Drum-type filtration device using a belt-shaped filter medium

Abstract

To provide a drum-type filter device using an endless annular belt-like filter medium which can obtain filtration efficiency without increasing a space on an inner peripheral side of an endless annular mesh belt and the endless annular belt-like filter medium.SOLUTION: When clean liquid CF that drops from a drum 36 through a belt-like filter medium 46 is received by a receiving gutter member 86, the clean liquid CF is drained from an open end 92 of the receiving gutter member 86 to a clean tank 14 so that a liquid surface of the clean liquid CF does not come into contact with the belt-like filter medium 46 that is placed along a lower circumference of circular members 32a and 32b over the half-circumference. As a result, there is no need to make a height of the receiving gutter member 86 high and no need to increase a space on an inner peripheral side of an endless annular mesh belt 38 and the endless annular belt-like filter medium 46, the liquid surface of the clean liquid CF in the receiving gutter member 86 does not come into contact with the belt-like filter medium 46 that is placed along the lower circumference of the circular members 32a and 32b over the half-circumference and consequently filtration efficiency of the clean liquid can be obtained.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a drum-type filtration device using an endless annular belt-shaped filter medium that includes a belt-shaped filter medium continuously fed along the lower half circumference of a drum, and removes foreign substances contained in a coolant by passing the coolant through the belt-shaped filter medium.

Background Art

[0002] In machining such as grinding machines and cutting machines used in the manufacture of automobile parts, bearings, etc., a used and dirty coolant (dirty liquid) used in machining or grinding is passed through a belt-shaped filter medium continuously fed along the lower half circumference of a drum, and a drum-type filtration device using a belt-shaped filter medium that removes foreign substances from the dirty liquid to obtain a purified clean liquid that can be reused has been proposed. For example, the drum-type filtration device using the belt-shaped filter medium described in FIGS. 1 to 9 of Patent Document 1 is one such example.

[0003] The drum-type filtration device using the above belt-shaped filter medium includes a pair of circular members fixed to a rotatable horizontal support shaft at a predetermined interval, a filter medium feeding device including an endless annular mesh belt extending along the lower half circumference of the pair of circular members, and a belt-shaped filter medium continuously fed while being sandwiched between the mesh belt and each circular member. While the belt-shaped filter medium is fed in the circumferential direction together with the pair of circular members and the mesh belt, the dirty coolant is passed from the inner peripheral side to the outer peripheral side of the belt-shaped filter medium, so that a purified coolant (clean liquid) can be obtained.

[0004] By the way, in the drum-type filtration device using the belt-shaped filter medium described in FIGS. 1 to 9 of Patent Document 1, the belt-shaped filter medium for filtering the dirty liquid is pulled out from a roll around which the unused belt-shaped filter medium is wound, and is continuously sent while being sandwiched between the mesh belt and each circular member. After that, the used belt-shaped filter medium is collected in a collection box. Since this belt-shaped filter medium is disposable, there has been a problem that the operating cost of the drum-type filtration device becomes high and the environmental load due to discarding the used belt-shaped filter medium increases.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the other hand, FIG. 10 of Patent Document 1 describes a drum-type filtration device using an endless annular (endless) belt-shaped filter medium that can reduce the operating cost of the drum-type filtration device and reduce the environmental load due to discarding the used belt-shaped filter medium. In this drum-type filtration device, it has been proposed to install a tank for collecting the clean liquid on the inner peripheral side of the endless annular mesh belt and the endless annular belt-shaped filter medium if there is sufficient space.

[0007] However, as shown in FIG. 10 of Patent Document 1, since a structure is such that the lower half circumference of a pair of circular members and a part of the endless annular mesh belt and the endless annular belt-shaped filter medium wound around the lower half circumference of the pair of circular members are accommodated in the tank, a part of the endless annular mesh belt and the endless annular belt-shaped filter medium wound around the lower half circumference of the pair of circular members is immersed in the clean liquid stored in the tank. For this reason, in a part of the endless annular belt-shaped filter medium wound around the lower half circumference of the pair of circular members, the area where there is no hydraulic pressure difference between the circular member side of the belt-shaped filter medium and the tank side of the belt-shaped filter medium increases, and there has been a problem that filtration efficiency cannot be obtained.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a drum-type filtration device using an endless belt-shaped filter medium that can obtain a filtration efficiency without increasing the space on the inner peripheral side of the endless mesh belt and the endless belt-shaped filter medium.

