JP2014205218A - Filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter device which prevents clogging of a drum filter and efficiently discharges removal objects in a filter tank to the exterior of the filter tank.SOLUTION: A filter device 10 includes: a filter tank 11; a conveyor 13 having a scraper 21; and a rotary drum filter 60. The drum filter 60 is disposed below a liquid surface Q3 of the filter tank 11. A fluid jet member 80 is disposed in the drum filter 60. Multiple jet holes 85 are formed in the fluid jet member 80. These jet holes 85 open toward an upper part of the drum filter 60 and circulation holes 61 located close to a sludge carrying-out passage 15. The fluid jet member 80 jets a fluid to the obliquely upward side from the jet holes 85 toward the circulation holes 61 located close to the sludge carrying-out passage 15. The fluid jet member 80 forms a liquid flow generation mechanism 90 for generating liquid flow Y1 flowing to the sludge carrying-out passage 15 near the liquid surface Q3 in the filter tank 11.

Description

  The present invention relates to a filtration device that purifies a liquid in which, for example, shavings or fine particles are mixed.

  In machine tools that perform machining such as cutting and grinding, a coolant (cutting fluid) is used to cool a workpiece or a tool. The coolant used for machining is mixed with objects to be removed such as swarf (swarf) and fine particles. In particular, in fields where weight reduction and corrosion resistance are required, there is a tendency for chips to diversify because materials such as aluminum and magnesium are used. In order to purify and reuse such coolant, various types of filtration devices have been proposed.

  For example, a mesh filter device disclosed in Patent Document 1 includes a filtration tank, a mesh filter disposed in the filtration tank, a scraper conveyor for carrying out sludge, a mesh drum functioning as a filter, and a mesh drum. A contact-type scraper for scraping off the attached removal target is provided. On the other hand, the filtration devices disclosed in Patent Documents 2 and 3 include a filtration tank, a scraper conveyor for carrying out sludge, a mesh drum, and a cleaning liquid injection nozzle arranged inside the mesh drum. In order to prevent clogging of the mesh drum, the cleaning liquid injection nozzle injects the cleaning liquid from the inside of the drum toward the upper part of the mesh drum (the part protruding on the liquid level). That is, it is a backwash type mesh drum.

Japanese Utility Model Publication 4-33929 Japanese Patent No. 2904334 Japanese Patent No. 3389126

  In the filtering device provided with the scraper as in Patent Document 1, the scraper is always in contact with the mesh drum. For this reason, the mesh drum is deformed or worn. On the other hand, the backwashing type mesh drum disclosed in Patent Documents 2 and 3 cleans the mesh drum with the cleaning liquid ejected from the cleaning liquid spray nozzle. For this reason, it is avoided that the mesh drum is worn, but the cleaning liquid sprayed from the inside of the mesh drum becomes mist and scatters to the outside of the mesh drum, which causes the working environment to deteriorate. Further, since the removal object such as metal debris and sludge peeled off from the mesh drum by spraying the cleaning liquid enters the filtration tank again, the removal object floats in the filtration tank forever. For this reason, there exists a problem that the removal target object in a filtration tank cannot be efficiently discharged | emitted out of a filtration tank. In particular, fine objects to be removed float as a large amount of bubbles on the entire liquid surface in the filtration layer, causing various problems.

  Accordingly, an object of the present invention is to provide a filtration device that can prevent clogging of a drum filter without using a contact-type scraper, and can efficiently discharge an object to be removed from the filtration tank to the outside of the filtration tank. It is in.

  The filtration device of the present invention includes a filtration tank that contains a liquid to be filtered, a discharge part provided at a position higher than the liquid level of the liquid in the filtration tank, and a bottom part of the filtration tank to the discharge part. A formed sludge carry-out path, a conveyor having a scraper that moves along the sludge carry-out path, a drum filter disposed below the liquid level in the filtration tank, and a filter rotation mechanism that rotates the drum filter And a liquid flow generation mechanism. The drum filter is formed of a cylindrical perforated plate having an outer surface and an inner surface, and a plurality of flow holes through which the liquid flows from the outer surface toward the inner surface are formed. The liquid flow generating mechanism includes a fluid ejecting member disposed inside the drum filter. The fluid ejecting member injects a fluid from the fluid ejecting member toward the flow hole near the sludge carrying-out path, thereby generating a flow toward the sludge carrying-out path on the liquid surface.

