JP3567392B2 - Sludge thickener - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for concentrating sludge in sewage, and more particularly to a press-floating type sludge concentrating apparatus for condensing sludge under pressure by attaching pressurized fine bubbles to the sludge.
[0002]
[Prior art]
FIG. 7 is a flow explanatory diagram showing an example of a conventional pressurized floating sludge concentrator. First, raw sludge to be treated is sent from a raw sludge storage tank 21 into a sludge tank 24 of a sludge concentrating device 23 through an inflow pipe 26 by a pump. At this time, pressurized air-dissolved water obtained by dissolving compressed air from the pressurized air-dissolved water tank 22 is fed into the inlet pipe 26 from the supply path 27 and mixed with the raw sludge. In the sludge tank 24, the fine bubbles in the pressurized air-dissolved water adhere to the sludge, and float up as floating sludge 28 by the buoyancy of the fine bubbles. The floating sludge 28 is deposited and concentrated at the upper part of the sludge water surface, and is periodically scraped in the direction of the arrow by a concentrated sludge scraper 25 having a scraper plate 25a attached to an endless chain or the like provided at the upper part of the sludge water surface. . The scraped floating sludge 28 is sent to a deaeration tank 29, and is stirred for a certain period of time by a stirring blade 29a. After performing a so-called deaeration process for separating attached bubbles, the sludge is collected as a concentrated sludge. Sludge to which fine bubbles have not adhered or sludge having a large specific gravity is settled as sludge and is collected by the settling sludge scraper 30 provided at the bottom of the sludge tank 24 and collected. The pressurized air-dissolved water separated from the floating sludge and the settled sludge is recovered as separated water.
[0003]
[Problems to be solved by the invention]
The above-described conventional sludge concentrator has the following problems.
(1) The speed of scraping the concentrated sludge by the concentrated sludge scraper 25 must be a speed (for example, about 60 cm / min) that does not cause a stirring action on the concentrated sludge. Because the concentrated sludge with the highest concentration among the concentrated sludge deposited and concentrated on the sludge water surface is the concentrated sludge at the top, and if the turbulence occurs when scraping the concentrated sludge at the top, the concentration of the lower layer is reduced. This is because they are mixed with low concentrated sludge, and the concentration of concentrated sludge to be recovered becomes low. When the scraping speed is increased, the sludge treatment time is shortened, but the concentrated sludge to be scraped is easily disturbed, the concentration of the concentrated sludge to be recovered is low, and the concentration of the sludge in the separation water is high. Would. If the speed is reduced, the sludge treatment time becomes longer, and the amount of floating sludge deposited increases, so that a large-scale apparatus is required. Since the concentration and condition of the raw sludge at each time differ, it is very difficult to determine the scraping speed value.
(2) As for the position of the scraping plate 25a in the height direction with respect to the sludge water surface, the closer to the sludge water surface, the more the concentrated sludge to be scraped at a time and the more efficient it is. Since the sludge is agitated, the concentration of the recovered sludge decreases as described above. It is also very difficult to set the position of the scraping plate 25a.
(3) Since the floating sludge is scraped and then passed to the stirring and deaeration step (29), the so-called sludge concentration flow efficiency is poor.
(4) The sludge that has flowed into the sludge concentrator 23 has to be frequently cleaned on the inner wall of the sludge tank 24 in order to easily adhere to and stack on the inner wall of the sludge tank 24.
[0004]
The present invention has been devised in order to solve the above-described problems, has a simple structure, can collect concentrated sludge at a high concentration, and can simultaneously perform a so-called deaeration process for removing fine bubbles in the concentrated sludge. It is an object of the present invention to provide a sludge concentrating device that does not need to frequently clean the inner wall of a sludge tank.
[0005]
[Means for Solving the Problems]
The present invention uses the following means to achieve the above object.
