JP2011231487A - Dust removing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust removing device which enables reduction in a replacement component cost and a replacement work cost.SOLUTION: The dust removing device comprises a plurality of screen plates 57 arranged endlessly for capturing dust in flowing water in a water channel (cistern) 52 and for pulling up the dust from the flowing water by the plurality of screen plates 57 driven to be rotated. In an inside of the water channel 52, a frame body 56 is included which comprises a driven disc 58 driven to be rotated by a drive means 65, a ring-shaped disc 59 at an upstream side of the driven disc 58, and connection plate 60a and 60b for connecting the driven disc 58 and the ring-shaped disc 59 at their outer periphery integrally. The screen plates 57 are disposed endlessly to an inside of the frame body 56 in a regular polygonal form, where a distal end 57b thereof is detachably fixed to the driven disc 58 and a proximal end 57c thereof is detachably fixed to the ring-shaped disc 59.

Description

  The present invention relates to a dust removing device.

  Conventionally, as shown in FIG. 12, a cylindrical screen body 5 in which a screen net 5 a is stretched in an endless state is disposed in a water channel 2, and a guide roller 6 is supported by an annular guide rail 7. There is a circular cup type dust removing device in which the endless chain 8 is driven by a sprocket 9a of a motor 9 to rotationally drive the screen body 5 in a circular shape (see Patent Document 1). Such a dust removing device is suitable for a water channel having a shallow water depth and a small flow rate.

Japanese Patent Laid-Open No. 11-181745

  However, in the circular cup type dust remover as in Patent Document 1, the screen net has a diameter of 1 to 2 m, and even when a part of the screen net is broken, the entire old screen net is removed and the entire new screen net is removed. It is necessary to install. Therefore, there is a problem that the cost of replacement parts (screen net) is increased and the replacement work takes time, so that the replacement work cost is also increased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a dust removing device that can reduce the replacement part cost and the replacement work cost.

  In order to solve the above-described problems, the present invention provides a dust removing device that pulls up dust from flowing water by rotating the screen plate while capturing the dust in flowing water in the water channel with a large number of screen plates arranged in an endless state. A driving disk that is rotationally driven by the driving means, a ring-shaped disk on the upstream side thereof, and a connecting plate that integrally connects the outer periphery of the driving disk and the ring-shaped disk inside the water channel. Each of the screen plates is arranged in a regular polygonal shape in an endless state inside the frame body, the front end portion is detachably fixed to the drive disk, and the rear end portion is The present invention provides a dust removing device that is detachably fixed to a ring-shaped disk.

  As in claim 2, in claim 1, a tip receiving member for inserting and fixing the tip of the screen plate is provided on the drive disk, and the rear end of the screen plate is placed on the ring-like disk. A rear end receiving member and a detachable pressing member that presses and fixes the rear end of the screen plate inserted into the rear end receiving portion may be provided.

  As in claim 3, in claim 1, a tip receiving member is provided on the driving disc so as to detachably fix the tip of the screen plate, and the ring-like disc has a rear end of the screen plate. It can be set as the structure provided with the rear-end receiving member which mounts a part and fixes it so that attachment or detachment is possible.

  As in a fourth aspect, in any one of the first to third aspects, the screen plate may be inserted so as to form a regular hexagonal shape.

  As in claim 5, there is provided a screw conveyor according to any one of claims 1 to 4, wherein the screw conveyor that collects the dust pulled up from the running water by the rotational drive of the screen plate and carries it out is provided. The conveyor may have a dewatering / compression mechanism built-in.

  As in claim 6, in any one of claims 1 to 5, a water tank corresponding to the water channel is installed on a floor surface, and an assembly of the frame body and the screen plate is incorporated in the water tank. The water tank has a water inlet pipe and an outlet pipe, a spray pipe for dropping the dust downward from the screen plate, and dust guide means for collecting and guiding the dropped dust to the outside. A lid that can be opened and closed is attached to the upper wall surface of the water tank to form a unit.

  According to the present invention, by rotating the screen plate with the frame, the screen plate can be pulled up from the running water while capturing the dust in the running water. Moreover, since the dust removing device is a cup type, it is suitable for a water channel having a shallow water depth and a small flow rate.

