JP2007000808A - Multiple disk dehydration equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively perform filtration also from spacers located between disks, thereby to improve the dehydration efficiency and filtration efficiency in a multiple disk dehydration equipment. <P>SOLUTION: A filter body is constituted by alternatively fitting disks 31 and spacers 32 having diameters smaller than that of the disks in a rotatable shaft body in a multiple state. The multiple disk dehydration equipment is equipped with a group of the filter mediums formed by continuously providing the required number of disks so that parts of the disks are superposed and performing filtration from the gaps of the superposed parts of the disks. The equipment forms a filtrate passage penetrating through the disks and spacers to discharge a filtrate leaked to the filtrate passage from the shaft end of the filter medium, and forms a filtration groove along the circumference of the spacer. The filtrate groove is radially extended, has one end opening so as to communicate with a passage hole 51 and has the other end opening in the peripheral face of the spacer, and leaks the filtrate to the passage hole through the passage hole. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multiple disk dewatering device that separates solids and filtrates by filtering sewage sludge, human waste sludge, and other industrial waste sludge.

  One of the filtration devices that separate sewage sludge, human waste sludge, and other industrial waste sludge to separate solids and filtrates is a multiple disk dewatering device.

  Conventionally, as a multiple disk dewatering device, there are those shown in Patent Literature 1 and Patent Literature 2. An outline of such a multiple disk dewatering device will be described with reference to FIGS.

  The multiple disk dewatering apparatus mainly includes a multiple disk dewatering machine 1 and an aggregating device 2 connected to the multiple disk dewatering machine 1.

  In the multiple disk dehydrator 1, an upper filter body group 4 and a lower filter body group 5 are arranged in the dehydration tank 3 so as to form a cake transport path 6. The cake transport path 6 The sectional area gradually decreases toward the downstream side, the downstream end opens on the wall surface of the dehydration tank 3 to form the discharge port 10, and the upstream side of the upper filter group 4 is connected to the lower filter group 5. On the other hand, the upper surface of the upstream end portion of the cake conveying path 6 is open.

  The upper filter body group 4 and the lower filter body group 5 are configured so that a required number of filter bodies 7 are partially polymerized, and the filter bodies 7 are formed on both side walls of the dehydration tank 3. The upper filter body group 4 and the lower filter body group 5 are driven so as to rotate toward the downstream side by a driving device (not shown).

  In the filter body 7, a large number of discs 9 are fixed to the rotary shaft 8 via spacers 20, and the discs 9 and 9 of the adjacent filter bodies 7 and 7 are partially in the gap formed by the spacer 20. A part of the filter bodies 7 and 7 adjacent to each other is polymerized, and a gap formed between the discs 9 and 9 of the adjacent filter bodies 7 and 7 serves as an eye for filtering the liquid. Further, a filtrate passage 11 is formed in the filter body 7 so as to penetrate the disk 9 and the spacer 20 in the axial direction.

  For each required number of spacers 20, for example, every five, a notch 40 is formed in the outer periphery of the spacer 20, and the filtrate passage 11 is opened by the notch 40 (FIG. 12). Middle, 20a). Accordingly, the filtered filtrate leaks to the filtrate passage 11 through the notch 40, and the filtrate passage 11 guides the leaked filtrate to the shaft end of the filter body 7, and from the side wall of the dehydration tank 3. It comes to discharge.

  The aggregating apparatus 2 has an aggregating tank 12, and the aggregating tank 12 is connected to the dehydrating tank 3 through an aggregating stock solution supply port 13. The coagulation tank 12 is connected to a stock solution supply line 14 and a coagulation liquid supply line 15. The coagulation tank 12 is supplied with a stock solution from the stock solution supply line 14 by a stock solution supply pump 16, and from the aggregate solution supply line 15. The aggregating liquid is supplied from the aggregating liquid supply pump 17.

  The agglomeration tank 12 is provided with a stirrer 18, and the agitation liquid is agitated by the agitator 18, thereby aggregating solids in the undiluted liquid.