First, as a means for collecting concentrated sludge at a high concentration and simultaneously degassing the concentrated sludge, a sludge tank for introducing sludge water mixed with pressurized air-dissolved water is mixed with pressurized air and floated. Floating sludge aggregating means for agglomerating the collected sludge in the sludge tank, and a rotary blade disposed on the liquid surface of the sludge water for repelling and degassing the concentrated and accumulated sludge are provided. In addition, the sludge tank is constituted by a bottomed cylindrical sedimentation sludge tank, and a closed cylindrical floating sludge tank fitted inside the sedimentation sludge tank, for discharging the sedimentation sludge to the sedimentation sludge tank. The concentrated sludge discharge pipe for discharging the degassed sludge was connected to the floating sludge tank. Further, the floating sludge aggregating means is constituted by a sludge guide plate having upper and lower portions opened, and the lower end portion of the sludge guide plate has an inner wall located below the lower end portion of the concentrated sludge discharge pipe. And the upper end was disposed inside a floating sludge tank located above the liquid level of the sludge water. Further, a motor for rotating and driving the rotor was mounted on the upper part of the floating sludge tank.
[0006]
Further, as means for reducing the frequency of cleaning the inner wall of the sludge tank, the settling sludge tank is rotated and driven by the motor, moves along the inner wall of the settling sludge tank, and deposits the sludge attached to the settling sludge tank. A scraper for settling sludge to be scraped was provided. In addition, the floating sludge tank is provided with a concentrated sludge scraper that is rotated by the motor, moves along the inner wall of the floating sludge tank, and scrapes the concentrated sludge attached to the floating sludge tank. Further, the sludge guide plate is provided with a floating sludge scraper that is driven to rotate by the motor, moves along the inner wall of the sludge guide plate, and scrapes the floating sludge attached to the sludge guide plate.
Then, in order to make the entire apparatus a simple structure with a small number of parts, a passage for discharging separated water to the outside is formed between the settling sludge tank and the floating sludge tank. Further, the rotary blade, the scraper for concentrated sludge, the scraper for floating sludge, and the scraper for settled sludge are mounted on the rotating shaft of one motor so that they can be rotated at different rotation speeds.
[0007]
In addition, for the purpose of increasing the floating efficiency of the floating sludge, a flow direction for guiding the flow of the sludge water upward in the vicinity of an ejection port for ejecting the sludge water to which the pressurized air dissolved water has been applied into the sludge tank. A regulating member was provided. In particular, the flow direction regulating member is a cylindrical member that surrounds the spout and has an open top and closed peripheral side and bottom surfaces.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. 1A and 1B are a top view and a side view of a sludge concentrating apparatus according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a sectional view taken along line BB in FIG. 4 is a cross-sectional view taken along the line CC in FIG. 1, FIG. 5 is an overall perspective view of the sludge concentrator, FIG. 6 (a) is an explanatory view of the main part, and FIG. 6 (b) is a partial explanatory view in another embodiment. It is.
In these figures, reference numeral 1 indicates a sludge concentrator. This sludge concentrator 1 takes in raw sludge to be treated together with pressurized air-dissolved water obtained by dissolving compressed air in water from an ejection port 10a, floats and concentrates sludge inside a sludge tank 18, and discharges the concentrated sludge into concentrated sludge. The settled sludge is discharged to the settled sludge discharge pipe 4 to the pipe 9 and the separated water separated from the floated or settled sludge to the separated water discharge pipe 7.
[0009]
The sludge tank 18 is constituted by a settling sludge tank 2 and a floating sludge tank 3 which are two housing members.
The sedimentation sludge tank 2 is a cylindrical member with a bottom and an open top. The lower part has a tapered shape with a lower part narrowed, and the bottom part again has a small diameter cylindrical shape. A hole 2a for discharging the settled sludge is formed in the side wall of the bottom cylindrical portion, and a settled sludge discharge pipe 4 is connected to the hole 2a. Around the upper edge of the settling sludge tank 2, a separated water receiving frame 5 having an L-shaped cross section is attached around the entire circumference as a receiver when the separated water overflows from the upper edge. A part of the separated water receiving frame 5 forms a housing 6, and a hole 6 a is formed at the bottom thereof, and a separated water discharge pipe 7 is connected to the housing 6.
[0010]
The floating sludge tank 3 is a closed cylindrical member having an open lower part, the outer diameter of which is smaller than the inner diameter of the sedimentation sludge tank 2 so as to form the passage 19 for the separated water, and a fixing member (not shown). ), It is fitted and fixed concentrically inside the settling sludge tank 2. A hole 3a for discharging degassed sludge is formed in the side wall of the floating sludge tank 3, and a concentrated sludge discharge pipe 9 is connected to the hole 3a. The concentrated sludge discharge pipe 9 penetrates a hole 2b formed in the side wall of the settling sludge tank 2 (the contact portion is sealed by welding or the like) and continues to the next processing step.
