JPH11253998A - Sludge concentrating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge concentrating apparatus capable of enhancing work efficiency and filtering treatment capacity by controlling the viscosity of conc. sludge obtained by concentrating excessive sludge generated in a waste water treatment process and capable of controlling the viscosity of conc. sludge in low cost. SOLUTION: A sludge concentrating apparatus has a sludge concentrating tank 1 concentrating excessive sludge generated in a waste water treatment process, a conc. sludge storage tank 2 storing conc. sludge, a transfer line 4 transferring the conc. sludge from the sludge concentrating tank 1 to the conc. sludge storage tank 2 and a pressure sensor 6 measuring the transfer pressure in the transfer line 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge concentrating apparatus for concentrating and reducing excess sludge generated in the process of treating wastewater such as human waste and sewage, and more particularly, to an apparatus for overconcentrating excess sludge. The present invention relates to a sludge concentrating device capable of preventing sludge.

[0002]

2. Description of the Related Art Conventionally, urban wastewater such as night soil and sewage,
Organic industrial wastewater from factories and the like is discharged to rivers and the like after being subjected to a treatment for removing various suspended substances (SS) and soluble organic substances contained therein. The treatment of the above-mentioned municipal wastewater and organic industrial wastewater is performed, for example, in a wastewater treatment plant using a system as shown in FIG. 5 as follows. First, in the raw wastewater to be treated, a relatively large suspended substance is settled and separated in the initial settling tank. Next, the water-soluble organic components in the raw water are decomposed by the activated sludge in the aeration tank. Subsequently, after the sludge is separated and settled in the final settling tank, it is discharged to a river or the like.

[0003] Excess sludge generated by the treatment using the above system is withdrawn from the system, transferred to a centralized treatment plant, and finally subjected to treatment such as incineration, landfill, composting, and the like. In order to reduce the cost of transfer to such a centralized treatment plant and facilitate the final treatment, it is preferable to concentrate the surplus sludge to some extent in a sludge concentration tank of a wastewater treatment plant, reduce the water content, and reduce the amount. . For example, if excess sludge with a concentration of 1% can be concentrated to 3% at a wastewater treatment plant, the amount of sludge transferred to the centralized treatment plant will be one-third.
Can be reduced.

[0004] The transfer of concentrated sludge to such a centralized treatment plant is usually performed using a vacuum truck. However, since there is a limit to the viscosity of the concentrated sludge that can be sucked by the vacuum truck, if the excess sludge is excessively concentrated, the viscosity of the concentrated sludge exceeds the range that can be sucked by the vacuum truck. Therefore, extra work such as work to remove clogging generated in the vacuum car and work to dilute the concentrated sludge with water occurs, which causes a problem that work efficiency is deteriorated. Also, in a sludge concentrator using a separation membrane to concentrate excess sludge, if excessive sludge is concentrated too much, the membrane pores of the separation membrane will be blocked by overconcentration, and the concentration treatment capacity of the separation membrane will be significantly reduced. Would.

As a method for preventing such over-concentration, there is known a method of monitoring the viscosity of the concentrated sludge and performing the concentration such that the viscosity is within a specified range.
However, since the viscometer and the torque meter used for monitoring the viscosity are very expensive, when they are attached to the sludge concentrator, there is a problem that the production cost of the sludge concentrator increases.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to control the viscosity of concentrated sludge obtained by concentrating excess sludge, thereby improving work efficiency and preventing a reduction in the concentration treatment capacity. Another object of the present invention is to provide a sludge concentrating apparatus capable of controlling the viscosity of concentrated sludge at low cost.

[0007]

SUMMARY OF THE INVENTION As a sludge concentrating device, a sludge concentrating tank for condensing excess sludge generated in a wastewater treatment process, a concentrated sludge storage tank for storing concentrated sludge, and the above-mentioned sludge concentrating tank. This problem can be solved by using a transfer line for transferring the concentrated sludge from the storage tank to the concentrated sludge storage tank and a pressure sensor for measuring a transfer pressure in the transfer line.

[0008] Further, as a sludge concentration device, a sludge concentration tank for condensing excess sludge generated in the process of wastewater treatment, a concentrated sludge storage tank for storing concentrated sludge, and a supply line for supplying surplus sludge to the sludge concentration tank. A discharge line connected in the middle of the supply line to feed concentrated sludge discharged from the sludge thickening tank to the supply line, and a branch from the supply line on the downstream side from a connection portion of the discharge line, and The problem can be solved by using a device having a transfer line for transferring the concentrated sludge to the sludge storage tank and a pressure sensor for measuring a transfer pressure in the transfer line.

