JP2017205691A - Sludge dehydrator and cleaning method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge dehydrator and a sludge dehydration method capable of eliminating needs for stopping utilization of a device for cleaning a dehydration separation liquid receiver or largely reducing cleaning frequency by preventing accumulation of sludge residue.SOLUTION: A concentration part B for separating aggregated sludge into concentrated sludge and concentrated separation liquid, a dehydration machine A for receiving the concentrated sludge from the concentration part and separating into a dehydration cake and a dehydration separation liquid, a dehydration separation liquid receiver for receiving the dehydration separation liquid from the dehydration part and a concentrated separation liquid for sending the concentrated separation liquid from the concentration part to the dehydration separation liquid receiver are provided, and the concentrated separation liquid is used as a cleaning liquid of the dehydration separation liquid receiver.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dehydrator used for sludge treatment, and more particularly to a dehydrator equipped with a cleaning mechanism for a dehydrator after dehydration.

  The present invention also relates to a method for cleaning a dewatering device used for sludge treatment, and more particularly, to a method for cleaning sludge residue accumulated in a dewatering separation liquid receiver of a dewatering device.

  The dewatering device is a device that separates sludge into solid-liquid separation into a dehydrated cake and a dehydrated separated liquid, and the dehydrated separated liquid is discharged to a dehydrated separated liquid receiver. In the dewatered separation liquid receiver, sludge that has fallen from the dewatering section during dewatering and sludge contained in a small amount in the dewatered separation liquid accumulate (hereinafter collectively referred to as “sludge residue”). In particular, in the case of a screw press type dehydrator, the closer to the dehydrated cake exit, the more pressure is applied to the dehydrated cake itself, so that more sludge residue leaks from the screen surface and more accumulated sludge residue becomes cake lump. In addition, sludge residue tends to accumulate at the corner of the dehydrated liquid receiver. If the sludge residue accumulates in the dehydrated liquid receiver, the dewatered liquid container will corrode or generate a bad odor. Therefore, it is necessary to wash the sludge residue accumulated in the dehydrated liquid receiver.

  In order to clean the sludge residue, it is necessary to stop the operation of the apparatus and manually clean the sludge residue. Cleaning by the operator after the operation of the apparatus is stopped reduces processing efficiency and is complicated.

Japanese Patent No. 3568778

  An object of the present invention is to prevent the accumulation of sludge residue, eliminate the need to stop the operation of the apparatus for cleaning the dewatered separation liquid receiver, or greatly reduce the frequency of cleaning, and sludge It is to provide a dehydration method.

  According to the present invention, there is provided a sludge dewatering apparatus and a sludge dewatering method that can directly supply a concentrated separation liquid to a dewatering separation liquid receiver and prevent sludge from accumulating in the dewatering separation liquid receiver.

Embodiments of the present invention are as follows.
[1] A concentration unit that separates the aggregated sludge into concentrated sludge and concentrated separated liquid;
A dehydration unit that receives the concentrated sludge from the concentration unit and separates it into a dehydrated cake and a dehydrated separation liquid;
A dehydrated liquid receiver that receives the dehydrated liquid separated from the dewatering section;
Concentrated separation liquid piping for sending the concentrated separation liquid from the concentration section to the dehydration separation liquid receiver,
Comprising
A sludge dewatering apparatus, wherein the concentrated separation liquid is used as a washing liquid for the dehydrated separation liquid receiver.
[2] The concentrated separation liquid pipe is attached to a side wall surface of the dehydrated separation liquid receiver, and an attachment angle between the central axis of the outlet and the central axis of the concentrated separation liquid pipe is 90 degrees or more and 180 degrees or less. The sludge dewatering device according to [1], characterized in that it exists.
[3] The outlet of the concentrated separation liquid pipe is attached to a position separated from the midpoint of the longitudinal axis by a distance of 20% or less of the total length of the longitudinal axis of the dehydrated separation liquid receiver. The sludge dewatering device according to [1] or [2].
[4] The dehydrating unit includes:
A liquid permeable tube;
The liquid permeable cylinder is slidably fitted in the longitudinal direction, and has a large diameter end portion having a uniform diameter over a certain distance from the distal end portion and a uniform diameter over a certain distance from the base end portion. A small-diameter end portion and a tapered shape portion between the large-diameter end portion and the small-diameter end portion, and on the circumference of the tapered shape portion and a part of the large-diameter end portion in contact with the tapered shape. A screw shaft having spirally provided blades;
At a position on the small diameter end side of the tapered portion of the screw shaft, a concentrated sludge inlet provided through the liquid permeable tube,
A spiral concentrated sludge transfer compression passage formed between the inner wall of the liquid permeable tube and the tapered portion of the screw shaft;
A compression chamber formed between the inner wall of the liquid permeable tube and the large diameter end;
A dewatering cake discharge port for discharging the dewatering cake from the compression chamber;
A shaft slide type screw press dewatering section comprising:
The sludge dewatering device according to any one of [1] to [3], wherein the dewatering separation liquid receiver is positioned below the liquid permeable cylinder.
[5] The concentration unit includes
An agglomerated sludge inlet for accepting the agglomerated sludge;
A guide member provided with a pressing part that sequentially conveys the aggregated sludge that has been charged, and
A concentrated sludge discharge port for sending the concentrated sludge separated into solid and liquid by pressing to the dehydration unit;
A concentrated liquid receiver connected to a concentrated liquid pipe for sending the concentrated liquid separated by squeezing to the dehydrated liquid receiver;
The sludge dewatering device according to any one of [1] to [4].
[6] The concentrating section and the dehydrating section are independent concentrating apparatuses and dehydrating apparatuses, respectively, and a concentrated separation liquid pipe from the concentrating apparatus is attached to a dehydrated liquid receiver of the dehydrating apparatus. The sludge dewatering device according to any one of [1] to [5].
[7] Separating the aggregated sludge into concentrated sludge and concentrated separation liquid,
The concentrated sludge is separated into a dehydrated cake and a dehydrated separation liquid,
The concentrated separation liquid is allowed to flow into the dehydrated separation liquid receiver,
The dehydrated separation liquid is dropped into the dehydrated separation liquid receiver,
A sludge dewatering method characterized by preventing sludge residue from accumulating in a dewatered separation liquid receiver.