  By supplying the stock solution from the stock solution supply line 14 and the aggregate solution from the aggregate solution supply line 15, the aggregate stock solution 19 overflows from the aggregate stock solution supply port 13 and is supplied to the dehydration tank 3. The supply amount of the agglomerated stock solution 19 is adjusted so as to form a free liquid level 21 at the upstream end opening portion of the cake transport path 6.

  The agglomerated stock solution 19 supplied to the cake transport path 6 is separated into filtrates by gravity filtration at the upstream portion of the cake transport path 6, and most of the separated filtrate is between the disks 9, 9. It falls from the eyes, and the remaining part leaks into the filtrate passage 11 and is discharged from the side wall of the dehydration tank 3 through the filtrate passage 11.

  The separated flocs that have been separated land on the lower filter body group 5 and are conveyed downstream by the rotation of the upper filter body group 4 and the lower filter body group 5. In addition, the aggregated floc is squeezed by the upper and lower upper filter body groups 4 and the lower filter body group 5 in the conveying process, and the filtrate is separated into a cake. That is, a gravity dewatering part is formed in the upstream part of the cake conveyance path 6, and a pressing dewatering part is formed in the downstream part.

  Most of the filtrate separated by the pressure falls through the eyes between the discs 9 and 9, falls below the lower filter body group 5, and the remainder leaks into the filtrate passage 11, and the filtrate passage 11 And is discharged from the side wall of the dehydration tank 3.

  Further, the dehydrated cake is discharged from the discharge port 10 by the conveying action of the upper filter body group 4 and the lower filter body group 5.

  In the above-described conventional multiple disk dewatering device, the filtrate separating action at the upstream portion of the cake conveying path 6 is liquid separation by gravity. Further, the eyes through which the filtrate passes are only from a slight gap formed in a portion where the adjacent filter bodies 7 and 7 are overlapped with each other and from the notch 40 formed in the spacer 20 for each predetermined number of sheets. .

  The spacer 32 occupies most of the lower filter body group 5 facing the cake transport path 6, and the spacer 32 is formed with the cutout portion 40 communicating with the filtrate passage 11. Even if the filtrate is leaked to the filtrate passage 11 through the portion 40, the cutout portion 40 is only formed in a very small part and is not sufficient for filtration. Furthermore, the eyes formed by forming the notched portions 40 become slit holes that are long enough to correspond to the diameter of the filtrate passage 11 penetrating the spacer 32, and the size of the eyes for filtering the filtrate is as described above. When the length of the cut portion 40 is L, L × t (spacer thickness). This is significantly larger than the gap formed in the overlapping portion of the discs 9 and 9, and has a problem that the aggregated floc easily leaks into the filtrate passage 11.

  Thus, when sufficient dehydration does not proceed in the gravity dehydration part, the moisture content of the cake that has entered the press dehydration part is large, and an effective squeezing action cannot be obtained. Further, when the dehydrating action in the gravity dehydrating part is small, there is a problem that the free liquid level 21 is slow to be lowered and the supply amount of the stock solution is limited, so that an increase in the processing amount cannot be expected.

JP 2004-330060 A

JP 2005-7327 A

  In view of such circumstances, the present invention enables effective filtration from a spacer located between the disks, and improves dewatering efficiency and filtration efficiency.

  According to the present invention, a filter body constituted by alternately and repeatedly fitting a disc on a rotatable shaft body and spacers having a smaller diameter than the disc is continuously provided so that a part of the disc is superposed. In a multiple disk dewatering device having a filter body group that is filtered through a gap between the overlapping portions of the disk, a filtrate passage that penetrates the disk and the spacer is formed to leak into the filtrate passage. The filtrate is discharged from the shaft end of the filter body, a filtration groove is formed over the entire circumference of the spacer, the filtration groove extends in the radial direction, and one end is opened so as to communicate with the passage hole, and the other end is formed. The present invention relates to a multiple disk dewatering device that opens to the peripheral surface of the spacer and allows the filtrate to leak into the passage hole through the filtration groove.

