JP4820784B2 - Rotating pressure dehydrator and sludge dewatering method using rotating pressure dehydrator - Google Patents

Description

  The present invention supplies sludge such as industrial wastewater sludge and sewage sludge into a dehydration chamber equipped with a disk-shaped filter plate having a filtration surface provided with a large number of water permeation holes on at least one side in the width direction. This is related to a rotary pressure dehydrator that concentrates and dehydrates the filtrate with a filter plate while rotating the sludge following the rotation of the disk-shaped filter plate, and a sludge dewatering method using the rotary pressure dehydrator. is there.

  Among the dehydrators for concentrating and dewatering sludge such as industrial wastewater sludge and sewage sludge, there is a rotary pressure dehydrator, for example. Hereinafter, two examples of typical rotary pressurization dehydrators according to the conventional example will be described. First, the rotary pressure dehydrator according to the conventional example 1 is attached to a boss member that supports an outer ring spacer, an inner ring spacer concentric with the outer ring spacer, and the inner ring spacer and is rotated by a drive shaft. An inner surface in the vicinity of the peripheral edge is provided with a pair of filter plates that are in sliding contact with the outer surface in the vicinity of the inner peripheral surface of the outer ring spacer. A dehydration chamber is formed between the outer ring spacer, the inner ring spacer, and the pair of filter plates. And the sludge (coagulant mixed already) supplied to the dehydration chamber from the upper sludge supply section partitioned by the partition spacer whose one end side is in sliding contact with the inner ring spacer is filtered by the pair of filtration plates and the pair of filtrations. Following the rotation of the plate, it is discharged as a dehydrated cake from the lower dehydrated cake discharge section. A pair of covers are provided outside the pair of filtration plates.

  This rotary pressure dehydrator is provided with a cleaning means for cleaning the pair of filter plates. One of the cleaning means is a scraper that is provided in the dehydration chamber and scrapes off dehydrated cake pieces clogged in the water permeation holes of the pair of filter plates, fine particle lump in the sludge and dehydrated cake pieces adhering to the inner surface. And the other one is a plurality of cleaning water spray nozzles that are provided on both side surfaces of the partition spacer and spray the cleaning water toward the inner surfaces of the pair of filter plates. Note that cleaning water is supplied to the plurality of cleaning water injection nozzles from a cleaning water inlet provided on the end face of the partition spacer. Further, in the rotary pressure dehydrator according to the conventional example 1, the cleaning water spray nozzles are provided on both side surfaces of the partition spacer as described above, and the cleaning water is sprayed on the outer surface of the filter plate on the cover. Providing an injection nozzle is also considered (for example, refer nonpatent literature 1).

Next, an outline of a continuous pressure dehydrator (hereinafter referred to as a rotary pressure dehydrator) according to Conventional Example 2 will be described. This rotary pressure dehydrator approximates the circulation trajectory of the nozzle tube to the filtration surface of the filter plate, and arbitrarily cleans the entire filtration surface of the filter plate during the dehydration operation. More specifically, a rotating ring and a driven rotating ring are rotatably disposed in front of and behind a filter plate forming a filtration chamber (corresponding to a dehydration processing chamber), and a plurality of these are fixed to the rotating ring and the driven rotating ring. The nozzle tube of this is opposed to the filtration surface of the filter plate. Then, the other end of the nozzle pipe is connected to a washing water pipe disposed along the outer peripheral surface of the filtration outer ring (corresponding to the outer ring spacer), and the nozzle pipes before and after the filtration plate are arranged along the filtration surface of the filtration plate. It is configured to be swingable. Therefore, according to the rotary pressure dehydrator according to the conventional example 2, the washing water is sprayed to a predetermined range of the arbitrarily clogged filter plate while revolving the nozzle tube concentrically with the drive shaft during the dehydration operation. The entire filter plate can be regenerated by washing (see, for example, Patent Document 1).
Rotary pressurization dehydrator, Japan Sewerage New Technology Promotion Organization, March 2002, p. 12-35 (Chapter 3 Section 1 Rotational pressure dehydrator structure and principle) JP 2004-237229 A