  ADVANTAGE OF THE INVENTION According to this invention, accumulation of the sludge residue in a dehydration separation liquid receptacle can be prevented, and generation | occurrence | production of corrosion, bad odor, etc. of a dehydration separation liquid receptacle can be prevented.

  In particular, the outlet of the concentrated separation liquid from the concentration section is provided in a predetermined range of the dehydrated separation liquid receiver in the dehydration section, the direction in which the concentrated separation liquid flows out is regulated, and the swirling flow of the concentrated separation liquid in the dehydration separation liquid receiver And the concentrated separation liquid is distributed to the corner of the dehydrated separation liquid receiver where the sludge residue is likely to be deposited, thereby preventing the accumulation of the sludge residue or washing the sludge residue deposit.

It is a flowchart which shows the flow of the sludge and concentrated separation liquid in the washing | cleaning method of this invention. It is a top view which shows the flow of the concentrated separation liquid in the dehydration separation liquid receiver of FIG. It is a perspective view which shows the attachment aspect of the concentration separation liquid piping with respect to the dehydration separation liquid receiver of FIG. It is a partial longitudinal side view of one embodiment of a shaft sliding screw press type dehydrator which is a dewatering part of the sludge dewatering device of the present invention. 5 is a partially longitudinal side view of the shaft sliding screw press type dehydrator of FIG. 4 when the screw shaft is advanced in the longitudinal direction and the compression chamber is reduced. FIG. It is a vertical side view of one Embodiment of the concentration part of the sludge dehydration apparatus of this invention. It is the sectional view on the AA line of FIG. It is a vertical side view which shows the use condition of the concentration part of FIG. It is sectional drawing of another embodiment of the concentration part of the sludge dehydration apparatus of this invention. It is sectional drawing of another embodiment of the concentration part of the sludge dehydration apparatus of this invention. It is a partial expansion perspective view of the concentration sludge discharge port of the concentration part of FIG. It is a photograph which shows the state of the liquid-permeable pipe | tube (screen pipe | tube) at the time of operation of the sludge dehydration apparatus of this invention, and a dehydration separation liquid receiver. It is a photograph which shows the state of the liquid-permeable pipe | tube (screen pipe | tube) at the time of operation of the conventional shaft sliding type screw press type dehydrator, and a dehydration separation liquid receiver. 14 is a photograph showing a state of a liquid permeable cylinder (screen cylinder) and a dehydrated separation liquid receiver after the operation of the shaft sliding screw press type dehydrator shown in FIG. 13 is stopped and washed.

Preferred embodiment

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto.

  FIG. 1 is a flowchart showing the flow of sludge and concentrated separated liquid in the sludge dewatering method of the present invention. In the flow shown in FIG. 1, the coagulated sludge is sent to a concentrating section or a concentrator B (hereinafter abbreviated as “concentrating section B”), and is divided into a concentrated sludge and a concentrated separation liquid. The concentrated sludge is sent to a dehydrating section in the dehydrator A, divided into a dehydrated cake and a dehydrated separation liquid, and the dehydrated separation liquid is discharged to a dehydrated liquid receiver in the dehydrator A. The concentrated separation liquid from the concentration section B is also sent to the dehydrated liquid receiver in the dehydrator A. In the dewatering separation liquid receiver, there are sludge residues such as sludge falling from the dehydration part and sludge contained in the dehydration separation liquid. The concentrated separation liquid from the concentration part B is supplied to the dehydration separation liquid receiver and flowed in advance. In this case, sludge residues that fall during the dehydration process can be allowed to flow without being deposited, or sludge residues that have accumulated in the dewatered separation liquid receiver can be washed.

  FIG. 2 is a plan view of the dehydrated separation liquid receiver in the dehydration section, and FIG. 3 is a perspective view showing a manner of attaching the concentrated separation liquid piping. The concentrated separation liquid outlet is attached at an angle to the end of the concentrated separation liquid pipe so that the concentrated separation liquid is supplied from the side wall surface of the dehydrated separation liquid receiver toward the center of the bottom surface of the dehydrated separation liquid receiver. It has been. The concentrated separation liquid outlet is located at a distance of 30% or less, preferably 20% or less, more preferably 15% or less of the total length of the dehydrated liquid receiver longitudinal axis from the midpoint of the dehydrated liquid receiver longitudinal axis. Is attached to the wall surface of the dehydrated separation liquid. After the concentrated separation liquid flows out to the dehydration separation liquid receiver at a predetermined angle, it collides with the side wall surface facing the dehydration separation liquid receiver, separates into the left and right in the direction of travel, flows to the entire surface of the dehydration separation liquid receiver, and sludge residue accumulates. The concentrated separated liquid also spreads to the corner of the dehydrated liquid receiver, which is easy to perform, and the sludge residue is washed and finally discharged from the discharge port of the dehydrated liquid receiver as a washing waste liquid. The concentrated separation liquid outlet may be provided in one or more locations on any one of the four side wall surfaces of the dehydrated separation liquid receiver, but the concentric separation liquid outlet faces symmetrically about the discharge port of the dehydrated separation liquid receiver. When one or more are attached to each of the two side wall surfaces, the concentrated separation liquid can be supplied in a countercurrent and turbulent flow can be generated, so the effect of cleaning the accumulated sludge residue is higher. Become. In addition, in the case where the dehydrated separation liquid receiver has a structure that has an inclination so that the discharge port is at the lowest position and the side wall surface is at the highest position, it is point-symmetric with respect to the discharge port. Preferably, two or more concentrated separation liquid outlets are attached to each side wall surface at a position that is not plane-symmetric with respect to the central axis.