Means for Solving the Problems

[0009] As a result of various studies on the drum-type filtration device by the present inventor in view of the above circumstances, instead of a tank that is installed on the inner peripheral side of the endless mesh belt and the endless belt-shaped filter medium and recovers the clean liquid, a shallow box-shaped gutter member that receives the clean liquid and discharges it to the clean tank is provided. Since a part of the endless mesh belt and the endless belt-shaped filter medium wound around the lower half circumference of the pair of circular members is not immersed in the clean liquid in the gutter member, a drum-type filtration device using an endless belt-shaped filter medium that can obtain a filtration efficiency without increasing the space on the inner peripheral side of the endless mesh belt and the endless belt-shaped filter medium was found. The present invention has been made based on such findings.

[0010] That is, the gist of the first invention is: (a) a drum in which a pair of circular members rotatably supported by a horizontal drum support shaft are interconnected via a connecting member of a predetermined length; a filter feeding device including an endless mesh belt extending along the lower outer periphery of the pair of circular members over a half circumference; an endless belt-shaped filter medium fed by the filter feeding device while being sandwiched between the mesh belt and the pair of circular members; and a clean tank for storing the clean liquid filtered by the belt-shaped filter medium, a drum-type filtration device using a belt-shaped filter medium, characterized in that (b) a receiving gutter member is provided at a position below the drum on the inner peripheral side of the endless mesh belt and the endless belt-shaped filter medium, for receiving the clean liquid falling from the drum through the belt-shaped filter medium and discharging it from the open end to the clean tank so that the liquid level of the clean liquid does not contact the belt-shaped filter medium. wherein, (c) the liquid receiving member includes a rectangular and longitudinal bottom plate formed longer than the width dimension in the rotational axis direction of the drum, and a pair of longitudinal edge plates erected respectively from side edges parallel to the longitudinal direction of the bottom plate, and (d) the bottom plate of the liquid receiving member is horizontally arranged It is to be provided.

Advantages of the Invention

[0011] First According to the drum-type filtration device using the belt-shaped filter medium of the invention, when the clean liquid falling from the drum through the belt-shaped filter medium is received by the receiving trough member, the clean liquid flows out from the open end of the receiving trough member to the clean tank so that the liquid level of the clean liquid does not contact the belt-shaped filter medium that is along the lower outer periphery of the circular member for a half turn. Thereby, it is not necessary to raise the receiving trough member and the space on the inner peripheral side of the endless annular mesh belt and the endless annular belt-shaped filter medium is not increased, and since the liquid level of the clean liquid in the receiving trough member does not contact the belt-shaped filter medium that is along the lower outer periphery of the circular member for a half turn, the filtration efficiency of the clean liquid can be obtained. Also, since the opening end is provided at at least one of both longitudinal ends of the liquid receiving member, the cleaning liquid in the liquid receiving member can flow out from the opening end without being retained. Further, since the bottom plate of the liquid receiving member is horizontally arranged, the space on the inner peripheral side of the endless annular mesh belt and the endless annular strip-shaped filter medium is not increased.

[0012] The gist of the second invention is as follows: (a) a drum in which a pair of circular members rotatably supported by a horizontal drum support shaft are interconnected via a connecting member of a predetermined length, a filter feeding device provided with an endless annular mesh belt extending along the lower outer periphery of the pair of circular members over a half circumference, an endless annular strip-shaped filter medium fed by the filter feeding device while being sandwiched between the mesh belt and the pair of circular members, and a clean tank for storing the clean liquid filtered by the strip-shaped filter medium, a drum-type filtering device using a strip-shaped filter medium, (b) provided at a position below the drum on the inner peripheral side of the endless annular mesh belt and the endless annular strip-shaped filter medium, receiving the clean liquid falling from the drum through the strip-shaped filter medium, and having a liquid receiving member for allowing the liquid level of the clean liquid to flow out to the clean tank from the opening end so as not to contact the strip-shaped filter medium, (c) The receiving trough member includes a rectangular and longitudinal bottom plate formed longer than the width dimension in the rotational axis direction of the drum, and a pair of longitudinal edge plates respectively erected from side edges parallel to the longitudinal direction of the bottom plate. wherein, (d) the liquid receiving member is provided with a flushing nozzle for injecting the clean liquid from the base end portion, which is one of both longitudinal end portions in the longitudinal direction, toward the opening end. According to the drum-type filtration device using the belt-shaped filter medium of the second invention, when the clean liquid falling from the drum through the belt-shaped filter medium is received by the receiving trough member, the clean liquid is caused to flow out from the open end of the receiving trough member to the clean tank so that the liquid level of the clean liquid does not contact the belt-shaped filter medium that is caused to extend along the lower outer periphery of the circular member for half a circumference. Thereby, it is not necessary to raise the receiving trough member and the space on the inner peripheral side of the endless annular mesh belt and the endless annular belt-shaped filter medium is not increased, and since the liquid level of the clean liquid in the receiving trough member does not contact the belt-shaped filter medium that is caused to extend along the lower outer periphery of the circular member for half a circumference, the filtration efficiency of the clean liquid can be obtained. Further, Since the open end is provided at at least one of both longitudinal ends of the receiving trough member, the clean liquid in the receiving trough member can flow out from the open end without being retained. Furthermore, the receiving trough member is provided with a flushing nozzle that injects the clean liquid from the base end portion of the receiving trough member toward the open end portion. Thereby, since the sludge that tends to stay in the receiving trough member is caused to flow out from the open end portion, the cycle of periodic cleaning of the receiving trough member can be lengthened.

