JPH09239400A - Sludge thickening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device which thickens the sludge in sewage, has a simple structure of the smaller number of apparatus parts, is capable of recovering the thickened sludge at a high concn., allows the simultaneous execution of a so-called deaeration treatment to remove the fine air bubbles in the thickened sludge and further, eliminates the need for frequently cleaning the inside walls of a sludge tank. SOLUTION: A sludge guide plate 8 which flocculates the floating sludge in a sludge tank 18 to be introduced with the sludge water contg. the water dissolved with pressurized air from an ejection port 10a in the sludge tank 18 is disposed into the sludge tank 18. The upper part of the sludge guide plate 8 is provided with rotary vanes 16 for splashing and deaerating the thickened and deposited sludge. The thickened sludge splashed by these vanes is recovered from a thickened sludge discharge pipe 9. The sludge tank 18 is composed to consist of two cylindrical settled sludge tank 2 and floated sludge tank 3. These sludge tanks are provided with scrapers 14 for the floating sludge, scrapers 15 for the settled sludge and scrapers 17 for the thickened sludge in order to scrape away the sludge stuck on the inside walls of these sludge tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for concentrating sludge in sewage, and more particularly to a pressure-floating type sludge concentrating apparatus for concentrating the sludge under pressure by floating fine sludge on the sludge. It is a thing.

[0002]

2. Description of the Related Art FIG. 7 is a flow chart showing an example of a conventional pressure floating type sludge concentrating device. First, the raw sludge to be treated is pumped from the raw sludge storage tank 21 by an inflow pipe 26.
It is sent to the inside of the sludge tank 24 of the sludge concentrating device 23. At this time, the pressurized air-dissolved water obtained by dissolving the compressed air from the pressurized air-dissolved water tank 22 is supplied to the supply path 2 in the middle of the inflow pipe 26.
It is sent from 7 and mixed with raw sludge. In the sludge tank 24, fine air bubbles in the pressurized air-dissolved water adhere to the sludge, and due to the buoyancy of the fine air bubbles, the floating sludge 28 is floated. The floating sludge 28 is accumulated and concentrated on the upper surface of the sludge water surface,
The sludge is periodically scraped in the arrow direction by a concentrated sludge scraping machine 25 having a scraping plate 25a attached to an endless chain or the like provided on the upper surface of the sludge water surface. The floated sludge 28 scraped off is sent to the deaeration tank 29, and the stirring blade 2
After being stirred for a certain period of time by 9a to perform a so-called deaeration process for separating attached bubbles, the sludge is recovered as concentrated sludge. The sludge to which no fine air bubbles are attached or the sludge having a large specific gravity becomes a settled sludge and is collected and collected by the settled sludge scraper 30 provided at the bottom of the sludge tank 24.
Further, the pressurized air-dissolved water separated from the floating sludge and the settled sludge is collected as separated water.

[0003]

The conventional sludge concentrating device described above has the following problems. (1) The scraping speed of the concentrated sludge by the concentrated sludge scraping machine 25 must be a speed (for example, about 60 cm / min) that does not cause a stirring action on the concentrated sludge. Because, of the concentrated sludge accumulated and concentrated on the water surface of the sludge, the highest concentration of sludge is the highest concentration sludge, and if turbulence occurs when scraping this highest concentration sludge, the concentration of the lower layer This is because the concentration of the concentrated sludge to be recovered will be low because it will be mixed with low concentrated sludge. If this scraping speed is increased, the sludge treatment time will be shortened, but the concentrated sludge to be scraped tends to be disturbed, the concentration of the recovered concentrated sludge will be low, and conversely the concentration of sludge in the separated water will be high. Will end up. Further, if the speed is slowed down, the sludge treatment time becomes long, and the amount of floating sludge accumulated increases, so that a large-scale device is required. It is very difficult to determine the scraping speed value because the concentration and state of the original sludge at that time are different. (2) As for the position of the scraping plate 25a in the height direction with respect to the water surface of sludge, it is more efficient to bring it closer to the water surface of sludge because the amount of concentrated sludge to be scraped at once increases, but while scraping a large amount of floating sludge. Since the sludge is agitated, the concentration of the recovered sludge becomes low as in the above. This scraping plate 25
Position setting of a is also very difficult. (3) Since the flotation sludge is scraped off and then passed to the stirring and degassing step (29), the so-called sludge concentration flow efficiency is poor. (4) The sludge that has flowed into the sludge concentrator 23 is the sludge tank 2
It was necessary to frequently clean the inner wall of the sludge tank 24 in order to easily attach and stack it on the inner wall of No. 4.