  The dehydrating unit includes a liquid permeable cylinder and a screw shaft that is slidably fitted to the liquid permeable cylinder. The dehydrated liquid receiver is positioned below the liquid permeable cylinder. The screw shaft includes a large-diameter end portion having a uniform diameter over a certain distance from the distal end portion, a small-diameter end portion having a uniform diameter over a certain distance from the base end portion, and a large-diameter end portion and a small-diameter end portion. And a blade formed in a spiral shape on the circumference of a part of the large-diameter end portion in contact with the tapered shape portion and the tapered shape portion. The liquid permeable cylinder is provided with a concentrated sludge inlet through the liquid permeable cylinder at a position on the small diameter end side of the tapered portion of the screw shaft. A spiral concentrated sludge transfer / compression passage is formed between the inner wall of the liquid permeable cylinder and the tapered portion of the screw shaft. A compression chamber is formed between the inner wall of the liquid permeable cylinder and the large diameter end. Since the diameter of the screw shaft increases from the concentrated sludge inlet toward the compression chamber, the concentrated sludge transfer compression passage is gradually narrowed and the compressive force against the concentrated sludge is increased. By advancing the screw shaft, the compressive force on the concentrated sludge gradually increases, and the concentrated sludge is dehydrated. When the compression chamber is reached, the screw shaft is advanced, the compression chamber is narrowed, and the compression force against the concentrated sludge is further increased to obtain a dehydrated cake. A dewatering cake discharge port is provided in communication with the compression chamber, and the dewatering cake is discharged from the compression chamber.

  The dehydrated liquid receiver is positioned below the liquid permeable cylinder and receives the dehydrated liquid separated during the dehydration process.

  4 and 5 are partially longitudinal side views of a screw press type dehydrating apparatus (dehydrating unit) according to an embodiment of the present invention.

  The screw press-type dewatering device permeates through an inlet 15 that receives concentrated sludge from a concentration section, which will be described later, a dehydrated cake discharge port 25 that discharges the dehydrated cake after dehydration, and a plurality of small holes 4 in the screen cylinder 2. A dehydrating / separating liquid receiver 17 is provided for receiving the dehydrating / separating liquid. On the side wall surface of the dehydrated separation liquid receiver 17, a pipe 24 for sending the concentrated separation liquid from the concentrator is attached. The dehydrated separation liquid receiver 17 has a portion corresponding to the tapered portion close to the large-diameter end of the screw shaft 3 being the lowest and a portion contacting the side wall surface being the highest, and is 0 ° to 45 °, preferably 2 °. The discharge port 26 is provided at the lowest position with an inclination of 20 ° or less. The concentrated sludge introduced into the dewatering part on the small-diameter end side of the screw shaft 3 from the concentrated sludge inlet is compressed and dewatered while being conveyed by the blades of the screw shaft 3, and dehydrated and separated on the small-diameter end side. The residual sludge that falls on the liquid receiver 17 is small, and the residual sludge that falls on the dehydrated separation liquid receiver 17 increases as it approaches the large diameter end portion. Therefore, the inclination of the bottom surface of the dehydrated separation liquid receiver 17 on the large diameter end portion side. To make it larger. The concentrated separator outlet 24 a of the concentrated separator pipe 24 is 90 degrees with respect to the central axis of the pipe 24 so as to supply the concentrated separator from the side wall surface of the dehydrated separator 17 toward the outlet 26. It is attached at a predetermined angle of not less than 180 degrees, preferably not less than 90 degrees and not more than 135 degrees. The concentrated separation liquid flows out to the dehydrated separation liquid receiver 17, then flows over the entire area of the dehydrated separation liquid receiver 17, and is discharged from the discharge port 26.

  The dewatering part of the screw press type dewatering device will be described in detail with reference to FIGS.

