tube 42 is disposed so as to cross two partition openings 18A (filter unit 26) arranged in the front-rear direction. Two blowout ports 42A for blowing out the compressed air supplied from the compressor are formed on the lower surface of each blow tube 42 (see FIG. 3). The two outlets 42A open at positions corresponding to (substantially the centers of) the two partition openings 18A arranged in the front-rear direction (see FIG. 3).

[Dust collection operation]
Next, the dust collecting operation of the dust collecting device 1 will be described with reference to FIGS.

  First, the operator depresses the ON / OFF button of the operation input unit 23A to activate the charging unit 10 and the dust collection unit 11 (the display / input unit 23B, the differential pressure gauge 23E, the exhaust fan 22, and the like) (operation start). Ready). Note that the setting may be such that the dust collection unit 11 is activated after the charging unit 10 is activated by pressing the ON / OFF button. Further, instead of the operation of the operation input unit 23A by the operator, the external input / output unit 23D may activate the charging unit 10 and the like by using the reception of the operation signal of the laser processing machine or the like as a trigger.

  Next, the control unit 23 controls the high-voltage power supply 14 of the charging unit 10 to apply a high voltage to the charge electrode 13 and generate a corona discharge between the discharge electrode and the ground electrode. Further, the control unit 23 rotates the exhaust fan 22 of the dust collection unit 11. Then, an airflow from the intake port 20 to the exhaust port 21 is formed, so that the dust-containing air passes from the outside through the first intake duct 15 and is taken into the charging unit 10 (see FIG. 1). The dust in the dust-containing air is charged by corona discharge while passing through the charging unit 10, attracts each other, agglomerates and coarsens (greater than 20 times the particle size).

  The dust-containing air containing the charged and coarsened dust passes through the second intake duct 16 from inside the charging unit 10 and is taken into the dirty room R1 of the dust collection unit 11 (see FIG. 1). The charged and coarse dust contained in the dust-containing air is removed while passing through each filter unit 26 of the dust collection filter unit 24 (see thick arrows in FIG. 3). Specifically, the charged and coarse dust adheres to the net member 30 by electrostatic force (Coulomb force). The dust-containing air that has passed through the mesh of the mesh member 30 is filtered through the dust while passing through the filtering member 31, and becomes clean air.

  The mesh member 30 has a function of collecting charged and coarse dust before the filtration by the filtering member 31 and aggregating the accumulated dust to further promote the coarsening. For example, even if the dust accumulated due to the continuous suction of the dust-containing air collapses and passes through the mesh member 30, the coarse dust adheres to the surface of the filter member 31 and cannot enter the inside. Thus, the clogging of the filtering member 31 can be suppressed as compared with the case where the mesh member 30 is not provided. In addition, even when dust removed by backwashing described later adheres to the filtering member 31 again, clogging of the filtering member 31 can be suppressed for the same reason.

  The clean air is exhausted into the clean room R2 from the opening 34A of the filter unit 26, and is exhausted to the outside from the exhaust port 21 through the clean room R2 (see FIG. 1).

  As described above, prior to the filtration of the dust by the filtering member 31, the dust that has been charged and coarsened by the mesh member 30 is roughly removed, so that the load on the filtering member 31 due to the attachment and deposition of the dust can be reduced. When the operator presses down the ON / OFF button of the operation input unit 23A (when the external input / output unit 23D receives a stop signal of the laser processing machine or the like), the control unit 23 controls the charging unit 10 and the dust collection unit. Stop 11 etc. Thereby, the dust collecting operation of the dust collecting device 1 is stopped. At this time, the charging unit 10 may be set to stop after the dust collection unit 11 stops, contrary to the start-up. Dust that has fallen without being collected by the filter unit 26 accumulates in the bucket 19.

[Dust removal operation]
Next, the dust removing operation (backwashing operation) of the dust collecting apparatus 1 will be described with reference to FIG. FIG. 5 is a cross-sectional view showing the filter unit 26 and the dust removing unit 12 (at the time of back washing).

  The threshold value of the pressure loss (differential pressure between the dirty room R1 and the clean room R2) of the filter unit 26 is stored in the storage device of the control unit 23 in advance. The control unit 23 compares the threshold value with the detection value of the differential pressure gauge 23E, and executes a dust removal operation when it determines that the detection value has exceeded the threshold value. Further, the control unit 23 performs the dust removing operation on the three dust collecting filter units 24 one by one. The execution timing of the dust removal operation is not limited to the above. For example, the dust removal operation may be performed when the dust collector 1 is stopped, or the dust removal operation may be performed at a timing set in advance by the clock / timer 23C. You may. The threshold of the differential pressure, the time (interval) of the timer, and the like are set in advance by the operator using the display / input unit 23B.