  In one embodiment, the fluid ejection member is disposed above the rotation center of the drum filter. The flow hole of the drum filter has an inflow opening that opens to the outer surface of the drum filter and an outflow opening that opens to the inner surface of the drum filter, and the diameter of the inflow opening is larger than the diameter of the outflow opening. It may be small. Furthermore, the diameter of the inlet of the flow hole of the drum filter may be larger than the thickness of the porous plate.

  An example of the filter rotation mechanism rotates the drum filter in a direction in which an upper portion of the drum filter moves toward the sludge carry-out path. The fluid supplied to the fluid supply mechanism may be a clean liquid filtered by the drum filter. Furthermore, it may have a primary filter disposed below the drum filter inside the filtration tank, and the diameter of the flow hole of the primary filter may be larger than the diameter of the flow hole of the drum filter.

  The filtration device of the present invention can separate the removal target attached to the outer surface of the drum filter from the drum filter by the fluid ejected from the fluid ejecting member. The fluid flowing toward the sludge discharge path near the liquid level in the filtration tank is ejected from the fluid ejection member, moves toward the liquid level through the circulation hole of the drum filter, and moves toward the sludge discharge path. Arise. For this reason, the removal target such as sludge floating near the liquid surface can reach the sludge carry-out path without staying in the filtration tank. For this reason, the removal target object in a filtration tank can be efficiently discharged | emitted out of a filtration tank through a sludge carrying-out path. Since the filtration device of the present invention can prevent clogging of the drum filter without using a contact-type scraper, the drum filter can be prevented from being worn or deformed, and the replacement frequency of the drum filter can be reduced. Easy maintenance.

Sectional drawing of the filtration apparatus which concerns on 1st Embodiment. Sectional drawing of the filtration apparatus which follows the F2-F2 line | wire in FIG. The perspective view of a part of filtration apparatus shown by FIG. Sectional drawing of the drum filter of the filtration apparatus shown by FIG. Sectional drawing which expands and shows a part of drum filter typically. The perspective view of a fluid ejection member. The perspective view of the fluid injection member which concerns on 2nd Embodiment.

Hereinafter, a filtration device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 shows an outline of equipment for removing foreign matter from coolant (cutting fluid) used in a machine tool 1 such as a machining center. The coolant discharged from the machine tool 1 is an example of the liquid Q1 to be filtered. Depending on the material to be processed, for example, aluminum alloy or magnesium alloy shavings, shavings such as iron-based metal, non-metallic fine particles such as carbon, etc. are mixed in the liquid Q1.

  The liquid Q1 containing the removal target such as shavings and fine particles is supplied from the machine tool 1 to the filtration device 10 through the flow path 2. The liquid Q1 is primarily filtered by the primary filter 40 of the filtration device 10 to become the liquid Q2, and this liquid Q2 is secondarily filtered by the drum filter 60 to become the clean liquid C. The purified clean liquid C is pumped up by the pump 3 and then supplied again to the machine tool 1 through the supply flow path 4. The primary filter 40 and the drum filter 60 will be described in detail later.

Below, the detail of the filtration apparatus 10 is demonstrated.
As shown in FIG. 1 and FIG. 2, the filtration device 10 includes a filtration tank 11 that contains a liquid Q1 to be filtered, a clean tank 12 that contains a filtered clean liquid C, and a sludge carry-out conveyor (scraper conveyor). 13. A liquid Q1 to be filtered is supplied from the flow path 2 to the filtration tank 11. The clean tank 12 is formed in the vicinity of the filtration tank 11.