  In the rotary pressure dehydrator according to the above-described conventional example 1, when the washing water injection nozzle for injecting the washing water to the outer surface of the filter plate is provided on the cover, during the operation of the dehydrator (during sludge dehydration), the filtration chamber Since sludge and dehydrated cake are in a clogged state, even if the washing water is sprayed on the outer surface of the filter plate during operation, the filter plate cannot be washed effectively. That is, in order to wash the filter plate effectively, it is necessary to wash the sludge or dehydrated cake in the filtration chamber, and then there is a problem such as a decrease in processing capacity due to the stop of operation. In addition, since the injection ports of the washing water injection nozzles provided on both side surfaces of the partition spacer are open on both side surfaces of the partition spacer having a thickness of about 40 mm at most, the inner surface of the filter plate and the injection port A large distance cannot be secured between them. Accordingly, since the region that can be cleaned by the cleaning water sprayed from one cleaning water spray nozzle is extremely narrow, a large number of cleaning water spray nozzles must be provided in the radial direction of the filter plate, which requires a large amount of cleaning water. There's a problem. In addition, in order to check the cleaning water injection nozzle, it is essential to remove the cover and partition spacer of the rotary pressure dehydrator and to assemble the removed cover and partition spacer. There is a problem that the cost increases. Furthermore, since the operation of the rotary pressurization dehydrator must be stopped when checking the washing water injection nozzle, there is also a problem that it is not preferable for improving the operating rate.

In the rotary pressure dehydrator according to the above-described conventional example 2, the rotating ring and the driven rotating ring having a plurality of nozzle tubes are configured to be driven by the cleaning driving machine, and thus the structure is complicated and the manufacturing cost increases. There is. In addition, since the rotary ring and the driven rotary ring are arranged inside the cover, in order to check the nozzle tube, the rotary pressure dehydrator cover, the cleaning drive machine removal work, the removed cover, the cleaning drive Since the assembly work of the machine is indispensable, there is a problem that the running cost of the rotary pressure dehydrator increases. In addition, when the nozzle tube is inspected, the operation of the rotary pressurization dehydrator must be stopped, which is not preferable for improving the operating rate.
In addition to the fact that the diameter of the water perforation hole of the filter plate is 1.0 mm at most, sludge, dehydrated cake, etc. are contained in the filtration chamber, so it is difficult for washing water to enter the water permeation hole and clogging. There is also a problem that the dehydrated cake pieces that have been removed cannot be removed reliably.

  Therefore, the object of the present invention is simple in structure, and can wash a wide area of the filtration surface of the filter plate with a single washing water jet nozzle, without removing the cover and partition spacer and assembling work. It is to provide a rotary pressure dehydrator capable of checking a washing water injection nozzle and a method of dewatering sludge using the rotary pressure dehydrator.

The inventors have realized the rotary pressure dehydrator according to the present invention in consideration of the following.
(1) During the operation of the dehydrator (during sludge dewatering), in order to effectively remove the dewatered cake pieces adhering to the inner peripheral surface and inner surface of the water permeation hole of the filter plate, the washing water injection nozzle is used. A space corresponding to the entire width of the filtration surface is provided between the sludge supply part side of the partition spacer and the dewatered cake discharge part side so that the sprayed washing water can pass through the water permeation hole and flow into the inside of the filtration plate. It only has to be provided.
(2) It is only necessary to widen the region that can be cleaned by increasing the interval between the injection port of the cleaning water injection nozzle and the filter plate.
(3) In order to facilitate the inspection of the cleaning water spray nozzle, the cleaning water spray nozzle may be detachably attached to the cover.

  Therefore, in order to solve the above-mentioned problem, the means adopted by the rotary pressurization dehydrator according to claim 1 of the present invention is rotated by a horizontal drive shaft and has a plurality of water permeable holes at least on one side in the width direction. A filter-like filter plate, an outer ring spacer that is in sliding contact with a side surface near the outer edge of the filter plate, and an inner ring spacer on the rotation center side of the filter plate, In the rotary pressurization dehydrator provided with a partition spacer that slidably contacts the inner side surface of the slag and that separates a sludge supply unit that supplies sludge into the dehydration chamber and a dehydrated cake discharge unit that discharges the dehydrated cake. Between the sludge supply part side and the dehydrated cake discharge part side, a space corresponding to the entire width of the filtration surface that extends from the vicinity of the outer periphery of the filter plate to the vicinity of the outer periphery of the inner ring spacer is provided. Outside Filtration plate cleaning means for cleaning the filtering surface of the filtration plate by jetting washing water toward the surface and is characterized in that is provided.