  When performing the dust removal operation, the control unit 23 stops the exhaust fan 22 of the dust collection unit 11. As described above, the dust removal operation is preferably performed in a state where the exhaust fan 22 is stopped to stop the suction of the dust-containing air. However, the present invention is not limited to this, and the suction of the dust-containing air may be performed without stopping the exhaust fan 22. You may go while continuing. In this case, the rotation speed of the exhaust fan 22 may be lower than normal (during the dust collection operation).

  When the dust collecting unit 11 is started, the electromagnetic valve 43 is controlled by the control unit 23 and closed. Then, compressed air is stored in the header tank 41 connected to the compressor.

  When the control unit 23 determines that the detected value has exceeded the threshold value, the solenoid valve 43 is controlled and opened by the control unit 23. Then, the compressed air stored in the header tank 41 is blown out from the two outlets 42A toward the openings 34A of the two filter units 26 through the blow tube 42 (see the dashed line in FIG. 5).

  The speed of the compressed air is increased through the venturi tube 35 from the opening 34A, and flows into the filter member 31 (see the thick arrow in FIG. 5). At this time, since the distance between the outer peripheral surface of the inner support 37 and the inner peripheral surface of the filter member 31 gradually decreases from above to below in the lower part of the filter member 31, the compressed air flowing into the filter member 31 is reduced. Flows to the lower portion of the filtering member 31 without greatly decreasing the flow velocity.

  The compressed air flowing into the inside of the filtering member 31 passes from the filtering member 31 toward the mesh member 30 (see a thick arrow in FIG. 5). The backflow of the compressed air to the filtering member 31 and the net member 30 removes dust attached to the filtering member 31 and the net member 30. As described above, the dust collected by the mesh member 30 and the filtering member 31 is removed by the compressed air blown from the downstream side in the flow direction to the upstream side through the opening 34A. The dust that has been blown off falls into a bucket 19 provided below the dust collecting unit 11, and the accumulated dust is appropriately discarded.

  Note that the control unit 23 performs control to close the electromagnetic valve 43 after a lapse of a predetermined time (several seconds) from the start of compressed air injection (the opening of the electromagnetic valve 43). As a result, the compressed air is stored in the header tank 41 again.

  According to the filter unit 26 according to the first embodiment described above, the charged dust in the dust-containing air can be collected by the mesh member 30, so that the dust in the dust-containing air that has passed through the mesh member 30 can be collected. Can be reduced. Accordingly, dust to be filtered by the filtering member 31 is reduced, so that clogging of the filtering member 31 can be suppressed. In addition, by blowing out compressed air from the opening 34A that discharges clean air into the filter unit 26, the air that has flowed back passes through the filtering member 31 and the mesh member 30, and is formed between the filtering member 31 and the mesh member 30. The attached dust can be removed at the same time. That is, dust removal (backwashing) between the mesh member 30 and the filtering member 31 can be performed at the same time.

  Further, according to the filter unit 26 according to the first embodiment, since the filtering member 31 is formed in a pleated shape in which mountain folds and valley folds are repeated, the filter member 31 has a larger surface area compared to a plate shape without folds. (Filtration area) can be increased. Thus, the filtering member 31 can continuously filter dust for a long period of time (the life of the filtering member 31 can be extended).

  Further, since a gap is formed between the mesh member 30 and the fold 31A of the filter member 31, even if the filter member 31 swells outward (upstream in the flow direction) during backwashing, the fold 31A is Contact with the net member 30 can be suppressed.

  Note that the gap between the mesh member 30 and the filtering member 31 can be adjusted in proportion to the length of the filtering member 31. For example, when the length of the filtering member 31 is 500 mm and the gap with the mesh member 30 is 5 mm, when the length of the filtering member 31 is 1000 mm, the gap with the mesh member 30 is 10 mm. In addition, when the filtering member 31 is shortened, the gap becomes narrow. Thereby, even if the filtration member 31 swells at the time of back washing, contact with the net member 30 can be suppressed.

  Furthermore, since the filtering member 31 is fixed to the inner support body 37 (each connection arm 37A and the connection band 37B) at the center in the vertical direction, it is possible to prevent the filtering member 31 from being greatly expanded outward during backwashing. it can. Note that a plurality of connection arms 37A and connection bands 37B may be provided in the up-down direction and connected to the filtering member 31 at a plurality of places in the up-down direction.

  Further, according to the filter unit 26 according to the first embodiment, the mesh member 30 and the filtering member 31 can be unitized by using the fixing member 32 and the attaching member 33. Thereby, the net member 30 and the filtering member 31 can be collectively attached to and detached from the dust collecting device 1, so that compared to the case where the mesh member 30 and the filtering member 31 are separately attached to and detached from the dust collecting device 1, Work can be performed easily.

  Further, according to the filter unit 26 according to the first embodiment, since the mesh member 30 is disposed so as to surround the outer periphery of the filter member 31, the mesh member 30 is disposed in the dust-containing air from the outer side in the circumferential direction to the inner side. Dust can be collected evenly. Thereby, the occurrence of uneven clogging in the filter member 31 is suppressed, and the load increase and wear of the filter member 31 can be made substantially uniform in the circumferential direction.