  A sludge carry-out path 15 is formed at the end of the filtration tank 11. The sludge carry-out path 15 extends obliquely upward through the liquid level Q3 of the filtration tank 11 and extends to the outside of the filtration tank 11. A discharge portion 16 is formed at the upper end of the sludge carry-out path 15. The discharge part 16 is provided at a position higher than the liquid level Q3 of the filtration tank 11. A conveyor drive mechanism 17 using a motor as a drive source is provided in the vicinity of the discharge unit 16.

  The conveyor 13 is disposed from the bottom 11 a of the filtration tank 11 to the sludge carry-out path 15 and the discharge unit 16. The conveyor 13 has a chain 20 (shown in FIGS. 2 and 3) and a plurality of scrapers 21. The chain 20 is wound around an upper sprocket 22 and a lower sprocket 23 and is moved in a direction indicated by an arrow A in FIG. The chain 20 is supported by guide members 25 and 26 (shown in FIG. 2) provided in the filtration tank 11 so as to be movable in the above direction.

  As shown in FIG. 1, the conveyor 13 has a lower part (forward path part) 13a and an upper part (return part) 13b. The lower portion 13 a of the conveyor 13 moves toward the discharge portion 16 along the bottom portion 11 a of the filtration tank 11 and the sludge carry-out path 15. The upper portion 13b of the conveyor 13 moves from the upper sprocket 22 toward the lower sprocket 23 in the direction opposite to the lower portion 13a above the lower portion 13a.

  The upper portion 13b of the conveyor 13 is directed toward the liquid surface Q3, a descending portion 13c that moves obliquely downward along the sludge carry-out path 15, a transverse portion 13d that moves substantially horizontally along the bottom portion 11a of the filtration tank 11, and the liquid surface Q3. And a rising portion 13e that moves obliquely upward. The scraper 21 is attached at predetermined intervals in the longitudinal direction of the chain 20.

  As shown in FIGS. 1 and 2, the scraper 21 has a first portion 21a. The first portion 21 a moves along the bottom portion 11 a of the filtration tank 11 in the lower portion 13 a of the conveyor 13. Further, the scraper 21 is provided with a second portion 21b facing away from the first portion 21a. The second portions 21b may be provided in all the scrapers 21, but may be provided in some scrapers 21 at a predetermined pitch. An example of the second portion 21b is a metal plate, but a blade made of an elastic material such as rubber may be employed.

  Sludge S such as shavings sinking to the bottom 11a of the filtration tank 11 is sent from the bottom 11a of the filtration tank 11 to the discharge part 16 via the sludge carry-out path 15 by the first portion 21a of the scraper 21. It has become. The sludge S that has reached the discharge unit 16 falls toward the collection box 35 (shown in FIG. 1).

  The filtration device 10 has a primary filter 40. The primary filter 40 is a panel member made of stainless steel with a large number of flow holes 41 (shown in FIG. 2) formed of, for example, punching metal. An example of the diameter of the flow hole 41 is φ1 mm. An example of the thickness of the primary filter 40 is 1 mm.

  The primary filter 40 is disposed between the lower part 13 a and the upper part 13 b of the conveyor 13 in the filtration tank 11. Moreover, the primary filter 40 is disposed along the moving direction of the conveyor 13 inside the filtration tank 11.

  As shown in FIGS. 1 and 2, the primary filter 40 has a bottom plate portion 45, a front side plate portion 46, and a rear side plate portion 47. The bottom plate portion 45 is disposed substantially horizontally along the traversing portion 13 d of the conveyor 13. As shown in FIG. 2, both side portions of the primary filter 40 are attached to support portions 11 b and 11 c provided on the side wall of the filtration tank 11.

  Of the guide members 25 and 26 shown in FIG. 2, the lower guide member 25 supports the lower portion 13 a of the conveyor 13. Moreover, the guide member 25 supports the lower portion 13a of the conveyor 13 so that the second portion 21b of the scraper 21 faces the lower surface of the bottom plate portion 45 of the primary filter 40 with a gap G1. doing. The upper guide member 26 supports the upper portion 13 b of the conveyor 13 so that the second portion 21 b of the scraper 21 contacts the upper surface of the bottom plate portion 45 of the primary filter 40.

