JP2023016958A - dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust collector which enables improvement of dust removal effect by dust removal part.

SOLUTION: A dust collector 1 includes a filter unit 26 which causes dust contained air, containing dust electrically charged by corona discharge, to circulate and collect dust. The dust collector 1 includes: a dust removal part 12 which blows compressed air to the filter unit 26 to remove dust collected by the filter unit 26; and a ground control unit 45 which switches the ground state. The filter unit 26 includes: a net member 30 which is electrically connected to a ground included in the dust collector 1 and causes electrically charged dust contained in the dust contained air to adhere to itself; and a filter member 31 which contacts with the downstream side as seen in a circulation direction of the net member 30 or is disposed facing the downstream side across a gap and filters dust contained in the dust contained air that has passed through the net member 30. The ground control unit 45 electrically connects the net member 30 with the ground when the dust removal part 12 is stopped and disconnects the net member 30 from the ground when the dust removal part 12 is operated.

SELECTED DRAWING: Figure 8

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a dust collector.

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

For example, the dust collector described in Patent Document 1 includes an electrostatic precipitator provided on the upstream side of the air flow path, a bag filter section provided on the downstream side of the electrostatic precipitator, and an electrostatic precipitator. A rectifying plate disposed between the bag filter section and a spray port for discharging the powder adsorbent between the rectifying plate and the electrostatic precipitator. The electric dust collector collects the dust in the dust-containing air while charging and aggregating the dust. Since the electrostatic precipitator collects 80 to 90% of the dust in the dust-containing air, it was possible to reduce the amount of dust entering the bag filter. Also, the 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 cloth of the bag filter by the rectifying plate. Furthermore, dust adhering to the filter cloth of the bag filter section is blown off by jetting compressed air from nozzles arranged above the bag filter section.

JP-A-11-90263

However, in the dust collector described in Patent Literature 1, if a rectifying plate is provided immediately before the bag filter portion and the powder adsorbent is not sprayed immediately before the rectifying plate, dust entering the bag filter portion can be reduced. I couldn't do it. In other words, it is possible to suppress clogging of the filter cloth in the bag filter section and reduce the cost associated with replacement of the filter cloth. There were costs.

In addition, in the dust collector described in Patent Document 1, although the electric dust collector disposed upstream of the bag filter collects 80 to 90% of the dust in the dust-containing air, the electric dust collector Sufficient consideration has not been given to removing the dust adhering to the dust portion.

SUMMARY OF THE INVENTION In view of the above-described problems, the present invention provides a dust collector capable of improving the dust removing effect of a dust removing section.

A first dust collector of the present invention is a dust collector provided with a filter unit that collects dust by circulating dust-laden air containing dust charged by corona discharge, wherein the dust is compressed toward the filter unit. A dust removal section that blows air to remove dust collected by the filter unit, and a ground control section that switches a ground state, and the filter unit is electrically connected to the ground provided in the dust collector. A connected net member for adhering electrically charged dust contained in the dust-containing air is arranged opposite to the downstream side of the flow direction of the net member with a contact or a gap therebetween, and is contained in the dust-containing air that has passed through the net member. a filter member for filtering dust, wherein the ground control unit electrically connects the net member and the ground when the dust removal unit is stopped, and when the dust removal unit is in operation. disconnecting the mesh member from the earth.

According to the first dust collector of the present invention, since the 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. It is possible to make the electrostatic force (Coulomb force) act stably.
Further, by grounding the net member when the dust removal unit is stopped, the charged dust can be stably collected by the net member. On the other hand, by releasing the grounding of the net member while the dust removing section is operating, the potential difference generated between the charged dust and the net member can be made unstable and the electrostatic force can be weakened. As a result, dust attached to the net member can be easily brushed off by the back-flowing air (compressed air). That is, it is possible to improve the dust removing effect of the dust removing section.
Furthermore, according to the filter unit provided in the dust collector, the charged dust in the dust-containing air can be roughly collected by the net member, so the amount of dust in the dust-containing air that has passed through the net member is reduced. can be made As a result, the amount of dust to be filtered by the filtering member is reduced, so clogging of the filtering member can be suppressed. In addition, since the dust collected on the net member aggregates and becomes coarse, the continuous suction of the dust-containing air causes the coarse and accumulated dust on the net member to collapse, pass through the net member, and pass through the filter member. Even if the dust adheres to the surface, it is difficult for the coarsened dust to enter the inside of the filtering member. Therefore, clogging of the filtering member can be suppressed as compared with the case without the mesh member.

A second dust collecting apparatus of the present invention is the first dust collecting apparatus described above, wherein the filter unit is fixed to the filtering member and has an opening through which clean air filtered to remove dust passes through the filtering member. The ground control unit includes a ground plate provided at a position facing the opening and electrically connected to the ground, and the ground plate protruding inside the opening, 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 and rotated in the other direction to separate from the ground plate.

In the second dust collector of the present invention, a rotating plate is rotatably provided in the area through which the clean air and the compressed air flow, and the rotating plate is oscillated by the flow of the clean air and the compressed air. bottom. According to this configuration, by passing clean air or compressed air through the opening, the rotating plate is grounded through the grounding plate, and the rotating plate is separated from the grounding plate and released from the ground. can be switched. As a result, for example, there is no need to separately provide power, a control circuit, or the like for switching the contact state of the rotating plate, and the grounding state of the net member can be switched with a simple structure.

A third dust collector of the present invention is, in the first or second dust collector described above, a charging unit that charges dust contained in the dust-containing air by corona discharge while allowing the dust-containing air to flow; It is preferable to further include a dust collection section including the filter unit provided downstream of the charging section in the flow direction.

According to the third dust collector of the present invention, since dust can be collected by the net member first, clogging of the filter member for filtering dust later can be suppressed. As a result, the replacement frequency of the filter unit can be reduced.

According to a fourth dust collector of the present invention, in any one of the first to third dust collectors, it is preferable that the mesh member is made of a conductive material.

According to a fifth dust collector of the present invention, in any one of the first to third dust collectors, the mesh member is preferably a metal wire mesh.