  Furthermore, each screen plate is arranged inside the frame so as to be in an endless state with a regular polygon shape, the front end is detachably fixed to the drive disc, and the rear end is detachable from the ring disc It is to be fixed. Therefore, when damage or the like occurs in a part of each screen plate, only the screen plate can be removed and a new screen plate can be attached. For this reason, the cost for replacement parts (screen plate) is reduced and the replacement work does not take time, so the replacement work cost is also reduced.

  According to claim 2, the front end portion of the screen plate is simply inserted and fixed to the front end receiving member of the drive disc from the opening of the ring-shaped disc, and the rear end portion of the screen plate is fixed to the rear end receiving member. Simply place it on the back end receiving member with the holding member and fix it. Therefore, the screen plate can be replaced easily and quickly.

  According to the third aspect, the front end portion of the screen plate is simply placed on the front end receiving member of the driving disk and fixed with a screw or the like, and the rear end portion of the screen plate is placed on the rear end receiving member or the screw or the like. Just fix with. Therefore, the screen plate can be replaced easily and quickly.

  According to the fourth aspect, the hexagonal cup type has six screen plates, and the replacement work cost can be reduced while maintaining the dust capturing rate as compared with the circular cup type of Patent Document 1.

  According to the fifth aspect, a screw conveyor with a dehydration / compression mechanism is provided instead of the trough that collects dust and simply carries it out. Therefore, since dust can be collected and compressed while being dehydrated, the installation space for each device is not required and the equipment cost is reduced as compared with the case where the trough, the dehydrator, and the compressor are separately installed.

  According to claim 6, the assembly is assembled in the water tank in the manufacturing plant, and the unitized unit with the inlet pipe etc. attached to the wall surface is transported to the water treatment plant by a truck etc. Install on the surface. And an inlet pipe etc. are connected to each main piping in a water treatment factory. Thereby, a dust remover can be installed on the floor in the water treatment plant. Therefore, compared to the case where the dust removal device is installed by digging a water channel in the ground in civil engineering work, the installation work of the dust removal device can be performed easily and quickly. If the dust remover is a small flow type, install multiple units side by side and connect the inlet pipes of each unit to each main pipe in the water treatment plant. You can also Furthermore, if the lid of the water tank is removed, maintenance such as screen plate replacement can be performed easily and quickly.

It is side surface sectional drawing of the dust removal apparatus of 1st Embodiment which concerns on this invention. It is a top view of FIG. (A) is a front view of FIG. 1, (b) is a plane sectional view of FIG. (A) (b) is a perspective view of the assembly body of a frame and a screen plate. (A) is sectional drawing of the fixing structure of a screen plate, (b) is a perspective view of the fixing structure of the rear-end part of a screen plate, (c) is a perspective view of the fixing structure of the front-end | tip part of a screen plate. It is a dust removal apparatus of 2nd Embodiment which concerns on this invention, (a) is side sectional drawing, (b) is front sectional drawing. (A) is a plane sectional view of Drawing 6 (a), and (b) is an important section enlarged view of Drawing 6 (a). It is a perspective view of the screw conveyor which made the casing part the cross section. It is sectional drawing of the curved cylinder part and hood part of the casing of FIG. It is a principal part fracture perspective view of a water tank. It is a top view when installing a plurality of water tanks. It is a dust removal apparatus of patent document 1, (a) is side sectional drawing, (b) is front sectional drawing.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. 1 is a side sectional view of the dust removing apparatus of the first embodiment, FIG. 2 is a plan view of FIG. 1, FIG. 3A is a front view of FIG. 1, and FIG. 4A and 4B are perspective views of the assembly 100 of the frame body 56 and the screen plate 57, FIG. 5A is a cross-sectional view of the fixing structure of the screen plate 57, and FIG. FIG. 5C is a perspective view of a fixing structure of the front end portion 57b of the screen plate 57. FIG.

  A water tank 52 corresponding to a water channel is installed on the floor surface 51. A water flow inlet pipe 53 is attached to one side wall surface 52b (upstream side wall surface) of the water tank 52, and the other side wall surface 52c (downstream side wall surface). Is provided with a water flow outlet pipe 54 at a position lower than the inlet pipe 53. Referring to FIG. 10, the water tank 52 is formed in a square box shape having an upper portion opened by a bottom wall surface 52 a and side wall surfaces 52 b to 52 e rising from four sides of the bottom wall surface 52 a, and the upper opening surface is opened and closed. A possible lid 52f is attached. The water tank 52 is made of, for example, PC concrete, steel, or FRP. The water channel need not be the water tank 52, and may be a water channel dug in the ground by civil engineering work.