  The side plate portion 46 on the front side of the primary filter 40 extends obliquely from the front end of the bottom plate portion 45 along the sludge carry-out path 15. In addition, the side plate portion 46 is along the descending portion 13 c of the conveyor 13. The rear side plate portion 47 extends obliquely from the rear end of the bottom plate portion 45 toward the liquid level Q3. Moreover, the side plate portion 47 extends in an oblique direction along the rising portion 13 e of the conveyor 13. The end portion 48 of the primary filter 40 may be equal to the height of the liquid level Q3, and even if it is positioned above or below the liquid level Q3, there is no practical problem. The flow hole 41 of the primary filter 40 may be formed in the entire panel member 40a, but may be formed in a part of the bottom plate portion 45 in order to reduce the cost.

  The inside of the filtration tank 11 is partitioned by a primary filter 40 into a first filtration tank part 51 and a second filtration tank part 52. The first filtration tank part 51 is formed between the bottom part 11 a of the filtration tank 11 and the primary filter 40. The second filtration tank 52 is formed on the upper side of the primary filter 40 in the filtration tank 11. The first filtration tank part 51 and the second filtration tank part 52 communicate with each other through the flow hole 41 of the primary filter 40.

  Further, the filtration device 10 has a cylindrical drum filter (secondary filter) 60. The drum filter 60 is disposed in the second filtration tank 52 above the bottom plate 45 of the primary filter 40 and above the upper portion 13 b of the conveyor 13. The number of drum filters 60 may be one, or may be plural as shown in FIG.

  The drum filter 60 is formed by forming a large number of flow holes 61 (shown in FIG. 5) by photoetching on a thin stainless steel spring plate having a thickness of about 0.2 mm, for example. End members 65 are provided at both ends of the drum filter 60. Each end member 65 is provided with a sprocket 67. A chain 69 of a filter rotating mechanism 68 (shown in FIG. 1) meshes with these sprockets 67. The chain 69 is moved by the motor of the filter rotating mechanism 68 to rotate each drum filter 60 in the direction indicated by the arrow B.

  The drum filter 60 is supported by a cylindrical support member 70 (shown in FIGS. 2 and 3) provided in the filtration tank 11 so as to be rotatable about a horizontal axis X1. The entire circumference of the drum filter 60 is located below the liquid level Q3. That is, the entire drum filter 60 is immersed in the liquid Q2.

  As shown in FIG. 2, a clean liquid circulation part 71 is formed inside the support member 70. The clean liquid circulation part 71 communicates with the space 60 a inside the drum filter 60. The space 60 a inside the drum filter 60 communicates with the clean tank 12 via the clean liquid circulation part 71. The clean liquid C that has flowed into the space 60 a inside the drum filter 60 can flow into the clean tank 12 through the clean liquid circulation portion 71.

  The drum filter 60 is obtained by rounding a perforated plate 74 (partially shown in FIG. 5) having a large number of flow holes 61 into a cylindrical shape, and has an outer surface 60b and an inner surface 60c. An inlet 61 a of the circulation hole 61 is opened on the outer surface 60 b of the drum filter 60. An outlet 61 b of the circulation hole 61 is opened on the inner surface 60 c of the drum filter 60. An example of the circulation hole 61 is circular, but may be other than circular. The liquid Q2 in the second filtration tank 52 flows from the outer surface 60b of the drum filter 60 toward the inner surface 60c and from the inlet 61a of the circulation hole 61 toward the outlet 61b.

  An example of the thickness T1 (shown in FIG. 5) of the perforated plate 74 that is a material of the drum filter 60 is 0.2 mm. An example of the diameter D1 of the inflow port 61a is φ0.2 mm. The diameter D1 of the inlet 61a is recommended to be equal to or greater than the thickness T1 of the porous plate 74. The diameter D1 of the inflow port 61a is smaller than the diameter D2 of the outflow port 61b. Moreover, the diameters D1 and D2 of the flow holes 61 are smaller than the diameter of the flow holes 41 of the primary filter 40. The thickness T1 of the drum filter 60, the diameters D1 and D2 of the flow holes 61, and the diameter of the flow holes 41 of the primary filter 40 are selected according to various conditions such as required filtration accuracy and flow rate. It is not limited to the above numerical values.