  The screw press type dehydrating apparatus A shown in FIGS. 4 and 5 has a cylindrical screen cylinder 2 arranged horizontally and fixed on a machine base 1, and is rotatable to the screen cylinder 2 and movable in the axial direction. Is provided with a screw shaft 3 fitted concentrically. The screw shaft 3 can move in the axial direction to change the axial direction position with respect to the screen cylinder 2. A large number of small holes 4 are provided through the peripheral wall of the screen cylinder 2. A screw blade 5 is spirally wound around the center of the screw shaft 3. On the machine base 1, a movable base 6 is provided outside the screen cylinder 2 so as to be movable along the axial direction of the screw shaft 3. A front bearing plate 7 and a rear bearing plate 8 are established on the movable base 6. The screw shaft 3 protruding from the closed end plate of the screen cylinder 2 is formed on the front bearing plate 7 and the rear bearing plate 8. The small-diameter end is supported in the radial direction and the axial direction. A variable speed electric motor 9 with a speed reducer is mounted on the rear bearing plate 8, and the rotation of the screw shaft 3 connects the rotation shaft of the variable speed electric motor 9 and the small-diameter end of the screw shaft 3 with a chain transmission mechanism 10. A driving device is configured on the movable table 6. A fixed plate 11 is established on the machine base 1, and a hydraulic cylinder 12 is fixed to the fixed plate 11 along the moving direction of the movable table 6, and a piston rod 13 protruding from the tip of the hydraulic cylinder 12 is provided. The tip end is connected to the rear bearing plate 8 and a hydraulic circuit for controlling the forward and backward movement of the piston rod 13 and the stop at a desired position is provided to constitute the axial direction changing device for the screw shaft 3. When the piston rod 13 is moved forward or backward by operating the hydraulic circuit, the movable base 6 moves forward or backward together with the rotary drive devices 9 and 10 and the bearing plates 7 and 8 of the screw shaft 3, and the screw shaft 3 moves forward or backward. It moves backward and the axial direction position of the screw shaft 3 with respect to the screen cylinder 2 is changed. The change of the axial direction position of the screw shaft 3 is performed by a simple operation. Moreover, when the axial direction position of the screw shaft 3 is changed, the positions of the rotary drive devices 9 and 10 of the screw shaft 3 are also changed by the changed distance. A spiral transfer compression passage 14 is formed between the screen cylinder 2 and the screw shaft 3 and in a tapered portion of the screw shaft 3 where the blades 5 are provided to compress the concentrated sludge while transferring it. The transfer compression passage 14 has a smaller sectional area on the outlet side than on the inlet side. In the upper part of the screen cylinder 2, an inlet 15 for introducing concentrated sludge is provided. The input port 15 is connected to the inlet side of the transfer compression passage 14. An annular shape or a cylinder having a rectangular cross section between the screen cylinder 2 and the screw shaft 3 and further compressing the concentrated sludge having passed through the transfer compression passage 14 at the large diameter end portion of the screw shaft 3 without the blade 5. A compression chamber 16 having a shape is formed. The compression chamber 16 uses the outlet of the transfer compression passage 14 as an inlet. Below the screen cylinder 2, a dehydrated liquid receiver 17 is provided for collecting the liquid separated from the concentrated sludge by flowing out of the screen cylinder 2 through the small holes 4 of the screen cylinder 2. On the machine base 1, a bearing plate 18 is established for bearing the large-diameter end of the screw shaft 3 protruding from the open end of the screen cylinder 2 only in the radial direction. An annular resistor 19 having a triangular cross section is fitted to the large-diameter end of the screw shaft 3 so as to be movable between the bearing plate 18 and the screen cylinder 2 in the axial direction. The resistor 19 can move in the axial direction and change the axial position relative to the screen cylinder 2. The resistor 19 faces the open end of the screen cylinder 2, that is, the outlet of the compression chamber 16, and increases or decreases the outflow resistance at the outlet of the compression chamber 16 according to the distance from the compression chamber 16. A plurality of hydraulic cylinders 20 are fixed to the bearing plate 18 along the moving direction of the resistor 19, the piston rod 21 of the hydraulic cylinder 20 passes through the bearing plate 18, and the tip of the piston rod 21 is connected to the resistor 19. In addition, a hydraulic circuit that controls the forward and backward movements of the piston rod 21 and the stop at the desired position is provided to constitute an axial position changing device for the resistor 19. Below the resistor 19 and the outlet of the compression chamber 16, a dewatering cake dropping path 22 that flows out while receiving resistance by the resistor 19 from the outlet of the compression chamber 16 is provided. In this screw press, in order to obtain a desired dewatering performance, when adjusting the length from the inlet to the outlet of the compression chamber 16, the screw shaft 3 is moved in the axial direction by the axial direction position changing device of the screw shaft 3. It moves and changes the axial direction position of the screw shaft 3 with respect to the screen cylinder 2. Then, the length of the compression chamber 16 increases or decreases. In the axial direction change device of the screw shaft 3, when the piston rod 13 is advanced and stopped at the advanced position, and the axial direction position of the screw shaft 3 is changed to the compression chamber 16 outlet side, as shown in FIG. The fitting length of the large-diameter end portion without the screen cylinder 2 and the blade 5 of the screw shaft 3 is reduced, and the length of the compression chamber 16 is reduced. Conversely, when the piston rod 13 is retracted and stopped at its retracted position, and the axial direction position of the screw shaft 3 is changed to the inlet side of the transfer compression passage 14, the length of the compression chamber 16 increases. When the length of the compression chamber 16 is increased, the space between the closed end plate of the screen cylinder 2 and the screw blades 5 of the screw shaft 3 decreases due to the retraction of the screw shaft 3. In the upper part of the screen tube 2 on the closed end plate side, a space 23 is provided in which concentrated sludge between the closed end plate of the screen tube 2 and the screw blades 5 of the screw shaft 3 escapes when the screw shaft 3 is retracted. Since the concentrated sludge can be sent forward by setting the rotational speed of the screw shaft 3 at the time of retraction early, the space 23 may not be provided.