According to the fourth and fifth dust collectors of the present invention, the net member is made of a conductive material such as a metal wire net, so that an electrostatic force ( Coulomb force) can be applied, and dust charged on the net member can be collected. In addition, since the net member attracts and adheres dust by electrostatic force, the mesh size of the net member can be set larger than in inertial dust collection in which dust is collided and collected. As a result, clogging of the mesh member can be suppressed.

ADVANTAGE OF THE INVENTION According to this invention, the dust-removal effect by a dust-removal part can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the dust collector which concerns on 1st Embodiment of this invention. It is a block diagram showing a control system of the dust collector according to the first 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 along IV-IV in FIG. 3; FIG. 4 is a cross-sectional view (during backwashing) showing the filter unit and the dust removal section according to the first embodiment of the present invention; FIG. 4 is a perspective view showing a filter unit according to a first modified example of the first embodiment of the present invention; It is a side view which shows the filter unit based on the 2nd modification of 1st Embodiment of this invention. FIG. 11 is a cross-sectional view showing a filter unit, a dust removal section, and a grounding control section according to a fourth modified example of the first embodiment of the present invention; FIG. 12 is a cross-sectional view (during backwashing) showing the filter unit, the dust removal section, and the grounding control section according to the fourth modification of the first embodiment of the present invention; It is a perspective view which shows the dust collector which concerns on 2nd Embodiment of this invention. It is a side view which shows the dust collector which concerns on 2nd Embodiment of this invention. FIG. 5 is a perspective view showing a filter unit according to a second embodiment of the invention; 13 is a cross-sectional view taken along line XIII-XIII of FIG. 12; FIG. FIG. 7 is a cross-sectional view (during backwashing) showing the filter unit according to the second embodiment of the present invention; FIG. 11 is a perspective view showing a filter unit according to a modified example of the second embodiment of the invention;

Embodiments of the present invention will be described below with reference to the accompanying drawings. In each figure, "Fr" indicates "front", "Rr" indicates "rear", "L" indicates "left", "R" indicates "right", and "U" indicates "Upper" is indicated and "D" indicates "Lower". In this specification, terms indicating directions and positions are used for convenience of description, but these terms are not intended to limit the technical scope of the present invention.

[First embodiment]
A dust collector 1 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a perspective view showing the dust collector 1. FIG. FIG. 2 is a block diagram showing the control system of the dust collector 1. As shown in FIG. FIG. 3 is a sectional view showing the filter unit 26 and the dust removal section 12. As shown in FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG.

[Configuration of dust collector]
The dust collector 1 is a device that charges and collects dust in dust-containing air by corona discharge. For example, the dust collector 1 is installed in a factory where metal processing is performed using a plasma processing machine or a laser processing machine. Further, for example, the dust collector 1 collects fine dust such as metal fumes generated during metal processing. Note that the dust collector 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 collector 1 is not limited to metal fumes, and any type of dust can be used as long as the particles can be charged and collected.

As shown in FIGS. 1 and 2 , the dust collector 1 includes a charging section 10 , a dust collection section 11 and a dust removal section 12 . The charging unit 10 has a function of charging dust contained in the dust-containing air by corona discharge while circulating the dust-containing air. The dust collector 11 has a function of collecting charged dust. The dust remover 12 has a function of brushing off the dust collected by the dust collector 11 . In the following description, "flow direction" refers to the direction in which dust-containing air flows. In addition, the terms "upstream" and "downstream" and similar terms refer to the concepts "upstream" and "downstream" and similar concepts in the flow direction of the dust-laden air.

[Charging part]
As shown in FIG. 2, the charging section 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 . A high-voltage power supply 14 applies a DC voltage of several kV to several tens of kV to the charge electrode 13 (between the discharge electrode and the ground electrode) to generate corona discharge 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 section 10 . A second intake duct 16 that communicates with the dust collecting section 11 is connected to the downstream side of the charging section 10 . In order to stably generate corona discharge, it is desirable that the ground electrode of charge electrode 13 is grounded. 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 collecting section 11, which will be described later, is connected to the ground.

[Dust collector]
As shown in FIG. 1, the dust collection 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 vertically divides the internal space into two. 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 indicated by a virtual line (chain double-dashed line) in order to show the inside of the clean room R2.

Six circular partition openings 18A are formed in the partition plate 18 . 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, which will be described later. Three sets of guide rail pairs (not shown) are provided on the lower surface of the partition plate 18 so as to correspond to the three rows of partition openings 18A in the left-right direction.

A filter inspection opening 17A is formed on the lower front side of the housing 17 to open the dirty room R1. 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). A bucket 19 for collecting fallen dust is provided below the dirty room R1 of the housing 17 . The housing 17 is provided with a bucket inspection door 19</b>D for opening and closing the bucket 19 . The housing 17 is grounded (not shown) by burying a metal rod or electric wire electrically connected to the housing 17 in the ground.

An intake port 20 communicating with the dirty room R1 is opened in 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. As shown in FIG. An exhaust port 21 communicating with the clean room R2 is opened in the upper surface of the housing 17, and an exhaust duct (not shown) is connected to the exhaust port 21. As shown in FIG. Further, an exhaust fan 22 (see FIG. 2) is provided inside the exhaust duct or inside the clean room R2 to form an air flow from the intake port 20 to the exhaust port 21. As shown in FIG.

As shown in FIG. 2, the dust collection 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 3 and two dust collection filter portions 24 (see FIG. 1).

The control unit 23 includes an arithmetic processing device, a storage device, and the like (not shown). An interface (not shown) of the control unit 23 is electrically connected to 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). It is The interface of the control unit 23 is also electrically connected to the high-voltage power supply 14 of the charging unit 10, an electromagnetic valve 43 of the dust removing unit 12, which will be described later, and the like.