[0011]
Inside the floating sludge tank 3, there is disposed a frusto-conical sludge guide plate 8 having upper and lower portions opened as floating sludge aggregating means. The sludge guide plate 8 is for guiding the floating sludge upward and coagulating, and for separating the floating sludge from the concentrated sludge degassed and degassed by the rotating blades 16 described later. The lower end is fixed and sealed to the inner wall of the floating sludge tank 3 located below the lower end of the concentrated sludge discharge pipe 9. The upper part of the sludge guide plate 8 forms a brim portion 8a that rises vertically over the entire circumference. As shown in FIG. 2 and FIG. 6 (a), the flange portion 8a rises so as to be located slightly above the liquid level (WL) of the sludge water flowing into the sludge concentration device 1. Yes, it is for accumulating and condensing the floating sludge aggregated on the liquid surface.
[0012]
Holes 2 c and 3 b (FIG. 2) are formed in the side walls of the settling sludge tank 2 and the floating sludge tank 3 located below the lower end of the sludge guide plate 8 on the side facing the concentrated sludge discharge pipe 9, respectively. Through these holes 2c and 3b, a sludge inflow pipe 10 through which raw sludge mixed with pressurized air-dissolved water flows penetrates (the contact portion is sealed by welding or the like) and extends to near the center of the sludge concentration device 1. The tip is formed as a jet port 10a. This sludge inflow pipe 10 is connected to a raw sludge inflow pipe 10b for sending raw sludge by a pump from a raw sludge tank (not shown) in which raw sludge is stored, and is connected to the sludge inflow pipe 10b so that compressed air is supplied to raw water at a high concentration. And a pressurized air dissolved water inflow pipe 10c for sending the dissolved compressed air dissolved water by a pump.
[0013]
Inside the settling sludge tank 2, a flow direction regulating member 11 for guiding the flow of the sludge water spouting from the spout 10a of the sludge inflow pipe 10 upward is provided. The flow direction regulating member 11 is a bottomed cylindrical member provided on the same axis as the sedimentation sludge tank 2 and having an open upper part and a closed peripheral side surface and bottom surface. As described above, the sludge inflow pipe 10 penetrates the hole formed in the side wall, and the contact portion is sealed and fixed by welding or the like. A hole is formed in the center of the bottom surface of the flow direction regulating member 11 so that a shaft 12a attached to a motor 12 described later can pass therethrough.
[0014]
A motor 12 is mounted on the center of the upper surface of the floating sludge tank 3, and the motor 12 has first, second and third shafts 12a and 12b whose rotation speed can be adjusted by a transmission (not shown). , 12c. The first shaft 12a extends downward, passes through a hole formed in the bottom surface of the flow direction regulating member 11, and is inserted into a bearing 13 supported on the bottom surface of the settling sludge tank 2. These three shafts having different rotation speeds are provided with wing-shaped members having respective purposes.
[0015]
First, a plurality of, in this embodiment, four brackets 14a, 15a are attached to the first shaft 12a at upper and lower sides, respectively, at right angles to the shaft 12a and radially so as to be at the same angle to each other. I have. At the tip of the upper bracket 14a, a floating sludge scraper 14 composed of a plate-like member having a shape and a length dimension along the inner wall of the sludge guide plate 8, respectively, and at the tip of the lower bracket 14b, A settling sludge scraper 15 made of a plate-like member having a shape and a length dimension along the inner wall of the tapered portion of the sludge tank 2 is attached. By rotating the first shaft 12a, the floating sludge scraper 14 moves and scrapes the floating sludge attached to the inner wall of the sludge guide plate 8 along the inner wall of the sludge guide plate 8 by the rotation. As shown in FIG. 3, the floating sludge scraper 14 has its rotation direction side in contact with the inner wall of the sludge guide plate 8 or comes close to form a slight gap (about several mm). The bracket 14a is attached to the bracket 14a so as to form a predetermined angle with respect to the tangential direction of the cross-sectional circle of FIG.