[0013] The gist of the third invention lies in the first invention or the second invention, The receiving trough member includes a base end edge plate erected from the edge of the base end portion which is one of both longitudinal ends in the longitudinal direction and connecting the pair of longitudinal edge plates, and at the edge of the tip end portion which is one of both longitudinal ends in the longitudinal direction, no edge plate is erected or even if an edge plate is erected, it is discontinuous so that the clean liquid can pass through, and the open end is formed. in the following Thereby, the clean liquid received in the receiving trough member is exclusively made to flow out from the open end.

[0017] The gist of the fourth invention lies in the first invention or the second invention, The width dimension of the receiving gutter member is smaller than the diameter of the drum, and a pair of liquid collecting plates that are inclined so as to receive the clean liquid that cannot be received by the receiving gutter member among the clean liquid that falls from the drum through the belt-shaped filter medium and flow it into the receiving gutter member are provided along with the receiving gutter member. As a result, the width dimension of the belt-shaped filter medium perpendicular to the longitudinal direction can be made smaller compared to the case where the dimension is such that all the clean liquid that falls from the drum through the belt-shaped filter medium is received, so there is an advantage that the drum type filtration device can be miniaturized.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the figures are schematic diagrams drawn by appropriately simplifying, and the shapes, dimensional ratios, etc. of each part are not necessarily drawn accurately.

Embodiment

[0020] FIG. 1 is a side view of a drum-type filtration device (hereinafter referred to as a filtration device) 10 using a belt-shaped filter medium according to an embodiment of the present invention, and is a schematic diagram shown in a cross-section cut by a vertical plane passing through the center in the width direction of the filtration device 10. In FIG. 1, the filtration device 10 includes a front wall 12c, a rear wall 12d, a pair of left and right side walls 12a and 12b connecting the front wall 12c and the rear wall 12d, and an upper wall 12e closing the opening of the space surrounded by the front wall 12c, the rear wall 12d, and the pair of side walls 12a and 12b from above, and a bottom wall 12f, and is provided on a clean tank 14 that stores the coolant after purification, that is, the clean liquid CF.

[0021] A notch 16 is formed at the end of the bottom wall 12f on the rear wall 12d side, and below the notch 16, a sludge storage container 18 that opens upward and stores sludge SG is disposed. Inside the case 12, a partition wall 12g is provided for partitioning the inside of the case 12 into a front space S1 that houses a drum 36, a filter feeding device 40, etc., and a rear space S2 that houses a sludge dewatering and separating device 22.

[0022] In order to rotatably support the drum 36, the filtration device 10 includes a cylindrical drum support shaft 30 horizontally spanned between a pair of side walls 12a and 12b, and a pair of circular members 32a and 32b rotatably supported by the drum support shaft 30. A cylindrical drum 36 is connected to each other in a state of facing each other at a certain interval via a longitudinal connecting member 34 of a predetermined length, and a filter feeding device 40 having an endless annular mesh belt 38 extending along the lower outer periphery of the pair of circular members 32a and 32b for half a circumference. The rotation center line CL of the drum 36 is also the center line of the cylindrical drum support shaft 30.

[0023] The filter feeding device 40 is provided so as to surround the drum 36 and includes a driving roller 42 around which an endless annular mesh belt 38 is wound and three driven rollers 44a, 44b, and 44c. When the driving roller 42 is rotationally driven by the electric motor M, the endless annular mesh belt 38 and the drum 36 are rotated. Thereby, an endless annular belt-shaped filter medium 46 partially sandwiched between the mesh belt 38 and the pair of circular members 32a, 32b is fed by the filter feeding device 40. The endless annular belt-shaped filter medium 46 is a belt-shaped filter made of a filter medium such as a non-woven fabric, a woven fabric, or a filter paper. Further, the mesh belt 38 is a metal mesh having a large number of meshes, a synthetic fiber, a carbon fiber, or a mesh made of a composite material.

