Drum-type filtration device

Abstract

To provide a drum-type filtration device that can easily wind a belt-shaped filter cloth around a winding shaft in the initial stage. [Solution] The drum-type filtration device (1) comprises an upper winding section (24) that unwinds the rolled up strip filter cloth (18) and sends it to the filter feeding device (41) and winds up the strip filter cloth, a lower winding section (27) that is positioned downstream of the filter feeding device in the conveying direction of the strip filter cloth and winds up the strip filter cloth sent out from the filter feeding device and unwinds the strip filter cloth, and cover members (62A, 62B) that are attached so as to cover a predetermined circumferential range of the outer peripheral surface of the winding shaft (61) around which the tip of the strip filter cloth of the upper winding section or the lower winding section is wound, and the cover member forms a gap (78) between the inner surface of at least one side edge in the rotational direction and the outer peripheral surface of the winding shaft into which the tip edge of the strip filter cloth can be inserted.

Description

[Technical Field]

[0001] The present disclosure relates to a drum-type filtration device. [Background technology]

[0002] Various drum-type filtration devices have been proposed. In the filter cloth reciprocating filtration device described in Patent Document 1, the filter cloth wound around one shaft is unwound, passes through a guide roll, a suction box, and a sprinkler pipe, and is fed as the drum rotates while adhering to the surface of the drum via the guide roll. The filter cloth then passes through a guide roll, a suction box, and a sprinkler pipe, passes through the guide roll, and is wound up around the other shaft. When the filter cloth has been completely unwound from one shaft, the drive units are reversed, the filter cloth is transported in the opposite direction, and the filter cloth wound around the other shaft is unwound and wound up around one shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Registered Utility Model No. 3026488 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional configuration, when attaching the tip of the filter cloth unwound from one shaft to the other shaft, the filter cloth was not sufficiently supported on the other shaft, making it difficult to initially wind the filter cloth around the other shaft.

[0005] An object of one aspect of the present disclosure is to provide a drum-type filtration device that allows for easy initial winding of a belt-shaped filter cloth onto a winding shaft. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a drum-type filtration device according to one aspect of the present disclosure includes a case having a front wall, a rear wall, and a pair of side walls connecting the front wall and the rear wall, a drum rotatably supported by a drum support shaft having both ends attached to the pair of side walls, a filter feeding device having an endless annular mesh belt disposed below the drum along the outer periphery of the drum, a longitudinal strip filter cloth sandwiched between the mesh belt and the drum and fed by the filter feeding device, and a winding device disposed above the drum for feeding the wound strip filter cloth to the filter feeding device. the upper winding section which discharges the strip filter cloth and winds up the strip filter cloth; a lower winding section which is positioned downstream of the filter feeding device in the conveying direction of the strip filter cloth and which winds up the strip filter cloth discharged from the filter feeding device and unwinds the strip filter cloth; and a cover member which is attached so as to cover a predetermined circumferential range of the outer circumferential surface of the winding shaft around which the tip of the strip filter cloth of the upper winding section or the lower winding section is wound, and the cover member forms a gap between the inner surface of at least one side edge in the rotational direction and the outer circumferential surface of the winding shaft into which the tip edge of the strip filter cloth can be inserted. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, the initial winding of the belt-shaped filter cloth onto the winding shaft can be easily performed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view illustrating the configuration of a drum-type filtration device according to an embodiment of the present invention. FIG. [Figure 2] FIG. 4 is an explanatory diagram illustrating the configuration of a lower winding section. [Figure 3] 1. FIG. 3 is a cross-sectional view taken along the X1-X1 arrows in FIG. 2, illustrating an example of winding up a strip-shaped filter cloth by inserting the leading end of the filter cloth between the winding shaft and a pair of cover members. [Figure 4] FIG. 10 is a side view of a pair of cover members arranged with their inner sides facing each other. [Figure 5]FIG. 10 is a front view of a pair of cover members arranged with their inner sides facing each other. [Figure 6] FIG. 10 is a perspective view showing an example of a cover member according to Modification 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Schematic configuration of drum-type filtration device] An embodiment of the present disclosure will be described in detail below with reference to FIGS. 1 to 5. A schematic configuration of a drum-type filtration device 1 according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a side view of the drum-type filtration device 1 according to this embodiment (hereinafter also referred to as the "filtration device"), and is a schematic cross-sectional view taken along a vertical plane passing through the center of the width of the filtration device 1. The filtration device 1 is a device that filters, for example, grinding fluid or cutting fluid used in machining bearings or the like. As shown in FIG. 1, the filtration device 1 includes a substantially box-shaped case 11 and a clean tank 12 that stores purified coolant, i.e., clean fluid CF. The case 11 is disposed on the clean tank 12. The clean tank 12 is disposed on a horizontal floor surface 13.