The present invention was devised to solve the above-mentioned problems and has a simple structure capable of collecting concentrated sludge at a high concentration, and at the same time performing so-called degassing treatment for removing fine bubbles in the concentrated sludge. It is an object of the present invention to provide a sludge concentrating device that can be performed and does not require frequent cleaning of the inner wall of the sludge tank.

[0005]

The present invention uses the following means in order to achieve the above object. First, as a means for collecting concentrated sludge in high concentration and simultaneously deaerating the concentrated sludge, a sludge tank that introduces sludge water mixed with pressurized air-dissolved water, and mixed with pressurized air and floated. Floating sludge aggregating means for aggregating the sludge in the sludge tank, and rotary blades disposed on the liquid surface of the sludge water for splashing and degassing the sludge concentrated and accumulated. In addition, the sludge tank,
It is composed of a bottomed cylindrical sedimentation sludge tank and a lidded cylindrical floating sludge tank that is fitted in the sedimentation sludge tank, and a sedimentation sludge discharge pipe for discharging the sedimentation sludge is connected to the sedimentation sludge tank. Further, a concentrated sludge discharge pipe for discharging deaerated sludge was connected to the floating sludge tank. Further, the floating sludge aggregating means is constituted by a sludge guide plate whose upper and lower parts are opened, and the lower end of the sludge guide plate is located below the lower end of the concentrated sludge discharge pipe. Was fixed and sealed at the same time, and its upper end was placed inside the floating sludge tank located above the liquid level of the sludge water. Further, a motor for rotating and driving the rotary blade was placed on the upper part of the floating sludge tank.

As a means for reducing the frequency of cleaning the inner wall of the sludge tank, the settling sludge tank is driven to rotate by the motor, moves along the inner wall of the settling sludge tank, and adheres to the settling sludge tank. A scraper for settling sludge for scraping off settling sludge was provided. Further, a concentrated sludge scraper, which is driven to rotate by the motor and moves along the inner wall of the floating sludge tank to scrape the concentrated sludge adhering to the floating sludge tank, is provided in the floating sludge tank. Further, the sludge guide plate was provided with a scraper for floating sludge that was driven to rotate by the motor and moved along the inner wall of the sludge guide plate to scrape the floating sludge adhering 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 sedimentation sludge tank and the floating sludge tank. Further, the rotary blade, the concentrated sludge scraper, the floating sludge scraper, and the settled sludge scraper are attached to the rotary shaft of one motor so that they can rotate at different rotational speeds.

Further, in order to improve the floating efficiency of the floating sludge, in order to guide the sludge water flow upward in the vicinity of the jet port for jetting the sludge water to which the pressurized air-dissolved water acts into the sludge tank. The flow direction regulating member of No. 1 is provided. In particular, the flow direction regulating member is a cylindrical member that surrounds the jet outlet and has an open upper portion and closed peripheral side surfaces and bottom surface.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments 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, and FIG. 3 is a sectional view taken along line BB in FIG.
4 is a sectional view taken along line CC in FIG. 1, FIG. 5 is an overall perspective view of the sludge concentrating device, and FIG.
(B) is a partial explanatory view in other embodiments. In these figures, reference numeral 1 indicates a sludge concentrator. This sludge concentrating device 1 takes in raw sludge to be treated together with pressurized air dissolved water in which compressed air is dissolved in water from a jet port 10a, floats sludge in a sludge tank 18 and concentrates the sludge, and discharges the concentrated sludge. The settling sludge is discharged to the pipe 9 to the settling sludge discharge pipe 4, and the separated water separated from the floated or settled sludge to the separated water discharge pipe 7.