The operation input unit 23A has an ON/OFF button or the like for switching start/stop of 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 contents input by the display/input unit 23B are stored in the storage device of the control unit 23 and used for controlling the operation of the dust collector 1 as appropriate. 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 the 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 part>
As shown in FIG. 1 , the three dust collection filter units 24 are arranged side by side in the left-right direction in the dirty room R<b>1 of the housing 17 . Since the three dust collection filter portions 24 have the same structure, one dust collection filter portion 24 will be described below.

The dust collection filter section 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 circulating dust-laden air containing dust charged by corona discharge and collecting dust. Since the two filter units 26 have the same structure, one filter unit 26 will be described below.

<Filter plate>
As shown in FIG. 1, the filter plate 25 is made of, for example, a metal material such as stainless steel, and is formed in a substantially rectangular plate shape elongated in the front-rear direction. Two insertion holes 25A (see FIG. 3) are formed in the filter plate 25 side by side in the front-rear direction. Left and right ends of the filter plate 25 are bent downward to form a pair of guide pieces 25B. A front end portion of the filter plate 25 is bent upward to form a contact piece 25C. A hole (not shown) is formed in the front side of the filter plate 25 to allow the wing bolt B1 (see FIG. 3) to pass therethrough.

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

(Net member)
As shown in FIGS. 1 and 3, the net 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 allows it to be inserted into the insertion hole 25A of the filter plate 25. As shown in FIG. The mesh member 30 is formed to have substantially the same diameter from top to bottom. The mesh member 30 is, for example, a wire mesh made of metal such as stainless steel (SUS304) having excellent corrosion resistance. Incidentally, in the attached drawings, the meshes of a part of the mesh member 30 are illustrated.

For the net member 30, a plain-woven wire mesh having a wire diameter of 1 mm or less and having several meshes to several tens of meshes is used. Specifically, the wire diameter of the mesh member 30 can be set in the range of 0.1 to 0.9 mm, preferably in the range of 0.3 to 0.8 mm, and more preferably in the range of 0.6 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 net member 30 can be set in the range of 1 to 20 meshes, preferably in the range of 3 to 10 meshes, more preferably in the range of 6 to 7 meshes. is more preferably set in the range of The mesh (opening diameter) of the mesh member 30 can be set in the range of 1 to 10 mm, preferably in the range of 2 to 5 mm, more preferably in the range of 3 to 4 mm. .

(Filtration 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 filter member 31 is formed to have substantially the same length in the axial direction as the net member 30 and has an outer diameter smaller than that of the net member 30 . The filtering member 31 is formed to have substantially the same diameter from top to bottom. The filtering member 31 is, for example, a nonwoven fabric made of resin fibers such as polypropylene or polyester. Note that the filtering member 31 may be formed of resin fibers (so-called electrets) that retain static electricity. The filtering member 31 is formed in a pleated shape in which a plurality of creases are formed by repeatedly mountain-folding and valley-folding a non-woven fabric. The folds of the filtering member 31 extend in the axial direction (vertical direction).

The filter member 31 is inserted into the net member 30 and arranged opposite to the inner peripheral surface of the net member 30 (on the downstream side in the flow direction) with a gap interposed therebetween. Specifically, the fold 31A located upstream in the distribution direction of the filtering member 31 faces the mesh member 30 with a gap (several millimeters) interposed therebetween. The net member 30 covers the outer peripheral surface of the filter member 31 and is arranged coaxially (on a concentric circle) with the filter member 31 . In this specification, the term "on the same axis (on a concentric circle)" does not mean that they are completely identical, but means that a manufacturing error of several millimeters is allowed.

(fixing member)
As shown in FIGS. 1 and 3 , upper ends (one ends) of the net member 30 and the filter member 31 are fixed to a fixing member 32 . The fixing member 32 has a circular opening 34</b>A through which clean air from which dust has been filtered through the filtering member 31 passes. 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 integrally formed.

The flange portion 34 is formed in a brim shape extending outward from an opening portion 34A (the upper end portion of the venturi tube 35) when viewed from above. That is, the flange portion 34 is formed in an annular shape when viewed from above. The outer diameter of the flange portion 34 is formed larger than the diameter of the insertion hole 25A of the filter plate 25 . Also, the diameter of the opening 34A 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 34A of the flange 34. As shown in FIG. The venturi tube 35 is a tube having a through hole continuous with the opening 34A. The venturi tube 35 is arranged coaxially with the flange portion 34 (opening portion 34</b>A) and has an outer diameter that allows it to be inserted into the filtering member 31 . The venturi tube 35 is formed in a substantially cylindrical shape that is constricted at the central portion rather than at the upper and lower ends. The venturi tube 35 has a function of increasing the flow velocity of air (clean air or compressed air) directed from the downstream side to the upstream side in the flow direction.

An annular depression is formed in the lower surface of the flange portion 34 for fitting the upper ends of the net member 30 and the filter member 31 . The upper ends of the net member 30 and the filter member 31 are fixed with an adhesive while being fitted in the recesses of the flange portion 34 . In this state, the venturi tube 35 is inserted into the filter member 31 and arranged to face the inner peripheral surface of the filter member 31 (a crease 31A positioned downstream in the flow direction) with a gap therebetween. In addition, the lower end of the venturi tube 35 is arranged above the center of the filter member 31 in the vertical direction.

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

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 protruding upward from the plate portion 36 . The outer diameter of the plate portion 36 is formed to be smaller than the diameter of the insertion hole 25A of the filter plate 25 and slightly larger than the outer diameter of the net member 30 . The inner support 37 is arranged on the same axis as the plate portion 36 and has an outer diameter that allows it to be inserted into the filter member 31 . The internal support 37 is formed so that its outer diameter gradually decreases from bottom to top.

As shown in FIGS. 3 and 4, a plurality of connecting arms 37A extend radially outward from the upper portion of the inner support 37. As shown in FIGS. The plurality of connection arms 37A are arranged at substantially equal intervals in the circumferential direction of the internal support 37. As shown in FIG. An annular connection band 37B is connected to the tip of each connection arm 37A. A plurality of grooves are formed on the surface of the connection band 37B.