Further, a membrane separation device provided with a separation membrane may be provided in the sludge concentration tank. Further, as the membrane separation device, having a hollow fiber membrane composed of a plurality of hollow fibers, and water collection pipes provided at both ends of the hollow fiber membrane,
A hollow fiber membrane module that allows the filtrate entering the hollow fiber to pass through an internal passage formed in the water collecting pipe may be used.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments.

(Embodiment 1) FIG. 1 is a schematic view showing an embodiment of a sludge concentrating apparatus according to the present invention. This sludge concentrating apparatus includes a sludge concentrating tank 1 for condensing excess sludge supplied from a final sedimentation tank (not shown), and a concentrated sludge storage tank 2 for storing the concentrated sludge concentrated in the sludge concentrating tank 1. ing.

A supply line 3 for supplying excess sludge is provided above the sludge thickening tank 1, and one end of a transfer line 4 is provided near the bottom of the sludge thickening tank 1 so as to communicate therewith. The other end of the line 4 is provided so as to communicate with the concentrated sludge storage tank 2. The transfer line 4 transfers the concentrated sludge concentrated in the sludge concentration tank 1 to the concentrated sludge storage tank 2.
The transfer line 4 is provided with a transfer pump 5 for transferring the concentrated sludge.
And a pressure sensor 6 for measuring the transfer pressure, and a regulating valve 7 for adjusting the transfer flow rate of the concentrated sludge as required.
Is provided.

The transfer pump 5 may be any pump capable of transferring the concentrated sludge, and is not particularly limited. A turbo-type pump such as an axial flow pump, a mixed flow pump, and a centrifugal pump;
Reciprocating pumps such as piston pumps, plunger pumps and wing pumps; rotary pumps such as gear pumps and vane pumps; Above all, a turbo type pump is suitably used because it is suitable for pumping a large amount of liquid.

The pressure sensor 6 is not particularly limited as long as it can measure the transfer pressure in the transfer line 4. Specifically, a Bourdon tube type, a diaphragm type, a bellows type, and the like, which are usually used in process control of a chemical plant, etc., can be mentioned. Among them, a diaphragm type with less sludge clogging is preferably used. Further, the pressure sensor 6 needs to be installed in the transfer line 4 downstream of the transfer pump 5 in order to measure the transfer pressure in the transfer line 4.

The regulating valve 7 is not particularly limited as long as it can regulate the transfer flow rate of the concentrated sludge, and examples thereof include a ball valve, a ball valve, a gate valve, and a needle valve. Among them, a gate valve is preferably used. Further, the regulating valve 7 needs to be provided in the transfer line 4 downstream of the pressure sensor 6. If the regulating valve 7 is provided upstream of the pressure sensor 6, it will be difficult to measure the transfer pressure in the transfer line 4.

Next, a sludge concentrating method using the sludge concentrating apparatus shown in FIG. 1 will be described. Excess sludge pumped from a final sedimentation tank (not shown) by a supply-side transfer pump (not shown) is supplied to the sludge concentration tank 1 through the supply line 3 and concentrated. At this time, as a method of concentrating the excess sludge performed in the sludge concentration tank 1, a known concentration method such as a gravity sedimentation method, a method using a coagulant in combination with the gravity sedimentation method, or the like is used.

The concentrated sludge that has been concentrated in the sludge thickening tank 1 and settled near the bottom of the sludge thickening tank 1 is transferred to the concentrated sludge storage tank 2 through the transfer line 4 by the transfer pump 5, and the excess sludge is removed. The separated water separated is drawn out from a pumping line provided at the upper part of the sludge concentration tank 1 by using an air lift pump or the like, or is taken out from the upper part of the sludge concentration tank 1 by overflowing.
Released into rivers. And the above-mentioned concentrated sludge storage tank 2
The concentrated sludge stored in the tank is later transferred to a centralized treatment plant or the like by a vacuum truck. Here, the viscosity of the concentrated sludge that can be sucked by a vacuum car is usually 2000 centipoise or less, preferably 1500 centipoise or less,
The concentrated sludge transferred to the concentrated sludge storage tank 2 needs to be within this viscosity range.