  As shown in FIG. 5, the flow hole 61 of the drum filter 60 of this embodiment is formed in a tapered shape so that the diameter D1 of the inlet 61a is smaller than the diameter D2 of the outlet 61b. The flow hole 61 having such a shape can be formed by etching a metal plate (for example, a stainless steel plate) from the inner surface 60c. That is, the drum filter 60 includes a perforated plate (etching plate) 74 in which a large number of flow holes (etching holes) 61 are formed by photoetching. The through holes 61 formed by etching do not have “burrs” like punching metal. Moreover, the inner surface of the flow hole 61 is not roughened such as a shear mark. For this reason, shavings are not easily caught and clogging is unlikely to occur.

  As shown in FIGS. 2 to 4, a fluid ejecting member 80 is disposed inside the drum filter 60. An example of the fluid ejecting member 80 is a pipe having a closed end. The fluid ejecting member 80 is connected to the discharge port 3 a of the pump 3 through a fluid supply pipe 81 and an on-off valve 82. The fluid ejecting member 80 has an axis X2 (shown in FIGS. 2 and 6) along the longitudinal direction. The fluid ejecting member 80 is disposed such that the axis X2 is substantially parallel to the axis X1 (shown in FIG. 2) of the drum filter 60. In addition, the fluid ejecting member 80 is disposed on the drum filter 60, that is, at a position closer to the liquid level Q3 than the rotation center X3 (shown in FIG. 4) of the drum filter 60.

  FIG. 6 shows an example of the fluid ejecting member 80. In the fluid ejection member 80, a plurality of ejection holes 85 are formed at predetermined intervals (pitch P) along the axis X2. These injection holes 85 open toward the sludge carry-out path 15 at an angle θ1 (shown in FIG. 6) with respect to the uppermost surface 80a of the fluid injection member 80 (shown by a two-dot chain line in FIG. 6). Thus, it is formed on the upper part of the fluid ejecting member 80.

  In the case of this embodiment, a fluid flow generating mechanism 90 is configured by the fluid ejecting member 80, the fluid supply pipe 81, the on-off valve 82, the pump 3, and the like. The clean liquid C filtered by the drum filter 60 is supplied to the fluid ejecting member 80 by the pump 3. However, a cleaning liquid other than the clean liquid C may be supplied to the fluid ejecting member 80 by a supply unit different from the pump 3.

Next, the operation of the filtration device 10 having the above configuration will be described.
The liquid Q1 discharged from the machine tool 1 is supplied to the first filtration tank portion 51 of the filtration tank 11 through the flow path 2. Sludge S (schematically shown in FIG. 1) containing shavings or the like sinking to the bottom of the first filtration tank 51 is discharged by the first portion 21 a of the scraper 21 as the conveyor 13 moves. It is conveyed toward.

  At least a part of the shavings, fine particles, etc. in the first filtration tank part 51 flows into the second filtration tank part 52 through the flow hole 41 from the lower surface side of the primary filter 40 together with the liquid Q1 while floating. . When the liquid Q1 passes through the flow hole 41 of the primary filter 40, primary filtration of relatively large shavings is performed. When the liquid Q1 passes through the flow hole 41, shavings, fine particles, etc. floating in the first filtration tank portion 51 adhere to the lower surface of the primary filter 40 in the vicinity of the inlet of the flow hole 41.

  The sludge adhering to the lower surface of the primary filter 40 is sludge S such as relatively large shavings that move with the scraper 21 when the scraper 21 of the lower portion 13a of the conveyor 13 moves along the bottom 11a of the filtration tank 11. When a part of is touched, it peels off from the lower surface of the primary filter 40. For this reason, it is possible to prevent clogging from occurring on the lower surface of the primary filter 40. In addition, the lower surface of the primary filter 40 may be directly cleaned by the second portion 21b by arranging the conveyor 13 so that the upper end of the second portion 21b of the scraper 21 is in contact with the lower surface of the primary filter 40. .