On the other hand, the settled sludge scraper 15 moves along the inner wall of the settled sludge tank 2 and scrapes the settled sludge attached to the tapered inner wall of the settled sludge tank 2 by its rotation. The scraper 15 for settling sludge, like the scraper 14 for floating sludge, contacts the rotating direction side with the tapered inner wall of the settling sludge tank 2 or approaches so as to form a slight gap, and has a circular cross section of the tapered inner wall. It is attached to the bracket 15a so as to form a predetermined angle with respect to the tangential direction.
If the peripheral speed of the shaft 12a is set to a high speed, the sludge scraped off by the floating sludge scraper 14 and the settled sludge 15 is disturbed in the tank, so it is not appropriate, and the low-speed rotation of about 2-3 m / min or less is not possible. desirable.
In this embodiment, the floating sludge scraper and the settled sludge scraper are attached to the same shaft. However, it is needless to say that another shaft may be provided and the number of rotations may be different.
[0016]
Next, a plurality of, in this embodiment, four, rectangular plate-like rotating blades 16 are attached to the second shaft 12b at right angles to the shaft 12b and radially so as to be at the same angle to each other. . By rotating the second shaft 12b, the rotary blade 16 rotates, and the concentrated sludge deposited in the flange portion 8a of the sludge guide plate 8 is repelled toward the inner wall of the floating sludge tank 3 to be deaerated. Is what you do. In order to efficiently repel floating sludge and deaerate the sludge, the dimension (L dimension in FIG. 6A) from the tip of the rotary blade 16 to the tip of the rotary blade 16 located 180 ° opposite to that of the flange 8a is The gap dimension (H dimension in FIG. 6A) between the lower edge of the rotary blade 16 and the upper edge of the flange 8a is approximately 0 to several mm.
The degassing of the concentrated sludge to which the air bubbles are attached is caused by the impact force against the rotating blade 16 and the impact force against the inner wall of the floating sludge tank 3 when the sludge is flipped tangentially to the rotation of the rotating blade 16. The rotational speed of the shaft 12b is desirably high-speed rotation of 100 rpm or more in order to increase the collision force.
[0017]
A plurality of, in this embodiment, four, brackets 17a are radially attached to the third shaft 12c at right angles to the shaft 12c and at right angles to each other. At the tip of the bracket 17a, a rectangle is formed along the inner wall of the rising sludge tank 3 and has a length from the upper end of the inner wall of the rising sludge tank 3 to the vicinity of the upper edge of the opening of the concentrated sludge discharge pipe 9 described above. A concentrated sludge scraper 17 made of a plate-like member is attached. By rotating the third shaft 12c, the concentrated sludge scraper 17 removes the concentrated sludge (sludge deaerated by the rotary blade 16) attached to the upper inner wall of the floating sludge tank 3 by the rotation thereof. Move along the inner wall of No. 3 and scrape it. As shown in FIG. 4, the scraper 17 for concentrated sludge crosses the floating sludge tank 3 on the rotation direction side in contact with the inner wall of the floating sludge tank 3 or close to form a slight gap (about several mm). It is attached to the bracket 17a so as to form a predetermined angle with respect to the tangential direction of the plane circle.
Since the concentrated sludge scraper 17 only scrapes off the concentrated sludge, it does not need to be rotated at a high speed. It depends on the amount of the concentrated sludge which is repelled by the rotating blades 16 and adheres to the floating sludge tank 3. A low speed rotation of 2-3 m / min or less is desirable.
[0018]
Next, the operation of the present device will be described.
The raw sludge flows through the raw sludge inflow pipe 10b from the raw sludge tank storing the raw sludge to be treated by a pump. On the other hand, the pressurized air-dissolved water flows through the air-dissolved water inflow pipe 10c from a pressurized air-dissolved water tank in which the compressed air-dissolved water in which the compressed air is dissolved in the raw water at a high concentration is stored. Both are mixed at the connection part of both pipes, and are ejected from the ejection port 10a as sludge water into the sludge concentration device 1. The ejected sludge first collides with the inner wall of the flow direction regulating member 11. Since the lower surface of the flow direction regulating member 11 is closed, the sludge water changes its flow upward along the inner wall of the flow direction regulating member 11. Further, fine bubbles generated from pressurized air-dissolved water at atmospheric pressure adhere to the raw sludge in the sludge water in the tank. The raw sludge floats as floating sludge due to the buoyancy of the attached fine bubbles.