  The rotary pressure dehydrator according to claim 2 of the present invention employs the rotary pressure dehydrator according to claim 1, wherein the filter plate cleaning means includes a plurality of radial filtration surfaces of the filter plate. The cleaning water jet nozzles for cleaning the outer edge side of the filter plate are formed by rotating the filter plate. It is characterized in that it is set to have a larger diameter than the diameter of the injection port of the cleaning water injection nozzle for cleaning the central region.

  The means adopted by the rotary pressure dehydrator according to claim 3 of the present invention is the rotary pressure dehydrator according to any one of claims 1 and 2, wherein the filter plate cleaning means is the filter plate. It is characterized in that it is detachably provided on a cover provided on the outer side of the anti-dehydration treatment chamber.

  The method employed by the sludge dewatering method by the rotary pressure dehydrator according to claim 4 of the present invention is the sludge dewatering method by the rotary pressure dehydrator according to any one of claims 1 to 3. In the operation of the rotary pressure dehydrator, the filtration surface of the filter plate is washed by spraying wash water from the filter plate washing means toward the outer surface of the filter plate. It is.

  In the rotary pressure dehydrator according to the first to third aspects of the present invention, the filtration surface that extends from the vicinity of the outer periphery of the filter plate to the vicinity of the outer periphery of the inner ring spacer between the sludge supply portion side and the dewatered cake discharge portion side of the partition spacer. A space corresponding to the entire width of the filter plate is provided, and a filter plate cleaning means for cleaning the filter surface of the filter plate by spraying cleaning water toward the outer surface of the filter plate covering the space is provided.

Therefore, according to the rotary pressure dehydrator according to claims 1 to 3 of the present invention, the following effects can be obtained.
(1) Inside the filter plate on which the washing water is jetted, a space is formed in which no sludge or dewatered cake is present, and the washing water can pass through the water permeation holes, so it is filtered during the operation of the dehydrator. The dehydrated cake pieces adhering to the inner peripheral surface and inner surface of the water permeable hole of the plate can be removed. Therefore, since the filter plate can be effectively washed without stopping the dehydrator, the processing capacity is improved.
(2) Since the interval between the injection port of the filter plate cleaning means and the filter plate can be increased, a wide area of the filtration surface can be cleaned with one injection port. As a result, since the number of injection ports can be reduced, the amount of cleaning water used can be reduced.

  In the rotary pressurization dehydrator according to claim 2 of the present invention, the filter plate cleaning means separately cleans the plurality of regions of the filter surface in the radial direction of the filter plate from the same number of wash water spray nozzles as the plurality of regions. The diameter of the injection port of the washing water injection nozzle that cleans the area on the outer edge side of the filter plate is set larger than the diameter of the injection port of the cleaning water injection nozzle that cleans the area on the rotation center side of the filtration plate Has been.

Accordingly, a large amount of cleaning water is injected into the outer edge side region where the peripheral speed of the filter plate is fast, and a small amount of cleaning water is injected into the region around the rotation center where the peripheral speed is slow. Thus, it is possible to make the amount smaller than the amount of washing water used when washing the region over the entire width of the filtration surface of the filter plate.
That is, when washing the area over the entire width of the filtration surface of the filter plate with a single wash water injection nozzle, an amount of wash water that can wash the region where the peripheral speed of the filter plate is fast must be injected, This is because cleaning water more than necessary is injected into the region on the rotation center side where the peripheral speed is slow.

  In the rotary pressure dehydrator according to claim 3 of the present invention, the filter plate washing means is detachably provided on a cover provided outside the filter plate on the side of the anti-dehydration treatment chamber.

Therefore, according to the rotary pressure dehydrator according to claim 3 of the present invention, the following effects can be obtained.
(1) Since the filter plate cleaning means provided in the cover is detachable, the filter plate cleaning means can be inspected in a short time without removing the cover and partition spacer and performing assembly work. .
(2) Since the filter plate cleaning means is simply attached to the cover, the structure is much simpler than that of the filter plate cleaning means according to Conventional Example 2.