The sludge tank 18 is composed of two housing members, a settling sludge tank 2 and a floating sludge tank 3. The settling sludge tank 2 is a bottomed cylindrical member having an open upper portion, and has a tapered shape in which a lower portion is narrowed at a lower portion thereof, and a cylindrical shape having a smaller diameter is again formed at a bottom portion. The side wall of the bottom cylindrical portion has a hole 2a for discharging the settled sludge.
And a settling sludge discharge pipe 4 is connected. Around the upper edge of the settling sludge tank 2, a separated water receiving frame 5 having an L-shaped cross section is attached over 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 6a is formed in the bottom portion of the housing 6 to which a separated water discharge pipe 7 is connected.

The floating sludge tank 3 is a cylindrical member with a lid whose bottom is opened, and the outer diameter of the floating sludge tank 3 is smaller than the inner diameter of the settling sludge tank 2 to the extent that a passage 19 for separated water is formed. (Not shown) is fitted and fixed concentrically inside the settling sludge tank 2. The side wall of the floating sludge tank 3 is provided with a hole 3a for discharging the degassed sludge, and a concentrated sludge discharge pipe 9 is connected to the hole 3a. The concentrated sludge discharge pipe 9 penetrates the hole 2b formed in the side wall of the settled sludge tank 2 (the contact portion is sealed by welding or the like), and is continued to the next treatment step.

Inside the floating sludge tank 3, there is provided a sludge guide plate 8 having a truncated cone shape with open upper and lower portions as floating sludge aggregating means. The sludge guide plate 8 is for guiding the flotation sludge upward and causing the flocculation to agglomerate, and for separating the degassed concentrated sludge blown off by a rotary blade 16 described later from the flotation sludge. 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 portion of the sludge guide plate 8 forms a brim portion 8a that stands vertically over the entire circumference thereof. As shown in FIGS. 2 and 6 (a), the brim portion 8a is set up so that it is located slightly above the liquid level (W.L.) of the sludge water that has flowed into the sludge concentrating device 1. It is for depositing and concentrating flocculated floating sludge on the liquid surface.

Holes 2c and 3b (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.
The sludge inflow pipe 10 through which the raw sludge mixed with the compressed air-dissolved water flows is penetrated through these holes 2c and 3b (the contact portion is sealed by welding or the like), and the sludge concentrating device 1 It extends to near the center of the inside, and its tip is the jet outlet 10a.
And The sludge inflow pipe 10 is connected to a raw sludge inflow pipe 10b for sending the raw sludge by a pump from a raw sludge tank (not shown) in which the raw sludge is stored, and is branched and connected to the raw water so that compressed air can be highly concentrated in the raw water. It comprises a pressurized air-dissolved water inflow pipe 10c for sending the dissolved pressurized air-dissolved water by a pump.

Inside the settling sludge tank 2, a sludge inflow pipe 10 is provided.
A flow direction regulating member 11 that guides the flow of sludge water ejected from the ejection port 10a of the above is provided. The flow direction control member 11 is a bottomed cylindrical member provided on the same axis as the settling sludge tank 2 with an open top and closed peripheral side and bottom surfaces, and the jet outlet 10a faces the inside thereof. 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. Also,
A motor 1 described later is provided at the center of the bottom surface of the flow direction regulating member 11.
A hole is formed so that the shaft 12a attached to the No. 2 can penetrate.

The motor 1 is provided at the center of the upper surface of the floating sludge tank 3.
2 is mounted, and three first, second and third shafts 12a, 12b, 12c whose rotation speeds can be adjusted by a transmission (not shown) are attached to the motor 12. The first shaft 12a extends downward and penetrates through the hole formed in the bottom surface of the flow direction regulating member 11 and is fitted into the bearing 13 supported on the bottom surface of the settling sludge tank 2. Feather-shaped members having different purposes are attached to the three shafts having different rotational speeds.