In order to make the viscosity of the concentrated sludge transferred to the concentrated sludge storage tank 2 fall within a specified range, the following method is used. First, a concentrated sludge having a viscosity in the upper limit of a specified range is transferred in advance, and a pressure loss is obtained from the transfer pressure in the transfer line 4 measured at this time, and this value is set as the upper limit of the pressure loss. Next, when the concentrated sludge is actually transferred to the concentrated sludge storage tank 2, the transfer pressure in the transfer line 4 is measured by the pressure sensor 6 provided in the transfer line 4, and the pressure loss in the transfer line 4 is obtained. When the pressure loss exceeds the upper limit of the pressure loss measured in advance, the viscosity of the concentrated sludge in the sludge concentration tank 1 is reduced by a method such as increasing the supply flow rate of the excess sludge to the sludge concentration tank 1, Transfer line 4 above
Pressure loss within the upper limit. In this way, the viscosity of the concentrated sludge can always be kept within the specified range. Here, the pressure loss is determined by the venturi method, the orifice method,
It can be determined by a known method such as a color tube method.

If the piping used for the transfer line 4 is too thick, the transfer pressure may be low, making it difficult to determine the pressure loss. In this case, the measurement is performed by squeezing the regulating valve 7 to increase the transfer pressure of the concentrated sludge. However, the upper limit value of the pressure loss according to the degree of restriction of the regulating valve 7 needs to be measured in advance.

In such a sludge concentrating apparatus, a pressure sensor 6 is provided in a transfer line 4 for transferring the concentrated sludge from the sludge thickening tank 1 to the concentrated sludge storage tank 2, so that the measurement was carried out with this pressure sensor. The pressure loss can be determined from the transfer pressure, and the viscosity of the concentrated sludge can be adjusted using the numerical value of the pressure loss so as to be within a specified range. Further, since the viscosity is adjusted using a pressure sensor instead of an expensive viscometer or torque meter, the cost of the apparatus can be reduced.

(Embodiment 2) FIG. 2 is a schematic view showing an embodiment of a sludge concentrating apparatus according to the present invention, in which the same components as in Embodiment 1 are denoted by the same reference numerals. This sludge thickener is
A sludge concentration tank 1 for condensing excess sludge supplied from a final sedimentation tank (not shown), and a concentrated sludge storage tank 2 for storing the concentrated sludge concentrated in the sludge concentration tank 1 are provided.

A supply line 8 for supplying excess sludge is provided above the sludge thickening tank 1, and one end of a discharge line 9 is provided near the bottom of the sludge thickening tank 1 so as to communicate therewith. The other end of the line 9 is connected in the middle of the supply line 8. One end of a transfer line 10 is provided in communication with the upper part of the concentrated sludge storage tank 2, and the other end of the transfer line 10 is provided in the middle of the supply line 8 on the downstream side from the connection part of the discharge line 9. Connected.

The supply line 8 is connected to the discharge line 9
The solenoid valve 11 and the transfer line 10
An electromagnetic valve 12 is provided on the downstream side from the connection part of the above, and a pump 13 is provided between the connection part of the discharge line 9 and the connection part of the transfer line 10. The discharge line 9 is
The concentrated sludge concentrated in the sludge concentration tank 1 is converted into the sludge concentration tank 1
The discharge line 9 is provided with a solenoid valve 14.

The transfer line 10 is connected to the discharge line 9
The concentrated sludge discharged to the supply line 8 is provided to transfer the concentrated sludge to the concentrated sludge storage tank 2. The transfer line 10 includes a pressure sensor 6 for measuring a transfer pressure, and a concentrated sludge. Adjustment valve 7 for adjusting the transfer amount
Is provided upstream from the pressure sensor 6. Further, an electromagnetic valve 15 is provided on the transfer line 10 on the upstream side from the pressure sensor 6.

The solenoid valve 11 prevents the concentrated sludge discharged from the discharge line 9 from flowing back upstream of the supply line, and the solenoid valve 12 controls the concentrated sludge discharged from the discharge line 9 to the sludge concentration. Prevent entry into tank 1. The solenoid valve 14 is connected to the sludge thickening tank 1 from the discharge line 9.
The electromagnetic valve 15 prevents the excess sludge from entering the transfer line 10 from above.

Next, a sludge concentrating method using the sludge concentrating apparatus shown in FIG. 2 will be described. Excess sludge pumped by a pump 13 from a final sedimentation tank (not shown) is supplied to the sludge concentration tank 1 through the supply line 8. At this time,
The solenoid valves 11 and 12 are opened, and the solenoid valves 14 and 15 are closed.