Here, the sludge component that has not adhered to the fine bubbles is settled as settled sludge. The settled sludge settled on the tapered inner wall of the settled sludge tank 2 is scraped off by the settled sludge scraper 15 rotating and moving along the tapered inner wall. Since the settling sludge scraper 15 scrapes at a low speed, the settling sludge settles to the bottom of the settling sludge tank 2 without being stirred in the sludge water. And it is conveyed to the settling sludge treatment process via the settling sludge discharge pipe 4. Excess pressurized air-dissolved water after the floating sludge and the settled sludge are separated passes through a passage 19 formed between the inner wall of the settled sludge tank 2 and the outer wall of the settled sludge tank 3 as separated water. The sediment sludge overflows from the upper edge of the tank 2 and flows out into the separation water receiving frame 5. Then, the water flows into the casing 6 formed in a part of the separated water receiving frame 5 and is discharged from the hole 6a to the separated water treatment step via the separated water discharge pipe 7.
[0019]
The floating sludge to which the fine bubbles adhere is gradually aggregated while floating inside the sludge guide plate 8 as floating sludge aggregating means, and is accumulated in the collar portion 8a. During the floating, the floating sludge adhering to the inner wall of the sludge guide plate 8 is scraped off by the floating sludge scraper 14 rotating and moving along the inner wall. Since the floating sludge scraper 14 scrapes off at the same low speed as the settled sludge scraper 15, the floating sludge starts to float again toward the sludge water surface near the flange 8a without being stirred in the sludge water. As shown in FIG. 6A, the liquid level of the sludge water is located near the rising edge of the flange 8a in order to increase the amount of floating sludge deposited and concentrate the sludge at a high concentration. . The floating sludge that has risen to the liquid level accumulates and is gradually concentrated. Then, of the accumulated concentrated sludge, the uppermost concentrated sludge having the highest concentration of sludge is repelled in the rotating direction by the rotating blade 16 rotating at a high speed. At this time, the sludge is easily degassed by the impact force due to the collision with the rotating blade 16 and the impact force due to the collision with the inner wall of the floating sludge tank 3. The concentrated sludge adhering to the inner wall of the floating sludge tank 3 is scraped off as needed by the concentrated sludge scraper 17 rotating and moving along the inner wall of the floating sludge tank 3, so that it does not dry and solidify on the wall surface. Then, the concentrated sludge that has been scraped is discharged to the concentrated sludge discharge pipe 9 through a hole 3a formed in the wall surface of the floating sludge tank 3 and collected.
[0020]
By the way, in the sludge concentrating apparatus according to the present invention described above, each of the blade-like members attached to the motor, the rotating blades, the scraper for the concentrated sludge, the scraper for the floating sludge, and the scraper for the settled sludge are all four sheets. The present invention is not limited to this, and one sheet may be used. Usually, it is 2 to 4 sheets.
If the rotor is attached to the shaft at an angle θ with respect to the motor rotation axis as shown in FIG. 6B, the concentrated sludge that has collided with the rotor is always repelled upward from the horizontal direction. Efficient deaeration can be performed without being returned to the concentrated sludge accumulated in the section 8a.
[0021]
In addition, the flow direction regulating member 11 is not limited to the above-described cylindrical shape, and may be any mode that guides the flow of the sludge water flowing into the sludge tank in the upward direction.
[0022]
【The invention's effect】
According to the sludge concentrator of the present invention having the above-described configuration, the following effects can be obtained.
(1) Of the sludge accumulated and concentrated on the sludge water surface, only the uppermost concentrated sludge, which has been sufficiently concentrated, is repelled by the rotating blades at a high speed, so that there is no turbulence and the sludge is mixed with the lower-concentration sludge. And a very high concentration of concentrated sludge can be recovered.
(2) Since the deaeration treatment of the concentrated sludge to which the microbubbles adhere can be performed simultaneously with the concentration of the sludge, there is no need to separately provide a deaeration treatment tank, and the efficiency of the sludge concentration flow is improved. (3) Since a scraper is provided to scrape off the concentrated sludge, floating sludge and settled sludge attached to the inner wall of the sludge tank, the frequency of cleaning the inner wall of the sludge tank is reduced.
(4) Since the sludge tank has a substantially cylindrical shape and the above-described rotary blades and each scraper are driven to rotate by one motor, a compact device with a small number of devices can be realized.