  The screw press-type dewatering device used in the sludge dewatering device of the present invention is not limited to the form shown in FIGS. 4 to 5 and may be appropriately modified and changed. For example, among the mechanisms (movable base, front bearing plate, rear bearing plate, variable speed motor, chain transmission mechanism, fixed plate, hydraulic cylinder) for sliding the screw shaft 3 back and forth, the hydraulic cylinder and the fixed plate are connected to the screen cylinder. A piston rod that is provided adjacent to the hydraulic cylinder and protrudes from the tip of the hydraulic cylinder is fixed to the movable base, and the rear bearing plate 8 in FIG.

  In the sludge dewatering apparatus of the present invention, the concentration mechanism is not particularly limited as long as the concentrated separation liquid can be discharged to the dewatering separation liquid receiver below the dehydration unit, and a normal concentration mechanism can be used.

  FIG. 6 is a longitudinal side view of a concentrating unit that can be used in the sludge dewatering apparatus of the present invention, FIG. 7 is a sectional view taken along line AA in FIG. 6, and FIG. 8 is a longitudinal side view showing a use state. is there.

  As shown in FIGS. 6 to 8, the concentrating unit is provided at the lower end of the drain chamber 103, the screen plate 101 that separates the aggregated sludge into the concentrated sludge and the concentrated separator, the drain chamber 103 that receives the concentrated separator. The drain outlet 103a is connected to a concentrated separation liquid pipe 24 for feeding the concentrated separated liquid to the dehydrated separation liquid receiver 17 of the screw press type dehydrator A.

  The configuration of the concentration unit will be described in detail with reference to FIGS. The screen plate 101 through which the water in the sludge passes is disposed obliquely, and a groove-shaped sludge passage 102 is formed in which the sludge flows on the screen plate 101 from the upper end to the lower end. The screen plate 101 is a wedge wire screen in which a plurality of wires having a wedge-shaped cross section are arranged in parallel with a gap left and right along the direction in which the sludge flows, and water in the sludge passes through the gap between the wires. The inclination angle of the screen plate 101 is 40 degrees from the horizontal plane. Under the sludge passage 102, as shown in FIG. 6, a drainage chamber 103 for collecting and discharging water that has passed through the screen plate 101 is provided. The brush device has bearings on the left and right side walls of the sludge passage 102 for a drive shaft 104 that traverses the upper portion of the screen plate 101 and a driven shaft 105 that traverses the lower portion of the screen plate 101. A chain wheel 106 is fixed to the left and right positions inside the bearings of the drive shaft 104 and the driven shaft 105 arranged in parallel in the front-rear direction, and an endless chain 107 is connected to the drive wheel 104 and the left wheel wheel 106 of the driven shaft 105. An endless chain 107 is engaged with the chain wheel 106 on the right side of the driven shaft 105 and is passed over. The base end side of the substrate of the brush 108 is fixed to the left and right chains 107 and is passed over in the left and right direction. A large number of brushes 108 protrude in parallel at equal intervals on the outer peripheral side of 107. The plurality of brushes 108 positioned below the both chains 107 are fitted in the sludge passage 102 along the transverse direction, and the tips of the hairs protruding from the tip side of the substrate come into contact with the screen plate 101. When the drive shaft 104 is rotated in the direction of the arrow shown in FIG. 6, the brush 108 that has traveled around the drive shaft 104 and reached the lower side of the chain 107 descends the sludge passage 102 while sweeping the screen plate 101, and below the screen plate 101. When it reaches, it moves away from the screen plate 101, rotates around the driven shaft 105, and reaches the upper side of the chain 107. The brush drive device fixes a gate-shaped mounting frame 109 across the sludge passage 102 and the brush device on the left and right side walls of the sludge passage 102, and an electric motor with a speed reducer on one end of the top plate of the mounting frame 109. 110 is attached, and the rotating shaft of the electric motor 110 and the end of the drive shaft 104 are connected by a chain transmission mechanism 111. When the electric motor 110 is driven, the drive shaft 104 rotates in the arrow direction shown in FIG. The washing water injection device fixes the water supply pipe 112 along the sludge passage 102 under one end of the top plate of the mounting frame 109, and fixes the base end of the water spray pipe 113 to a plurality of locations of the water supply pipe 112, respectively. A plurality of water spray pipes 113 for injecting cleaning water onto the brush 108 and the screen plate 101 are arranged in parallel along the transverse direction of the sludge passage 102. Although not shown, the water supply pipe 112 is connected to a water source via a pump. An electric control circuit is provided that drives the motor that operates the pump for a set time in seconds every set time in minutes.