The excess sludge supplied from the supply line 8 is concentrated in the sludge concentration tank 1. During the concentration, the solenoid valves 11 and 12 are closed, and the supply of the excess sludge is stopped. After the concentration is completed, the solenoid valves 14 and 15 are opened. The concentrated sludge that has been concentrated and settled in the vicinity of the bottom of the sludge thickening tank 1 is discharged to the supply line 8 through the discharge line 9 by the pump 13, and is transferred to the concentrated sludge storage tank 2 through the transfer line 10.
Separated water separated from excess sludge is drawn out from a pumping line provided at the upper part of the sludge thickening tank 1 by using an air lift pump or the like, or is taken out by overflowing from the upper part of the sludge thickening tank 1. , And discharged into rivers.

When transferring the concentrated sludge, the transfer line 1
The transfer pressure within 0 is measured by the pressure sensor 6 to determine the pressure loss. When the pressure loss exceeds the upper limit of the pressure loss obtained in the same manner as in Embodiment 1, the solenoid valves 14 and 15 are closed to stop the discharge and transfer of the concentrated sludge. Then, solenoid valve 1
By opening 1 and 12, excess sludge is supplied to the sludge thickening tank 1, and the viscosity of the thickened sludge is adjusted within a specified range. After the supply of the excess sludge, the electromagnetic valves 11 and 12 are closed, the supply of the excess sludge is stopped, and the discharge and transfer of the concentrated sludge are restarted.

In such a sludge concentrating apparatus, a pressure sensor 6 is provided in the transfer line 4 for transferring the concentrated sludge from the sludge thickening tank 1 to the thickened sludge storage tank 2, so that the measurement was carried out by this pressure sensor. The pressure loss can be determined from the transfer pressure, and the viscosity of the concentrated sludge can be adjusted using the numerical value of the pressure loss so as to be within a specified range. Further, since the viscosity is adjusted using a pressure sensor instead of an expensive viscometer or torque meter, the cost of the apparatus can be reduced. Further, since the supply of the excess sludge and the discharge and transfer of the concentrated sludge are performed by one pump, the cost of the apparatus can be further reduced.

(Embodiment 3) FIG. 3 is a schematic view showing an example of a sludge concentrating apparatus in which a membrane separation device is attached to the sludge concentrating tank 1 of Embodiment 1, and the same components as those of Embodiment 1 have the same reference numerals. Is attached. A supply line 3 for supplying excess sludge is provided at the top of the sludge thickening tank 1, and a transfer line 4 for transferring the concentrated sludge to the concentrated sludge storage tank 2 is provided near the bottom of the sludge thickening tank 1. Inside the concentration tank 1, a membrane separator 16 and an air diffuser 1 disposed below the membrane separator 16 are provided.
7 are provided. The membrane separation device 16 includes:
A pipe 18 for discharging a filtrate filtered by membrane separation,
A suction pump 19 is provided, and the air diffuser 17 is provided with a blower 20 for sending air to the air diffuser 17.

The shape of the separation membrane used in the membrane separation device 16 may be any as long as it can separate sludge and water, and for example, a known membrane such as a flat membrane, a tubular membrane, or a hollow fiber membrane can be used. Above all, a hollow fiber membrane is preferably used in that the membrane area per unit volume is large. Further, as the membrane separation device 16, for example, a hollow fiber membrane module having a hollow fiber membrane shown in FIG. 4 can be used. This hollow fiber membrane module includes a separation membrane 21 composed of a hollow fiber membrane composed of a plurality of hollow fibers, and water collecting pipes 22 provided at both ends of the separation membrane 21.

Various porous materials can be used as the material of the separation membrane 21, and examples thereof include polyolefin, polysulfone, polyacrylonitrile, and cellulose. Above all, a polyolefin-based material is preferable in consideration of high chemical resistance, high elongation of the film, and the like. The pore size of the separation membrane 21 is not particularly limited, but is preferably in the range of 0.01 to 10 μm.

The separation membrane 21 is preferably a so-called permanent hydrophilization membrane having a hydrophilic group on the surface.
When the surface of the separation membrane 21 is hydrophobic, a hydrophobic interaction acts between the organic matter in the excess sludge and the surface of the separation membrane 21 to cause organic matter adsorption on the membrane surface, which leads to membrane pore blockage,
This is because the filtration life is likely to be short.