  The liquid Q2 that has flowed into the second filtration tank 52 through the flow hole 41 of the primary filter 40 flows through the flow hole 61 of the drum filter 60 and flows into the space 60 a inside the drum filter 60. Shavings, particles, or the like having a size that cannot pass through the circulation hole 61 adhere to the vicinity of the inlet 61 a of the circulation hole 61.

  The clean liquid C that has flowed into the drum filter 60 flows into the clean tank 12 through the clean liquid circulation portion 71. The clean liquid C in the clean tank 12 is pumped up by the pump 3 and supplied to the machine tool 1 again through the supply channel 4. For this reason, the clean coolant (clean liquid C) always filtered with high precision can be supplied to the machine tool 1, and the machine tool 1 can be normally functioned.

  A part of the clean liquid C discharged from the pump 3 is sent to the fluid ejecting member 80 through the on-off valve 82 and the fluid supply pipe 81. The clean liquid C sent to the fluid ejecting member 80 is ejected from the ejection hole 85 toward the inner surface 60c of the drum filter 60, as indicated by an arrow FW in FIGS. Since the injection hole 85 faces the sludge carry-out path 15 toward the liquid surface Q3, the clean liquid C that has been vigorously ejected obliquely from the injection hole 85 as shown by the arrow FW in FIGS. The liquid level Q3 in the filtration tank 11 moves toward the sludge carry-out path 15 while rising from the outer surface 60b of the drum filter 60 toward the liquid level Q3 through the circulation hole 61.

  Therefore, a liquid flow (indicated by an arrow Y1 in FIG. 4) toward the sludge carry-out path 15 occurs in the vicinity of the liquid surface Q3 in the filtration tank 11. Moreover, the drum filter 60 is rotated by the filter rotating mechanism 68 in the direction indicated by the arrow B, that is, in the direction in which the upper surface of the drum filter 60 moves toward the sludge carry-out path 15. For this reason, the liquid flow (indicated by arrow Y1) toward the sludge carry-out path 15 in the vicinity of the liquid level Q3 can be promoted.

  Since such a liquid flow can be generated in the vicinity of the liquid surface Q3, the removal target such as the sludge S floating along with the bubbles near the liquid surface Q3 moves as indicated by the arrow Y2. For this reason, the removal target floating near the liquid surface Q3 can reach the sludge carry-out path 15 relatively quickly, and can be moved toward the discharge unit 16 by the conveyor 13.

  The fine sludge S that has fallen on the primary filter 40 is conveyed toward the end 48 of the primary filter 40 by the second portion 21b of the scraper 21 as the conveyor 13 moves, and the first filtration is performed from the end 48. It is dropped into the tank part 51. That is, the upper surface of the primary filter 40 is cleaned by the second portion 21 b of the scraper 21.

  Sludge S dropped in the first filtration tank 51 is precipitated in the first filtration tank 51 together with the shavings contained in the liquid Q1 flowing into the first filtration tank 51 from the flow path 2. . The sludge S that has settled in the first filtration tank section 51 is conveyed toward the discharge section 16 by the first portion 21 a of the scraper 21.

  The primary filter 40 has low filtration accuracy so that the drum filter 60 can sufficiently exhibit the filtration performance in the relatively clean liquid Q2. That is, after relatively large shavings are filtered by the primary filter 40, further fine shavings and particles are filtered by the drum filter 60. For this reason, the drum filter 60 which is thin and easily damaged can be prevented from being damaged by large shavings.

  According to the filtration device 10 of the present embodiment, the removal target attached to the drum filter 60 is separated from the drum filter 60 by the clean liquid C ejected from the ejection holes 85 of the fluid ejection member 80, and the liquid surface Q3 of the filtration layer 11 is removed. And can be moved toward the sludge carry-out path 15. For this reason, the removal target object in the filtration tank 11 can be efficiently conveyed to the discharge part 16. Moreover, since the clogging of the drum filter 60 can be prevented without using a contact-type scraper, it is possible to prevent the drum filter 60 from being worn or deformed, and the durability of the drum filter 60 can be greatly improved. For this reason, maintenance is easy, for example, the frequency of replacing the drum filter 60 can be reduced.