As shown in FIG. 3, the upper surface of the plate portion 36 is formed with an annular recess for fitting the lower end portions of the net member 30 and the filter member 31 . The lower ends of the net member 30 and the filter member 31 are fixed with an adhesive while being fitted in the recesses of the plate portion 36 . The inner support 37 is inserted into the filter member 31, and the connection band 37B is attached to the inner peripheral surface of the filter member 31 (the crease 31A located downstream in the flow direction) via the adhesive applied to the groove on the surface. Fixed. In this state, the internal support 37 is arranged to face the inner peripheral surface of the filter member 31 (the crease 31A positioned downstream in the flow direction) with a gap therebetween. Specifically, since the internal support 37 is tapered upward, the distance between the outer peripheral surface of the internal support 37 and the inner peripheral surface of the filter member 31 gradually increases (widens) from the bottom to the top. Become. Also, the upper end of the internal support 37 is arranged near the center of the filter member 31 in the vertical direction. Accordingly, the upper end of the internal support 37 is spaced downward from the lower end of the venturi tube 35 to form a space therebetween.

[Assembly of dust collection filter]
Next, with reference to FIG. 3, the procedure for assembling the dust collection filter portion 24 will be described. The dust collection filter section 24 is configured by supporting two filter units 26 on the filter plate 25 .

Specifically, each filter unit 26 is inserted from the upper surface of the filter plate 25 into the insertion hole 25A. Each filter unit 26 is supported in a state of being suspended from the filter plate 25 by abutting the flange portion 34 of each filter unit 26 on the peripheral edge portion of the insertion hole 25A. The assembly work of the dust collection filter part 24 is completed by the above.

[Installation of the dust collection filter]
Next, with reference to FIGS. 1 and 3, a procedure for attaching the dust collection filter section 24 to the housing 17 will be described. Since the procedures for attaching the three dust collection filter portions 24 are the same, the procedure for attaching one dust collection filter portion 24 will be described below.

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

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

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

As shown in FIG. 1, the header tank 41 is a cylindrical pipe extending in the left-right direction within 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 factory-installed compressor (not shown).

The three blow tubes 42 are connected to the header tank 41 via three solenoid valves 43. As shown in FIG. 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 arranged to cross two partition openings 18A (filter units 26) aligned in the front-rear direction. Two outlets 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 are open at positions corresponding to (substantially the centers of) the two partition openings 18A aligned in the front-rear direction (see FIG. 3).

[Dust collection operation]
Next, the dust collection operation of the dust collector 1 will be described with reference to FIGS. 1 to 3. FIG.

First, the operator presses the ON/OFF button of the operation input section 23A to activate the charging section 10 and the dust collection section 11 (display/input section 23B, differential pressure gauge 23E, exhaust fan 22, etc.) (start operation). 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 or the like using the reception of the operation signal of the laser processing machine or the like as a trigger.

Next, the control section 23 controls the high voltage power supply 14 of the charging section 10 to apply a high voltage to the charge electrode 13, thereby generating corona discharge between the discharge electrode and the ground electrode. Further, the control section 23 rotates the exhaust fan 22 of the dust collection section 11 . As a result, an airflow is formed from the intake port 20 toward the exhaust port 21, so that dust-laden air is taken into the charging section 10 from the outside through the first intake duct 15 (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, aggregates, and becomes coarse (the particle diameter becomes 20 times or more coarse).

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

The net member 30 has a function of collecting charged and coarsened dust prior to filtration by the filtering member 31 and aggregating the deposited dust to further promote coarsening. For example, even if dust accumulated with continuous suction of dust-containing air breaks down and passes through the net member 30, the coarsened dust adheres to the surface of the filtering member 31 and cannot enter inside. Thus, clogging of the filter member 31 can be suppressed as compared with the case where the net member 30 is not provided. It should be noted that clogging of the filter member 31 can be suppressed for the same reason even when dust removed by backwashing, which will be described later, re-adheres to the filter member 31 .

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

As described above, since the net member 30 roughly removes charged and coarsened dust prior to filtering the dust by the filtering member 31, the load on the filtering member 31 due to adhesion and accumulation of dust can be reduced. When the operator presses the ON/OFF button of the operation input unit 23A (when the external input/output unit 23D receives a signal to stop the laser processing machine or the like), the control unit 23 controls the charging unit 10 and the dust collecting unit. Stop the 11th class. As a result, the dust collection operation of the dust collector 1 is stopped. At this time, the charging unit 10 may be set to stop after the dust collecting unit 11 stops, contrary to the time of startup. Also, 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 collector 1 will be described with reference to FIG. FIG. 5 is a sectional view showing the filter unit 26 and the dust removal section 12 (during backwashing).

The storage device of the control unit 23 stores in advance the threshold value of the pressure loss of the filter unit 26 (differential pressure between the dirty room R1 and the clean room R2). The control unit 23 compares the threshold value with the detection value of the differential pressure gauge 23E, and executes the dust removal operation when it determines that the detection value exceeds the threshold value. In addition, the control unit 23 sequentially removes dust from the three dust collection filter units 24 one by one. The execution timing of the dust removal operation is not limited to the above. may Note that the threshold value 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.

Further, when performing the dust removal operation, the control section 23 stops the exhaust fan 22 of the dust collection section 11 . In this manner, the dust removal operation is preferably performed in a state in which the exhaust fan 22 is stopped to stop the suction of the dust-containing air. You can continue. In this case, the number of revolutions of the exhaust fan 22 may be decreased from that during normal operation (during dust collection operation).

When the dust collection unit 11 is activated, the solenoid valve 43 is controlled by the control unit 23 to be closed. Compressed air is then stored in the header tank 41 connected to the compressor.

When the controller 23 determines that the detected value exceeds the threshold value, the electromagnetic valve 43 is controlled by the controller 23 to open. Then, the compressed air stored in the header tank 41 passes through the blow tube 42 and is ejected from the two outlets 42A toward the openings 34A of the two filter units 26 (see the dashed line in FIG. 5).