A sludge dewatering method using a rotary pressure dehydrator according to a fourth aspect of the present invention is the filtration plate washing during the operation of the rotary pressure dehydrator according to any one of the first to third aspects. Washing water is jetted from the means toward the outer surface of the filter plate to clean the filter surface of the filter plate. Therefore, according to the sludge dewatering method using the rotary pressure dehydrator according to claim 4 of the present invention, the following effects can be obtained.
(1) Inside the filter plate on which the washing water is jetted, a space is formed in which no sludge or dewatered cake is present, and the washing water can pass through the water permeation holes, so it is filtered during the operation of the dehydrator. The dehydrated cake pieces adhering to the inner peripheral surface and inner surface of the water permeable hole of the plate can be removed. Therefore, since the filter plate can be effectively washed without stopping the dehydrator, the processing capacity is improved.
(2) Since the interval between the injection port of the filter plate cleaning means and the filter plate can be increased, a wide area of the filtration surface can be cleaned with one injection port. As a result, since the number of injection ports can be reduced, the amount of cleaning water used can be reduced.

  Hereinafter, a rotary pressure dehydrator according to an embodiment of the present invention for carrying out the sludge dewatering method of the present invention will be described with reference to the attached drawings. 1 is a partially omitted side view showing a schematic configuration of a rotary pressurizing dehydrator shown with a part of a cover cut away, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is B of FIG. FIG. 4 (a) is an explanatory diagram of the state of attachment of the scraper to the outer ring spacer, FIG. 4 (b) is a view taken along the arrow C in FIG. 4 (a), and FIG. It is composition explanatory drawing of a board washing | cleaning means.

  Reference numeral 1 shown in the figure is a rotary pressurizing dehydrator according to an embodiment of the present invention. The rotary pressure dehydrator 1 includes a drive shaft 2 that is rotated at a rotational speed of 0.5 to 1.3 rpm by a drive device with a speed reducer (not shown). The drive shaft 2 is fitted with a boss member 3 that is rotated through a key 2a by the rotation of the drive shaft 2 and rotates a first filter plate and a second filter plate, which will be described later. The boss member 3 includes a first filter plate support boss 31, a second filter plate support boss 32, and a spacer support interposed between the first filter plate support boss 31 and the second filter plate support boss 32. It is comprised from the boss | hub 33 and the mechanical fastening means 34 which consists of a fastening bolt, a nut, and a washer which fastens these integrally.

  Specifically, the first filter plate support boss 31 constituting the boss member 3 is fitted to the shaft end side of the drive shaft 2 and includes a flange portion on the drive device side (not shown). The second filter plate support boss 32 constituting the boss member 3 is fitted to the drive device side (not shown) of the drive shaft 2, and the flange of the first filter plate support boss 31 is attached to the shaft end side of the drive shaft 2. A flange portion having the same outer diameter as the portion is provided. The outer diameter of the spacer support boss 33 constituting the boss member 3 fitted between the first filter plate support boss 31 fitted to the drive shaft 2 and the second filter plate support boss 32 is the first , 2 The filter plate support bosses 31 and 32 are formed in a disk shape having a smaller diameter than the outer diameter of the flange portion. These are integrally fastened by the mechanical fastening means 34 penetrating the flange portions of the first and second filter plate support bosses 31 and 32 and the spacer support boss 33.

  The flange portion of the first filter plate support boss 31 includes a large-diameter flange portion 31a on the shaft end side and a small-diameter flange portion 31b on the spacer support boss 33 side whose outer diameter is slightly smaller than the outer diameter of the spacer support boss 33. It is made up of. And the fitting hole provided in the center part of the disk-shaped 1st filtration board 7 provided with many water permeable holes 7a is fitted by the small diameter flange part 31b of the said flange part, and this 1st filtration is carried out. The side surface on the fitting hole side of the plate 7 is fixed in a state where it abuts on the surface on the spacer support boss 33 side of the large-diameter flange portion 31a. In addition, the code | symbol 7b is a reinforcement rib for reinforcing the 1st filtration board 7, and although this reinforcement rib 7b is abbreviate | omitting illustration, it provides radially centering on the rotation center O of this 1st filtration board 7. It has been.