[0010] The case 11 has a front wall 11C, a rear wall 11D, a pair of side walls 11A and 11B (see FIG. 2) connecting the front wall 11C and the rear wall 11D, a top wall 11D that closes from above the opening of the space surrounded by the front wall 11C, the rear wall 11D, and the pair of side walls 11A and 11B, and a bottom wall 11E. A communication hole (not shown) is formed in the bottom wall 11E to allow the purified clean liquid CF to fall into the clean tank 12. A notch 15 is formed in the end of the bottom wall 11E on the rear wall 11D side, and a sludge storage container 16 that opens upward and is disposed below the notch 15 for storing sludge SG.

[0011] A recessed groove 22 is formed in the upper wall 11D of the case 11, in which a cylindrical first roll 21 is rotatably disposed, around which one end of a strip filter cloth 18 of a predetermined width that functions as a strip filter is wound. The first roll 21 is rotatably supported by the side walls 11A and 11B. A filter cloth inlet 25 is formed penetrating the bottom of the recessed groove 22 (between the front wall 11C and the lower end of the recessed groove 22) and through which the strip filter cloth 18, unwound from the first roll 21 and hung on a guide shaft 23, is introduced into the case 11. The strip filter cloth 18 is a strip filter made of a filter material such as a nonwoven fabric or a woven fabric, but is not limited thereto, and the material may be appropriately selected depending on the purpose of filtration.

[0012] The guide shaft 23 is disposed between the side walls 11A, 11B horizontally relative to the floor surface 13, and both ends are attached by bolts or the like. A pair of guide members 19A, 19B are disposed between the first roll 21 and the guide shaft 23. The pair of guide members 19A, 19B are attached to the pair of side walls 11A, 11B and press both side edges of the strip filter cloth 18 inward in the width direction perpendicular to the unwinding and winding directions of the strip filter cloth 18. One of the guide members 19B is shown in FIG. 1. The pair of guide members 19A, 19B are disposed between the guide shaft 23 and the upper winding section 24 in the unwinding direction of the strip filter cloth 18. More specifically, the pair of guide members 19A, 19B are disposed between the guide shaft 23 and the first roll 21, and are disposed closer to the front wall 11C than the maximum outer circumferential surface of the first roll 21.

[0013] In the filtration device 1, a cylindrical drum support shaft 31 is hung horizontally between a pair of side walls 11A, 11B to rotatably support a drum 36. The drum 36 is formed by a pair of circular members 32 rotatably supported by the drum support shaft 31 and connected to each other via a longitudinal connecting member 33 of a predetermined length so that they face each other at a fixed interval. The filtration device 1 further includes a filter feeding device 41 having an endless circular mesh belt 38 that runs along half the circumference of the lower outer periphery of the pair of circular members 32. The rotation center line CL of the drum 36 is also the center line of the cylindrical drum support shaft 31.

[0014] Above the sludge storage container 16, a cylindrical second roll 26, around which the other end of the strip filter cloth 18 is wound, is rotatably supported by the side walls 11A and 11B inside the rear wall 11D. The filter feeding device 41 includes a first torque motor TM1 that applies a constant torque to generate tension on the strip filter cloth 18 of the first roll 21 located above, and a second torque motor TM2 that applies a constant torque to generate tension on the strip filter cloth 18 of the second roll 26. The first torque motor TM1 and the second torque motor TM2 are attached to the side wall 11B. As a result, the long strip filter cloth 18 is unwound from the first roll 21 while being applied with a constant tension, and is then taken up by the second roll 26 from the filter feeding device 41 via the sludge deliquor separation device 28, preventing slack.

[0015] The first torque motor TM1, which is disposed above the drum 36, constitutes an upper winding section 24 that unwinds the strip filter cloth 18 wound around the first roll 21 and feeds it to the filter feeding device 41, and winds up the strip filter cloth 18. The second torque motor TM2, which is disposed downstream of the filter feeding device 41 in the conveying direction of the strip filter cloth 18, constitutes a lower winding section 27 that winds up the strip filter cloth 18 fed from the filter feeding device 41, and unwinds the strip filter cloth 18.