Compressed air flows through the venturi tube 35 from the opening 34A, is accelerated, and flows inside the filtering member 31 (see the thick arrow in FIG. 5). At this time, since the gap between the outer peripheral surface of the internal support 37 and the inner peripheral surface of the filtering member 31 is gradually narrowed from the top to the bottom in the lower portion of the filtering member 31, the compressed air flowing into the filtering member 31 flows to the lower part of the filtering member 31 without significantly reducing the flow velocity.

The compressed air that has flowed inside the filtering member 31 passes from the filtering member 31 toward the net member 30 (see the thick arrow in FIG. 5). Compressed air flows back against the filter member 31 and the net member 30, so that the dust adhering to the filter member 31 and the net member 30 is shaken off. Thus, the dust collected by the net member 30 and the filter member 31 is removed by the compressed air blown from the downstream side to the upstream side in the distribution direction through the openings 34A. The dust that has been shaken off falls into a bucket 19 provided in the lower portion of the dust collection section 11, and the deposited dust is discarded as appropriate.

Note that the control unit 23 performs control to close the electromagnetic valve 43 after a predetermined time (several seconds) has elapsed since the start of injection of the compressed air (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 net member 30. Therefore, the dust in the dust-containing air that has passed through the net member 30 can be can be reduced. As a result, the amount of dust to be filtered by the filtering member 31 is reduced, so clogging of the filtering member 31 can be suppressed. In addition, by blowing compressed air toward the inside of the filter unit 26 from the opening 34A for discharging clean air, the backflowing air passes through the filtering member 31 and the net member 30, and the filtering member 31 and the net member 30 Adhered dust can be brushed off at the same time. That is, the net member 30 and the filter member 31 can be dust-removed (backwashed) at the same time.

In addition, according to the filter unit 26 according to the first embodiment, the filter member 31 is formed in a pleated shape in which mountain folds and valley folds are repeated. (filtration area) can be increased. As a result, the filter member 31 can continue to filter dust for a long period of time (the life of the filter member 31 can be extended).

In addition, 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 net member 30 and the filter member 31 can also be adjusted in proportion to the length of the filter member 31 . For example, when the length of the filter member 31 is 500 mm and the gap with the net member 30 is 5 mm, the gap with the net member 30 is 10 mm when the length of the filter member 31 is 1000 mm. In addition, when the filter member 31 is shortened, the gap is also narrowed. As a result, contact with the net member 30 can be suppressed even if the filter member 31 swells during backwashing.

Furthermore, since the filter member 31 is fixed to the internal support 37 (each of the connection arms 37A and the connection band 37B) at the central portion in the vertical direction, it is possible to prevent the filter member 31 from greatly expanding outward during backwashing. can. A plurality of connection arms 37A and connection bands 37B may be provided in the vertical direction and connected to the filtering member 31 at a plurality of locations in the vertical direction.

Further, according to the filter unit 26 according to the first embodiment, the net member 30 and the filter member 31 can be unitized using the fixing member 32 and the mounting member 33 . As a result, the net member 30 and the filter member 31 can be attached/detached to/from the dust collector 1 collectively. Work can be done easily.

Further, according to the filter unit 26 according to the first embodiment, since the net member 30 is arranged so as to surround the outer periphery of the filter member 31, the net member 30 moves in the dust-containing air from the outer side to the inner side in the circumferential direction. Dust can be collected evenly. As a result, uneven occurrence of clogging in the filter member 31 is suppressed, and an increase in load and abrasion of the filter member 31 can be made substantially uniform over the circumferential direction.

Further, according to the filter unit 26 according to the first embodiment, by forming the net member 30 with a conductive material (eg, metal), the electrostatic force generated by the potential difference between the charged dust and the net member 30 (Coulomb force) can be applied, and dust charged on the net member 30 can be collected. In addition, since the net member 30 attracts and adheres dust by electrostatic force, the opening of the net member 30 can be set larger than in inertial dust collection in which dust is collided and collected. Thereby, clogging of the net member 30 can be suppressed.

Further, according to the dust collector 1 according to the first embodiment, since dust can be collected by the net member 30 first, clogging of the filtering member 31 that filters dust later can be suppressed. . As a result, the replacement frequency of the filter unit 26 can be reduced. Further, by blowing compressed air into the filter unit 26 from the clean air discharge opening 34A, the dust adhering to the filter 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 net member 30 is formed in a cylindrical shape having substantially the same diameter from top to bottom, 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 the upper and lower ends (both axial ends) toward the central portion. ing. Therefore, the gap between the net member 38 and the filter member 31 is formed so as to gradually increase (widen) from both upper and lower sides toward the center. In this specification, the “vertical (axial) central portion” of the net member 38 and the filter member 31 does not strictly require the central portion, but rather the upper and lower ends (both axial ends). It means an intermediate region sandwiched between the upper and lower ends excluding the . Therefore, it is also possible to adjust the position where the net member 38 has the maximum diameter, corresponding to the position where the filter member 31 tends to expand radially outward. For example, in the filter member 31 of the filter unit 26 according to the first embodiment, the mesh member 38 has the maximum diameter between the flange portion 34 and the connection arm 37A (connection band 37B) of the internal support 37. preferably formed.

According to the filter unit 26 according to the first modified example of the first embodiment described above, since the net member 30 has a shape that swells at the center in the vertical direction, during backwashing, the center of the filter member 31 in the vertical direction It can be allowed to bulge outwards. As a result, it is possible to prevent the vertical central portion of the filter member 31 , which tends to bulge outward, from coming into contact with the net member 30 .

[Second Modification of First Embodiment]
In addition, in the filter unit 26 according to the first embodiment, a space is provided between the venturi tube 35 and the internal support 37 inside the filtering member 31, so the filtering member 31 is placed 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 31B that is wrapped around the outer peripheral surface of the filter member 31 is provided at the portion of the filter member 31 that easily swells. The belt 31B is made of, for example, metal such as stainless steel or synthetic resin. In addition, FIG. 7 shows a state in which approximately half of the circumference of the mesh member 30 is removed in order 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 tends to swell during backwashing can be pressed by the belt 31B. Further, the belt 31B preferably also functions as a spacer that maintains the gap between the filter member 31 and the net member 30. As shown in FIG.