  The flange portion of the second filter plate support boss 32 includes a large-diameter flange portion 32a on the drive device side (not shown) and a small-diameter flange on the spacer support boss 33 side whose outer diameter is slightly smaller than the outer diameter of the spacer support boss 33. It consists of part 32b. And the fitting hole provided in the center part of the disk-shaped 2nd filtration board 8 provided with many water-permeable holes 8a is fitted by the small diameter flange part 32b of the said flange part, and this 2nd filtration is carried out. The side surface on the fitting hole side of the plate 8 is fixed in a state where it abuts on the surface on the spacer support boss 33 side of the large-diameter flange portion 32a. In addition, the code | symbol 8b is a reinforcement rib for reinforcing the 2nd filtration plate 8, and although this reinforcement rib 8b is abbreviate | omitting illustration, it is provided radially centering on the rotation center of this 2nd filtration plate 8. FIG. ing.

An annular inner ring spacer 4 in which a sliding bearing 4a is fitted in a fitting hole is rotatably fitted to the spacer support boss portion 33. The width of the inner ring spacer 4 is the side surface of the spacer ring. The first filter plate 7 and the second filter plate 8 are set so as to be in sliding contact with the inner surface of the fitting hole side.
An outer ring spacer 5 is provided on the outer side of the inner ring spacer 4 so as to be concentric with the center of the diameter of the inner ring spacer 4, and on the side surface of the outer ring spacer 5, the first filter plate 7 and the second filter plate 8 are arranged. The side surface near the outer edge is configured to be in sliding contact. The first filter plate 7 and the second filter plate 8 of the rotary pressurization dehydrator 1 according to the embodiment of the present invention are punching metal having a water permeable hole having a diameter of 0.5 mm. By the way, in the rotary pressure dehydrator, the diameter of the water permeation hole of the filter plate is set in a range of 0.3 to 1.0 mm from the viewpoint of suppressing sludge clogging into the water permeation hole of the filter plate. Is preferred.

  The outer ring spacer 5 is provided with a partition spacer 6 having a concave curved surface in close contact with the outer peripheral surface of the inner ring spacer 4 on the center side of the outer ring spacer 5. The partition spacer 6 is formed in a bifurcated shape including an upper partition spacer 6a and a lower partition spacer 6b at a lower position across the space 6c from the upper partition spacer 6a. A sludge inflow port 11a having a configuration that will be described later and that opens in the lateral direction is formed below the lower partition spacer 6b. In addition, a dehydrated cake discharge portion 10 that opens in the lateral direction is provided above the upper partition spacer 6a.

  Between the outer peripheral surface of the inner ring spacer 4, the inner peripheral surface of the outer ring spacer 5, the first filter plate 7, and the second filter plate 8, the sludge inlet 11 a is connected to the dehydrated cake discharge unit 10 side. The dehydration treatment chamber is divided into a filtration zone 11b for filtering the conditioned sludge flowing in from the sludge inlet 11a and a squeezing dehydration zone 11c for squeezing and dewatering the sludge from which filtered water has been removed. 11 is formed. The sludge inlet 11a is attached with a sludge inlet 9a that opens downward, and a sludge supply unit 9 that supplies the sludge to the sludge inlet 11a through a sludge channel. Further, a back pressure plate 15 for applying a back pressure to the squeezed dewatered sludge in the squeezing and dewatering zone 11 c of the dewatering treatment chamber 11 is provided vertically at the discharge port 10 a of the dewatered cake discharge unit 10. The back pressure plate 15 is configured to be pressed by an air spring or actuator (not shown) to narrow the width of the discharge port 10a.

  In the dehydration chamber 11, the edges are in acute contact with the opposing surfaces (inner surfaces) of the first filter plate 7 and the second filter plate 8, so that the first filter plate 7 and the second filter plate 11 are in contact with each other. A plurality of scrapers 11d are provided to scrape and remove fine particle clusters and dewatered cake in the sludge adhering to each of the opposing inner side surfaces of the plate 8. Since the state of attachment of the scraper 11d to the outer ring spacer 5 and the inner ring spacer 4 is exactly the same, the state of attachment of the scraper to the side of the outer ring spacer will be described as an example with reference to FIGS. 4 (a) and 4 (b).

  That is, one end of each scraper 11d is fastened to the side surface of the outer ring spacer 5 by two countersunk screws 11e. Therefore, the inner ring spacer 4 of the rotary pressurizing dehydrator 1 according to the embodiment of the present invention is not rotated by the drive shaft 2 like the conventional inner ring spacer. However, since the dewatered cake slides on the outer peripheral surface of the inner ring spacer 4 as the first and second filter plates 7 and 8 rotate in the same manner as the dehydrated cake that contacts the inner peripheral surface of the outer ring spacer 5, There is no problem with the dehydration process.