  Further, according to the filter unit 26 according to the first embodiment, since the mesh member 30 is formed of a conductive material (for example, metal), the electrostatic force generated by the potential difference between the charged dust and the mesh member 30 is obtained. (Coulomb force) can be applied, and dust charged on the net member 30 can be collected. In addition, since the mesh member 30 attracts and attaches the dust by the electrostatic force, the mesh of the mesh member 30 can be set to be larger than that of the inertial dust collection in which the dust collides and collects dust. Thereby, clogging of the net member 30 can be suppressed.

  Further, according to the dust collecting apparatus 1 according to the first embodiment, since the dust can be collected by the net member 30 first, the clogging of the filter member 31 that filters the dust later can be suppressed. . As a result, the frequency of replacing the filter unit 26 can be reduced. In addition, by blowing compressed air from the opening 34A for discharging clean air into the filter unit 26, dust attached to the filtering member 31 and the net member 30 can be removed at the same time.

[First Modification of First Embodiment]
In the filter unit 26 according to the first embodiment described above, the mesh member 30 is formed in a cylindrical shape having substantially the same diameter from the upper part to the lower part, but the present invention is not limited to this. As shown in FIG. 6, in the filter unit 26 according to the first modification, the mesh member 38 has a shape that gradually expands radially outward from both upper and lower ends (both axial ends) toward the center. ing. Therefore, the gap between the mesh member 38 and the filtering member 31 is formed so as to gradually increase (widen) from the upper and lower sides toward the center. In the present specification, the "vertical (axial) center" of the mesh member 38 or the filtering member 31 does not require a strict center, but means both upper and lower ends (axial both ends). Means an intermediate region sandwiched between upper and lower ends. Therefore, the position where the filtering member 31 has the maximum diameter at the mesh member 38 can be adjusted corresponding to the position where the filtering member 31 is likely to expand radially outward. For example, in the case of the filter member 31 of the filter unit 26 according to the first embodiment, the mesh member 38 has a maximum diameter between the flange portion 34 and the connection arm 37A (connection band 37B) of the internal support 37. Preferably, it is formed.

  According to the filter unit 26 according to the first modified example of the first embodiment described above, since the mesh member 30 has a bulging shape at the center in the vertical direction, the mesh member 30 is formed at the center in the vertical direction of the filtering member 31 during backwashing. It can be allowed to bulge outward. Thereby, it is possible to suppress the vertical central portion of the filtering member 31 that easily swells outward from coming into contact with the net member 30.

[Second Modification of First Embodiment]
Further, in the filter unit 26 according to the first embodiment, since the space between the venturi tube 35 and the internal support member 37 is a space inside the filter member 31, the filter member 31 is located at a position corresponding to this space. It was easy to swell radially outward. Therefore, as shown in FIG. 7, in the filter unit 26 according to the second modified example, a belt 31 </ b> B wound around the outer peripheral surface of the filter member 31 is provided at a portion where the filter member 31 easily swells. The belt 31B is formed of, for example, a metal such as stainless steel or a synthetic resin. Note that FIG. 7 shows a state in which the mesh member 30 for approximately half a circumference has been removed to show the filtering member 31 and the belt 31B.

  According to the filter unit 26 according to the first modified example of the first embodiment described above, the portion of the filter member 31 that is likely to swell during backwashing can be pressed by the belt 31B. Further, it is preferable that the belt 31B also has a function as a spacer for maintaining a gap between the filtering member 31 and the net member 30.

[Third Modification of First Embodiment]
In the dust collector 1 according to the first embodiment described above, the net member 30 is not grounded, but may be grounded. For example, the net member 30 may be electrically connected to a ground provided in the dust collector 1. As a specific grounding method, for example, the mesh member 30 and a metal portion such as the partition plate 18 may be connected by a metal wire (not shown). Further, for example, the mesh member 30 may be fixed to the filter plate 25 with metal bolts. Further, a conductive material containing a conductive substance such as a metal filler may be applied to the concave portion on the back surface of the flange portion 34, and the mesh member 30 may be fitted into the concave portion of the flange portion 34. In this case, when the dust collecting filter unit 24 is assembled, the conductive material comes into contact with the mesh member 30 and the filter plate 25, and the mesh member 30 is connected to the ground via the filter plate 25 and the like. The ground refers to the ground electrode of the housing 17 (the metal part thereof), the ground electrode provided in the charging unit 10, and the like, in addition to the ground electrode of the entire dust collector 1. It only needs to be connected.

  According to the dust collecting apparatus 1 according to the third modification of the first embodiment described above, since the accumulated charges can be removed by grounding the mesh member 30, the dust collected between the charged dust and the mesh member 30 can be removed. By generating a stable potential difference therebetween, the electrostatic force (Coulomb force) can be stably applied.