  The present invention also relates to a multiple disk dewatering device in which the spacer and the disk are integrally formed, and the spacer is ring-shaped over the entire circumference at predetermined intervals so as to form a filtration groove. The present invention relates to a multiple disk dewatering device formed by protruding protrusions.

  The present invention also relates to a multiple disk dewatering device in which the filtration groove has a shape with a gradually increasing cross-sectional area toward the center, and multiple disk dewatering in which protrusions are formed at a required interval on the circumferential surface of the disk. It concerns the device.

  According to the present invention, a filter body constituted by alternately and repeatedly inserting a disk and a spacer having a smaller diameter than the disk on a rotatable shaft body, a required number of consecutive disks are superposed. In a multiple disk dewatering device comprising a filter body group configured to filter through a gap in the overlapped portion of the disk, a filtrate passage that penetrates the disk and the spacer is formed to form the filtrate passage The filtrate leaked into the filter body is discharged from the shaft end of the filter body, and a filtration groove is formed over the entire circumference of the spacer. The filtration groove extends in the radial direction and opens so that one end communicates with the passage hole. Since the end is opened to the peripheral surface of the spacer and the filtrate leaks to the passage hole through the filtration groove, the peripheral surface of the spacer also contributes to the filtering action, and the filtration efficiency is increased.

  In addition, according to the present invention, the spacer and the disc are integrally formed, so that the number of parts is reduced and the manufacturing cost of the apparatus is reduced.

  Further, according to the present invention, the filtration groove has a shape in which the cross-sectional area gradually increases toward the center, so that the flocs can be easily removed and clogging is prevented.

  According to the present invention, since the protrusions are formed on the peripheral surface of the disk at a required interval, the protrusions scrape off the flocs adhering to the gap formed in the overlapped portion of the disk, and Exhibits excellent effects such as preventing clogging.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 and FIG. 2 show an example of a multiple disk dewatering apparatus in which the present invention is implemented, particularly a multiple disk dewatering apparatus in which the cake transport path 6 has a closed structure.

  First, the multiple disk dewatering device will be described.

  In FIGS. 1 and 2, the same components as those shown in FIG. 11 are denoted by the same reference numerals.

  An upper filter body group 4 and a lower filter body group 5 are provided in the dehydration tank 3 so as to face each other vertically, and a cake transport path 6 is formed between the upper filter body group 4 and the lower filter body group 5.

  The upper filter body group 4 and the lower filter body group 5 are configured such that a required number of filter bodies 7 are partially polymerized and connected in series. The structure of the filter body 7 is the same as that described in the conventional multiple disk dewatering device, and thus the description thereof is omitted.

  An upstream end filter body group 23 is provided at the upstream end of the cake transport path 6. The upstream end filter body group 23 is constituted by the filter body 7, similar to the upper filter body group 4 and the lower filter body group 5, and the filter body 7 located at the upper and lower ends of the upstream end filter body group 23. Are connected to the upper filter body group 4 and the lower filter body group 5 so as to partially overlap with the filter body 7 located at the upstream end.

  Accordingly, the cake transport path 6 is a space closed by both side walls of the dehydration tank 3, the upper filter body group 4, the lower filter body group 5, and the upstream end filter body group 23.

  The filter bodies 7 constituting the upper filter body group 4, the lower filter body group 5, and the upstream end filter body group 23 are respectively connected to a driving source (not shown), and the aggregation stock solution in the cake transport path 6, or It is rotated to give the flock a downstream force.

  The discharge port 10 opened at the downstream end of the cake transport path 6 is provided with a resistance plate 24 as discharge resistance applying means. The resistance plate 24 is rotatably supported at the upper end by the dehydration tank 3 and is suspended so as to close the discharge port 10 by its own weight. Further, a required number of weight plates 25 can be attached to and detached from the resistance plate 24, and the closing force of the discharge port 10 can be adjusted by the number of weight plates 25.

  The coagulation tank 12 having a sealed structure and the dehydration tank 3 are connected to each other by a coagulation stock solution supply pipe 26, and the coagulation stock solution supply pipe 26 opens at the upstream end of the cake conveyance path 6 on the side wall of the dehydration tank 3.