The water collecting pipe 22 has a cylindrical shape in which an internal passage 23 is formed. One end of the water collecting pipe 22 is closed, and the other end is connected to the pipe 18. The collecting pipe 22 shown in FIG.
Is cylindrical, but is not limited to this.
For example, the outer shape may be a square pole. Further, a slit 25 is formed in the side wall 24 of the water collecting pipe 22 along the longitudinal direction thereof. The ends of the separation membrane 21 are inserted into the slits 25 and closed with a sealing material to be filled, and the separation membrane 21 is firmly supported and fixed. here,
The ends of the separation membrane 21 are both ends in the fiber direction of the hollow fiber, and both ends of each hollow fiber are located in the internal passage 23 of the water collecting pipe 22.

The width of the slit 25 is preferably 30 mm or less, more preferably 10 mm or less. This is because, by reducing the width of the slit 25, the hollow fibers constituting the separation membrane 21 can be more easily arranged in a line. When the hollow fibers are not aligned and the hollow fiber membrane is formed in a disturbed manner, a plurality of hollow fibers are bundled and adhered and integrated due to adhesion of sludge and the like, and the surface area as a separation membrane cannot be effectively utilized,
Separation performance decreases.

The above-mentioned sealing material converges and fixes each hollow fiber membrane of the separation membrane 21 to the slit 25 while keeping the end of the hollow fiber membrane in an open state, and also connects the internal passage 23 of the water collecting pipe 22 with liquid from outside. It is formed by filling the slit 25 with a liquid made of an epoxy resin, an unsaturated polyester resin, polyurethane, or the like and hardening it.

Further, two or more rows of separation membranes are inserted and fixed in one slit, or two or more slits are formed in one water collecting pipe, and the separation membrane is inserted in each slit.
By fixing, a plurality of separation membranes 21 can be formed in one hollow fiber membrane module. A plurality of such hollow fiber membrane modules can be arranged in the sludge concentration tank 1. By arranging a plurality of hollow fiber membrane modules, processing performance can be improved.

The air diffuser 17 is a hollow body having a large number of pores formed therein, and is connected to a blower 20 for feeding air into the air diffuser 17. A gas such as air can be sent into the inside 1 as bubbles.
By using the air diffuser 17, the separation membrane of the membrane separator 16 is subjected to air scrubbing treatment, that is, the air diffuser 17.
The separation membrane is oscillated by bubbles rising and rising from the water and a water flow generated thereby, and a treatment for removing sludge attached to the membrane surface of the separation membrane can be performed.

Next, a sludge concentrating method using the sludge concentrating apparatus shown in FIG. 3 will be described. First, surplus sludge is supplied into the sludge concentration tank 1 through the supply line 3. Next, the suction pump 19 is operated, and the excess sludge in the sludge concentration tank 1 is filtered by the membrane separator 16. The filtrate filtered by the membrane separation device 16 is discharged out of the sludge concentration tank 1 through the pipe 18 and discharged as it is to a river or the like. The concentrated sludge settled near the bottom of the sludge thickening tank 1 is discharged to the concentrated sludge storage tank 2 through the transfer line 4. Further, a series of concentration processes, that is, supply of excess sludge to the sludge concentration tank 1, concentration of excess sludge, and transfer of concentrated sludge to the concentrated sludge storage tank 2 can be continuously performed. By continuously performing a series of concentration steps, the efficiency of the concentration operation can be improved.

When discharging the concentrated sludge, the transfer pressure in the transfer line 4 is measured by the pressure sensor 6 as in the first embodiment.
And determine the pressure loss. When this pressure loss exceeds the upper limit of the previously measured pressure loss, the supply flow rate of the excess sludge to the sludge concentration tank 1 is increased,
The viscosity of the concentrated sludge is adjusted by, for example, adjusting the amount of filtration of the membrane separation device 16.

In the process of performing the sludge concentration process, the blower 20 is operated as necessary, and air is sent into the sludge concentration tank 1 through the diffuser pipe 17 in the form of air bubbles, and the membrane separation device 16 is subjected to the air scrubbing process. By applying
Sludge adhering to the membrane surface is removed to prevent a decrease in filtration efficiency due to blockage of the membrane pores, and stable operation can be performed for a long period of time.

In the sludge concentration treatment, it is preferable to add a flocculant to the sludge concentration tank 1 as required. By adding the coagulant, the interaction between the sludge and the separation membrane is weakened, and the sludge can be prevented from adhering to the separation membrane. The coagulant is not particularly limited as long as it can coarsen the fine flocs of the sludge. For example, a cationic, anionic, nonionic or amphoteric polymer flocculant can be mentioned, and among them, a cationic polymer flocculant is suitably used.

