JP5187540B2 - Sludge concentrator and cleaning method therefor - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a screw press type sludge concentrating device and a cleaning method therefor that concentrates a sludge introduced from a sludge agglomeration tank into a filter cylinder by rotationally driving a spiral screw in the filter cylinder. Is.

  In order to discard or incinerate various types of sludge, the sludge is dehydrated with a dehydrator. The higher the concentration of the sludge supplied to the dehydrator, the more efficiently the dehydration can be performed. Therefore, prior to the sludge dewatering process, the sludge is aggregated with a flocculant, and moisture is separated from the aggregated sludge (aggregated sludge) to concentrate the sludge to a concentration suitable for the dewatering process. Various sludge concentrators have been proposed and put into practical use.

  As such a sludge concentrating device, an example of a screw press type sludge concentrating device previously proposed by the present applicant is shown in FIG. 3 (see, for example, Patent Document 1).

  That is, FIG. 3 is a schematic diagram showing the basic configuration of a conventional sludge concentrating device 1 ′. The sludge concentrating device 1 ′ shown in FIG. 3 includes a cylindrical tank-shaped sludge aggregating tank 2 having an open top surface and a solid sludge condensing tank. The liquid separation means 3 and a separation liquid tank 4 that contains the separation liquid are included.

  A sludge supply pipe 5 is connected to the bottom of the sludge agglomeration tank 2, and a stirrer 6 that is rotationally driven by a motor M <b> 1 is accommodated in the sludge agglomeration tank 2.

  The solid-liquid separation means 3 has a cylindrical filter tube 8 disposed in a vertical direction inside a cylindrical tank-shaped outer tube 7 having a sealed structure, and a spiral screw 9 is rotatably accommodated in the filter tube 8. Configured.

  Here, the peripheral surface of the portion of the filtration cylinder 8 facing the outer cylinder 7 constitutes a filtration surface 8a made of a punching plate, a wedge wire, or the like. An agglomerated sludge introduction pipe 10 led out from the upper side of the agglomeration tank 2 is connected. A concentrated sludge discharge pipe 11 is led out from the upper side of the filter cylinder 8.

  The spiral screw 9 is rotationally driven by a motor M2 as a drive source, and the outer diameter thereof is set to be slightly smaller than the inner diameter of the filtration surface 8a of the filter cylinder 8, and the spiral screw 9 A minute gap is formed between the outer peripheral edge of 9 and the filtration surface 8 a of the filtration cylinder 8.

  Further, the separation liquid tank 4 is connected to the upper and lower side portions of the outer cylinder 7 by two upper and lower connecting pipes 12, and a separation liquid discharge pipe 13 is led out from the upper side.

  In the sludge concentrator 1 ′ having the above configuration, sludge (raw mud) is supplied from the sludge supply pipe 5 to the sludge agglomeration tank 2, but before that, a flocculant is added to the sludge. Here, as the flocculant, any one can be used as long as it is used for sludge flocculation / dehydration treatment. Aluminum sulfate, polyaluminum chloride, ferric chloride, ferrous sulfate, poly Inorganic flocculants such as iron (polyferric sulfate), cationic, anionic, nonionic polymer flocculants, amphoteric polymer flocculants can be used, or inorganic flocculants and polymer flocculants can be used. It can also be used together.

  Thus, when the sludge to which the flocculant has been added is supplied into the sludge aggregation tank 2, the sludge and the flocculant are agitated in the sludge aggregation tank 2 by the agitator 6 that is driven to rotate by the motor M1, The sludge is agglomerated sludge by aggregating solid components contained therein. The agglomerated sludge is introduced from the agglomerated sludge introduction pipe 10 into the filter cylinder 8 from below.

  In the solid-liquid separation means 3, the spiral screw 9 is driven to rotate at a predetermined speed in the filter cylinder 8 by the motor M 2, and the condensed sludge introduced into the filter cylinder 8 is rotated by the rotating spiral screw 9. While being conveyed upward, the water contained therein passes through the filtration surface 8a of the filtration cylinder 8 and is discharged as a separation liquid into the outer cylinder 7, and this separation liquid is separated from the upper and lower connecting pipes 12 into the separation liquid. It is sent to the tank 4 and accommodated. The liquid level in the filter cylinder 8 is set slightly higher than the liquid level in the outer cylinder 7, and the water separated from the sludge using the differential pressure based on the difference between the two liquid levels (head difference) as the filtration pressure. However, the sludge is stably concentrated through the filtration surface 8a of the filter cylinder 8 as a separation liquid.