[Fourth Modification of First Embodiment]
In the dust collector 1 according to the third modification of the first embodiment described above, the net member 30 is always grounded, but the present invention is not limited to this. As shown in FIGS. 8 and 9, in the dust collection device 1 according to the fourth modified example, when the dust removal unit 12 is stopped, the net member 30 is electrically connected to the ground, and the dust removal unit 12 operates. And a ground control unit 45 for releasing the connection between the net member 30 and the ground when the connection is established. As shown in FIG. 8, the ground control unit 45 includes a ground plate 46 provided at a position facing the opening 34A of the fixing member 32, and a rotating plate 47 provided so as to protrude inside the opening 34A. , Including. The ground plate 46 and the rotation plate 47 are each formed in a substantially plate shape with a metal material such as stainless steel, for example.

  The ground plate 46 is fixed to the partition plate 18 with metal bolts, and is electrically connected to the ground via the partition plate 18. The tip of the ground plate 46 is bent obliquely upward toward the center of the opening 34A so as to block the flow of air. The rotating plate 47 is disposed on the upper surface of the flange portion 34, and is fastened to the flange portion 34 by a metal plate (not shown) provided in a recess on the back surface of the flange portion 34 and a metal bolt. Thus, the net member 30 and the rotating plate 47 are electrically connected via the metal plate. The turning plate 47 has a turning arm 47B that turns (swings) about a turning shaft 47A. The rotating arm 47B extends toward the center of the opening 34A so as to block the flow of air.

  As shown in FIG. 8, when the dust removing unit 12 is stopped (during the dust collection operation), the rotating arm 47B of the rotating plate 47 is pushed out by the clean air in which the dust is filtered by the filter unit 26 and rotated. It rotates upward (one side) around the driving shaft 47 </ b> A and comes into contact with the bent tip of the ground plate 46. Therefore, the net member 30 is connected to the ground via the turning plate 47 and the ground plate 46.

  On the other hand, as shown in FIG. 9, when the dust removing unit 12 is operating (during the dust removing operation), the rotating arm 47B of the rotating plate 47 is pushed by the compressed air blown out from the outlet 42A and rotated. It rotates downward (the other side) about the shaft 47A and separates from the ground plate 46. Therefore, the net member 30 is disconnected from the ground.

  According to the dust collecting apparatus 1 according to the fourth modified example of the first embodiment described above, the charged dust is stabilized by the net member 30 by grounding the net member 30 when the dust removing unit 12 is stopped. And can be collected. On the other hand, by releasing the grounding of the net member 30 when the dust removing unit 12 is operating, the electrostatic force between the charged dust and the net member 30 can be reduced. Thus, dust adhering to the net member 30 can be easily removed by the backflowing air (compressed air). That is, the dust removing effect of the dust removing unit 12 can be improved.

  Further, in the dust collecting apparatus 1 according to the fourth modification, the rotating plate 47 is rotatably provided in an area (opening 34A) in which the clean air and the compressed air flow, and the flow of the clean air and the compressed air is performed. The rotating plate 47 is configured to swing. According to this configuration, when the clean air or the compressed air passes through the opening 34A, the rotating plate 47 is grounded via the grounding plate 46, and the rotating plate 47 is separated from the grounding plate 46 and grounded. It is possible to switch between the state in which it is released and the state in which it is released. Accordingly, for example, there is no need to separately provide a power or control circuit for switching the contact state of the rotating plate 47, and the ground state of the net member 30 can be switched with a simple structure.

  In addition, the grounding control unit 45 is configured to swing the rotating plate 47 using the air passing through the opening 34A, but the present invention is not limited to this. For example, a motor (not shown) driven and controlled by the control unit 23 may be provided, and the rotating arm 47B may be rotated around the rotating shaft 47A by this motor. In addition, for example, a switch (not shown) for switching between conduction and interruption is provided on a conduction path between the net member 30 and the ground, and the control unit 23 switches based on the operation and stop of the dust removal unit 12. May be controlled.

  In addition, the filter unit 26 according to the first embodiment is attached to the dust collection device 1 in a standing posture in which its axis extends in the vertical direction, but the present invention is not limited to this. For example, the filter unit 26 may be attached to the dust collector 1 in a recumbent posture in which its axis extends in the front-rear direction or the left-right direction, or may be attached to the dust collector 1 in an obliquely inclined posture.

  In addition, the filter unit 26 (the net member 30, the filter member 31) according to the first embodiment is formed in a cylindrical shape, but is not limited thereto, and may be formed in a rectangular tube shape having a polygonal cross section such as a triangle or a quadrangle. It may be formed (not shown).