  A first cover 12 is disposed outside the first filter plate 7, and a flange portion of the first cover 12 is fixed to a side surface of the outer ring spacer 5. A second cover 13 is disposed outside the second filter plate 8, and a flange portion of the second cover 13 is fixed to a side surface of the outer ring spacer 5. A drain pipe 14 projecting downward is provided at the lower part of each of the first cover 12 and the second cover 13, and is supplied into the dehydration treatment chamber 11 through the sludge supply unit 9 and the sludge inlet 9 a, The water in the sludge discharged into the first cover 12 and the second cover 13 through the numerous water-permeable holes 7a and 8a provided in the first and second filter plates 7 and 8 is the drainage. The pipe 14 is drained out of the machine.

  Two types of detachable cleaning water jets for cleaning the first filter plate 7 by spraying cleaning water onto the outer surface side region of the first filter plate 7 covering the space 6 c of the partition spacer 6 on the first cover 12. A first filter plate cleaning means 16 having a nozzle is provided. Also, two types of detachable cleanings for cleaning the second filter plate 8 by spraying cleaning water onto the outer surface side region of the second filter plate 8 covering the space 6c of the partition spacer 6 on the second cover 13. A second filter plate cleaning means (not shown) provided with a water injection nozzle is provided. Since the first filter plate cleaning unit 16 and the second filter plate cleaning unit have the same configuration, the configuration of the first filter plate cleaning unit 16 will be described.

  That is, the first filter plate cleaning means 16 is detachably attached to the first cover 12 (position indicated by N in FIG. 1), and the outer cleaning water jet is supplied with cleaning water via the quick coupler 16c. There are provided two types of cleaning water jet nozzles: a nozzle 16a and an inner cleaning water jet nozzle 16b to which cleaning water is supplied via a quick coupler 16c. The outer cleaning water spray nozzle 16a cleans the region on the outer edge side where the peripheral speed in the radial direction of the first filter plate 7 is fast, and the inner cleaning water spray nozzle 16b has a radius of the first filter plate 7. The region on the rotation center side where the peripheral speed in the direction is slow is washed. Therefore, the diameter of the injection port of the outer cleaning water spray nozzle 16a that cleans the region on the outer edge side of the first filter plate 7 is the inner cleaning water spray nozzle 16b that cleans the region on the rotation center side of the first filter plate 7. The diameter of the injection port is set to be larger than the diameter of the injection port, and an amount of cleaning water corresponding to the peripheral speed of the region to be cleaned is jetted. The quick coupler 16c is provided with a hose nipple to which a cleaning water supply hose 16d to which cleaning water is supplied from a cleaning water supply pump (not shown) is connected.

Hereinafter, the operation mode of the rotary pressure dehydrator 1 according to the embodiment of the present invention will be described. That is, according to the rotary pressurization dehydrator 1 according to the embodiment of the present invention, the sludge conditioned by the addition and mixing of the polymer flocculant is a maximum of 100 kPa (about 1.. 0 kgf / cm ² ). The dewatering in which the pressurized sludge is rotated at a slow speed of 0.5 to 1.3 rpm via the sludge inlet 9a, the sludge flow path, and the sludge inlet 11a that open to the lower side of the sludge supply section 9. Continuously supplied to the filtration zone 11b below the processing chamber 11 and efficiently dehydrated. And the sludge supplied to the lower filtration zone 11b of the dehydration processing chamber 11 is filtered in the filtration zone 11b, and the fluidity is gradually lost.

  Sludge whose fluidity has been reduced by filtration in the filtration zone 11b is gradually forming a cake layer on the surfaces of the disk-shaped first filter plate 7 and the second filter plate 8 provided with a large number of water permeation holes. The first filter plate 7 and the second filter plate 8 are rotated to move toward the squeezing and dehydrating zone 11c. Since the trapping of the solid matter is improved by the cake layer formed on the surfaces of the first filter plate 7 and the second filter plate 8, the filtrate is cleaned.

The sludge in the compressed dewatering zone 11c region has a maximum back pressure of 600 kPa by pressing force control of the back pressure plate 15 (air spring, actuator air pressure control) provided at the discharge port 10a of the dewatered cake discharge unit 10. It is kept at a constant pressure (adjustable) of (about 6.0 kgf / cm ² ). The sludge that has lost its fluidity is squeezed and dehydrated by the shearing force of the first filter plate 7 and the second filter plate 8 and the back pressure of the back pressure plate 15. Next, the dehydrated cake having a low water content that has been pressed and dehydrated is pushed out of the back pressure plate 15 and discharged from the dehydrated cake discharge unit 10 to the outside of the machine.