  Further, as shown in FIG. 8, an outlet a of the agglomeration reaction tank is disposed on the upper end inlet of the sludge passage 102, and below the lower end outlet of the sludge passage 102, the screw press type dehydrator shown in FIGS. A concentrated sludge inlet 15 is disposed. The electric motor 110 of the brush driving device is driven, the electric control circuit of the washing water injection device is operated, and the sludge generated by the floc flows from the outlet a of the coagulation reaction tank to the upper end inlet of the sludge passage 102. Then, each brush 108 sequentially rotates around the drive shaft 104 and fits in the upper part of the sludge passage 102 along the transverse direction thereof, descends the sludge passage 102 while sweeping the screen plate 101, and lowers the sludge passage 102. When it reaches, it moves away from the screen plate 101, exits the sludge passage 102, and rotates around the driven shaft 105. On the other hand, the generated sludge S containing floc flows down the sludge passage 102 from the upper end inlet to the lower end outlet of the sludge passage 102, but the sludge passage 102 sweeps the screen plate 101 at a speed slower than the natural flow speed of the sludge S. The sludge passage 102 flows down while being dammed up by the brush 108 that goes down. The sludge S flowing on the screen plate 101 at the moving speed of the brush 108 passes through the screen plate 101 and flows into the drainage chamber 103, and the water content is reduced and the sludge reaches the lower part of the sludge passage 102. When the brush 108 that has blocked the sludge S leaves the screen plate 101 and exits the sludge passage 102, S falls from the lower end outlet of the sludge passage 102 to the concentrated sludge inlet 15 of the screw press type dehydrator. Each time a set time in minutes elapses after the electric control circuit of the cleaning water injection device is operated, the cleaning water is sprayed from each sprinkling tube 113 for a set time in seconds, and the brush 108 and the screen plate 101 are moved. Washing is performed, and the washing water passes through the screen plate 101 and flows into the drainage chamber 103 to remove clogging of the screen plate 101. In the sludge concentrator of this example, the time during which the sludge S flowing down while the sludge passage 102 is blocked by the brush 108 flows through the sludge passage 2 is about 12 seconds. In the conventional case where the sludge S naturally flows down the sludge passage 102, the time is about 1 to 3 seconds. Therefore, in the sludge concentrator of this example, since the time during which the sludge S flows on the screen plate 101 becomes longer, the amount of water passing through the screen plate 101 increases, and the concentration rate increases. The interval at which the cleaning water jetting device is operated is 15 to 90 minutes, preferably 30 to 60 minutes, and the time for the cleaning water jetting device to operate is 5 to 30 seconds, preferably 10 to 20 seconds. In the conventional case in which the brush 108 does not always sweep the screen plate 101, the interval at which the cleaning water injection device is activated is 10 minutes, and the time for which the cleaning water injection device is operated is 10 seconds. Therefore, in the sludge concentrator of the present example, the interval at which the cleaning water injection device operates is long, so that the amount of cleaning water used is reduced.

  The inclination angle of the screen plate 101 is not limited to 40 °, and may be about 20 ° from the horizontal plane. When the screen plate 101 has a gentle inclination, the sludge S flowing down the sludge passage 102 while being damped by the brush 108 that goes down the sludge passage 102 while sweeping the screen plate 101 is reduced in fluidity due to a decrease in a large amount of water. However, the sludge S staying on the screen plate 101 is pushed by the next brush 108 and descends on the screen plate 101, and the screw 108 It falls to the concentrated sludge inlet 15 of the press-type dewatering device. Regardless of the inclination angle of the screen plate 101, the speed at which the sludge S flows down the sludge passage 102 is controlled by the brush 108 that goes down the sludge passage 102, so the range for selecting the inclination angle of the screen plate 101 is wide. The degree of freedom in designing the sludge passage 102 is high.

  The screen plate 101 may be a punching metal having a large number of holes, other screens or filters. The cleaning water spraying device may be configured such that the sprinkling pipe 113 is disposed below the screen plate 101 and the cleaning water is sprayed onto the lower surface of the screen plate 101.

  The concentrated and separated water separated by the screen plate 101 of the concentration section B is sent from the water distribution port 103a and the piping (not shown) of the drainage chamber 103 to the dehydrated separator receiver 17 below the screw press type dehydrator. At this time, the outlet of the pipe connected to the water distribution pipe 103a is located at a position separated from the midpoint of the longitudinal axis by a distance of 20% or less of the total length of the longitudinal axis of the dehydrated separation liquid receiver 17 so as to be separated from the middle point of the longitudinal axis. Reference numeral 24 denotes a side wall surface of the dehydrated liquid receiver 17. The concentrated separation liquid flows out to the dehydrated liquid receiver 17 immediately after the concentrated separation and flows over the entire surface of the dehydrated liquid container 17. Since the sludge residue that falls together with the separation liquid that permeates the screen cylinder 2 (liquid permeable cylinder) during the dehydration process falls into the concentrated separation liquid flowing over the entire surface of the dehydration separation liquid receiver 17, Accumulation is prevented. The concentrated separated liquid, dehydrated separated liquid, and sludge residue are finally discharged from the outlet 26 of the dehydrated separated liquid receiver 17 as washing waste liquid.

  FIG. 9 shows an overall cross-sectional view of another aspect of the concentration unit. The concentrating unit shown in FIG. 9 includes an agglomerated sludge charging hopper 201 for injecting the agglomerated sludge, a guide member 203 having a plurality of rotating plates 204 and a pressing tool 215 for sequentially conveying the agglomerated sludge that has been charged, A concentrated sludge discharge port 206 for sending the concentrated sludge from which the liquid has been removed by the tool to the concentrated sludge inlet 15 of the screw press type dewatering device, and a waste liquid port 219 for receiving the concentrated separated liquid separated by the pressing tool. The waste liquid port 219 is connected to the concentrated separation liquid pipe 24.