  Then, the separation liquid stored in the separation liquid tank 4 is discharged to the outside through the separation liquid discharge pipe 13. Further, the aggregated sludge conveyed upward in the filter cylinder 8 by the rotation of the spiral screw 9 is concentrated by separating the water in the middle thereof to become concentrated sludge, and this concentrated sludge is the concentrated sludge discharge pipe. 11 is discharged to the outside and is subjected to a dehydration process by a dehydrator (not shown).

  By the way, in such a sludge concentrating device 1 ′, if the concentration operation is continued, solid substances such as suspended substances adhere to the filtration holes of the filtration surface 8 a of the filtration cylinder 8 and clogging occurs.

  Therefore, the filtration surface 8a of the filter cylinder 8 is regularly cleaned by backwashing, and an example is shown in FIG. 4 (see Patent Document 2).

  FIG. 4 is a block diagram of a conventional sludge concentrating device 1 ′ equipped with a cleaning means. In FIG. 4, reference numeral 14 denotes a backwash fluid storage tank, and the backwash fluid storage tank 14 has a wash water supply pipe 15. The cleaning water supplied from is stored, and this cleaning water is pressurized to a predetermined pressure by the compressed air supplied from the compressed air supply pipe 16 into the backwash fluid storage tank 14. And the backwash water supply pipe | tube 17 derived | led-out from the backwash fluid storage tank 14 is connected to the side part of the outer cylinder 7 of the solid-liquid separation means 3, and valve | bulb V1 'is provided in the middle. In FIG. 4, 18 is a drain pipe, and V2 'and V3' are valves.

  Thus, when clogging occurs on the filtration surface 8a of the filter cylinder 8 due to the operation of the sludge concentrating device 1 ', the valve V1' is opened, and the pressurized water stored in the backwash fluid reservoir 14 is backwashed. As shown in FIG. 5A, solid matter such as suspended matter that is clogged in the filtration surface 8a of the filtration cylinder 8 is injected from the backwash water supply pipe 17 into the outer cylinder 7. It is removed by backwashing water, thereby eliminating clogging of the filtration surface 8a.

JP 2003-164899 A JP 2004-121955 A

  By the way, since dirt such as solid matter adhering to the inner surface of the filtration surface 8a of the filtration cylinder 8 is always scraped off by the spiral screw 9 rotating in the filtration cylinder 8, no dirt is generated on the inner surface of the filtration surface 8a. On the outer surface side of the filtration surface 8a, the solid matter leaked to the separation liquid side in the outer cylinder 7 through the filtration surface 8a is flocked and enlarged by the coagulant remaining in the separation liquid, and FIG. As shown in FIG. 2, there is a problem that the enlarged solid matter adheres to the outer surface of the filtration surface 8a as dirt and clogs the filtration surface 8a.

  As described above, the problem related to the clogging of the filtration surface 8a of the filtration cylinder 8 can be dealt with by the conventional washing means and washing method shown in FIG. 4, but the problem of the contamination of the outer surface of the filtration surface 8a is considered. A conventional cleaning means and cleaning method cannot cope with it, and a solution to this problem has been desired.

  The present invention has been made in view of the above problems, and its intended treatment is a sludge concentrating device capable of preventing the dirt on the outer surface of the filter cylinder and ensuring the required treatment amount and solids recovery rate, and It is to provide a cleaning method for this.

In order to achieve the above object, the invention according to claim 1 is characterized in that a filter cylinder is accommodated in an outer cylinder , a spiral screw is rotatably accommodated in the filter cylinder, and the spiral screw is driven to rotate. While conveying the sludge introduced into the filter cylinder from the sludge aggregation tank, the water contained in the sludge passes through the filtration surface of the filter cylinder and is stored in the outer cylinder as a separation liquid to concentrate the sludge. At the same time, in the sludge concentrating device for discharging the concentrated sludge from the inside of the filter cylinder, the cleaning body constituted by sandwiching both sides of the elastic ring elastically contacting the outer periphery of the filter cylinder with the metal ring is filtered. It is provided to be movable in the length direction of the cylinder.