  In the rotary pressure dehydrator 1 according to the embodiment of the present invention, in the sludge dewatering process as described above, the outer washing water spray nozzle is disposed in the outer edge side region where the radial peripheral speed of the first filter plate 7 is fast. A large amount of washing water corresponding to the peripheral speed of the first filter plate 7 is jetted from the jet nozzle having a large diameter of 16a. Further, a small amount of washing water corresponding to the circumferential speed of the first filter plate 7 from the small-diameter injection port of the inner washing water injection nozzle 16b in the region on the rotation center side where the peripheral speed in the radial direction of the first filter plate 7 is slow. Is injected. Of course, also on the outer surface of the second filter plate 8, the region on the outer edge side where the peripheral speed of the second filter plate 8 is fast from each of the two types of detachable cleaning water spray nozzles of the second filter plate cleaning means. The amount of cleaning water corresponding to the respective peripheral speeds is injected into the rotation center side region where the peripheral speed is slow.

Therefore, according to the rotary pressure dehydrator 1 according to the embodiment of the present invention, the following effects can be obtained.
(1) Since the interval between the outer cleaning water spray nozzle of the filter plate cleaning means, the spray port of the inner cleaning water spray nozzle and the outer surfaces of the first and second filter plates 7 and 8 can be increased, A wide area of the filtration surface can be washed with one washing water jet nozzle. As a result, since the number of cleaning water jet nozzles can be reduced, the amount of cleaning water used can be reduced.
(2) Since the space 6c is formed inside the first and second filter plates 7 and 8 to which the cleaning water is injected, the cleaning water can pass through the water transmission holes 7a and 8a. 2 Filtration plates 7 and 8 Dehydrated cake pieces adhering to the inner peripheral surface and inner surface of the water permeation holes 7a and 8a can be removed.
(3) Since the first filter plate cleaning means 16 provided in the first cover 12 and the wash water spray nozzles of the second filter plate cleaning means provided in the second cover 13 are detachable, the cover, The cleaning water jet nozzles of the first filter plate cleaning means 16 and the second filter plate cleaning means can be inspected in a short time without removing the partition spacer and performing assembly work.
(4) Since the filter plate cleaning means is simply configured to be attached to the first and second covers 12 and 13, the configuration is much simpler than the filter plate cleaning means according to Conventional Example 2.

  Further, in the rotary pressurization dehydrator 1 according to the embodiment of the present invention, the outer peripheral water injection nozzle is used to change the peripheral speed of the first and second filter plates 7 and 8 from the outer washing water injection nozzle to the region on the outer edge side. A large amount of washing water is jetted, and a small amount of washing is performed from the inner washing water jet nozzle in the region of the rotation center side where the circumferential speed of the first and second filter plates 7 and 8 is slow. Water is jetted. Therefore, the amount of washing water used can be made smaller than the amount of washing water used when washing the entire area of the filtration surface of the filter plate with a single washing water jet nozzle, so that a water saving effect can be obtained.

  By the way, in the said embodiment, the rotary pressurization dehydrator by which the disk-shaped filter plate which has the filtration surface in which many water permeation holes are provided in the both sides of the width direction of the dehydration processing chamber 11 is arrange | positioned. Described as an example. However, for example, if a disc-shaped filter plate is disposed in any one of the width directions of the dehydration chamber, a certain effect can be obtained. Further, the rotary pressure dehydrator that supplies the sludge to be dehydrated from the lower sludge supply unit and discharges the dehydrated cake from the upper dehydrated cake discharge unit has been described as an example. However, the technical idea of the present invention is also applied to the rotary pressure dehydrator according to the conventional example in which the sludge is supplied from the upper sludge supply section and the dehydrated cake discharge section is discharged from the lower dewatered cake discharge section. can do. Furthermore, the rotary pressurization dehydrator which used the punching metal for the filter plate was demonstrated as an example. However, any member that can separate sludge and moisture, such as a wedge wire screen, can be used, and is not particularly limited to punching metal.