  The concentration unit will be described in detail with reference to FIG. A casing 202b surrounded by a thin plate is attached on a frame 202a constituting a box-like lower part. 201 is an agglomerated sludge charging hopper. Inside the casing 202b, an upper open side wall is provided in front and rear to be parallel to the left and right direction, and a groove-shaped transport path is formed between the side walls 205 and 205 for transporting the coagulated sludge. Further, a large number of rotating shafts 207 are supported between the side walls 205 and 205 in the front-rear direction and at equal intervals, and the rotating shaft 207 has a large number of ellipsoidal rotating plates 204 at the same phase and at regular intervals. The shaft is integrated. The rotating plate 204 is shifted in phase by 90 ° for each adjacent rotating shaft, and the upper outer peripheral surface (feeding surface) forms a wave as a whole by rotating each shaft simultaneously in the same direction at the same speed. It can operate in the transport direction (left direction) and can exert a large scraping force and transport force. On each rotary shaft 207, a guide member 203 made of a plate-like member is inserted and supported in a vertical direction along the transport direction so as to be inserted on both sides of each rotary plate 204 of each axis. Yes. The upper end surface of the guide member 203 forms a smooth guide surface that guides the coagulated sludge sent by the rotation of the rotating plate 204 in the feeding direction, and there is a gap into which the rotating plate 204 is inserted between the guide members 203. A narrow slit for dropping the separated liquid is formed between two adjacent rotating plates 204 formed. The slit may be of a size that allows liquid to pass without passing through the coagulated sludge, and is about 0.5 mm to about 4.0 mm, preferably about 0.8 mm to about 2.0 mm. The guide member 203 is locked and supported by a receiving portion 208 attached to the left and right ends under the conveyance path. Reference numeral 203b denotes a hook portion formed so as to engage with the receiving portion 208. The upper end surface of the guide member 203 is a guide surface for sending the coagulated sludge in the transport direction, and the lower end side thereof is provided with a notch 203a at each rotation axis corresponding position so as to avoid the rotation shaft 207 and further to the lower side. ing. Pulleys 211 are respectively engaged at both ends of each rotary shaft 207, and adjacent pulleys 211 are alternately wound around the front and rear sides by a timing belt 213, so that each shaft is driven by a motor 212 installed in the lower frame 202a. Can be rotated at the same speed and accurately in the same direction at the same time. Reference numeral 214 denotes a belt around which one of the pulleys 211 on the drive motor 212 side is wound. Each rotating shaft 207 is rotated slowly at a speed of, for example, about 10 to 50 rpm by the motor 212, and the aggregated sludge thrown on the guide member 203 is lifted from below to the circumferential surface of the rotating plate 204 of each row while being guided by the guide member 203. It is sent out in the direction of the discharge port 206 along the upper surface. The upper part of the casing 202b is provided with a squeezing tool 215 on which an arm 217 made of a stainless steel plate or the like, on which a weight 216 is mounted so that the weight can be increased or decreased, is pivotally supported by a shaft 218 so as to swing up and down. . The squeezing tool 215 swings following the movement of the peripheral surface of the rotating plate 204 in the vertical direction, and presses the coagulated sludge to dehydrate it. The pressing tool 215 is provided or weight-adjusted according to the necessity such as the type of coagulated sludge and the required degree of concentration. Although two pressing tools 215 are provided in FIG. 9, one pressing tool may be used. In addition, instead of the weight 216, the pressing tool 215 may be provided with a roller (not fixed) that is rotatably supported at the tip of the arm 217 and that is squeezed by rolling on the upper surface of the aggregated sludge. Alternatively, an air cylinder or a hydraulic cylinder may be used instead of the arm 217 and the weight 216. Aggregated sludge is in the process of moving on the upper surface of the guide member 203 and the rotating plate 204, water and other from the gap between the rotating plate 204 and the guide member 203 in the slit and the gap between the peripheral surfaces of the adjacent rotating plates 204. The liquid component is filtered downward and discharged from the waste liquid port 219 to the outside, and the solid component (concentrated sludge) collected on the guide member 203 is sequentially filtered and dehydrated while being sent to the peripheral surface of the rotating plate 204 and discharged. It is discharged from 206. By using the elliptical rotating plate 204, the lifting and conveying force is increased more than the eccentric rotating disc, and the conveying force is increased twice, so that the conveying ability is increased. The gap between the matching ellipses and the surfaces of the ellipses can always be kept constant. By keeping the gap narrow and constant, the collection and dewatering performance of the small-diameter solid material itself is improved, and there is no stagnation of the solid material in this part due to the rotation in the lifting direction of the front rotating plate 204, There is no need to remove the collected matter accumulated on the fixed plate as in the prior art, and cleaning is easy. By arranging a large number of guide members in a grid shape along the direction of transporting the coagulated sludge, the transport becomes smooth and the plate-shaped member is used in the vertical direction, so that a strong pressing load can be applied from the top, and compression (concentration) There is an advantage that the effect can be increased. Further, by making the rotating plate elliptical so that the distance between the peripheral surfaces can be always narrow and constant, no untreated material remains, the dehydrating power is 1.2 times, and the filtration flow rate is constant. Further, since the undulation is increased by making the rotating plate into an elliptical shape, the transportability of the concentrated sludge is improved, and the transport capability is increased as compared with the disk.