The amount of the polymer flocculant to be added depends on the properties of the sludge, but is preferably 0.1 to 5 parts by weight, more preferably 100 parts by weight of the suspended solid (SS). 0.1 to 1 part by weight. If the addition amount is less than 0.1 part by weight, coarsening of the floc is insufficient, and if it exceeds 5 parts by weight, the floc may be redispersed or the adhesion of the floc to the separation membrane may be increased. Absent. As a method of adding the polymer flocculant, a method of directly adding the polymer flocculant to the sludge concentration tank 1, a method of adding the polymer flocculant in the supply line 3, and the like can be used.

In such a sludge concentrating apparatus, since a pressure sensor is provided in the transfer line 4 for discharging the concentrated sludge from the sludge thickening tank 1, a pressure loss is obtained from the transfer pressure measured by the pressure sensor. The viscosity of the concentrated sludge can be adjusted using the numerical value of the pressure loss so as to be within a specified range. Further, since the viscosity is adjusted using a pressure sensor instead of an expensive viscometer or torque meter, the cost of the apparatus can be reduced. Furthermore, since the sludge concentration treatment uses the membrane separation device 16 provided with a separation membrane, the concentration can be performed more efficiently than the conventional method using a coagulant, gravity sedimentation, and the like. Further, when a hollow fiber membrane module having a hollow fiber membrane having a large membrane area per unit volume is used, concentration can be performed more efficiently.

[0045]

As described above, in the sludge thickening apparatus of the present invention, the viscosity of the thickened sludge can be controlled, so that the clogging that occurs when the thickened sludge is sucked into the vacuum vehicle can be prevented. An extra operation such as an operation of diluting the concentrated sludge with water can be reduced, and the operation efficiency can be improved. Further, in a sludge concentrator using a membrane separation device for concentrating excess sludge, since the membrane pores of the separation membrane are not blocked by overconcentration, it is possible to prevent a reduction in the concentration treatment capacity. Further, since an inexpensive pressure sensor is used as a sensor for monitoring the viscosity of the concentrated sludge, the viscosity of the concentrated sludge can be controlled at a lower cost than when a viscometer or a torque meter is used.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a sludge concentration apparatus of the present invention.

FIG. 2 is a schematic view showing one embodiment of a sludge concentration apparatus of the present invention.

FIG. 3 is a schematic view showing one embodiment of a sludge concentration device of the present invention.

FIG. 4 is a diagram showing an example of a hollow fiber membrane module used in the sludge concentration device of the present invention.

FIG. 5 is a flowchart showing an example of a conventional wastewater treatment system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sludge thickening tank, 2 ... Thickened sludge storage tank, 4 ... Transfer line, 6 ... Pressure sensor, 8 ... Supply line, 9 ... Discharge line, 10 ... Transfer Line, 16 ... membrane separation device, 2
DESCRIPTION OF SYMBOLS 1 ... Hollow fiber membrane, 22 ... Water collecting pipe, 23 ... Internal path

Claims (4)

[Claims] 1. A sludge thickening tank for thickening excess sludge generated in a wastewater treatment process, a thickened sludge storage tank for storing thickened sludge, and a transfer for transferring thickened sludge from the thickened sludge tank to the thickened sludge storage tank. A sludge concentrator having a line and a pressure sensor for measuring a transfer pressure in the transfer line. 2. A sludge thickening tank for thickening excess sludge generated in a wastewater treatment process, a thickened sludge storage tank for storing thickened sludge, a supply line for feeding excess sludge to the sludge thickening tank, and a supply line for the sludge thickening tank. And a discharge line for feeding the concentrated sludge discharged from the sludge concentration tank to the supply line, and a branch from the supply line on the downstream side from a connection portion of the discharge line to concentrate the concentrated sludge into the concentrated sludge storage tank. A sludge concentrator having a transfer line for transferring sludge and a pressure sensor for measuring a transfer pressure in the transfer line. 3. The sludge concentration tank is provided with a membrane separation device provided with a separation membrane.
Or the sludge concentrator according to claim 2. 4. The separation membrane of the membrane separation device has a hollow fiber membrane composed of a plurality of hollow fibers, and water collecting pipes provided at both ends of the hollow fiber membrane, and enters the hollow fiber. 4. The sludge concentrator according to claim 3, wherein the filtrate is a hollow fiber membrane module that can pass through an internal passage formed in the water collecting pipe.