[0024] Among the three driven rollers 44a, 44b, and 44c, the driven roller 44c is positioned at a height equal to or higher than that of the driving roller 42, and the pair of driven rollers 44a and 44b are horizontally spaced apart from each other at a height position below the drum 36 and separated from the drum 36 by a predetermined distance. The belt-shaped filter medium 46 sent from the filter feeding device 40 to the sludge dewatering and separating device 22 returns to the lower side of the pair of driven rollers 44a and 44b and is again sandwiched between the mesh belt 38 and the pair of circular members 32a, 32b through the driven roller 44c.

[0025] The cylindrical drum support shaft 30 allows the dirty liquid DF discharged from a grinding machine or a grinding wheel using a coolant to flow onto the belt-shaped filter medium 46 in the drum 36. Thereby, the dirty liquid DF staying on the belt-shaped filter medium 46 in the drum 36 is passed downward through the belt-shaped filter medium 46, so that sludge SG is deposited on the outer peripheral surface of the belt-shaped filter medium 46.

[0026] FIG. 2 is a view for explaining a drum support shaft 30 that rotatably supports a drum 36, and is a vertical sectional view taken along line II-II of FIG. 1. In FIG. 2, a state where a mesh belt 38 and a belt-shaped filter medium 46 are not wound around the drum 36 is shown. As shown in FIG. 2, the tip portion (right end portion) 30a and the base end portion (left end portion) 30b of the cylindrical drum support shaft 30 are supported in a penetrating state by a pair of right and left support flanges 48a, 48b fastened to a pair of side walls 12a, 12b, respectively, so as to be concentric with the horizontal rotation axis C1. The drum support shaft 30 is detachably attached to the case 12 by a push screw 50 provided so as to be screwed in the radial direction of the drum support shaft 30 to the support flange 48a on the tip portion 30a side of the drum support shaft 30 among the support flanges 48a, 48b. A dirty liquid pipe 52 for guiding a coolant, that is, a dirty liquid DF discharged from a grinding machine (not shown) is connected to the base end portion 30b of the drum support shaft 30, and the dirty liquid DF is caused to flow into the case 12 from a longitudinal discharge port 30d formed in an intermediate portion 30c in the longitudinal direction (rotation axis C1 direction) of the drum support shaft 30.

[0027] The drum 36 is positioned so as to be separated from the pair of side walls 12a, 12b by interposing a pair of cylindrical collars 52a, 52b between the pair of circular members 32a, 32b and the pair of side walls 12a, 12b on the drum support shaft 30.

[0028] An inflow buffer box 54 is attached to the intermediate portion 30c of the drum support shaft 30 so as to cover the longitudinal discharge port 30d. The inflow buffer box 54 is detachably fixed by fastening ears 56a, 56b protruding in the rotation axis C1 direction from the inflow buffer box 54 to the drum support shaft 30 with bolts 60. The wire W is an electric wire connecting the liquid level sensor 68 and the motor control device 70 shown in FIG. 1.

[0029] Figure 3 is a sectional view taken along line III-III of Figure 2, which illustrates the interior of the inflow buffer box 54. As shown in Figure 3, the inflow buffer box 54 includes a longitudinally elongated upper plate 54e, a bottom plate 54f, a front plate 54c, and a rear plate 54d that are horizontally longer than the discharge port 30d of the drum support shaft 30, and a pair of end plates 54a, 54b that close the longitudinally shaped space surrounded by them from the right and left, forming a rectangular parallelepiped. Further, the inflow buffer box 54 is provided with an inclined plate 62 for converting the flow direction of the dirty liquid DF and a weir plate 64 having a predetermined height for suppressing the flow velocity of the dirty liquid DF.

[0030] The inclined plate 62 of the inflow buffer box 54 protrudes obliquely downward from the lower edge of the front plate 54c toward the rear plate 54d side, receives the dirty liquid DF flowing down from the discharge port 30d of the drum support shaft 30, and converts its direction toward the rear plate 54d side. The weir plate 64 of the inflow buffer box 54 is provided on the bottom plate 54f in a direction intersecting the flow of the dirty liquid DF that falls from the inclined plate 62, reverses from the rear plate 54d, and flows on the bottom plate 54f, for example, in a direction parallel to the rotation axis C1, and suppresses the flow velocity of the dirty liquid DF flowing along it on the bottom plate 54f. The inclined plate 62 and the weir plate 64 have a longitudinal shape equivalent to the longitudinal dimension of the inflow buffer box 54. Therefore, the inclined plate 62 and the weir plate 64 have a width dimension L2 that is larger than the longitudinal dimension L1 of the discharge port 30d.