According to a second aspect of the invention of claim 1 Symbol placement, the cleaning body suspended by ropes, characterized in that moving the cleaning body in the longitudinal direction of the filtration tube by pulling the rope.

According to a third aspect of the present invention, a filtration cylinder is accommodated in an outer cylinder, a spiral screw is rotatably accommodated in the filtration cylinder, and the spiral screw is driven to rotate, whereby the filtration cylinder is removed from the sludge aggregation tank. While conveying the sludge introduced into the inside, the water contained in the sludge is passed through the filtration surface of the filter cylinder and stored in the outer cylinder as a separation liquid to concentrate the sludge. As a cleaning method of the sludge concentrator that discharges from the inside of the filter cylinder,
By moving a cleaning body configured by sandwiching both sides of an elastic ring elastically contacting the outer periphery of the filtration surface of the filtration tube with a metal ring in the length direction of the filtration tube, the outer surface of the filtration tube is filtered. It is characterized by removing attached dirt.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the dirt in the filter hole of the filter cylinder is removed by further injecting backwash air into the outer cylinder.

According to the first and third aspects of the present invention, the dirt adhering to the outer surface of the filter cylinder is effectively scraped by the cleaning body that moves in the length direction of the filter cylinder while the elastic ring is in sliding contact with the outer surface of the filter surface. Therefore, the clogging of the filter cylinder is prevented, and a required processing amount and a solid recovery rate (SS recovery rate) are ensured.

According to the second aspect of the present invention, the dirt on the outer surface of the filter cylinder can be reliably removed by the cleaning body by pulling up the rope that suspends the cleaning body and moving the cleaning body in the length direction of the filter cylinder. .

According to the invention of claim 4, since the inside of the filtration hole of the filtration surface of the filter cylinder is backwashed by the backwash air injected into the outer cylinder in addition to the backwash fluid, the dirt adhering to the outer surface of the filtration surface is removed. Along with the removal, clogging of the filtration surface is prevented.

It is the schematic which shows the basic composition of the sludge concentration apparatus which concerns on this invention. (A) is a top view of the washing body used for washing | cleaning of the sludge concentration apparatus based on this invention, (b) is the BB sectional drawing of (a). It is the schematic which shows the basic composition of the conventional sludge concentration apparatus. It is the schematic of the sludge concentration apparatus provided with the conventional washing | cleaning means. (A) is a fragmentary sectional view which shows the mode of washing | cleaning by back washing of a filtration surface, (b) is a fragmentary sectional view which shows the mode of the stain | pollution | contamination of a filtration surface outer surface.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing a basic configuration of a sludge concentrating device according to the present invention, FIG. 2 (a) is a plan view of a cleaning body, and FIG. 2 (b) is a sectional view taken along line BB of FIG. In these drawings, the same elements as those shown in FIGS. 3 and 4 are denoted by the same reference numerals, and the repetitive description thereof will be omitted below.

  In the concentrated sludge apparatus shown in FIG. 1, the condensed sludge introduced into the upper part of the filtration cylinder 8 of the solid-liquid separation means 3 from the aggregated sludge introduction pipe 10 passes through the inside of the filtration cylinder 8 by the spiral screw 9 rotated by the motor M2. While being transported downward, the moisture contained therein is separated and passes through the filtration surface 8a of the filtration cylinder 8, and this moisture is accommodated in the space between the outer cylinder 7 and the filtration cylinder 8 as a separation liquid. The liquid is discharged from the liquid discharge pipe 13 to the outside. The concentrated sludge from which moisture has been removed is discharged from the lower part of the filter cylinder 8 to the concentrated sludge discharge pipe 11.

  By the way, in the sludge concentration apparatus 1 which concerns on this Embodiment, the washing body 25 which moves up and down along the outer peripheral surface of the filter cylinder 8 is used as the cleaning means which removes the dirt adhering to the outer surface of the filter surface 8a of the filter cylinder 8. "Is provided.

  Here, as shown in FIG. 2 (b), the cleaning body 25 ″ sandwiches a rubber elastic ring 29 elastically contacting the outer surface of the filtration surface 8 a of the filtration cylinder 8 with a steel metal ring 30. The inner diameter d1 of the elastic ring 29 is set smaller than the outer diameter d3 of the filter cylinder 8 (d1 <d3), and the inner diameter d2 of the metal ring 30 is larger than the outer diameter d3 of the filter cylinder 8 ( d2> d3) is set, and the inner peripheral surface of the metal ring 30 maintains a non-contact state with respect to the outer peripheral surface of the filter tube 8.