First, the first shaft 12a has a plurality of brackets 14 on each of the upper side and the lower side, and four brackets 14 in this embodiment.
a and 15a are attached at right angles to the shaft 12a and radially so as to form the same angle with each other. A floating sludge scraper 14 made of a plate-like member having a shape and a length dimension along the inner wall of the sludge guide plate 8 is provided at the tip of the upper bracket 14a, and sedimentation is provided at the tip of the lower bracket 14b. The sludge scraper 15 for sedimentation, which is a plate-like member having a shape and a length 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 adhered to the inner wall of the sludge guide plate 8 along the inner wall of the sludge guide plate 8 by the rotation thereof. As shown in FIG. 3, the floating sludge scraper 14 contacts the rotation direction side of the sludge guide plate 8 with the inner wall of the sludge guide plate 8 or is close to the sludge guide plate 8 to form a slight gap (about several mm). Is attached to the bracket 14a so as to form a predetermined angle with respect to the tangential direction of the cross section circle. On the other hand, the settled sludge scraper 15 moves and scrapes the settled sludge attached to the tapered inner wall of the settled sludge tank 2 along the inner wall by its rotation. The sludge scraper 15 for sedimentation sludge is the scraper 14 for floating sludge.
Similarly, the rotation direction side is in contact with the taper inner wall of the settling sludge tank 2 or is close to the taper inner wall so as to form a slight gap, and the bracket 15a is formed so as to form a predetermined angle with respect to the tangential direction of the cross section of the taper inner wall. Is attached to. Shaft 12
When the peripheral speed of a is set to a high speed, the scraper 14 for floating sludge
Further, sludge scraped off by the sludge for settling sludge 15 is disturbed in the tank and is not appropriate. It is desirable to rotate at a low speed of about 2 to 3 m / min or less. In this form,
I attached the scraper for flotation sludge and the scraper for sedimentation sludge to the same shaft.
Alternatively, the number of rotations may be one and the number of rotations may be different.

Next, a plurality of sheets are attached to the second shaft 12b,
In the present embodiment, four rectangular blade-shaped rotary blades 16 are mounted at right angles to the shaft 12b and radially so as to form the same angle. Second shaft 12
By rotating b, this rotary blade 16 rotates,
The concentrated sludge accumulated in the collar portion 8a of the sludge guide plate 8 is splashed toward the inner wall of the floating sludge tank 3 to be deaerated. The dimension from the tip of the rotary blade 16 to the tip of the rotary blade 16 positioned 180 degrees opposite (L in FIG. 6A) in order to efficiently splash the floating sludge and deaerate it.
The dimension is approximately the same as the diameter of the collar 8a, and the gap between the lower edge of the rotary blade 16 and the upper edge of the collar 8a (see FIG. 6).
(H dimension in (a)) is about 0 to several mm. Further, deaeration of the concentrated sludge with bubbles adheres to the rotary blade 16 and the collision force against the inner wall of the flotation sludge tank 3 when it is bounced tangentially to the rotation of the rotary blade 16. The rotation speed of the shaft 12b is preferably 100 rpm or more in order to increase the collision force.

A plurality of, in the present 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 having a shape along the inner wall of the floating sludge tank 3 and having a length from the upper end of the inner wall of the floating sludge tank 3 to the vicinity of the upper edge of the opening of the concentrated sludge discharge pipe 9 described above Scraper for concentrated sludge 1 consisting of plate-shaped members
7 is attached. By rotating the third shaft 12c, the concentrated sludge scraper 17 causes the concentrated sludge adhered to the upper inner wall of the floating sludge tank 3 (sludge degassed by the rotary blade 16) to float in the floating sludge tank. Move along the inner wall of 3 and scrape. As shown in FIG. 4, the concentrated sludge scraper 17 contacts the inner wall of the flotation sludge tank 3 on the rotation direction side or is close to form a slight gap (about several mm), and traverses the flotation sludge tank 3. The bracket 17a is attached so as to form a predetermined angle with respect to the tangential direction of the face circle. Since the concentrated sludge scraper 17 only scrapes the concentrated sludge off, it does not need to rotate at a high speed, and the peripheral speed of the shaft 12c depends on the amount of concentrated sludge that is splashed off by the rotor blades 16 and adheres to the floating sludge tank 3. A low speed rotation of 2 to 3 m / min or less is desirable.