  An assembly 100 of a frame 56 and a screen plate 57 is incorporated in the water tank 52. The frame 56 includes a drive disk 58, a ring-shaped disk 59 on the upstream side thereof, and connection plates 60a and 60b that integrally connect the outer periphery of the drive disk 58 and the ring-shaped disk 59. ing.

  As shown in FIG. 4B, the reinforcing plate 61 is fixed radially on the back surface of the driving disk 58, and the driving shaft 62 is fixed at the center of the reinforcing plate 61.

  A base 64 is provided at a position that is supported by the floor 51 and is higher than the outlet pipe 54 through the other side wall surface 52c of the water tank 52. The base 64 is provided with an electric motor with a speed reducer (driving means). 65 is installed.

  The drive shaft 62 of the drive disk 58 of the frame 56 is rotatably supported by a bearing 66 of the base 64, and the drive shaft 62 and the output shaft of the electric motor 65 are coupled by a coupling 67. The frame body 56 is directly rotated by the motor 65.

  The ring-shaped disk 59 has a large regular hexagonal opening 59a at the center. The outer peripheral portions of the ring-shaped disc 59 and the driving disc 58 are connected by connecting plates 60a extending in the water flow direction corresponding to the respective corner portions (six locations in this example) of the opening 59a, The connection plates 60a are connected by a connection plate 60b extending in the side direction of the opening 59a. The opening 59a is not necessarily limited to a regular hexagon, and may be a regular triangle to a regular pentagon, or a regular heptagon or more. Note that the opening 59a may be circular in the second embodiment of FIGS.

  The screen plate 57 is a rectangular porous panel made of synthetic resin in which a large number of water passage holes (see FIG. 1) are formed vertically and horizontally. In FIG. 4, a combination of three narrow screen plates 57 arranged side by side with respect to one side of the opening 59 a is illustrated, but a single wide screen plate 57 may be used. The screen plate 57 may be a rectangular frame-like panel attached with a wire mesh.

  The screen plate 57 is inserted into the frame 56 from the opening 59a of the ring-shaped disk 59 so as to be in an endless state in a regular hexagonal shape, and the front end 57b is detachably fixed to the drive disk 58. The end 57c is detachably fixed to the ring-shaped disk 59.

  Specifically, as shown in FIGS. 5A to 5C, a concave groove-shaped tip receiving member 69 for inserting and fixing the tip portion 57b of the screen plate 57 is fixed to the inner surface of the drive disc 58 by screws 69a. It is fixed and provided.

  A rear end receiving member 70 on which the rear end portion 57c of the screen plate 57 is placed is fixed to the inner surface of the ring-shaped disk with screws 70a. Further, in order to press and fix the rear end portion 57c of the screen plate 57 to the rear end receiving member 70, a substantially L-shaped presser member 71 is provided which is detachably fixed by a screw 71a.

  When the screen plate 57 is attached, the front end portion 57b of the screen plate 57 is inserted into the front end receiving member 69 as indicated by the arrow a in FIG. 5A, and the rear end of the screen plate 57 is indicated as indicated by the arrow b. After the portion 57 c is placed on the rear end receiving member 70, the rear end portion 57 c of the screen plate 57 is pressed and fixed to the rear end receiving member 70 by the pressing member 71. When removing the screen plate 57, the procedure is the reverse of the above.

  In this way, each screen plate 57 inserted into the frame body 56 so as to form a regular hexagonal shape has both end portions in the rotation direction in contact with the connecting plate 60a in an endless state, so that dust flows out from this portion. There is no fear.

  As shown in FIG. 1, the lower portion of the screen plate 57 is located near the bottom of the water tank 52, which is a water channel, and the upper portion is located above the water level L3. Since the water flow outlet pipe 54 is attached at a position lower than the inlet pipe 53, the electric motor 65 and the bearing 66 are not likely to be submerged.