[Third Modification of First Embodiment]
Although the net member 30 is not grounded in the dust collector 1 according to the first embodiment described above, it may be grounded. For example, the net member 30 may be electrically connected to the ground provided in the dust collector 1 . As a specific grounding method, for example, the mesh member 30 and the metal portion such as the partition plate 18 may be connected with a metal wire (not shown). Alternatively, for example, the net member 30 may be fixed to the filter plate 25 with metal bolts. Furthermore, a conductive material containing a conductive substance such as a metal filler may be applied to the concave portion of the back surface of the flange portion 34 to fit the net member 30 into the concave portion of the flange portion 34 . In this case, when the dust collection filter section 24 is assembled, the conductive material contacts the mesh member 30 and the filter plate 25, and the mesh member 30 is grounded via the filter plate 25 and the like. The grounding means the earthing electrode of the dust collector 1 as a whole, the housing 17 (the metal part thereof), the earthing electrode provided in the charging section 10, and the like. It should be connected.

According to the dust collector 1 according to the third modification of the first embodiment described above, since the accumulated electric charges can be removed by grounding the net member 30, the charged dust and the net member 30 can be separated from each other. It is possible to generate a stable potential difference between them to stably act an electrostatic force (Coulomb force).

[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, the dust collector 1 according to the fourth modification electrically connects the net member 30 and the ground when the dust removal section 12 is stopped, and the dust removal section 12 operates. A ground control unit 45 is further provided for releasing the connection between the mesh member 30 and the ground when it is connected. As shown in FIG. 8, the grounding control unit 45 includes a grounding plate 46 provided at a position facing the opening 34A of the fixed member 32, and a rotating plate 47 provided so as to protrude inside the opening 34A. , contains The ground plate 46 and the rotating plate 47 are each made of a metal material such as stainless steel and formed into a substantially plate shape.

The ground plate 46 is fixed to the partition plate 18 with metal bolts and 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 air circulation. The rotating plate 47 is arranged on the upper surface of the flange portion 34 and is fastened to the flange portion 34 with a metal plate (not shown) provided in a recess on the back surface of the flange portion 34 and metal bolts. Thereby, the mesh member 30 and the rotating plate 47 are electrically connected via the metal plate. The rotating plate 47 has a rotating arm 47B that rotates (swings) around a rotating shaft 47A. The rotating arm 47B extends toward the center of the opening 34A so as to block air circulation.

As shown in FIG. 8, when the dust removing unit 12 is stopped (during dust collection operation), the rotating arm 47B of the rotating plate 47 is pushed out by the clean air from which the dust has been filtered by the filter unit 26 and rotates. It rotates upward (to one side) about the drive shaft 47A and contacts the bent tip of the ground plate 46 . Therefore, the mesh member 30 is connected to the ground via the rotary plate 47, the ground plate 46, and the like.

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

According to the dust collector 1 according to the fourth modification of the first embodiment described above, by grounding the net member 30 when the dust removal unit 12 is stopped, the charged dust is stabilized by the net member 30. can be collected by On the other hand, by releasing the grounding of the net member 30 while the dust removing section 12 is operating, the electrostatic force between the charged dust and the net member 30 can be weakened. As a result, the dust adhering to the net member 30 can be easily brushed off by the backflowing air (compressed air). That is, the dust removing effect of the dust removing section 12 can be improved.

In addition, in the dust collector 1 according to the fourth modification, the rotation plate 47 is rotatably provided in the area (opening 34A) through which the clean air and the compressed air circulate. The configuration is such that the rotary plate 47 is swung. According to this configuration, by passing clean air or compressed air through the opening 34A, the rotary plate 47 is grounded via the ground plate 46, and the rotary plate 47 is separated from the ground plate 46 and grounded. It is possible to switch between the released state and the released state. As a result, for example, there is no need to separately provide power, a control circuit, or the like for switching the contact state of the rotating plate 47, and the grounding state of the net member 30 can be switched with a simple structure.

In addition, although the ground control unit 45 is configured to swing the rotary plate 47 using the air passing through the opening 34A, 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 to rotate the rotating arm 47B around the rotating shaft 47A. In addition, for example, a switch (not shown) for switching between conduction and interruption is provided on the conduction path between the mesh member 30 and the ground, and the control unit 23 switches based on the operation and stop of the dust removal unit 12. switching control may be performed.

Although the filter unit 26 according to the first embodiment is attached to the dust collector 1 in an upright posture with its axis extended in the vertical direction, 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 position with its axis extended in the front-rear direction or in the left-right direction, or may be attached to the dust collector 1 in a tilted position.

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

[Second embodiment]
A dust collector 2 according to a second embodiment will be described with reference to FIGS. 10 to 14 . FIG. 10 is a perspective view showing the dust collector 2. FIG. FIG. 11 is a side view showing the dust collector 2. FIG. FIG. 12 is a perspective view showing the filter unit 56. FIG. 13 is a cross-sectional view taken along line XIII-XIII of FIG. 12. FIG. FIG. 14 is a sectional view showing the filter unit 56 (during backwashing). In addition, in the following description, the same code|symbol is attached|subjected about the structure similar to the dust collector 1 which concerns on 1st Embodiment (a 1st and 2nd modification is included.), and the same description is abbreviate|omitted.

As shown in FIGS. 10 and 11 , the dust collector 2 includes a charging section 10 , a dust collection section 50 and a dust removal section 12 .

[Dust collector]
The dust collector 50 has a substantially rectangular parallelepiped housing 51 that is elongated 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 rear dirty room R1 and a front clean room R2. A filter inspection door 51A is provided on the front surface of the housing 51 to open the clean room R2. 10 and 11, the housing 51 is indicated by imaginary lines (two-dot chain lines) in order to show the inside of the housing 51. As shown in FIG.

The vertical partition plate 52V has four substantially rectangular partition openings (not shown) elongated in the vertical direction. The four partition openings are arranged in a grid of 2 rows and 2 columns. A flat plate-shaped opening/closing plate 53 is attached to each partition opening so as to be able to be opened and closed. A vertically elongated slit opening 53A is formed in the central portion of each opening/closing plate 53 .