  Therefore, the rotary pressurization dehydrator according to the above embodiment is only a specific example of the present invention, and design changes and the like can be freely made without departing from the technical idea of the present invention. The form of the machine is not limited to the form of the rotary pressure dehydrator according to the above embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially omitted side view showing a schematic configuration of a rotary pressure dehydrator according to an embodiment of the present invention, with a part of a cover cut away. It is the sectional view on the AA line of FIG. It is the B section enlarged view of FIG. FIG. 4 (a) is an explanatory view of the state of attachment of the scraper to the outer ring spacer, and FIG. 4 (b) is a view as seen from the direction C of FIG. 4 (a), according to the embodiment of the present invention. It is a structure explanatory drawing of the filter plate washing | cleaning means seen from the D direction of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rotary pressure dehydrator, 2 ... Drive shaft, 2a ... Key, 3 ... Boss member, 31 ... 1st filter plate support boss, 31a ... Large diameter flange part, 31b ... Small diameter flange part, 32 ... 2nd filter plate Support boss, 32a ... large diameter flange, 32b ... small diameter flange, 33 ... spacer support boss, 34 ... fastening means, 4 ... inner ring spacer, 4a ... slide bearing, 5 ... outer ring spacer, 6 ... partition spacer, 6a ... upper part Partition spacer, 6b ... Lower partition spacer, 6c ... Space, 7 ... First filter plate, 7a ... Water permeation hole, 7b ... Reinforcement rib, 8 ... Second filter plate, 8a ... Water permeation hole, 8b ... Reinforcement rib, 9 DESCRIPTION OF SYMBOLS ... Sludge supply part, 9a ... Sludge inlet 10 ... Dehydrated cake discharge part, 10a ... Discharge port, 11 ... Dehydration processing chamber, 11a ... Sludge inlet, 11b ... Filtration zone, 11c ... Compression dehydration zone, 11d ... Scraper, 11e ... Flat head screw , 12 ... 1st cover, 13 ... 2nd cover, 14 ... Drain pipe, 15 ... Back pressure plate, 16 ... 1st filter plate washing | cleaning means, 16a ... Outer washing water injection nozzle, 16b ... Inner washing water injection nozzle, 16c ... Quick coupler, 16d ... Washing water supply hose O ... Rotation center of filter plate (drive shaft)

Claims (4)

  A disk-shaped filter plate that is rotated by a horizontal drive shaft and has a large number of water-permeable holes on at least one side in the width direction, an outer ring spacer that is in sliding contact with a side surface near the outer edge of the filter plate, and the filter plate A dewatering chamber configured by an inner ring spacer on the rotation center side of the filter plate, a sludge supply section that is in sliding contact with the inner surface of the filter plate, and that supplies sludge into the dewatering chamber, and a dewatering unit that discharges the dewatered cake In the rotary pressurization dehydrator provided with a partition spacer for partitioning the cake discharge section, between the sludge supply section side of the partition spacer and the dewatered cake discharge section side, from the vicinity of the outer periphery of the filter plate to the vicinity of the outer periphery of the inner ring spacer A space corresponding to the entire width of the filtration surface is provided, and a filtration plate cleaning means for cleaning the filtration surface of the filtration plate by spraying washing water toward the outer surface of the filtration plate covering the space is provided. This Rotation pressurized dehydration machine according to claim.   The filter plate cleaning means includes a plurality of wash water spray nozzles as many as the plurality of regions for individually cleaning a plurality of regions on the radial filtration surface of the filter plate, and has a region on the outer edge side of the filter plate. The diameter of the injection port of the cleaning water injection nozzle to be cleaned is set to be larger than the diameter of the injection port of the cleaning water injection nozzle for cleaning the region on the rotation center side of the filter plate. A rotary pressure dehydrator as described in 1.   The said filter plate washing | cleaning means is provided in the cover provided in the outer side of the anti-dehydration process chamber side of the said filter plate so that attachment or detachment is possible, The statement to any one of Claim 1 or 2 characterized by the above-mentioned. The rotary pressure dehydrator as described.   The method for dewatering sludge with a rotary pressure dehydrator according to any one of claims 1 to 3, wherein the filter plate cleaning means removes the filter plate during operation of the rotary pressure dehydrator. A method for dewatering sludge by a rotary pressure dehydrator, wherein washing water is sprayed toward an outer surface to wash the filtration surface of the filter plate.

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