Next, the operation of this apparatus will be described. From the raw sludge tank in which the raw sludge to be treated is stored, the raw sludge flows in the raw sludge inflow pipe 10b by a pump. On the other hand, the pressurized air-dissolved water flows through the air-dissolved water inflow pipe 10c from the 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 connecting portion of both pipes and ejected as sludge water into the interior of the sludge concentrator 1 from the ejection port 10a. The ejected sludge water 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. In addition, for raw sludge in sludge water,
Under atmospheric pressure, fine bubbles generated from pressurized air-dissolved water adhere. The raw sludge floats as floating sludge due to the buoyancy of the adhered fine bubbles. Here, the sludge components that have not adhered to the fine bubbles are 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 which rotates and moves along the tapered inner wall. Since the sludge scraper 15 for scraping sludge scrapes at a low speed, the sludge settles down to the bottom of the sludge sludge tank 2 without being stirred in the sludge water. Then, it is conveyed to the settling sludge treatment step via the settling sludge discharge pipe 4. Further, the excess pressurized air-dissolved water after the separation of the floating sludge and the settling sludge passes as a separated water through a passage 19 formed between the inner wall of the settling sludge tank 2 and the outer wall of the floating sludge tank 3. It overflows from the upper edge of the settling sludge tank 2 and flows into the separated water receiving frame 5. Then, the housing 6 formed in a part of the separated water receiving frame 5
And is discharged to the separated water treatment step from the hole 6a through the separated water discharge pipe 7.

The floating sludge to which the fine air bubbles are attached is gradually aggregated while floating inside the sludge guide plate 8 as the flocculation sludge aggregating means, and is accumulated in the collar portion 8a.
During the floating, the floating sludge adhered to the inner wall of the sludge guide plate 8 is scraped off by the floating sludge scraper 14 which rotates and moves along the inner wall. Scraper for floating sludge 1
Since No. 4 scrapes off at the same low speed as the settling sludge scraper 15, the floating sludge begins to float again toward the water surface of the sludge near the brim 8a without being stirred in the sludge water. As shown in FIG. 6A, the liquid level of sludge water is located near the rising edge of the brim portion 8a of the brim portion 8a in order to increase the deposition amount of the floating sludge and concentrate the sludge to a high concentration. . The floating sludge that has floated to the surface of the liquid accumulates and is gradually concentrated. The uppermost concentrated sludge having the highest sludge concentration among the accumulated concentrated sludge is repelled in the rotating direction by the rotary blades 16 rotating at a high speed. At this time, the sludge is easily deaerated by the impact force caused by the collision with the rotary blades 16 and the impact force caused by 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 by the concentrated sludge scraper 17 that rotates and moves along the inner wall of the floating sludge tank 3 at any time, so that it does not dry and solidify on the wall surface. Then, the scraped thickened sludge is discharged and collected into the thickened sludge discharge pipe 9 through the hole 3a formed in the wall surface of the floating sludge tank 3.

In the sludge concentrating apparatus according to the present invention described above, each of the blade-shaped members attached to the motor, the rotor, the scraper for the concentrated sludge, the scraper for the floating sludge, and the scraper for the settled sludge are four in number. However, the present invention is not limited to this, and one sheet may be used. Usually, it is 2-4 sheets. As shown in FIG. 6 (b), if the rotary blade is attached to the shaft by inclining it by an angle θ with respect to the motor rotary shaft, the concentrated sludge colliding with the rotary blade is always splashed upward from the horizontal direction. Efficient degassing can be performed without returning to the concentrated sludge accumulated in the portion 8a.

Further, the flow direction restricting member 11 is not limited to the above-mentioned cylindrical member, but may be any member that guides the sludge water flowing into the sludge tank in the upward direction.

[0022]

According to the sludge concentrating apparatus of the present invention having the above-mentioned structure, the following effects can be obtained. (1) Sludge Of the sludge accumulated and condensed on the surface of the water, only the uppermost concentrated sludge, which has been sufficiently concentrated, is repelled at high speed by the rotor blades, so it does not cause turbulence and mix with the lower concentration of sludge. It is possible to collect concentrated sludge of extremely high concentration. (2) Since the deaeration process of the concentrated sludge having fine air bubbles can be performed at the same time as the concentration of the sludge, it is not necessary to separately provide a deaeration treatment tank, and the sludge concentration flow efficiency is improved. (3) Since the scraper for scraping off the concentrated sludge, the floating sludge, and the settled sludge adhering to the inner wall of the sludge tank is provided, 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 rotary blades and the scrapers are driven to rotate by one motor, a compact device having 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 improved.