[0016] The filter feeding device 41 is provided so as to surround the drum 36, and includes a drive roller 42 and three driven rollers 44A, 44B, and 44C around which an endless circular mesh belt 38 is wound, and an electric motor M that drives and rotates the drive roller 42. When the drive roller 42 is driven and rotated, the endless circular mesh belt 38 and the drum 36 are rotated. As a result, the strip-shaped filter cloth 18 unwound from the first roll 21 is sandwiched between the mesh belt 38 and the pair of circular members 32 in a semicircular shape, and is then fed from the filter feeding device 41 toward the second roll 26 via the sludge deliquor separation device 28. The mesh belt 38 is a mesh having numerous meshes and made of metal, synthetic fiber, carbon fiber, or composite material.

[0017] Of the three driven rollers 44A, 44B, and 44C, the driven roller 44C is disposed at a height equal to or higher than that of the drive roller 42. The pair of driven rollers 44A and 44B are positioned at a height such that the mesh belt 38 stretched between the pair of driven rollers 44A and 44B is positioned a predetermined distance below the drum 36, and are also disposed a predetermined distance apart in the horizontal direction. The strip-shaped filter cloth 18 sent from the filter feeding device 41 to the sludge deliquification separation device 28 is wound around the second roll 26.

[0018] The cylindrical drum support shaft 31 is configured so that contaminated fluid DF discharged from a polishing machine or grinding machine that uses coolant can flow into the interior of the drum support shaft 31 via piping connected from the outside of the filtration device 1. The contaminated fluid DF that has flowed into the interior of the drum support shaft 31 flows into the drum 36 from a discharge port (not shown) formed in the drum support shaft 31. As a result, the contaminated fluid DF remaining on the strip filter cloth 18 inside the drum 36 is passed downward through the strip filter cloth 18, and sludge SG is deposited on the outer peripheral surface of the strip filter cloth 18.

[0019] The filter feeding device 41 is provided on the drum support shaft 31 and includes a liquid level sensor 46 that detects the liquid level of the dirty liquid DF remaining on the strip-shaped filter cloth 18 inside the drum 36, and a motor control device 48 that controls the rotation of the drive roller 42. The motor control device 48 adjusts the rotation speed of the drive roller 42 driven by the electric motor M so that the liquid level detected by the liquid level sensor 46 becomes a preset liquid level height, thereby appropriately controlling the feed speed (forward speed) of the strip-shaped filter cloth 18.

[0020] When the amount of the filter cloth 18 fed forward toward the sludge deliquification separator 28 reaches a predetermined amount, the filter feed device 41 reciprocates, moving the filter cloth 18 backward a predetermined distance in the opposite direction, and then feeding the filter cloth 18 forward again. This allows the filter feed device 41 to use the filter cloth 18 multiple times to filter the coolant.

[0021] For example, when the filter feeding device 41 reaches a position where the number of remaining turns of the strip filter cloth 18 unwound from the first roll 21 becomes zero, the inflow of the dirty liquid DF from the drum support shaft 31 is stopped. Then, the filter feeding device 41 moves the strip filter cloth 18 backward to a position where the number of remaining turns of the strip filter cloth 18 on the second roll 26 becomes zero so that the portion of the strip filter cloth 18 from which sludge has been removed by the sludge deliquor separation device 28 is wound onto the first roll 21.

[0022] Next, with the inflow of dirty liquid DF from the drum support shaft 31 resumed, the filter feeding device 41 unwinds the portion of the strip filter cloth 18 wound around the first roll 21 from which sludge has been removed by the sludge drainage separation device 28. The filter feeding device 41 then advances the strip filter cloth 18 again so that it is wound around the second roll 26 via the sludge drainage separation device 28. The filter feeding device 41 then repeats this forward and backward movement of the strip filter cloth 18.