(5) Since the flow direction regulating member for guiding the flow of the sludge water flowing into the sludge tank to the upper direction is provided, the sludge water in the sludge tank is not disturbed, and the floating efficiency of the floating sludge is increased.
[Brief description of the drawings]
1 (a) and 1 (b) are a top view and a side view of a sludge concentrator according to the present invention.
FIG. 2 is a sectional view taken along the line AA in FIG.
FIG. 3 is a sectional view taken along line BB in FIG.
FIG. 4 is a sectional view taken along line CC in FIG. 1;
FIG. 5 is an overall perspective view of a sludge concentration device.
FIG. 6A is an explanatory view of a main part, and FIG. 6B is an explanatory view of a main part in another embodiment.
FIG. 7 is a flowchart illustrating an example of a conventional pressurized floating type sludge concentrator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sludge concentrating apparatus 2 Settling sludge tank 3 Floating sludge tank 4 Settling sludge discharge pipe 5 Separated water receiving frame 6 Housing 7 Separated water discharge pipe 8 Sludge guide plate 9 Concentrated sludge discharge pipe 10 Sludge inflow pipe 10a Spout port 10b Raw sludge inflow pipe 10c Air-dissolved water inflow pipe 11 Flow direction regulating member 12 Motor 12a, 12b, 12c Shaft 13 Bearing 14 Scraper for floating sludge 14a Bracket 15 Scraper for precipitated sludge 15a Bracket 16 Rotating blade 17 Scraper for concentrated sludge 17a Bracket 18 Sludge tank 19 Passage

Claims (11)

A sludge tank for introducing sludge water mixed with pressurized air dissolved water, floating sludge aggregating means for mixing the floated sludge mixed with the pressurized air in the sludge tank, and disposed on the liquid surface of the sludge water. A sludge concentrator, comprising: a rotating blade for repelling and deaerating the concentrated and accumulated sludge. The sludge tank is constituted by a bottomed cylindrical sedimentation sludge tank and a covered cylindrical floating sludge tank fitted inside the sedimentation sludge tank. The sludge concentrator according to claim 1, wherein a sludge discharge pipe is connected, and a concentrated sludge discharge pipe for discharging degassed sludge is connected to the floating sludge tank. The floating sludge aggregating means is constituted by a sludge guide plate having upper and lower portions opened, and the lower end portion of the sludge guide plate is fixed to the inner wall of a sludge tank located below the lower end portion of the concentrated sludge discharge pipe. The sludge concentrator according to claim 1 or 2, wherein the sludge concentrator is sealed, and an upper end thereof is disposed inside a floating sludge tank located above a liquid level of the sludge water. The sludge concentrator according to any one of claims 1 to 3, wherein a motor for rotating and driving the rotary blade is mounted on an upper part of the floating sludge tank. The sludge tank for settling sludge which is rotated and driven by the motor and moves along the inner wall of the settling sludge tank to scrape the settling sludge attached to the settling sludge tank is provided in the settling sludge tank. Item 5. A sludge concentrating device according to any one of Items 4. 3. The floating sludge tank is provided with a concentrated sludge scraper that is rotated by the motor, moves along the inner wall of the floating sludge tank, and scrapes the concentrated sludge attached to the floating sludge tank. Item 5. A sludge concentrating device according to any one of Items 4. The sludge guide plate is provided with a floating sludge scraper which is driven to rotate by the motor, moves along an inner wall of the sludge guide plate, and scrapes floating sludge attached to the sludge guide plate. Item 5. A sludge concentrating device according to any one of Items 4. The sludge concentrator according to any one of claims 2 to 7, wherein a passage for discharging separated water to the outside is formed between the settling sludge tank and the floating sludge tank. 3. The scraper for concentrated sludge, the scraper for floating sludge, and the scraper for settled sludge are attached to a rotating shaft of one motor, and are capable of rotating at different rotational speeds. A sludge concentrator according to any one of claims 1 to 7. The flow direction regulating member for guiding the flow of the sludge water upward is provided in the vicinity of an ejection port for ejecting the sludge water that has been acted on by the pressurized air dissolved water into the sludge tank. A sludge concentrator according to any one of claims 9 to 9. The sludge according to any one of claims 1 to 9, wherein the flow direction regulating member is a cylindrical member that surrounds the jet port, is open at an upper portion, and has a closed peripheral side surface and a bottom surface. Concentrator.

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