  A pressure gauge 29 is provided at an appropriate position such as the upstream end of the aggregation tank 12, the aggregation stock solution supply pipe 26, or the cake conveyance path 6 so that the pressure in the upstream portion of the cake conveyance path 6 is detected. It has become.

  The coagulation tank 12 is connected with a stock solution supply line 14 and a coagulation liquid supply line 15, and the stock solution or the coagulation liquid can be pumped to the coagulation tank 12 by a stock solution supply pump 16 and a coagulation solution supply pump 17, respectively. . The agglomeration tank 12 has a closed structure, but an accumulator (not shown) capable of absorbing pressure fluctuations in the cake conveyance path 6 may be connected to the agglomeration tank 12.

  The stock solution in the agglomeration tank 12 is agitated by the agitator 18, and the aggregating action by the agglomerated liquid is promoted.

  Next, the filter body 7 and the like will be described in detail with reference to FIGS.

  A lower part of the lower filter body group 5 of the dehydration tank 3 is a filtrate storage part 27, and a filtrate storage side chamber 28 is formed on both sides or one side of the dehydration tank 3. Is configured to store the filtrate dropped by the gravity dehydration unit and the filtrate separated by the pressure dehydration unit, and the upper filter body group 4 and the lower filter body are stored in the filtrate storage side chamber 28 as described later. The collected filtrate flows into the filtrate passage 11 formed in the group 5.

  FIG. 3 shows the filter body 7, and discs 31 are fitted in multiple numbers on the shaft body 30, and spacers 32 are provided between the disks 31, 31. It has a rod shape. The outer diameter of the spacer 32 is smaller than the outer diameter of the disk 31, and the thickness of the spacer 32 is slightly larger than the thickness of the disk 31. In FIG. 3, for the sake of easy understanding, the thickness of the spacer 32 is shown large.

  A groove 33 is formed by the disk 31 and the spacer 32 on the outer peripheral portion of the filter body 7, and the disk 31 of the filter body 7 adjacent to the groove 33 is fitted into the filter body 7. And the adjacent filter body 7 are partially polymerized. An eye 38 through which the filtrate passes is formed between the tip of the disk 31 and the peripheral surface of the spacer 32.

  In the filter body 7, the filtrate passage 11 penetrating the disk 31 and the spacer 32 is formed at a position where the circumference is equally divided, for example, at a position where the circumference is equally divided in FIG. 4.

  The side wall 34 adjacent to the filtrate storage side chamber 28 of the dehydration tank 3 is provided with a required number of filtrate inlets 35, and the filtrate inlets 35 have the same diameter as the circumference in which the filtrate passage 11 is provided. It is arranged on the circumference. The shape of the filtrate inlet 35 is substantially the same as the filtrate passage 11 or slightly larger than the filtrate passage 11. Therefore, every time the filtrate inlet 11 and the filtrate passage 11 rotate at a pitch angle in which the filtrate passage 11 is drilled, the filtrate passage 11 and the filtrate inlet 35 coincide with each other. In the illustrated example, the filtrate passage 11 and the filtrate inlet 35 coincide with each other when the filter body 7 rotates 45 °.

  A hole 39 is provided in at least one portion of the other side wall 36 of the dehydration tank 3, and a cleaning nozzle 37 is provided adjacent to the hole 39, and a jet water stream flows from the cleaning nozzle 37 toward the filtrate passage 11. It comes to be injected.

In addition, the jet direction of the jet water flow is inclined with respect to the axis of the filtrate passage 11, and the inclination angle θ is 0, where L is the total length of the filtrate passage 11 and D is the diameter of the filtrate passage 11. <Θ <α≈tan ⁻¹ (D / L). The angle of inclination does not have to be strict, and it is essential that the jet water flow penetrates or passes through the filtrate passage 11 and is inclined to the axis of the filtrate passage 11.

  Next, the disk 31 and the spacer 32 will be described with reference to FIGS.