[0023] The sludge drainage separation device 28 includes a pair of nipping rollers 52 that continuously nip and press the sludge SG accumulated on the outer peripheral surface of the strip filter cloth 18 delivered from the filter feeding device 41. The sludge drainage separation device 28 also includes a pair of guide rollers 54, 56 positioned diagonally below the pair of nipping rollers 52 and spaced a predetermined distance apart in the vertical direction. The sludge drainage separation device 28 also includes a rotating brush 58 that separates the cake-like sludge SG that has been drained by the pair of nipping rollers 52 and that accumulates on the outer peripheral surface of the strip filter cloth 18, which is guided in contact with the lower outer peripheral surface of the lower guide roller 56. The clean liquid CF that is nipped between the pair of nipping rollers 52 from the sludge SG on the outer peripheral surface of the strip filter cloth 18 and falls through the strip filter cloth 18 is then guided into the clean tank 12 via a clean liquid guide plate 59.

[0024] In order to clamp the belt-shaped filter cloth 18 between the pair of clamping rollers 52, the pair of clamping rollers 52 is preferably configured so that at least one of the pair of clamping rollers 52 is made of an elastic material that is elastically deformable in the radial direction, such as synthetic rubber, or a roller biasing mechanism is provided that biases one bearing of the pair of clamping rollers 52 toward the other bearing.

[0025] [Schematic configuration of the lower winding section 27] Next, the schematic configuration of the lower winding section 27 will be described with reference to Figs. 2 to 5. Fig. 2 is an explanatory diagram illustrating the configuration of the lower winding section 27. Fig. 3 is a cross-sectional view taken along the arrows X1-X1 in Fig. 2, illustrating an example in which the leading end of the strip-shaped filter cloth 18 is inserted between the winding shaft 61 and the pair of cover members 62A, 62B and wound around the winding shaft 61. Fig. 4 is a side view of the pair of cover members 62A, 62B when the inner sides of the pair of cover members 62A, 62B are arranged opposite each other. Fig. 5 is a front view of the pair of cover members 62A, 62B when the inner sides of the pair of cover members 62A, 62B are arranged opposite each other.

[0026] 2 and 3, the winding shaft 61 is formed in a cylindrical shape with both ends closed. A pair of flanges 63, which are generally ring-shaped in side view and extend a predetermined length radially outward from the outer peripheral surface of both ends of the winding shaft 61, are provided on the outer peripheral surface. The outermost diameter of the pair of flanges 63 is set to be slightly larger than the maximum outer peripheral diameter of the second roll 26. The distance between the pair of flanges 63 is set to be approximately equal to the width of the strip-shaped filter cloth 18 to be wound up.

[0027] A motor shaft 65 of a second torque motor TM2 attached to the outer surface of the side wall 11B is fitted into the center of the end face of the winding shaft 61 on the side wall 11B side, along the central axis of the winding shaft 61, and fixed thereto by screws or the like. A substantially cylindrical shaft portion 66 is provided on the end face of the winding shaft 61 on the side wall 11A side, protruding a predetermined length outward from the center of the end face along the central axis of the winding shaft 61. The shaft portion 66 is inserted into a through-hole 67 formed in the side wall 11A at a position opposite the motor shaft 65 of the second torque motor TM2, and is rotatably supported by being fitted into a rotation support portion 68 attached to the outer surface of the side wall 11A. The rotation support portion 68 is formed, for example, by a metal bearing or the like.

[0028] A pair of cover members 62A, 62B having a generally semicircular cross section are attached to the outer peripheral surface of the winding shaft 61 between the pair of flange portions 63, facing each other in the diameter direction, over substantially the entire axial length. As shown in FIGS. 4 and 5, the pair of cover members 62A, 62B are formed to have a generally semicircular cross section with a curvature radius that is a predetermined length longer than the radius of the cross section of the winding shaft 61, i.e., the radius of the outer peripheral surface of the winding shaft 61, and a central angle that is a predetermined angle smaller than 180 degrees. The pair of cover members 62A, 62B are formed to have a vertically elongated rectangular shape in a plan view. Each cover member 62A, 62B is made of metal such as aluminum or stainless steel, or synthetic resin.

[0029] Furthermore, the pair of cover members 62A, 62B have a plurality of, for example, three, countersunk holes 71 for flat head screws that penetrate radially and are arranged at equal intervals along the longitudinal direction at the apex of the semicircular cross section. Furthermore, as shown in Fig. 4, both circumferential end edges of the pair of cover members 62A, 62B are formed with inclined portions 72 that are inclined at a predetermined angle from the edge of the radially outer surface toward the circumferentially inner side. Meanwhile, as shown in Fig. 3, the winding shaft 61 has screw holes 75 formed at positions that face the countersunk holes 71 for flat head screws of the pair of cover members 62A, 62B that are arranged on the outer circumferential surface so as to face each other in the diameter direction.