  FIG. 7 shows a fluid ejection member 80 ′ according to the second embodiment. The fluid ejecting member 80 'has an ejection hole 100 made of a slit extending in the direction of the axis X2. Since the filtration device provided with the fluid ejecting member 80 'is common to the filtration device 10 provided with the fluid ejecting member 80 of the first embodiment, the configuration and action other than that are common to the common parts of both. The reference numerals are attached and the description is omitted.

  It should be noted that, in carrying out the present invention, it is possible to implement various modifications of the components of the invention, such as the specific configuration and arrangement of the conveyor, drum filter, and liquid flow generation mechanism, including the filtration tank constituting the filtration device. Needless to say. For example, the primary filter 40 described in the above embodiment may not be disposed in the filtration tank 11. The number of drum filters may be one, or three or more drum filters may be arranged in the filtration tank in parallel with each other in the moving direction of the conveyor. The filter rotation mechanism may be configured to rotate the drum filter by the chain of the conveyor. The injection member of the liquid flow generation mechanism may inject only the liquid, or may inject a mixed fluid of liquid and air (bubbles). Further, by supplying high-pressure air to the fluid ejecting member, only bubbles may be ejected vigorously toward the drum filter.

  DESCRIPTION OF SYMBOLS 10 ... Filtration apparatus, 11 ... Filtration tank, Q3 ... Liquid level, 13 ... Conveyor, 15 ... Sludge delivery path, 16 ... Discharge part, 21 ... Scraper, 40 ... Primary filter, 60 ... Drum filter, 61 ... Distribution hole, 61a ... Inlet, 61b ... Outlet, 68 ... Filter rotation mechanism, 74 ... Perforated plate, 80, 80 '... Fluid injection member, 85 ... Injection hole, 90 ... Liquid flow generation mechanism, 100 ... Injection hole, Y1 ... Liquid surface Nearby liquid flow.

Claims (7)

A filtration tank containing the liquid to be filtered;
A discharge part provided at a position higher than the liquid level of the liquid in the filtration tank;
A sludge carry-out path formed from the bottom of the filtration tank to the discharge part;
A conveyor having a scraper that moves along the sludge carry-out path;
A drum filter that is disposed below the liquid surface in the filtration tank, is formed of a cylindrical perforated plate having an outer surface and an inner surface, and has a plurality of flow holes through which the liquid flows from the outer surface toward the inner surface; ,
A filter rotating mechanism for rotating the drum filter;
A liquid flow generating mechanism for generating a flow toward the sludge carrying-out path on the liquid surface by ejecting fluid from the fluid ejecting member disposed inside the drum filter toward the flow hole near the sludge carrying-out path; ,
A filtration apparatus comprising:   The filtration device according to claim 1, wherein the fluid ejection member is disposed above a rotation center of the drum filter.   The flow hole of the drum filter has an inlet opening to the outer surface of the drum filter and an outlet opening to the inner surface of the drum filter, and the diameter of the inlet is smaller than the diameter of the outlet. The filtration apparatus according to claim 1 or 2, wherein   The filtration device according to any one of claims 1 to 3, wherein a diameter of an inlet of the circulation hole of the drum filter is larger than a thickness of the perforated plate.   The filtration device according to claim 1, wherein the filter rotation mechanism rotates the drum filter in a direction in which an upper portion of the drum filter moves toward the sludge carry-out path.   The filtration device according to claim 1, wherein the fluid supplied to the fluid supply mechanism is a clean liquid filtered by the drum filter.   2. The filter according to claim 1, further comprising: a primary filter disposed below the drum filter in the filtration tank, wherein the diameter of the flow hole of the primary filter is larger than the diameter of the flow hole of the drum filter. The filtration apparatus as described in.

Images