  Then, as indicated by the arrow in FIG. 3B, the water flow taken into the water tank 52 from the inlet pipe 53 passes from the opening 59a of the ring-shaped disc 59 to the outside of the screen plate 57, and then exits the outlet pipe. The water is discharged from 54 to the outside of the water tank 52. Note that a sealing material 55 that contacts the outer surface of the ring-shaped disk 59 and seals it in a watertight manner is attached to the enlarged portion 53 a of the inlet pipe 53.

  As shown in FIG. 1, a spray pipe 75 to which water is supplied from a submersible pump 73 in the water tank 52 via a water supply pipe 74 is disposed above the frame body 56. The high-pressure water sprayed from the spray pipe 75 causes the dust pulled up from the running water by the rotational drive of the screen plate 57 by the frame body 56 to fall downward from the screen plate 57.

  The falling dust is collected by a trough (dust guide means) 76 below the dust and guided to the outside of the water tank 52.

  If it is a dust removal apparatus of 1st Embodiment, it can pull up from flowing water, capturing the dust in flowing water by rotationally driving the screen plate 57 with the frame 56. FIG. Further, since the dust removing device is a hexagonal cup type, it is suitable for a water channel having a shallow water depth and a small flow rate (see water level L3 in FIG. 1).

  Further, each screen plate 57 is inserted into the inside of the frame body 56 from the opening 59a of the ring-shaped disk 59 so as to be an endless state in a regular hexagonal shape, and the tip portion 57b is detachably fixed to the drive disk 58, The rear end 57c is detachably fixed to the ring-shaped disk 59. Therefore, when a part of each screen plate 57 is damaged or the like, only the screen plate 57 can be removed and a new screen plate 57 can be attached. For this reason, the cost for replacement parts (screen plate 57) is reduced and the replacement work does not take time, so the replacement work cost is also reduced.

  Further, the front end portion 57b of the screen plate 57 is merely inserted and fixed to the front end receiving member 69 of the drive disc 58, and the rear end portion 57c of the screen plate 57 is placed on the rear end receiving member 70 and is pressed. Then, it is only pressed and fixed to the rear end receiving member 70. Accordingly, the screen plate 57 can be replaced easily and quickly.

  Further, the hexagonal cup type has six screen plates, and the replacement work cost can be reduced while maintaining the dust capture rate as compared with the circular cup type of Patent Document 1.

  In addition, since the drive shaft 62 of the frame 56 is directly driven to rotate by the electric motor 65, an expensive chain and sprocket as in Patent Document 1 are not required, and the apparatus cost is reduced.

  6 and 7 show the dust removing device of the second embodiment. FIG. 6 (a) is a side sectional view, FIG. 7 (b) is a front sectional view, FIG. 7 (a) is a plan sectional view, and FIG. It is a principal part enlarged view of FIG.

  The drive disk 58 is formed with pinwheel racks 58a whose outer periphery is cut into a V shape at equal angular intervals on the circumference.

  The outer peripheral portions of the ring-shaped disc 59 and the drive disc 58 are connected by connecting plates 60a extending in the water flow direction corresponding to the respective corner portions (six locations in this example) of the opening 59a.

  On the inner surface of the drive disc 58, an L-shaped tip receiving member 78 is provided which is mounted with a screw 77 or the like and is fixed with a screw 77 from the outside.

  On the inner surface of the ring-shaped disc 59, an L-shaped rear end receiving member 79 is provided, which is mounted on the rear end portion 57c of the screen plate 57 and fixed with screws 77 from the outside. .

  In addition, a plurality of (six in this example) guide rollers 80 are provided on the outer surface of the ring-shaped disk 59, and the guide roller 80 at the lower part of the ring-shaped disk 59 is guided inside the water tank 52. A semicircular roller guide 81 is provided. The semicircular roller guide 81 supports the ring-shaped disk 59 side of the frame 56 so as not to bend downward.

  And if the pinwheel 82 of the electric motor (driving means) 65 with a reduction gear installed in the upper part of the water tank 52 is meshed with the pinwheel rack 58a of the driving disc 58, the driving disc 58 from the electric motor 65 through the pinwheel 82 is used. Is rotated.

  The second embodiment is a pin wheel type driving means, and the electric motor 65 comes to be located substantially above the water level L3, so there is no possibility of being submerged.