  4 to 7 show a disc 47 with a spacer when the disc 31 constituting the filter body 7 and the spacer 32 are integrated.

  Here, the disc 31 and the spacer 32 are integrally formed as a disc 47 with a spacer by synthetic resin, for example, and the shaft body 30 (see FIG. 3) is formed at the center of the disc 31. A fitting hole 48 that penetrates is formed, and a thick boss portion 49 is formed around the fitting hole 48. A passage hole 51 for forming the filtrate passage 11 is formed around the boss portion 49. Around the passage hole 51, wedge-shaped protrusions 52 are formed so as to protrude over the entire circumference at a required circumferential pitch. The thickness of the portion where the projection 52 is formed is the same as the thickness of the boss portion 49.

  As shown in FIG. 6, a filtration groove 53 is formed between the protrusions 52, 52. The filtration groove 53 has a tapered shape with a narrow outer peripheral side and a wide central side.

  When the disc 31 is incorporated in the shaft body 30 and the discs 31 and 31 are superposed, the protrusion 52 comes into contact with the adjacent disc 31 and the filtration groove 53 functions as a filtration hole extending in the radial direction. To do. The protrusion 52 functions as the spacer 32 shown in FIG. The formed filtration hole has an outer end opened to the peripheral surface of the spacer 32 and an inner end opened to communicate with the passage hole 51. Further, since the filtration groove 53 has a wide cross-sectional area on the center side, it can be easily removed even when agglomerated floc flows, and the filtration hole is prevented from being clogged. Further, the size of the opening that opens to the outer periphery can be set to the same size as the eye 38 (see FIG. 3) by appropriately setting the interval between the passage holes 51.

  Projections 50 are provided on the outer periphery of the disc 31 at a required interval. The protrusion 50 scrapes off the agglomerated floc adhering to the portion of the disc 31 that is adjacent to the eye 38.

  Further, as another method for forming the filtration hole, a combination of the disc 31 and the spacer 32 separately manufactured as in the related art may be used.

  Next, the case where a disc and a spacer are manufactured separately will be described.

  8 and 9 show a spacer 54 interposed between the disks 31 and 31, and the spacer 54 forms a filtration hole. The spacer 54 is formed by pressing a ring-shaped thin plate so that the cross section has a rectangular wave shape to form a filtration hole 55 extending in the radial direction.

  The spacer 54 is fitted into the disc 31 and fixed by a necessary means such as caulking, and the disc 31 integrated with the spacer 54 is fitted into the shaft body 30 to a predetermined number, and the filter 7 Is configured.

  In the above embodiment, a filtration hole that is opened over the entire circumference of the filter body 7 is formed, and the filtrate is guided to the filtrate passage 11 through the filtration hole. Since the filtration holes are formed over the entire circumference of the filter body 7, eyes for uniform filtration are formed in the entire lower filter body group 5, so that the filtration efficiency is greatly improved.

  The filtration groove 53 may be partially provided on the circumference. For example, you may provide corresponding to the range in which the said passage hole 51 is provided.

  In order to form the disc 31 integrally, if synthetic resin is used, the cost can be reduced and the weight can be reduced. However, if a synthetic resin disc is used, the upper filter group 4 is considered in consideration of the strength of the disc 31. The gravity filter dehydration part of the lower filter body group 5 may be used depending on the load, such as using the synthetic resin disk 31 and the pressing dewatering part using a metal plate. Further, it may be reinforced by interposing a metal plate disk for each required number of disks made of synthetic resin. Alternatively, the outer peripheral portion of the disc 31 is made of a metal material such as stainless steel, the central portion is made of a synthetic resin, and the outer peripheral portion and the central portion are press-fitted or integrally molded by molding or the like. May be reinforced.

  Hereinafter, the operation of the multiple disk dewatering device described above will be described.