[0030] 2 and 3, the countersunk screw holes 71 of the pair of cover members 62A, 62B are arranged to overlap with the screw holes 75 between the pair of flange portions 63 of the winding shaft 61. The pair of cover members 62A, 62B can be attached to the outer circumferential surface of the winding shaft 61 by screwing flat head screws 76 into the countersunk screw holes 71 of the pair of cover members 62A, 62B.

[0031] As shown in Fig. 3, the radius of curvature of the semicircular cross section of the pair of cover members 62A, 62B is longer than the radius of the cross section of the winding shaft 61 by a predetermined length. Therefore, gaps 78 into which the leading edge of the strip filter cloth 18 can be inserted are formed between the inner surfaces of both circumferential ends of the pair of cover members 62A, 62B attached to the outer circumferential surface of the winding shaft 61 and the outer circumferential surface of the winding shaft 61. Each gap 78 gradually narrows from both circumferential ends of the pair of cover members 62A, 62B toward the circumferential center and is formed over the entire length of each cover member 62A, 62B. Furthermore, the radial spacing at the inlet of each gap 78 is set to be greater than the thickness of the strip filter cloth 18.

[0032] 2 and 3, a slit 81 into which the leading edge of the strip filter cloth 18 can be inserted is formed between opposing side edges in the rotational direction of a pair of cover members 62A, 62B attached to the outer peripheral surface of the winding shaft 61. The slit 81 is formed to have a width of, for example, about 2 to 4 mm in the circumferential direction of the winding shaft 61.

[0033] 3, the operator inserts the leading end of the strip filter cloth 18 into the slit 81 between the pair of cover members 62A, 62B. Next, the operator brings the leading end of the strip filter cloth 18 into contact with the outer circumferential surface of the winding shaft 61 along the inclined portion 72 and pushes it further inward, thereby inserting the leading end of the strip filter cloth 18 into the inner side of the gap 78 and clamping it. Then, the operator rotates the winding shaft 61 in the opposite direction to the insertion direction of the strip filter cloth 18, thereby folding the strip filter cloth 18 at the slit 81 and winding it around the outer circumferential surfaces of the pair of cover members 62A, 62B.

[0034] As described above in detail, in the drum-type filtration device 1 according to this embodiment, the leading edge of the strip filter cloth 18 is inserted into the gap 78 formed between the outer peripheral surface of the winding shaft 31 and the inner surfaces of the side edges of each cover member 62A, 62B. This facilitates the initial winding of the strip filter cloth 18 around the winding shaft 61. Furthermore, the winding force of the strip filter cloth 18 around the winding shaft 61 can be increased, thereby shortening the initial winding length of the strip filter cloth 18 and increasing the effective length of the strip filter cloth 18 that can be used for filtration. For example, the initial winding length of the strip filter cloth 18 around the winding shaft 61 can be shortened from approximately 10 meters to approximately 5 meters.

[0035] Furthermore, the leading edge of the strip filter cloth 18 is inserted into a slit 81 formed between the side edges of the pair of cover members 62A, 62B. As a result, the leading edge of the strip filter cloth 18 is inserted along the outer peripheral surface of the winding shaft 61 into a gap 78 formed between the outer peripheral surface of the winding shaft 61 and the inner surfaces of the side edges of each of the cover members 62A, 62B. By inserting the leading edge of the strip filter cloth 18 into the slit 81, the initial winding of the strip filter cloth 18 around the winding shaft 61 can be performed even more easily.

[0036] The pair of cover members 62A, 62B are formed to have a substantially semicircular cross section with a radius of curvature larger than the radius of the cross section of the winding shaft 61, i.e., the radius of the outer peripheral surface. Therefore, when the inner peripheral surface of each cover member 62A, 62B is attached to the outer peripheral surface of the winding shaft 61, a gap 78 can be formed between the inner surfaces of both side edges in the rotation direction of each cover member 62A, 62B and the outer peripheral surface of the winding shaft 61, into which the leading edge of the strip filter cloth 18 can be inserted.