[Brief description of drawings]

FIG. 1 (a) and (b) are a top view and a side view of a sludge concentrating device according to the present invention.

FIG. 2 is a sectional view taken along 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.

FIG. 5 is an overall perspective view of a sludge concentrating device.

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 an explanatory flow diagram showing an example of a conventional pressure floating type sludge concentrating device.

[Explanation of symbols]

 1 Sludge Concentrator 2 Sedimentation Sludge Tank 3 Floating Sludge Tank 4 Sedimentation Sludge Discharge Pipe 5 Separation Water Receiving Frame 6 Housing 7 Separation Water Discharge Pipe 8 Sludge Guide Plate 9 Condensed Sludge Discharge Pipe 10 Sludge Inlet Pipe 10a Jet 10b Raw Sludge Inflow Pipe 10c Air-dissolved water inflow pipe 11 Flow direction regulating member 12 Motors 12a, 12b, 12c Shaft 13 Bearing 14 Floating sludge scraper 14a Bracket 15 Slag sludge scraper 15a Bracket 16 Rotor blades 17 Condensed sludge scraper 17a Bracket 18 Sludge tank 19 Passage

Claims (11)

[Claims] 1. A sludge tank for introducing sludge water mixed with pressurized air-dissolved water, a floating sludge aggregating means for aggregating sludge that is mixed with pressurized air and floated in the sludge tank, and a liquid surface of the sludge water. A sludge concentrating device, which is provided on the upper side of the sludge and has rotary blades for repelling and degassing concentrated and accumulated sludge. 2. The sludge tank is constituted by a bottomed cylindrical sedimentation sludge tank and a lidded cylindrical floating sludge tank fitted in the sedimentation sludge tank, and the sedimentation sludge tank is filled with the sedimentation sludge. The sludge concentrating device according to claim 1, wherein a sedimentation sludge discharge pipe for discharging is connected, and a concentrated sludge discharge pipe for discharging deaerated sludge is connected to the floating sludge tank. 3. The floating sludge aggregating means is constituted by a sludge guide plate whose upper and lower parts are opened, and the lower end of the sludge guide plate is located below the lower end of the concentrated sludge discharge pipe. The sludge concentrate according to claim 1 or 2, wherein the sludge is fixed and sealed to the inner wall of the tank, and the upper end thereof is arranged inside the floating sludge tank located above the liquid level of the sludge water. apparatus. 4. The sludge concentrating device according to claim 1, wherein a motor for rotating and driving the rotary blade is mounted on an upper portion of the floating sludge tank. 5. The settled sludge scraper, which is driven to rotate by the motor and moves along the inner wall of the settled sludge tank to scrape the settled sludge adhering to the settled sludge tank, is provided in the settled sludge tank. The sludge concentrating device according to any one of claims 2 to 4. 6. The sludge scraper for concentrated sludge, which is driven to rotate by the motor and moves along the inner wall of the floating sludge tank to scrape the concentrated sludge adhering to the floating sludge tank, is provided in the floating sludge tank. The sludge concentrating device according to any one of claims 2 to 4. 7. The sludge guide plate is driven to rotate by the motor and moved along the inner wall of the sludge guide plate,
The sludge concentrating device according to any one of claims 2 to 4, further comprising a floating sludge scraper for scraping the floating sludge adhered to the sludge guide plate. 8. Between the settling sludge tank and the floating sludge tank,
The sludge concentrator according to any one of claims 2 to 7, wherein a passage for discharging separated water is formed outside. 9. The rotary blade, the concentrated sludge scraper, the floating sludge scraper, and the settled sludge scraper are attached to a rotary shaft of a single motor, and can rotate at different rotational speeds. Claim 2
The sludge concentrating device according to claim 7. 10. A flow direction restricting member for guiding the flow of the sludge water upward is provided in the vicinity of an ejection port for ejecting the sludge water to which the pressurized air-dissolved water is applied into the sludge tank. The sludge concentrating device according to any one of claims 1 to 9. 11. The flow direction restricting member is a cylindrical member that surrounds the jet outlet, is open at an upper portion, and is closed at a peripheral side surface and a bottom surface, according to any one of claims 1 to 9. The sludge concentrating device described in Crab.