  The stock solution supply pump 16 and the aggregate solution supply pump 17 are driven to pump the stock solution and aggregate solution into the aggregation tank 12. The stock solution and the flocculated liquid are stirred in the flocculation tank 12 to form a flocculated stock solution in which the solid content in the stock solution is flocculated, and is fed to the upstream portion of the cake transport path 6 through the flocculated stock solution supply pipe 26.

  Since the discharge port 10 is closed by the resistance plate 24, the discharge port 10 is not discharged in any state of the agglomerated stock solution or cake until the cake transport path 6 rises to a predetermined pressure.

  In the cake conveying path 6, the aggregated undiluted solution is separated into aggregated flocs and filtrate at the eyes 38, and the filtrate passes through the eyes 38 and falls into the filtrate reservoir 27, and the filtration groove that opens to the entire circumference of the spacer 32. It flows into the filtrate passage 11 through 53, and flows out into the filtrate storage side chamber 28 through the filtrate inlet 35.

  By increasing the pressure inside the cake transport path 6, the filtrate separation action in the gravity dehydration unit is promoted, and the filtrate separation processing amount increases. Therefore, the moisture content of the cake transferred to the pressing and dehydrating portion is reduced, the cake pressing action in the pressing and dehydrating portion becomes effective, and the amount of dewatering treatment from the cake increases.

  The cake dehydrated in the gravity dewatering unit is squeezed in the squeezing and dewatering unit on the upstream side of the cake conveying path 6.

  The liquid contained in the cake is filtered and separated by pressing, and a part of the filtrate separated by the pressing and dewatering part leaks out to the filtrate passage 11 through the filtration groove 53 of the spacer 32, and the filtrate passage. 11 and flows into the filtrate storage side chamber 28 through the filtrate inlet 35.

  Further, when the cake conveying path 6 is pressurized, the filtrate may leak to the upper side of the upper filter body group 4 and accumulate on the upper filter body group 4 in some cases. In this case, the upper filter body group 4 is inclined so as to be inclined downward toward the filtrate storage side chamber 28, or the dehydration tank 3 itself is inclined so that the filtrate storage side chamber 28 side is downward. As the upper filter body group 4 is inclined, the filtrate collected on the upper filter body group 4 is dropped and discharged into the filtrate storage side chamber 28.

  In addition, a pressure in the discharge direction acts on the cake by pressurizing the inside of the cake transport path 6, and further, the moisture content of the cake decreases, so that the upper filter body group 4 and the lower filter body group 5 The conveying power of the cake increases. The conveyed cake pushes up the resistance plate 24 and is discharged from the discharge port 10. By adjusting the number of the weight plates 25, the closing force of the discharge port 10 by the resistance plate 24 can be adjusted, and the resistance at the time of discharging the cake can be changed, so that the moisture content of the cake can be adjusted. It becomes.

  Control of the pressure inside the cake transport path 6 is also performed by controlling the supply amounts of the stock solution supply pump 16 and the coagulated solution supply pump 17. The pressure of the cake transport path 6 is detected by the pressure gauge 29, and the detection result is fed back to the driving of the stock solution supply pump 16 and the coagulated liquid supply pump 17, so that the pressure of the cake transport path 6 becomes a predetermined pressure. In addition, the supply amount of the stock solution and the aggregate solution is controlled. For example, about 0.05 MPA is selected as the predetermined value of the pressure to be controlled.

  Thus, the aggregation stock solution is pumped so that the detected pressure becomes a predetermined value, and the filtration state can be adapted to the state of the aggregation stock solution, and the filtration efficiency can be maintained and improved.

  In the case where an accumulator is provided, the fluctuation in pressure is absorbed by the accumulator, so that the supply amount of the stock solution supply pump 16 and the aggregate solution supply pump 17 can be a fixed amount supply.

  By continuing filtration and dehydration of the aggregated stock solution, the aggregated floc adheres to the disk 31 and also adheres to the inner wall of the filtrate passage 11. Aggregated floc adhering to the disk 31 is scraped and removed by sliding between the polymerized disks 31 and 31.

  Further, the flocs flocs adhering to the inner wall of the filtrate passage 11 or the flocs clogging the filtrate passage 11 are removed by jetting a jet water flow from the washing nozzle 37 to the filtrate passage 11.