[0037] The leading edge of the strip filter cloth 18 can be inserted over its entire width into the gap 78 formed between the outer peripheral surface of the winding shaft 61 and the inner surfaces of the side edge portions of each cover member 62A, 62B, making it easier to initially wind the strip filter cloth 18 around the winding shaft 61. In addition, the winding force of the strip filter cloth 18 around the winding shaft 61 can be made even stronger.

[0038] [Variations] A modification of the above embodiment will be described. In the following description, for the sake of convenience, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0039] [Variation 1] For example, as shown in Fig. 6, a plurality of sawtooth-shaped protrusions 83 may be provided on both side edges in the circumferential direction of the pair of cover members 62A, 62B, that is, in the rotational direction. Fig. 6 is a perspective view showing an example of cover members 62A, 62B according to Modification 1. Note that a plurality of sawtooth-shaped protrusions 83 may be provided only on the side edges of the pair of cover members 62A, 62B in the rotational direction in which the strip filter cloth 18 is wound up. This allows the strip filter cloth 18 to be caught on the plurality of sawtooth-shaped protrusions 83, thereby increasing the winding force of the strip filter cloth 18 around the winding shaft 61 and further increasing the effective length of the strip filter cloth 18 that can be used for filtration.

[0040] [Variation 2] Alternatively, for example, only one of the pair of cover members 62A, 62B may be attached to the winding shaft 61 with a flat head screw 76. The leading edge of the strip filter cloth 18 may be inserted into a gap 78 between the outer peripheral surface of the winding shaft 61 and the side edge of the cover member 62A or 62B attached to the winding shaft 61 that faces in the rotation direction in which the strip filter cloth 18 is wound up.

[0041] This allows the leading edge of the strip filter cloth 18 to be inserted into the gap 78 formed between the outer peripheral surface of the winding shaft 51 and the inner surface of the side edge of the cover member 62A or 62B, thereby facilitating the initial winding of the strip filter cloth 18 around the winding shaft 61. Furthermore, the winding force of the strip filter cloth 18 around the winding shaft 61 can be increased, which shortens the initial winding length of the strip filter cloth 18 and increases the effective length of the strip filter cloth 18 that can be used for filtration.

[0042] [Variation 3] Furthermore, for example, at least one of the pair of cover members 62A, 62B may be attached with a flat head screw 76 to the outer peripheral surface of a winding shaft (not shown) around which the leading end of the strip filter cloth 18 of the upper winding section 24 is wound. This allows the leading edge of the strip filter cloth 18 to be inserted into a gap 78 formed between the outer peripheral surface of the winding shaft (not shown) and the inner surface of the side edge of the cover member 62A or 62B, making it easy to initially wind the strip filter cloth 18 around the winding shaft. This also increases the winding force of the strip filter cloth 18 around the winding shaft, shortening the initial winding length of the strip filter cloth 18 and increasing the effective length of the strip filter cloth 18 that can be used for filtration.

[0043] [Variation 4] Alternatively, instead of cover member 62A, multiple short cover members having substantially the same cross-sectional shape as cover member 62A may be attached at predetermined intervals along the axial direction to the outer peripheral surface of winding shaft 61 between the pair of flange portions 63 using flat head screws 76. Alternatively, instead of cover member 62B, multiple short cover members having substantially the same cross-sectional shape as cover member 62B may be attached at predetermined intervals along the axial direction to the outer peripheral surface of winding shaft 61 between the pair of flange portions 63 using flat head screws 76.

[0044] This allows the initial winding of the strip filter cloth 18 around the winding shaft to be easily performed by inserting the leading edge of the strip filter cloth 18 into the gap 78 formed between the outer peripheral surface of the winding shaft 61 and the inner surfaces of the side edges of the multiple cover members. Also, the winding force of the strip filter cloth 18 around the winding shaft 61 can be increased, which shortens the initial winding length of the strip filter cloth 18 and increases the effective length of the strip filter cloth 18 that can be used for filtration.