[Second embodiment]
The dust collector 2 according to the second embodiment will be described with reference to FIGS. FIG. 10 is a perspective view showing the dust collector 2. FIG. 11 is a side view showing the dust collector 2. FIG. 12 is a perspective view showing the filter unit 56. FIG. 13 is a sectional view taken along line XIII-XIII of FIG. FIG. 14 is a sectional view showing the filter unit 56 (at the time of back washing). In the following description, the same components as those of the dust collector 1 according to the first embodiment (including the first and second modifications) are denoted by the same reference numerals, and the same description will be omitted.

  As shown in FIGS. 10 and 11, the dust collecting device 2 includes a charging unit 10, a dust collecting unit 50, and a dust removing unit 12.

[Dust collection unit]
The dust collecting unit 50 includes a substantially rectangular parallelepiped casing 51 that is long in the vertical direction. The housing 51 is provided with a metal partition plate 52 that divides the internal space into two in the front-rear direction. The partition plate 52 has a vertical partition plate 52V that stands substantially vertically, and an inclined partition plate 52S that is inclined upward and obliquely rearward from the upper end of the vertical partition plate 52V. The internal space of the housing 51 is partitioned by a partition plate 52 into a dirty room R1 at the rear and a clean room R2 at the front. Note that a filter inspection door 51A for opening the clean room R2 is provided on the front surface of the housing 51. In FIGS. 10 and 11, the housing 51 is indicated by a virtual line (two-dot chain line) to show the inside of the housing 51.

  The vertical partition plate 52V is formed with four substantially rectangular partition openings (not shown) that are long in the vertical direction. The four partition openings are arranged in a 2 × 2 grid. Further, a flat opening / closing plate 53 is attached to each partition opening so as to be openable and closable. At the center of each opening / closing plate 53, a slit opening 53A which is elongated vertically is formed.

  An intake port 20 communicating with the dirty room R <b> 1 is opened on the upper right side surface of the housing 51, and the charging section 10 is connected to the intake port 20 via the second intake duct 16. On the upper surface of the housing 51, an exhaust unit 54 including the exhaust fan 22 is provided. An exhaust port 21 to which an exhaust duct (not shown) is connected is opened on the top surface of the exhaust unit 54. The exhaust part 54 connects the clean room R2 and the exhaust port 21 (exhaust duct).

  The dust collecting unit 50 includes the control unit 23, an operation input unit 23A and the like (see FIG. 2) connected to the control unit 23, and four filter units 56. Since the four filter units 56 have the same structure, only one filter unit 56 will be described below.

<Filter unit>
As shown in FIG. 12, the filter unit 56 is formed in a substantially rectangular parallelepiped shape that is long in the front-back direction and flat in the left-right direction. As shown in FIGS. 12 and 13, the filter unit 56 includes a pair of net members 60, a pair of filtration members 61, a fixing member 62, and a mounting member 63.

(Mesh member, filtration member)
As shown in FIGS. 12 and 13, each net member 60 is a metal net formed in a plate shape. As shown in FIG. 13, each filtering member 61 is formed in a substantially rectangular shape when viewed from the side, and is formed in a pleated shape in which a plurality of folds 61 </ b> A extending in the vertical direction are provided on the nonwoven fabric. The pair of filtering members 61 are arranged so as to face each other across the gap G. The pair of net members 60 are arranged to face each other with the pair of filter members 61 interposed therebetween. The pair of filtering members 61 (folds 61A located on the upstream side in the distribution direction) are arranged opposite to each other on the inner side surfaces (downstream side in the distribution direction) of the pair of net members 60 with a gap (several mm) therebetween.

(Fixing member)
As shown in FIGS. 12 and 13, the front ends (one ends) of the pair of net members 60 and the pair of filtration members 61 are fixed to fixing members 62. As shown in FIG. 13, the opening 64 </ b> A of the fixing member 62 is formed corresponding to the gap G between the pair of filtering members 61. The fixing member 62 includes a flange portion 64 and a rod portion 65.

  The flange portion 64 is formed in a flange shape extending outward from the opening 64A when viewed from the front. When viewed from the front, the flange portion 64 is formed in a substantially rectangular shape that is larger than the partition opening portion opened in the vertical partition plate 52V. On the back surface of the flange portion 64, a rectangular recess for fitting the front ends of the mesh member 60 and the filtering member 61 is formed. The rod portion 65 is provided between a pair of support arms 64B extending rearward from upper and lower ends of the flange portion 64. The rod portion 65 is formed in a substantially columnar shape, and is disposed in the gap G between the pair of filtration members 61.

(Mounting member)
As shown in FIGS. 12 and 13, the rear ends (the other ends) and the upper and lower ends of the pair of net members 60 and the pair of filter members 61 are fixed to the mounting member 63. Specifically, the mounting member 63 is constituted by a pair of left and right joining members 63A. The joining member 63A is a synthetic resin frame formed to cover the ends (excluding the front end) of the mesh member 60 and the filtering member 61. The joining member 63A is formed in a U-shape (U-shape) having an open front when viewed from the side.