  As shown in FIGS. 10A, 10B, and 10C, the washing of the filtrate passage 11 is such that the jet direction of the jet water flow is inclined with respect to the axis of the filtrate passage 11. Therefore, when the filter body 7 rotates, the jet water flow first collides with the wall surface on the cleaning nozzle 37 side (front side) (see FIG. 10A), and then comes into contact with the rotation of the filter body 7. The position gradually moves to the back (see FIG. 10B), and finally passes through the filtrate passage 11 (see FIG. 10C). Therefore, the penetration of the filtrate passage 11 and the cleaning of the wall surface of the filtrate passage 11 can be performed simultaneously by the jet water flow.

  Further, by providing a plurality of the washing nozzles 37 and changing the jet direction of the jet water flow from each washing nozzle 37, it becomes possible to wash different portions of the wall surface of the filtrate passage 11 for each washing nozzle 37. The entire 11 wall surfaces can be cleaned. Further, a jet water flow direction from the washing nozzle 37 may be combined in parallel with the axis of the filtrate passage 11.

  In addition, although the said embodiment demonstrated the multiple disk dehydration apparatus with which the cake conveyance path 6 was closed, it can implement in the multiple disk dehydration apparatus with which the cake conveyance path 6 shown in FIG. 11 is open. Needless to say.

It is a schematic explanatory drawing which shows embodiment of this invention. It is an AA arrow line view of FIG. It is a fragmentary top view of the lower filter body group in embodiment of this invention. The disc used for embodiment of this invention is shown, and it is a B arrow view of FIG. It is a side view of the disc used for embodiment of this invention. It is the C section enlarged view of FIG. It is the D section enlarged view of FIG. It is a partial front view of the spacer part which shows the example of the other disc used for embodiment of this invention, and comprises a disc. It is a fragmentary top view of this spacer part. (A), (B), (C) is explanatory drawing about the filtrate channel | path washing | cleaning in this invention. It is a schematic perspective view which shows the conventional multiple disc dehydrator. It is a side view of the filter body used for the conventional multiple disc dehydrator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Dehydration tank 4 Upper filter body group 5 Lower filter body group 6 Cake conveyance path 7 Filter body 8 Rotating shaft 10 Discharge port 11 Filtrate passage 13 Aggregation stock solution supply port 14 Stock solution supply line 15 Condensate supply line 16 Stock solution supply pump 17 Aggregation solution Supply pump 23 Upstream end filter body group 24 Resistance plate 30 Shaft body 31 Disk 32 Spacer 33 Groove 37 Cleaning nozzle 38 Eye 47 Spacer disk 49 Boss part 50 Projection part 51 Passage hole 52 Projection 53 Filtration groove 54 Spacer 55 Filtration hole

Claims (5)

  A filter body comprising a disc and a plurality of spacers, each having a smaller diameter than the disc, are arranged on the rotatable shaft so as to overlap each other. In the multiple disk dewatering device comprising a filter body group that is filtered from the gap between the polymerized portions, a filtrate passage penetrating the disk and the spacer is formed, and the filtrate leaked into the filtrate passage is passed through the filtrate passage. The filter body is discharged from the shaft end, and a filtration groove is formed over the entire circumference of the spacer. The filtration groove extends in the radial direction and is open so that one end communicates with the passage hole and the other end is the circumferential surface of the spacer. The multiple disk dewatering device is characterized in that the filtrate leaks into the passage hole through the filtration groove.   The multiple disk dewatering device according to claim 1, wherein the spacer and the disk are integrally formed.   3. The multiple disk dewatering device according to claim 2, wherein the spacer is formed by a protrusion protruding in a ring shape over the entire circumference at a predetermined interval so as to form a filtration groove.   The multiple disk dewatering device according to claim 1, wherein the filtration groove has a shape in which a sectional area gradually increases toward a center.   The multiple disk dewatering device according to claim 1, wherein protrusions are formed at a required interval on a peripheral surface of the disk.

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