  In the second embodiment, each screen plate 57 is placed across the front end receiving member 78 and the rear end receiving member 79, and is fixed to each receiving member 78, 79 so as to be detachable with screws 77 from the outside. . Therefore, when a part of each screen plate 57 is damaged or the like, only the screen plate 57 can be removed and a new screen plate 57 can be attached. For this reason, the cost for replacement parts (screen plate 57) is reduced and the replacement work does not take time, so the replacement work cost is also reduced.

  Further, the front end portion 57 b and the rear end portion 57 c of the screen plate 57 are simply placed on the receiving members 78 and 79 and fixed with screws 77. Accordingly, the screen plate 57 can be replaced easily and quickly.

  In each of the above embodiments, the dust that has been pulled up from the running water by the rotational drive of the screen plate 57 and dropped from the screen plate 57 is only collected by the trough 76 and guided to the outside of the water tank 52.

  On the other hand, as shown in FIG. 8 and FIG. 9, the dust dropped from the screen plate 57 is collected by a screw conveyor (dust guide means) 42 having a built-in dehydration / compression mechanism. it can.

  That is, the spiral screw conveyor 42 is housed in the casing 43 and is rotationally driven by the electric motor 49. The casing 43 is curved downward at the distal end side of the screw conveyor 42 at the hopper portion 43a for collecting the dropped dust, the feed tube portion 43b into which the screw conveyor 42 is fitted, and the proximal end of the screw conveyor 42. It is comprised with the curved cylinder part 43c made.

  The screw conveyor 42 has a wide pitch for smoothly sending out dust collected by the hopper 43a (see arrow d in FIG. 8) until the middle between the hopper 43a and the curved cylinder 43c. After that, it is formed at a narrow pitch for primarily compressing the dust up to the vicinity of the curved cylindrical portion 43c. Further, the vicinity of the base end is formed in a reverse spiral shape for sending dust back to the curved cylindrical portion 43c side.

  A hood portion 43d that extends downward is formed at the lower end of the curved cylinder portion 43c, and a cone body 44 having a center hole 44a is disposed inside the hood portion 43d.

  The cone body 44 is supported inside the hood portion 43d so that the center hole 44a is fitted into a shaft member 45 whose upper end is fixed to the center of a substantially Y-shaped support member 50 in a plan view so as to be movable up and down. Yes. A male screw 45a is formed in the lower portion of the shaft member 45, and a stroke adjusting nut 46 is screwed into the male screw 45a. A spring receiving seat 47 is disposed above the stroke adjusting nut 46 via a washer 47 a, and a compression coil spring 48 is mounted between the spring receiving seat 47 and the cone body 44. The cone body 44 is provided with a cover portion 44 b that covers the outer periphery of the compression coil spring 48.

  The cone body 44 normally closes the opening by abutting against the inner surface of the hood portion 43d by the urging force of the compression coil spring 48 (see the left half of FIG. 9). Further, when the dust sent from the feed tube portion 43 b to the curved tube portion 43 c is secondarily compressed and the dust feed force exceeds the bias force of the compression coil spring 48, it resists the bias force of the compression coil spring 48. Then, the cone body 44 is opened from the inner surface of the hood 43d (see the right half of FIG. 9). Thereby, as indicated by an arrow c, the dust is carried out to the outside while being secondarily compressed.

  In this way, instead of the trough 76 that collects dust and simply carries it out to the outside, the screw conveyor 42 with a dehydration / compression mechanism is provided so that dust can be collected and compressed while dewatering, Compared with the case where the dehydrating device and the compressing device are separately installed, the installation space for each device becomes unnecessary and the equipment cost is also reduced.

  As shown in FIG. 10, a water tank 52 corresponding to a water channel is installed on the floor surface 51, and an assembly 100 of a frame body 56 and a screen plate 57 is incorporated into the water tank 52. Further, the water flow inlet pipe 53 and the screw conveyor 42 are attached to the side wall surfaces 52d and 52b of the water tank 52, and the water flow outlet pipe 53 and the spray pipe 75 are attached to the other side wall surface 52c. Further, a lid 52 f that can be opened and closed is attached to the upper wall surface of the water tank 52. In addition, the inlet pipe 52, the outlet pipe 53, and the spray pipe 27 can be attached to any of the side wall surfaces 52b to 52e, and can also be attached to the bottom wall surface 52a and the upper wall surface (lid 52f).