[0031] An outlet 66 that longitudinally opens and allows the dirty liquid DF that has exceeded the weir plate 64 to flow out is formed in the inflow buffer box 54 between the lower edge of the front plate 54c and the weir plate 64. In the inflow buffer box 54, the dirty liquid DF discharged from the discharge port 30d formed in the drum support shaft 30 is received by the inclined plate 62 and its direction is changed, further collides with the rear plate 54d and its direction is reversed, thereby relaxing the flow velocity, and is further retained by the weir plate 64 to eliminate the turbulent flow, and then flows out from the outlet 66 after exceeding the weir plate 64. As a result, the dirty liquid DF flowing out from the outlet 66 of the inflow buffer box 54 gently flows into the liquid level L of the dirty liquid DF staying on the forward-side belt-like member 46f wound around the lower half circumference of the drum 36.

[0032] Returning to FIG. 1, the filter feeding device 40 is provided on the drum support shaft 30, and includes a liquid level sensor 68 for detecting the liquid level of the dirty liquid DF staying on the belt-like filter medium 46 in the drum 36, and a motor control device 70 for controlling the rotation of the drive roller 42. The rotation amount of the drive roller 42 by the electric motor M is adjusted so that the liquid level detected by the liquid level sensor 68 becomes a preset liquid level height, and the feeding speed of the belt-like filter medium 46 is appropriately controlled.

[0033] The sludge dewatering and separating device 22 includes, in the rear space S2, a pair of pressing rollers 72 for continuously pressing the sludge SG deposited on the outer peripheral surface of the belt-like filter medium 46 sent out from the filter feeding device 40 in a substantially horizontal direction, a pair of guide rollers 74 and 76 located obliquely below the pressing rollers 72 and spaced apart by a predetermined distance in the vertical direction, and a rotary brush 78 for separating the cake-like sludge SG, which is the sludge SG deposited on the outer peripheral surface of the belt-like filter medium 46 located between the pair of guide rollers 74 and 76 and dewatered by the pressing rollers 72, from the outer peripheral surface of the belt-like filter medium 46, and an injection nozzle 80 for separating the sludge SG adhering to the outer peripheral surface of the belt-like filter medium 46 by injecting a fluid such as air or coolant from the inner peripheral surface of the belt-like filter medium 46 at a position downstream of the rotary brush 78. The clean liquid CF that has dropped from the pressing rollers 72 through the belt-like filter medium 46 by the pressing of the sludge SG on the outer peripheral surface of the belt-like filter medium 46 flows into the clean tank 14 through the clean liquid guide passage 84 from a side surface opening 82 formed to penetrate one of the side walls 12a and 12b.

[0034] In order to press the belt-like filter medium 46 between the pair of pressing rollers 72, the pair of pressing rollers 72 are preferably configured such that at least one of the pair of pressing rollers 72 is provided with an elastic member such as a synthetic rubber, which is elastically deformable in the radial direction. Alternatively, a roller biasing mechanism is provided in which one bearing of the pair of pressing rollers 72 is biased toward the other bearing.

[0035] As shown in FIGS. 1 and 2, below the drum 36, between the endless annular belt-shaped filter medium 46, the forward path-side belt-shaped filter medium 46f sandwiched between the mesh belt 38 and the pair of circular members 32a and 32b and sent to the rotary brush 78, and the return path-side belt-shaped filter medium 46b from the rotary brush 78 of the sludge dewatering and separating device 22 to the drum 36, within the space on the inner peripheral side of the endless annular mesh belt 38, a trough member 86 that receives the clean liquid CF that has dropped downward through the forward path-side belt-shaped filter medium 46f from the dirty liquid DF staying on the belt-shaped filter medium 46 within the drum 36 is horizontally disposed by being fitted into a pair of mounting holes 88 respectively formed through the side walls 12a and 12b of the filtering device 10.

[0036] The trough member 86 has a longitudinal dimension larger than the interval between the side walls 12a and 12b. In the mounted state, the tip and the base end of the trough member 86 respectively protrude outward from the pair of mounting holes 88 formed in the side walls 12a and 12b. The trough member 86 is insertable and removable with respect to the pair of mounting holes 88.