An intake port 20 that communicates with the dirty room R1 is open on the right side surface of the upper portion of the housing 51, and the charging section 10 is connected to the intake port 20 via the second intake duct 16. As shown in FIG. An exhaust unit 54 incorporating an exhaust fan 22 is provided on the upper surface of the housing 51 . An exhaust port 21 to which an exhaust duct (not shown) is connected is opened on the top surface of the exhaust portion 54 . The exhaust part 54 communicates the clean room R2 and the exhaust port 21 (exhaust duct).

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

<Filter unit>
As shown in FIG. 12, the filter unit 56 as a whole is formed in a substantially rectangular parallelepiped shape that is long in the front-rear 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 filter members 61, a fixing member 62, and a mounting member 63. As shown in FIGS.

(Net member, filter member)
As shown in FIGS. 12 and 13, each mesh member 60 is a plate-shaped wire mesh. As shown in FIG. 13, each filter member 61 is formed in a substantially rectangular shape when viewed from the side, and is formed in a pleated shape with a plurality of vertically extending creases 61A formed in a nonwoven fabric. A pair of filtering members 61 are arranged so as to face each other with a gap G interposed therebetween. A pair of net members 60 are arranged to face each other with a pair of filter members 61 interposed therebetween. A pair of filter members 61 (folds 61A located on the upstream side in the distribution direction) are arranged opposite to each other with a gap (several millimeters) between the inner surfaces (downstream side in the distribution direction) of the pair of net members 60 .

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

The flange portion 64 is formed in a brim shape extending outward from the opening portion 64A when viewed from the front. The flange portion 64 is formed in a substantially rectangular shape that is larger than the partition opening in the vertical partition plate 52V when viewed from the front. A rectangular recess for fitting the front ends of the net member 60 and the filter member 61 is formed on the rear surface of the flange portion 64 . The rod-shaped portion 65 is constructed between a pair of support arms 64B extending rearward from the upper and lower ends of the flange portion 64 . The rod-shaped portion 65 is formed in a substantially columnar shape and arranged in the gap G between the pair of filter members 61 .

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

One joint member 63A is insert-molded so as to be integrated with one net member 60 and one filter member 61 . For example, after loading the net member 60 and the filter member 61 into a mold (not shown), 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 joint member 63A, and the right half or left half of the filter unit 56 is formed.

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

[Dust remover]
As shown in FIGS. 10 and 11, the dust removal section 12 includes a header tank 41 connected to the compressor, and two blow tubes 42 connected to the header tank 41 via two electromagnetic valves 43. there is

The header tank 41 extends horizontally in the upper part of 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 two rows of filter units 56 arranged in the horizontal direction. The blow tube 42 is detachably attached to the floor surface or the like of the clean room R2. Two outlets 42A are opened in the rear surface of each blow tube 42 at positions corresponding to the two vertically aligned openings 64A (slit openings 53A) (see FIG. 13).

[Mounting the filter unit]
Next, a procedure for attaching the filter unit 56 to the housing 51 will be described. Since the mounting procedure for the four filter units 56 is the same, the mounting procedure for 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 . 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 in front into the dirty room R1 through 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. A support frame (not shown) for supporting the inserted filter unit 56 is provided in the dirty room R1.

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 through the slit opening 53A of the opening/closing plate 53. As shown in FIG. After attaching the filter unit 56, the operator attaches the blow tube 42 and closes the filter inspection door 51A.

[Dust collection operation]
Next, the dust collection operation of the dust collector 2 will be briefly described with reference to FIGS. 10 to 13. FIG.

When the charging unit 10 and the dust collecting 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 becomes coarse, and then moves into the dirty room R1 of the dust collecting unit 50. (see FIG. 10). The dust-laden air taken into the dirty room R1 flows as a downdraft between the inner surface of the housing 51 and the filter unit 56 or between the filter units 56 adjacent to each other on the left and right (see FIG. 10).

The dust-laden air passes from both left and right sides of the filter unit 56 toward the center (see FIG. 12). The charged and coarsened 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 coarsened dust adheres to the pair of net members 60 by electrostatic force, and the dust-containing air that has passed through the pair of net members 60 is filtered by the pair of filter members 61 to become clean air.

The clean air joins at the gap G between the pair of filtering members 61 and is exhausted into the clean room R2 through the opening 64A (slit opening 53A) (see FIG. 13). The clean air becomes an ascending current, flows through the clean room R2, passes through the exhaust section 54, and is exhausted to the outside through the exhaust port 21 (see FIG. 11).

As described above, since the net member 60 roughly removes charged and coarsened dust prior to filtering the dust by the filtering member 61, the load on the filtering member 61 due to adhesion and accumulation of 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 collector 2 will be briefly described with reference to FIG. 14 .

When the controller 23 determines that the detected value of the differential pressure gauge 23E exceeds the threshold value, the solenoid valve 43 is controlled by the controller 23 to open. Then, the compressed air stored in the header tank 41 passes through the blow tube 42 and is ejected from the two outlets 42A toward the openings 64A of the two filter units 56 (see broken lines in FIG. 14).

The ejected compressed air collides with the rod-shaped portion 65 arranged in the gap G of the pair of filter members 61 and is diffused. The compressed air diffused in the gap G flows back from the pair of filter members 61 toward the pair of net members 60 to shake off dust adhering to each filter member 61 and each net member 60 . It should be noted that the dust that has been shaken off falls into the bucket 19, and the accumulated dust is discarded as appropriate.