  One joining member 63A is insert-molded so as to be integrated with one mesh member 60 and one filtering member 61. For example, after loading the mesh member 60 and the filtering member 61 into a mold (not shown), a synthetic resin is injected into the mold to form the joining member 63A. Thereby, one net member 60 and one filter member 61 are fixed by the joining member 63A, and the right half or the left half of the filter unit 56 is formed.

  After the pair of filter units 56 formed in half are connected with the pair of filter members 61 facing each other, the pair of filter members 61 and the like are fitted into the recesses of the flange portion 64 and adhered. As described above, the filter unit 56 is assembled.

[Dust removal unit]
As shown in FIGS. 10 and 11, the dust removing unit 12 includes a header tank 41 connected to a compressor, and two blow tubes 42 connected to the header tank 41 via two solenoid valves 43. I have.

  The header tank 41 extends in the left-right direction at the upper part in the clean room R2. The two blow tubes 42 extend vertically from the header tank 41 to the floor of the clean room R2 at positions corresponding to the filter units 56 arranged in two rows in the left-right direction. The blow tube 42 is detachably attached to a floor surface or the like of the clean room R2. On the rear surface of each blow tube 42, two outlets 42A are opened at positions corresponding to the two openings 64A (slit openings 53A) arranged vertically (see FIG. 13).

[Installation of filter unit]
Next, a procedure for attaching the filter unit 56 to the housing 51 will be described. Since the mounting procedure of the four filter units 56 is the same, the mounting procedure of one filter unit 56 will be described below.

  First, the operator opens the filter inspection door 51A to open the clean room R2, and then removes the blow tube 42. Subsequently, the operator opens the opening / closing plate 53 to open the partition opening. The operator inserts the filter unit 56 with the fixing member 62 toward the front into the dirty room R1 from the partition opening. Next, the operator closes the opening / closing plate 53, and fixes the flange portion 64 by sandwiching it between the opening / closing plate 53 and the vertical partition plate 52V. The dirty room R1 is provided with a support frame (not shown) for supporting the inserted filter unit 56.

  As described above, the filter unit 56 is fixed at a predetermined position in the dirty room R1 (see FIGS. 10 and 11). In this state, the opening 64A of the filter unit 56 is exposed to the clean room R2 via the slit opening 53A of the opening / closing plate 53. After attaching the filter unit 56, the worker attaches the blow tube 42 and closes the filter inspection door 51A.

[Dust collection operation]
Next, the dust collecting operation of the dust collecting device 2 will be briefly described with reference to FIGS.

  When the charging unit 10 and the dust collection unit 11 are activated and the dust collection operation is started, the dust in the dust-containing air is charged by the charging unit 10 and coarsened, and then, in the dirty room R1 of the dust collection unit 50. (See FIG. 10). The dust-containing air taken into the dirty room R1 flows between the inner surface of the housing 51 and the filter unit 56 or between the filter units 56 adjacent on the left and right as a downward airflow (see FIG. 10).

  The dust-containing air passes from the left and right sides of the filter unit 56 toward the center (see FIG. 12). The charged and coarse dust contained in the dust-containing air is removed while passing through the filter unit 56 from both left and right sides toward the center (gap G) (see FIG. 13). Specifically, the charged and coarse dust adheres to the pair of net members 60 by electrostatic force, and the dust-containing air passing through the pair of net members 60 is filtered by the pair of filter members 61 to become clean air.

  The clean air merges in the gap G between the pair of filtration members 61 and is exhausted from the opening 64A (slit opening 53A) into the clean room R2 (see FIG. 13). The clean air flows through the clean room R2 as an ascending airflow, and is exhausted to the outside from the exhaust port 21 through the exhaust unit 54 (see FIG. 11).

  As described above, prior to the filtering of the dust by the filtering member 61, since the mesh member 60 roughly removes the dust that has been charged and coarsened, the load on the filtering member 61 due to the attachment and deposition of the dust can be reduced. Dust that has fallen without being collected by the filter unit 56 accumulates in the bucket 19.

[Dust removal operation]
Next, the dust removing operation (backwashing operation) of the dust collecting device 2 will be briefly described with reference to FIG.

  When the control unit 23 determines that the detection value of the differential pressure gauge 23E has exceeded the threshold value, the control unit 23 controls the solenoid valve 43 to open. Then, the compressed air stored in the header tank 41 is blown out from the two outlets 42A toward the openings 64A of the two filter units 56 through the blow tube 42 (see the broken line in FIG. 14).

  The jetted compressed air collides with the rod-shaped portion 65 disposed in the gap G of the pair of filter members 61 and is diffused. The compressed air diffused in the gap G flows backward from the pair of filter members 61 toward the pair of net members 60, and removes dust attached to the filter members 61 and the net members 60. The dust that has been washed off falls into the bucket 19, and the accumulated dust is appropriately discarded.