  And the washing | cleaning body 25 comprised as mentioned above is suspended by the rope 31, as shown in FIG. 1, and is located in the lower end of the filter cylinder 8 like illustration at the time of washing | cleaning.

Thus, when cleaning is necessary because the filtration surface 8a of the filter cylinder 8 is clogged by the concentration operation, the compressed air is injected into the outer cylinder 7 from the compressed air supply pipe 23 and filtered. The solid matter causing clogging on the filtration surface 8a of the tube 8 is removed, and the washing 31 "is moved up and down along the outer peripheral surface of the filtration tube 8 by raising and lowering the rope 31. Note that the rope If the 31 is pulled upward, the cleaning body 25 ″ is raised, and if the force pulling the rope 31 is released, the cleaning body 25 ″ is lowered by its own weight. Move up and down along.

  When the cleaning body 25 ″ moves up and down along the outer peripheral surface of the filter cylinder 8 as described above, the elastic ring 29 is in elastic contact with the outer surface of the filter surface 8a as described above. Slides along the outer surface of the filtration surface 8a, and the dirt adhering to the outer surface of the filtration surface 8a is scraped off by the elastic ring 29.

  Therefore, according to the present embodiment, clogging of the filtration surface 8a of the filtration cylinder 8 is prevented by backwashing with compressed air, and dirt adhering to the outer surface of the filtration surface 8a is deposited on the outer circumferential surface of the filtration cylinder 8. Since it is effectively removed by the cleaning body 25 ″ that moves up and down along the way, the required throughput and solids recovery rate (SS recovery rate) are ensured.

  The present invention is applicable to a screw press type sludge concentrating device and a cleaning method therefor, regardless of the type of sludge to be treated.

DESCRIPTION OF SYMBOLS 3 Solid-liquid separation means 7 Outer cylinder 8 Filter cylinder 8a Filtration surface 9 Spiral screw 10 Aggregated sludge introduction pipe 11 Concentrated sludge discharge pipe 13 Separation liquid discharge pipe 23 Compressed air supply pipe 25 "Washing body 29 Elastic ring 30 Metal ring 31 Rope M2 motor

Claims (4)

A filter cylinder is accommodated in the outer cylinder, a spiral screw is rotatably accommodated in the filter cylinder, and the sludge introduced into the filter cylinder is conveyed from the sludge agglomeration tank by rotationally driving the spiral screw. Meanwhile, the sludge that passes the water contained in the sludge through the filtration surface of the filter cylinder and stores it in the outer cylinder as a separation liquid to concentrate the sludge and discharge the concentrated sludge from the inside of the filter cylinder. In the concentrator,
A sludge concentrating device comprising a cleaning body configured by sandwiching both surfaces of an elastic ring elastically contacting the outer periphery of the filtration surface of the filtration tube with a metal ring so as to be movable in the length direction of the filtration tube. . Wherein the cleaning body suspended by the rope, according to claim 1 Symbol placement of the sludge concentrating apparatus and moving in the longitudinal direction of the filtration cylinder cleaning member by pulling the rope. A filter cylinder is accommodated in the outer cylinder, a spiral screw is rotatably accommodated in the filter cylinder, and the sludge introduced into the filter cylinder is conveyed from the sludge agglomeration tank by rotationally driving the spiral screw. Meanwhile, the sludge that passes the water contained in the sludge through the filtration surface of the filter cylinder and stores it in the outer cylinder as a separation liquid to concentrate the sludge and discharge the concentrated sludge from the inside of the filter cylinder. A cleaning method for a concentrator,
By moving a cleaning body configured by sandwiching both sides of an elastic ring elastically contacting the outer periphery of the filtration surface of the filtration tube with a metal ring in the length direction of the filtration tube, the outer surface of the filtration tube is filtered. A method for cleaning a sludge concentrator, characterized by removing attached dirt. 4. The method for cleaning a sludge concentrating device according to claim 3, wherein the dirt in the filter hole of the filter cylinder is removed by jetting backwash air into the outer cylinder.

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