  FIG. 10 is a cross-sectional view of the concentration unit 320 having another configuration. Aggregated sludge charging hopper 321, aggregated sludge moving means 322, pressurizing means 328 provided above aggregated sludge moving means 322, and water capturing means 323 provided below aggregated sludge moving means 322. The pressurizing means 328 is provided with a pressure plate 328A obliquely so as to provide a gap with the belt 324 before the sludge discharge port 326 of the aggregated sludge moving means 322, and the aggregated sludge is moved to the aggregated sludge moving means 322. When the sludge is moved to the sludge discharge port side in the horizontal direction, the pressure is applied from above when passing through the gap between the pressure plate 328A and the belt 324. At this time, one or two or more pressure plates 328A may be provided, and the pressure plate 328A may be provided so that the installation angle is fixed, or provided so that the installation angle can be changed at any time. In addition, it can be pivotally supported so as to be swingable up and down. By changing the angle of the pressure plate 328A and the size of the gap with the belt 324, the pressure applied to the coagulated sludge can be adjusted, and the concentration ratio can be adjusted. Further, instead of the pressure plate 328A, for example, a roller may be installed. The concentrated sludge (concentrated sludge) is extruded and discharged from the concentrated sludge discharge port 326. As shown in FIG. 11, comb-shaped cutting blades 331 are installed in the concentrated sludge discharge port 326 so that the blades are in the vertical direction at appropriate intervals in the horizontal direction. With such a comb-shaped cutting blade, a vertical slit can be formed in the extruded concentrated sludge. The cutting blade is not limited to a comb shape, for example, a cutting blade assembled in a lattice shape when viewed from the top, or a cutting blade assembled at an appropriate interval in the length direction or width direction of the concentrated sludge when viewed from the top surface It is good also as a structure which can be raised / lowered from upper direction with respect to concentrated sludge. Further, the comb-shaped cutting blade is not limited to a mode in which the comb-shaped cutting blade is erected in the vertical direction, and may have an inclination within ± 45 °, preferably within ± 30 °. The concentrated separated liquid separated from the coagulated sludge by the pressurizing means 328 is sent to the concentrated separated liquid pipe 24 from the concentrated separated liquid discharge port 329 at the bottom of the concentrated section 320.

  The situation of the dehydrated separation liquid receiver when the sludge dewatering device of the present invention is operated (FIG. 12), and the situation of the dehydrated separation liquid receiver when the conventional shaft sliding screw press type dehydrator is operated (FIG. 13) Is shown in comparison. Although a large amount of sludge residue can be confirmed in the dewatering separation liquid receiver of the conventional sludge dewatering apparatus, no sludge residue can be confirmed in the dewatering separation liquid receiver of the sludge dewatering apparatus of the present invention.

  FIG. 14 shows a state of receiving the dehydrated separation liquid after the operation of the conventional shaft sliding screw press type dehydrating apparatus shown in FIG. 13 is stopped and the cleaning operation is performed. In particular, it can be seen that sludge residues remain on the corners and side walls.

Claims (7)

A concentration section for separating the agglomerated sludge into concentrated sludge and concentrated separation liquid;
A dehydration unit that receives the concentrated sludge from the concentration unit and separates it into a dehydrated cake and a dehydrated separation liquid;
A dehydrated liquid receiver that receives the dehydrated liquid separated from the dewatering section;
Concentrated separation liquid piping for sending the concentrated separation liquid from the concentration section to the dehydration separation liquid receiver,
Comprising
A sludge dewatering apparatus, wherein the concentrated separation liquid is used as a washing liquid for the dehydrated separation liquid receiver.   The concentrated separation liquid pipe is attached to the side wall surface of the dehydrated separation liquid receiver, and the attachment angle between the central axis of the outlet and the central axis of the concentrated separation liquid pipe is 90 degrees or more and 180 degrees or less. The sludge dewatering device according to claim 1, characterized in that it is characterized in that   The outlet of the concentrated separation liquid pipe is attached to a position separated from a midpoint of the longitudinal axis by a distance of 20% or less of the total length of the longitudinal axis of the dehydrated separation liquid receiver. The sludge dewatering device according to 1 or 2. The dehydrating part
A liquid permeable tube;
The liquid permeable cylinder is slidably fitted in the longitudinal direction, and has a large diameter end portion having a uniform diameter over a certain distance from the distal end portion and a uniform diameter over a certain distance from the base end portion. A small-diameter end portion and a tapered shape portion between the large-diameter end portion and the small-diameter end portion, and on the circumference of the tapered shape portion and a part of the large-diameter end portion in contact with the tapered shape. A screw shaft having spirally provided blades;
At a position on the small diameter end side of the tapered portion of the screw shaft, a concentrated sludge inlet provided through the liquid permeable tube,
A spiral concentrated sludge transfer compression passage formed between the inner wall of the liquid permeable tube and the tapered portion of the screw shaft;
A compression chamber formed between the inner wall of the liquid permeable tube and the large diameter end;
A dewatering cake discharge port for discharging the dewatering cake from the compression chamber;
A shaft slide type screw press dewatering section comprising:
The sludge dewatering device according to any one of claims 1 to 3, wherein the dewatered liquid receiver is positioned below the liquid permeable cylinder. The concentration unit includes
An agglomerated sludge inlet for accepting the agglomerated sludge;
A guide member provided with a pressing part that sequentially conveys the aggregated sludge that has been charged, and
A concentrated sludge discharge port for sending the concentrated sludge separated into solid and liquid by pressing to the dehydration unit;
A concentrated liquid receiver connected to a concentrated liquid pipe that sends the concentrated liquid separated by squeezing to the dehydrated liquid receiver;
The sludge dewatering device according to claim 1, comprising:   The concentrating unit and the dehydrating unit are respectively an independent concentrating device and a dehydrating device, and a concentrated separation liquid pipe from the concentrating device is attached to a dehydrated liquid receiver of the dehydrating device. Item 6. The sludge dewatering device according to any one of Items 1 to 5. Separating the coagulated sludge into concentrated sludge and concentrated separation liquid,
The concentrated sludge is separated into a dehydrated cake and a dehydrated separation liquid,
The concentrated separation liquid is allowed to flow into the dehydrated separation liquid receiver,
The dehydrated separation liquid is dropped into the dehydrated separation liquid receiver,
A sludge dewatering method characterized by preventing sludge residue from accumulating in a dewatered separation liquid receiver.