  According to the filter unit 56 according to the second embodiment described above, since the pair of filtering members 61 are disposed between the pair of mesh members 60, the dust-containing air after the mesh members 60 collect dust. While passing through the filter member 61. Thereby, dust in the dust-containing air that has passed through the mesh member 60 can be reduced, and clogging of the filtering member 61 can be suppressed. Further, by blowing out compressed air from the opening 64A for discharging clean air into the filter unit 56, the backflowed air passes through the pair of filter members 61 and the pair of net members 60, and the dust adhering thereto is removed. Can be paid off at the same time.

  Further, according to the filter unit 56 according to the second embodiment, dust-containing air can be taken in from both sides of the pair of net members 60, and a large amount of dust-containing air can be collected by the pair of net members 60 and the pair of filter members 61. Can remove dust.

[Modification of Second Embodiment]
In the filter unit 56 according to the second embodiment described above, the mesh member 60 is a plate-shaped wire mesh, but the present invention is not limited to this. As shown in FIG. 15, the mesh member 70 may be formed in a box shape (substantially U-shaped (U-shaped) cross section) that covers from the side surface to the upper and lower ends of the filtering member 61. That is, the upper and lower sides of the net member 70 are bent so as to cover the upper and lower end surfaces of the filtering member 61. The rear side of the mesh member 70 is bent so as to cover the rear end face of the filtering member 61. In this case, the pair of net members 70 are disposed opposite to each other on the outer side surface, the upper and lower end surfaces, and the rear end surface of the pair of filter members 61 with a gap therebetween.

  As shown in FIG. 15, the pair of joining members 73A of the attachment member 73 is formed thinner than the joining member 63A of the second embodiment, and is fixed to the distal end of the bent surface of the net member 70. I have. Thereby, since the joining member 73A does not completely cover the bent surface of the net member 70, the bent surface of the net member 70 can be exposed. In addition, it is possible to prevent the removed dust from being deposited on the joining member 73A. In addition, since the dust removed by the backwash falls from the lower end of the mesh member 70, it is possible to suppress the dust removed from reattaching to the filter member 61. As a result, clogging of the filtering member 61 can be prevented.

  In addition, the structure like the net member 70 described above can be applied not only to the filter unit 56 according to the second embodiment (including the modification) but also to the filter unit in which the lower end surface of the filter member is exposed. . For example, the mesh member may be formed to have a substantially L-shaped cross section that covers from the side surface to the lower end of the filtering member. The net member can be formed into a substantially L-shaped cross section by various methods, such as bending a plate-shaped net member or knitting the net member into a substantially L-shaped cross section. According to this configuration, it is possible to suppress the adhesion of dust to the lower end surface of the filtering member during the dust collection operation, and to drop the dust removed to the bucket 19 without accumulating around the lower end portion of the filter unit during the dust removal operation. Can be done. This suppresses the re-adhered dust from re-adhering to the filter member, and as a result, the clogging of the filter member can be suppressed.

  Note that the mesh member 70 may have a shape that covers the outer side surface and the upper and lower end surfaces of the filtering member 61 and does not cover the rear end surface of the filtering member 61. That is, the rear side of the net member 70 may not be bent. In this case, the rear surface of the joining member 73A may be shaped to cover the rear ends of the mesh member 70 and the filtering member 61.

  In the filter unit 56 according to the second embodiment (including modified examples; the same applies hereinafter), the mesh members 60 and 70 are formed substantially parallel to the side surface of the filter member 61. It is not limited to this. The same technical idea as that of the filter unit 26 according to the first modification of the first embodiment is applied to the filter unit 56 according to the second embodiment, and the mesh members 60 and 70 are positioned more centrally than both the upper and lower sides and the left and right sides. It may be formed so as to bulge outward in the region (not shown).

  Further, the same technical idea as that of the filter unit 26 according to the second modified example of the first embodiment is applied to the filter unit 56 according to the second embodiment, and a belt ( (Not shown). Furthermore, the same grounding structure (not shown) as the dust collector 1 according to the third modification or the fourth modification of the first embodiment is applied to the dust collector 2 according to the second embodiment. Good.

  In the filter units 26, 56 according to the first and second embodiments (including the respective modifications, the same applies hereinafter), wire meshes are used as the mesh members 30, 60, 70, but the present invention is not limited thereto. Not limited. For example, the mesh members 30, 60, and 70 may be formed by punching a metal plate with a plurality of holes, such as punched metal.

  In the filter units 26 and 56 according to the first and second embodiments, the mesh members 30, 60 and 70 are made of stainless steel. However, the present invention is not limited to this, and a metal having conductivity such as iron or an aluminum alloy may be used. It may be formed. The net members 30, 60, and 70 are not limited to those made of metal, and may be formed by forming conductive fibers such as conductive resin and carbon in a net shape.