[0037] As shown in FIG. 1, the trough member 86 has a width dimension in the front-rear direction that is sufficiently smaller than the diameter of the drum 36, and as shown in FIGS. 2 and 4, a rectangular horizontal bottom plate 86a that is sufficiently larger than the width in the direction of the rotation axis C1 of the drum 36, a pair of longitudinal edge plates 86b of a predetermined height erected respectively from the side edge edges of the bottom plate 86a, a base end side edge plate 86c of the same height as the longitudinal edge plates 86b erected from the base end edge of the bottom plate 86a, and a plurality (five in this embodiment) of flush nozzles 90 fixed to the base end side edge plate 86c at equal intervals in the width direction of the trough member 86 and toward the open end 92 which is the tip side edge of the trough member 86. The flush nozzles 90 inject the clean liquid CF toward the open end 92 which is the tip side edge of the trough member 86 to move the sludge on the trough member 86.

[0038] The liquid receiving member 86 has a relatively shallow box-shaped tray shape. Along the leading edge of the liquid receiving member 86, there is no edge plate erected, or even if there is an edge plate along the leading edge, its height is set discontinuously and low relative to the longitudinal edge plate 86b, and it has an open end 92 through which the cleaning liquid CF received by the liquid receiving member 86 passes. The cleaning liquid CF received by the liquid receiving member 86 passes through the open end 92 at the leading end side and falls, and is dropped into the cleaning tank 14 through the cleaning liquid passage 94. Therefore, even in the narrow space inside the mesh belt 38, a space is formed between the forward path side strip-shaped filter medium 46f wound around the lower half circumference of the drum 36 and the liquid receiving member 86 so that the liquid level of the cleaning liquid CF in the liquid receiving member 86 does not contact the forward path side strip-shaped filter medium 46f wound around the lower half circumference of the drum 36.

[0039] Since the liquid receiving member 86 is horizontally arranged or can be arranged at most with a gentle inclination in the narrow space directly below the drum 36 within the endless annular mesh belt 38 and the strip-shaped filter medium 46, sludge SG is likely to accumulate. Therefore, the cleaning liquid CF in the cleaning tank 14 pumped by the electric pump 96 is jetted from the flush nozzle 90 toward the leading edge of the liquid receiving member 86. As a result, even if the height of the liquid receiving member 86 is small, the cleaning liquid CF flows into the cleaning tank 14, so that the space between the drum 36 and the cleaning tank 14 can be reduced, and the filtering device 10 can be configured compactly.

[0040] The width dimension of the liquid receiving member 86 orthogonal to the longitudinal direction is smaller than the diameter of the drum 36. Among the cleaning liquid CF that has fallen downward from the drum 36 through the forward path side strip-shaped filter medium 46f, a pair of liquid collecting plates 98 that are inclined and approach each other downward so as to receive the cleaning liquid that cannot be received by the liquid receiving member 86 and flow it into the liquid receiving member 86 are fixedly provided on both sides of the liquid receiving member 86 in the front-rear direction of the drum type filtering device 10 and are fixed to the pair of side walls 12a, 12b. The pair of liquid collecting plates 98 are inclined so as to approach each other downward.

[0041] FIG. 5 is a plan view showing an enlarged flash nozzle 90. Since this flash nozzle 90 injects the cleaning liquid CF linearly toward the tip-side edge of the receiving member 86, five injection lines with circular cross-sections are formed in parallel from a plurality of flash nozzles 90. Instead of this flash nozzle 90, a flash nozzle 100 shown in FIG. 6, a flash nozzle 102 shown in FIG. 7, or a flash nozzle 104 shown in FIG. 8 may be used. The flash nozzle 100 injects the cleaning liquid CF radially. In this case, the number of flash nozzles 100 can be reduced. The flash nozzle 102 injects the cleaning liquid CF with a flat cross-section. In this case, since an injection effective for moving the sludge SG can be obtained, the amount of the cleaning liquid CF to be injected can be reduced. The flash nozzle 104 injects the cleaning liquid CF with wide injection lines arranged flat like a comb. In this case, the number of flash nozzles 104 can be reduced, and the amount of the cleaning liquid CF to be injected can be reduced.

[0042] As described above, according to the filtration device 10 of the present embodiment, when the cleaning liquid CF falling from the drum 36 through the belt-shaped filter medium 46 is received by the receiving member 86, the cleaning liquid CF is caused to flow out from the open end 92 of the receiving member 86 to the cleaning tank 14 so that the liquid level of the cleaning liquid CF does not contact the belt-shaped filter medium 46 that is caused to extend along the lower outer periphery of the circular members 32a and 32b over a half circumference. Thereby, it is not necessary to raise the receiving member 86, and the space on the inner peripheral side of the endless annular mesh belt 38 and the endless annular belt-shaped filter medium 46 is not increased. Also, since the liquid level of the cleaning liquid CF in the receiving member 86 does not contact the belt-shaped filter medium 46 that is caused to extend along the lower outer periphery of the circular members 32a and 32b over a half circumference, the filtration efficiency of the cleaning liquid is obtained.