[0045] [summary] The drum-type filtration device of the first embodiment includes a case having a front wall, a rear wall, and a pair of side walls connecting the front wall and the rear wall, a drum rotatably supported by a drum support shaft having both ends attached to the pair of side walls, a filter feeding device having an endless annular mesh belt disposed below the drum along the outer periphery of the drum, a longitudinal strip filter cloth sandwiched between the mesh belt and the drum and fed by the filter feeding device, a winding device disposed above the drum for feeding the wound strip filter cloth to the filter feeding device, and the upper winding section winding up the filter cloth; a lower winding section positioned downstream of the filter feeding device in the conveying direction of the strip filter cloth and winding up the strip filter cloth fed out from the filter feeding device and unwinding the strip filter cloth; and a cover member attached so as to cover a predetermined circumferential range of the outer circumferential surface of the winding shaft around which the tip of the strip filter cloth of the upper winding section or the lower winding section is wound, and the cover member forms a gap between the inner surface of at least one side edge in the rotational direction and the outer circumferential surface of the winding shaft into which the tip edge of the strip filter cloth can be inserted.

[0046] The second aspect is a drum-type filtration device of the first aspect, in which a pair of the cover members are attached to the outer peripheral surface of the winding shaft facing each other, and a slit is formed between the opposing side edges of the pair of cover members attached to the outer peripheral surface in the rotational direction, into which the leading edge of the strip-shaped filter cloth can be inserted.

[0047] A third aspect is a drum-type filtration device according to the first or second aspect, wherein the winding shaft has a circular cross section, and the cover member has an arc-shaped cross section with a radius of curvature that is a predetermined length longer than the radius of the cross section of the winding shaft.

[0048] A fourth aspect is the drum-type filtration device according to any one of the first to third aspects, wherein the cover member is attached so as to cover the entire axial length of the outer circumferential surface of the winding shaft.

[0049] A fifth aspect is the drum-type filtration device according to any one of the first to fourth aspects, wherein the cover member has a plurality of sawtooth-shaped protrusions provided on at least one side edge in the rotation direction.

[0050] [Additional Notes] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0051] 1: Drum type filtration device 11: Case 11A, 11B: Side wall 11C: Front wall 11D: Back wall 13:Floor 18: Belt-shaped filter cloth 24: Upper winding section 27: Lower winding section 31: Drum support shaft 36: Drums 38: Mesh belt 41: Filter feeder 61: Winding shaft 62A, 62B: Cover member 78: Gap 81: Slit 82: Protrusion

Claims

1. a case having a front wall, a rear wall, and a pair of side walls connecting the front wall and the rear wall; a drum in which a pair of circular members are rotatably supported by a cylindrical drum support shaft, both ends of which are attached to the pair of side walls, and are connected to each other via a connecting member of a predetermined length, and contaminated fluid that has flowed into the drum support shaft flows into the drum through a discharge port formed in the drum support shaft; a filter feeding device that has an endless circular mesh belt that is disposed below the drum and that is disposed along half of the outer periphery of the lower side of the pair of circular members, and that rotates the mesh belt and the drum; a longitudinal belt-shaped filter cloth that is sandwiched between the mesh belt and the drum in a semicircular shape and sent by the filter sending device to filter the contaminated liquid downward; an upper winding section disposed above the drum, which unwinds the wound filter cloth to the filter feeding device and winds up the filter cloth; a lower winding section disposed downstream of the filter feeding device in the conveying direction of the belt-shaped filter cloth, for winding up the belt-shaped filter cloth fed from the filter feeding device and unwinding the belt-shaped filter cloth; a cover member attached to the outer peripheral surface of the winding shaft so as to cover a predetermined range in the circumferential direction of the outer peripheral surface of the winding shaft around which the leading end of the belt-shaped filter cloth of the upper winding section or the lower winding section is wound; Equipped with The cover member forms a gap between an inner surface of at least one side edge portion in the rotation direction and the outer circumferential surface of the winding shaft, into which the leading edge of the belt-shaped filter cloth can be inserted. Drum-type filtration device.

2. The cover members are attached as a pair to the outer peripheral surface of the winding shaft so as to face each other, A slit into which the leading edge of the belt-shaped filter cloth can be inserted is formed between the opposing side edge portions of the pair of cover members attached to the outer circumferential surface in the rotation direction. The drum-type filtration device according to claim 1.

3. The winding shaft has a circular cross section, The cover member is formed in an arc-shaped cross section having a curvature radius that is longer by a predetermined length than the radius of the cross section of the winding shaft. The drum-type filtration device according to claim 1 or 2.

4. The cover member is attached so as to cover the entire axial length of the outer circumferential surface of the winding shaft. The drum-type filtration device according to claim 1 or 2.

5. The cover member has a plurality of sawtooth-shaped protrusions provided on at least one side edge in the rotation direction. The drum-type filtration device according to claim 1 or 2.

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