  In the filter units 26 and 56 according to the first and second embodiments, the filtering members 31 and 61 are formed in a pleated shape, but the present invention is not limited to this. For example, the filtering members 26 and 61 may be formed of one unbroken thick filter material, or may be formed by laminating a plurality of sheet-like filter materials (neither is shown).

  In the filter units 26 and 56 according to the first and second embodiments, the filtering members 31 and 61 face the inner peripheral surfaces of the net members 30, 60 and 70 with a gap therebetween. It is not limited to this. For example, when the swelling of the filtering members 31 and 61 at the time of back washing is small, even if the filtering members 31 and 61 are in contact with the inner surfaces of the mesh members 30, 60 and 70 (downstream in the flow direction), they are opposed to each other. Good.

  In the filter units 26 and 56 according to the first and second embodiments, the fixing members 32 and 62 are fixed to the net members 30 and 60 and the filtering members 31 and 61, but the present invention is not limited to this. . The fixing members 32 and 62 only need to be fixed to at least the filtering members 31 and 61 among the mesh members 30 and 60 and the filtering members 31 and 61. The net members 30, 60 may be fixed to other members.

  Note that the description of the above embodiment shows one mode of the filter unit and the dust collector according to the present invention, and the technical scope of the present invention is not limited to the above embodiment.

  INDUSTRIAL APPLICABILITY The technology of the present invention can be used for a filter unit and a dust collecting device for collecting fine particles generated from a processing machine such as a metal and a resin.

1, 2 Dust collecting device 10 Charging unit 11, 50 Dust collecting unit 12 Dust removing unit 26, 56 Filter unit 30, 60, 70 Mesh member 31, 61 Filtering member 31A, 61A Fold 32, 62 Fixing member 33, 63 Mounting member 34A, 64A Opening 45 Grounding controller 46 Grounding plate 47 Rotating plate

Claims (12)

A filter unit for collecting dust by flowing dust-containing air containing dust charged by corona discharge,
A mesh member for adhering the charged dust contained in the dust-containing air,
A filter member that is disposed opposite to the contact or gap with the downstream side in the flow direction of the mesh member and that filters dust contained in the dust-containing air that has passed through the mesh member,
A fixing member fixed to the filtering member, the fixing member having an opening through which clean air filtered dust is passed through the filtering member,
A filter unit, wherein dust collected by the mesh member and the filter member is removed by compressed air blown from a downstream side in a flow direction to an upstream side through the opening. The filtering member is formed in a plurality of pleated pleats,
2. The filter unit according to claim 1, wherein the fold located on the upstream side in the flow direction of the filter member faces the mesh member with a gap interposed therebetween. 3. One end of the mesh member and the filtering member is fixed to the fixing member,
3. The filter unit according to claim 1, wherein the other ends of the mesh member and the filtering member are fixed to a mounting member. 4. The mesh member and the filtration member are formed in a cylindrical shape extending in the axial direction,
4. The filter unit according to claim 1, wherein the mesh member covers an outer peripheral surface of the filter member and is arranged on the same axis as the filter member. 5. One end of the mesh member and the filtering member is fixed to the fixing member,
The other end of the mesh member and the filtering member is fixed to a mounting member,
The filter unit according to claim 4, wherein the mesh member has a shape that gradually expands radially outward from both ends in the axial direction toward the center. A pair of the filtering members are arranged so as to face each other with a gap therebetween,
A pair of the mesh members are arranged so as to face each other across the pair of filtration members,
The filter unit according to claim 1, wherein the opening of the fixing member is formed to correspond to a gap between the pair of filtering members. The filtering member is formed in a pleated shape,
The filter unit according to any one of claims 2 to 6, wherein the mesh member is formed to have a substantially L-shaped cross section that covers from a side surface to a lower end of the filter member.   The filter unit according to any one of claims 1 to 7, wherein the mesh member is formed of a conductive material. A charging unit that charges dust contained in the dust-containing air by corona discharge while flowing the dust-containing air,
A dust collector including the filter unit according to any one of claims 1 to 8, which is provided downstream of the charging unit in the flow direction.
A dust removing unit that blows compressed air toward the filter unit to remove dust collected by the filter unit.   The dust collector according to claim 9, wherein the mesh member is electrically connected to a ground provided in the dust collector.   When the dust removing unit is stopped, the mesh member is electrically connected to the ground, and when the dust removing unit is operating, a ground control unit that releases the connection between the mesh member and the ground is provided. The dust collector according to claim 10, further comprising: The ground control unit,
A ground plate provided at a position facing the opening and electrically connected to the ground;
The filter unit is provided so as to protrude inside the opening, and when the dust removing unit is stopped, the dust is pushed out by the clean air filtered by the filter unit and rotates to one side to contact the ground plate, The dust collector according to claim 11, further comprising: a rotating plate that is pushed out by the compressed air when the dust removing unit is operating, rotates to the other side, and separates from the ground plate.

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