  If it is such a structure, what assembled the assembly 100 in the water tank 52 in a manufacturing factory, attached the inlet pipe 53 etc. to the wall surfaces 52b-52d, and unitized it will be conveyed to a water treatment factory with a truck etc. This is installed on the floor 51 of this water treatment plant. Then, as shown in FIG. 11, the inlet pipe 53 is connected to the main pumping water supply pipe 90 in the water treatment plant, the outlet pipe 54 is connected to the main drain pipe 91, and the spray pipe 75 is connected to the main water pipe 92. To do. The dust carried out from the screw conveyor 42 can be collected in a dust storage box or the like installed on the floor 51. A trough 76 can be attached instead of the screw conveyor 42.

  Thereby, a dust removal apparatus can be installed in the floor surface 51 in a water treatment factory. Therefore, compared to the case where the dust removal device is installed by digging a water channel in the ground in civil engineering work, the installation work of the dust removal device can be performed easily and quickly.

In addition, when the dust removing device is a small flow type (for example, the amount of treated water is 2500 to 5000 m ³ / day), a plurality of water tanks (units) 52 are arranged side by side as shown in FIG. If the 52 inlet pipes 53 and the like are connected to the main pipes 90 to 92 in the water treatment plant, respectively, a large flow rate type can be easily obtained.

  Furthermore, if the lid 52f of the water tank 52 is removed, maintenance such as replacement of the screen plate 57 can be performed easily and quickly. Further, since the electric motors 49 and 65 are outside the water tank 52, no waterproof measures are required, and maintenance can be performed easily and quickly. The dust carried out from the screw conveyor 42 or the trough 76 can be collected at once by using a belt conveyor or the like.

42 Screw conveyor (dust guide means)
43 Casing 52 Water tank (water channel)
52f Lid 53 Inlet pipe 54 Outlet pipe 56 Frame 57 Screen plate 57b Front end 57c Rear end 58 Drive disc 59 Ring disc 59a Opening 60a, 60b Connection plate 62 Drive shaft 65 Electric motor (drive means)
69 Front end receiving member 70 Rear end receiving member 71 Presser member 75 Spray pipe 76 Trough (dust guide means)
78 Front end receiving member 79 Rear end receiving portion 100 Assembly

Claims (6)

In the dust removal device that pulls up dust from running water by rotating the screen plate while capturing dust in running water in the water channel with multiple screen plates arranged in an endless state,
The water channel is composed of a drive disk that is rotationally driven by a drive means, a ring-shaped disk on the upstream side thereof, and a connecting plate that integrally connects the outer periphery of the drive disk and the ring-shaped disk. Each of the screen plates is arranged in an endless polygonal shape inside the frame body, the front end portion is detachably fixed to the drive disc, and the rear end portion is a ring. A dust removing device, wherein the dust removing device is detachably fixed to a circular disk.   A front end receiving member for inserting and fixing the front end portion of the screen plate to the drive disc is provided, a rear end receiving member for placing the rear end portion of the screen plate on the ring-shaped disc, and a rear end receiving portion on the rear end receiving portion. 2. A dust removing device according to claim 1, further comprising a detachable pressing member that presses and fixes the rear end of the screen plate.   A front end receiving member is provided on the drive disc so that the front end portion of the screen plate is placed and fixed detachably, and a rear end receptacle is mounted on the ring-shaped disc so that the rear end portion of the screen plate is fixed removably. The dust removing apparatus according to claim 1, wherein a member is provided.   The dust removing device according to any one of claims 1 to 3, wherein the screen plate is inserted so as to form a regular hexagonal shape.   The screw conveyor which collects the dust pulled up from the running water by the rotational drive of the screen plate and carries it out is provided, and the dewatering / compression mechanism is built in the screw conveyor. The dust removal apparatus as described in any one of -4.   A water tank corresponding to the water channel is installed on the floor surface, and an assembly of the frame body and the screen plate is incorporated inside the water tank. A water flow inlet pipe, an outlet pipe, and dust are screened on the wall surface of the water tank. A spray tube that drops downward from the plate and a dust guide means that collects the falling dust and guides it to the outside are attached, and an openable / closable lid is attached to the upper wall surface of the water tank to form a unit. The dust removing device according to any one of claims 1 to 5, wherein the dust removing device is provided.

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