[0043] Further, according to the filtration device 10 of the present embodiment, the receiving trough member 86 includes a rectangular and longitudinal bottom plate 86a formed longer than the width dimension in the rotational axis direction of the drum 36, and a pair of longitudinal edge plates 86b erected respectively from side edges parallel to the longitudinal direction of the bottom plate 86a. Thereby, since the opening end 92 is provided at at least one of both longitudinal ends of the receiving trough member 86, the clean liquid CF in the receiving trough member 86 can be made to flow out from the opening end 92 without being retained.

[0044] Further, according to the filtration device 10 of the present embodiment, the receiving trough member 86 includes a base end edge plate 86c erected from the edge of the base end portion which is one of both longitudinal ends in the longitudinal direction and connecting the pair of longitudinal edge plates 86b. At the edge of the tip end portion which is one of both longitudinal ends in the longitudinal direction, either no edge plate is erected, or even if an edge plate is erected, the height of the edge plate is discontinuously lowered so that the clean liquid can pass through, and the opening end 92 is formed. Thereby, the clean liquid CF received in the receiving trough member 86 is made to flow out exclusively from the opening end 92.

[0045] Further, according to the filtration device 10 of the present embodiment, the bottom plate 86a of the receiving trough member 86 is arranged horizontally. Thereby, the space on the inner peripheral side of the endless annular mesh belt 38 and the endless annular belt-shaped filter medium 46 is not increased.

[0046] Further, according to the filtration device 10 of the present embodiment, the receiving trough member 86 is provided with a flushing nozzle 90 that injects the clean liquid CF from the base end portion of the receiving trough member 86 toward the opening end. Thereby, since the sludge SG that tends to stay in the receiving trough member 86 is made to flow out from the opening end 92, the period of regular cleaning of the receiving trough member 86 can be lengthened.

[0047] Further, according to the filtration device 10 of the present embodiment, a plurality of flushing nozzles 90 are fixed to the base end side edge plate 86c erected at the edge of the base end portion of the receiving trough member 86. Thereby, the flushing nozzle 90 can be removed from the drum type filtration device 10 together with the receiving trough member 86.

[0048] Further, according to the filtration device 10 of the present embodiment, the width dimension of the receiving trough member 86 is smaller than the diameter of the drum 36, and a pair of liquid collecting plates 98 that receive the clean liquid CF that cannot be received by the receiving trough member 86 among the clean liquid CF that falls from the drum 36 through the strip-shaped filter medium 46 and are inclined so as to flow into the receiving trough member 86 are provided in the receiving trough member 86. Thereby, compared with the case where the width dimension orthogonal to the longitudinal direction of the strip-shaped filter medium 86 is set to a dimension that can receive all the clean liquid CF that falls from the drum 36 through the strip-shaped filter medium 46, it can be made smaller, so there is an advantage that the drum-type filtration device 10 can be miniaturized.

Embodiment

[0049] Hereinafter, the main part of another sludge dewatering and separating device 24 different from the sludge dewatering and separating device 22 will be described with reference to the schematic diagram of FIG. 9. In the following description, the same reference numerals are given to the parts common to the above-described embodiment, and the description thereof is omitted.

[0050] In FIG. 9, in the process of the forward-side strip-shaped filter medium 46f sent out from the driving roller 42 of the filter feeding device 40 returning as the return-side strip-shaped filter medium 46b to the driven roller 44a of the filter feeding device 40, the forward-side strip-shaped filter medium 46f is bent at an acute bending angle α and guided. A guide roller 108 having a relatively small diameter, for example, 30 mmφ or less, preferably 20 mmφ or less, is provided in the sludge dewatering and separating device 24. In the moving direction of the forward-side strip-shaped filter medium 46f, the pinch roller 72 is provided at an upstream position of the guide roller 108, and the rotating brush 78 and the injection nozzle 80 are provided at a downstream position of the guide roller 108. Since the smaller the bending angle α is, the larger the cracks are generated in the sludge SG, it is preferably 60° or less, more preferably 30° or less.

[0051] In the sludge dewatering and separation device 24 of this embodiment, before the forward-side belt filter medium 46f reaches the guide roller 108, the sludge SG attached to the outer peripheral surface of the forward-side belt filter medium 46f is dewatered by the pinch roller 72 and becomes a cake shape. Further, since cracks are formed in the sludge due to the sharp bending during the process of the forward-side belt filter medium 46f passing through the guide roller 108, the peeling efficiency of the sludge SG from the belt filter medium 46 by the rotary brush 78 and the injection nozzle 80 is enhanced.