According to the filter unit 56 according to the second embodiment described above, since the pair of filter members 61 is arranged between the pair of the net members 60, the dust-containing air after the net members 60 have collected the dust is removed. can be filtered while passing through the filtering member 61 . As a result, dust in the dust-containing air that has passed through the net member 60 can be reduced, and clogging of the filter member 61 can be suppressed. In addition, by blowing compressed air toward the inside of the filter unit 56 from the opening 64A for discharging clean air, the backflowing air passes through the pair of filter members 61 and the pair of net members 60, and dust adhering to them 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 taken in by the pair of net members 60 and the pair of filter members 61. dust can be removed from

[Modification of Second Embodiment]
In addition, 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 net member 70 may be formed in a box shape (substantially U-shaped cross section) covering from the side surface of the filter member 61 to the upper and lower ends. That is, both upper and lower sides of the net member 70 are bent so as to cover the upper and lower end surfaces of the filter member 61 . Further, the rear side of the net 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 arranged to face the outer side surfaces, the upper and lower end surfaces, and the rear end surfaces of the pair of filter members 61 with a gap therebetween.

Further, as shown in FIG. 15, a pair of joint members 73A of the mounting member 73 are formed thinner than the joint members 63A of the second embodiment, and are fixed to the tip of the bent surface of the net member 70. there is Accordingly, 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 accumulating on the joint member 73A. In addition, since the dust removed by backwashing falls from the lower end of the net member 70 , it is possible to prevent the removed dust from adhering again to the filter member 61 . As a result, clogging of the filtering member 61 can be prevented.

Note that the configuration of the net member 70 described above is not limited to the filter unit 56 according to the second embodiment (including modifications), and can be applied to a filter unit in which the lower end surface of the filter member is exposed. . For example, the net member may be formed to have a substantially L-shaped cross-section covering from the side surface to the lower end of the filtering member. The net member can be formed to have an approximately L-shaped cross section by various methods such as bending a plate-like net member or weaving the net member into an approximately L-shaped cross section. According to this configuration, it is possible to prevent dust from adhering to the lower end surface of the filter member during the dust collecting operation, and during the dust removing operation, the removed dust falls into the bucket 19 without accumulating around the lower end portion of the filter unit. can be made This prevents the removed dust from adhering to the filtering member again, and as a result, clogging of the filtering member can be suppressed.

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

In addition, in the filter unit 56 according to the second embodiment (including modifications; the same applies hereinafter), the net members 60 and 70 are formed substantially parallel to the side surface of the filter member 61, but the present invention It is not limited to this. The same technical concept as that of the filter unit 26 according to the first modified example of the first embodiment is applied to the filter unit 56 according to the second embodiment, and the mesh members 60 and 70 are arranged in the center rather than 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).

In addition, the same technical idea as the filter unit 26 according to the second modification of the first embodiment is applied to the filter unit 56 according to the second embodiment, and a belt ( (not shown) may be wrapped. Furthermore, even if a grounding structure (not shown) similar to that of the dust collector 1 according to the third or fourth modification of the first embodiment is applied to the dust collector 2 according to the second embodiment, good.

In addition, in the filter units 26 and 56 according to the first and second embodiments (including each modification; the same shall apply hereinafter), wire mesh is used as the mesh members 30, 60 and 70, but the present invention Not limited. For example, the net members 30, 60, 70 may be a metal plate with a plurality of holes, such as punching metal.

Further, in the filter units 26, 56 according to the first and second embodiments, the net members 30, 60, 70 are made of stainless steel. may be formed. Moreover, the mesh members 30, 60, and 70 are not limited to being made of metal, and may be made of conductive fibers such as conductive resin or carbon formed in a mesh shape.

Further, in the filter units 26, 56 according to the first and second embodiments, the filtering members 31, 61 are formed in pleats, but the present invention is not limited to this. For example, the filter members 26 and 61 may be formed of a single thick filter material without creases, or may be formed by laminating a plurality of sheet-like filter materials (neither is shown).

Further, in the filter units 26, 56 according to the first and second embodiments, the filter members 31, 61 face the inner peripheral surfaces of the net members 30, 60, 70 with a gap therebetween. It is not limited to this. For example, when the swelling of the filter members 31 and 61 during backwashing is small, even if the filter members 31 and 61 are in contact with the inner surfaces of the net members 30, 60 and 70 (on the downstream side in the flow direction), they face each other. good.

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

It should be noted that the description of the above embodiment shows one aspect of 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 in a dust collector for collecting fine particles generated from a machine for processing metals, resins, or the like.

Reference Signs List 1, 2 dust collector 10 charging section 11, 50 dust collection section 12 dust removal section 26, 56 filter unit 30, 60, 70 net member 31, 61 filtering member 32, 62 fixing member 34A, 64A opening 45 ground control section 46 Ground plate 47 Rotating plate

Claims (5)

A dust collector comprising a filter unit that collects dust by circulating dust-laden air containing dust charged by corona discharge,
a dust removal unit that blows compressed air toward the filter unit to remove dust collected by the filter unit;
a grounding control unit that switches the grounding state,
The filter unit is
a net member that is electrically connected to the ground provided in the dust collector and adheres charged dust contained in the dust-containing air;
a filtering member arranged opposite to the downstream side of the net member in the flow direction with a contact or gap in between, and filtering dust contained in the dust-containing air that has passed through the net member;
The ground control unit electrically connects the net member and the ground when the dust removing unit is stopped, and disconnects the net member and the ground when the dust removing unit is operating. A dust collector characterized by releasing. The filter unit further comprises a fixing member fixed to the filtering member and having an opening through which clean air from which dust has been filtered passes through the filtering member,
The ground control unit
a ground plate provided at a position facing the opening and electrically connected to the ground;
When the dust removal unit is stopped, the dust is pushed out by the clean air filtered by the filter unit and rotated in one direction to contact the ground plate. 2. The dust collector according to claim 1, further comprising a rotating plate that is pushed out by the compressed air and rotates in the opposite direction to separate from the ground plate when the dust removing unit is in operation. a charging unit that charges dust contained in the dust-containing air by corona discharge while circulating the dust-containing air;
3. The dust collector according to claim 1, further comprising a dust collection section including the filter unit provided downstream of the charging section in the flow direction. 4. A dust collector according to any one of claims 1 to 3, wherein said net member is made of a conductive material. 4. The dust collector according to any one of claims 1 to 3, wherein said net member is a wire net made of metal.

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