[0052] As described above, one embodiment of the present invention has been described with reference to the drawings, but the present invention is also applicable in other aspects.

[0053] For example, in the above-described embodiment, the receiving gutter member 86 was horizontal, but it may be inclined to some extent such that the opening end 92 side is lower.

[0054] Also, in the above-described embodiment, the opening end 92 of the receiving gutter member 86 was provided at one end of the longitudinal direction of the receiving gutter member 86, but it may be provided at both ends.

[0055] Also, in the above-described embodiment, five flush nozzles 90 were provided in the receiving gutter member 86, but it is not necessarily five, and it may be four or less, or it may not be provided.

[0056] Note that the above is merely one embodiment, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

Explanation of Reference Numerals

[0057] 10: Filtration device (drum-type filtration device using a belt filter medium) 14: Clean tank 30: Drum support shaft 32a, 32b: Circular members 36: Drum 38: Mesh belt 40: Filter feeding device 46: Belt filter medium 72: Pinch roller 86: Downspout member 86a: Bottom plate 86b: Longitudinal edge plate 86c: Base-end side edge plate 88: Mounting hole 90, 100, 102, 104: Flash nozzle 92: Open end 98: Liquid collecting plate

Claims

1. A drum-type filtration device using a strip-shaped filter medium, comprising: a drum in which a pair of circular members rotatably supported by a horizontal drum support shaft are interconnected via a connecting member of a predetermined length; a filter feed device having an endless annular mesh belt extending along the lower outer periphery of the pair of circular members over a semi-circle; an endless annular strip-shaped filter medium fed by the filter feed device while being sandwiched between the mesh belt and the pair of circular members; and a clean tank for storing the clean liquid filtered by the strip-shaped filter medium, a receiving gutter member provided at a position below the drum on the inner peripheral side of the endless annular mesh belt and the endless annular strip-shaped filter medium, for receiving the clean liquid that falls from the drum through the strip-shaped filter medium, and having an open end formed so as to allow the clean liquid to flow out to the clean tank without the liquid level of the clean liquid contacting the strip-shaped filter medium, wherein the receiving gutter member includes a rectangular and longitudinal bottom plate formed longer than the width dimension of the drum in the rotational axis direction of the drum, and a pair of longitudinal edge plates respectively erected from side edges parallel to the longitudinal direction of the bottom plate, and the bottom plate of the receiving gutter member is horizontally disposed, characterized in that it is a drum-type filtration device using a strip-shaped filter medium.

2. A drum-type filtration device using a strip-shaped filter medium, comprising: a drum in which a pair of circular members rotatably supported by a horizontal drum support shaft are interconnected via a connecting member of a predetermined length; a filter feed device having an endless annular mesh belt extending along the lower outer periphery of the pair of circular members over a semi-circle; an endless annular strip-shaped filter medium fed by the filter feed device while being sandwiched between the mesh belt and the pair of circular members; and a clean tank for storing the clean liquid filtered by the strip-shaped filter medium, a receiving gutter member provided at a position below the drum on the inner peripheral side of the endless annular mesh belt and the endless annular strip-shaped filter medium, for receiving the clean liquid that falls from the drum through the strip-shaped filter medium, and having an open end formed so as to allow the clean liquid to flow out to the clean tank without the liquid level of the clean liquid contacting the strip-shaped filter medium, wherein the receiving gutter member includes a rectangular and longitudinal bottom plate formed longer than the width dimension of the drum in the rotational axis direction of the drum, and a pair of longitudinal edge plates respectively erected from side edges parallel to the longitudinal direction of the bottom plate, The receiving trough member is provided with a flushing nozzle that injects the cleaning liquid from the base end portion, which is one of the both end portions in the longitudinal direction, toward the opening end. A drum-type filtration device using a strip-shaped filter medium, characterized in that.

3. The receiving trough member includes a base end edge plate that stands up from the edge of the base end portion, which is one of the both end portions in the longitudinal direction, and connects the pair of longitudinal edge plates. The opening end is formed at the edge of the tip end portion, which is one of the both end portions in the longitudinal direction. A drum-type filtration device using a strip-shaped filter medium according to claim 1 or 2, characterized in that.

4. The width dimension of the receiving trough member is smaller than the diameter of the drum. A pair of liquid collecting plates that receive the cleaning liquid that cannot be received by the receiving trough member among the cleaning liquid that falls through the strip-shaped filter medium from the drum and are inclined so as to flow into the receiving trough member are provided in parallel with the receiving trough member. A drum-type filtration device using a strip-shaped filter medium according to claim 1 or 2, characterized in that.

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