JP4125419B2 - Septic tank and flow control device thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a septic tank and a flow rate control device thereof, and more specifically, a septic tank that can stabilize the liquid level of a processing tank for performing a membrane separation process in the septic tank, has few failures, and has high reliability. The present invention relates to the flow control device.
[0002]
[Prior art]
The septic tank based on the membrane separation activated sludge method discharges the first treatment tank into which the water to be treated flows, the second treatment tank on which the membrane separation device is mounted, and the treatment liquid treated in the second treatment tank. And at least three chambers with the third treatment tank. In such a septic tank, it is important to make the liquid level of the second treatment tank on which the membrane separation device is mounted constant.
[0003]
By making the liquid level of the second treatment tank constant, the water head pressure acting on the membrane separation device becomes constant, and the membrane separation treatment in the membrane separation device is stabilized.
[0004]
For this reason, for example, as shown in Japanese Patent Application Laid-Open No. 09-136092 , a flow rate adjusting tank is provided in the septic tank, and the liquid in a processing tank in which a membrane separation device is built in the subsequent processing tank from the flow rate adjusting tank A septic tank provided with a float switch has been proposed so that the surface is constant. In this septic tank, the liquid level of the flow rate adjusting tank is detected by a float switch, and the pump is controlled according to the liquid level position.
[0005]
[Problems to be solved by the invention]
However, in the septic tank that detects the liquid level of the tank as an electric signal by the float switch in this way, when the electrical system of the switch fails, it may not function as a septic tank. In addition, the electric system that controls the driving and stopping of the pump by the float switch has a problem that there are more failures than the electric system that keeps operating the pump.
[0006]
The present invention has been made in view of such a situation, and can stabilize the liquid level of a processing tank for performing a membrane separation process in the septic tank, and has a low failure and high reliability, and its flow rate control device. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the septic tank according to the present invention comprises:
A first treatment tank for temporarily storing a liquid to be treated;
A second treatment tank in which a liquid to be treated stored in the first treatment tank is introduced and a membrane separation device is attached;
A septic tank having a flow rate control device for controlling the flow rate of the liquid to be treated flowing from the first treatment tank to the second treatment tank,
The flow rate control device is
A reservoir capable of temporarily storing the liquid to be treated flowing from the first treatment tank; and
A return passage that is connected to the storage section and has a return flow path for returning the liquid to be processed temporarily stored in the storage section to the first processing tank;
A guide tube in which a guide channel for guiding the liquid to be processed flowing into the storage section into the second processing tank is formed;
It is mounted inside the guide tube, moves according to the liquid level position of the second processing tank, and closes the guide channel when the liquid level of the second processing tank reaches the maximum liquid level position. A float member configured to open the guide flow path to the maximum when the liquid level reaches the lowest liquid level position;
Have
[0008]
The flow control device according to the present invention is
A storage part capable of temporarily storing the liquid to be processed flowing in from the first processing tank, and the storage part that is connected to the storage part and temporarily stored in the storage part. A return passage in which a return channel for returning to the treatment tank is formed;
A guide tube formed with a guide channel for guiding the liquid to be processed flowing into the storage section into the second processing tank;
It is mounted inside the guide tube, moves according to the liquid level position of the second processing tank, and closes the guide channel when the liquid level of the second processing tank reaches the maximum liquid level position. And a float member configured to open the guide flow path to the maximum when the liquid level reaches the lowest liquid level position.
[0009]
The septic tank according to the present invention may include a treatment tank other than the first treatment tank and the second treatment tank.
In the present invention, the first treatment tank is not particularly limited, but may be a tank in which anaerobic bacteria are housed and performing anaerobic treatment and / or a tank for performing denitrification treatment.
[0010]
In the present invention, the membrane separation device is not particularly limited. For example, the membrane separation device is formed by arranging a large number of plate-like filtration membranes in parallel, and the biological treatment liquid and sludge are separated into solid and liquid by the filtration membrane. It performs processing such as. Although it does not specifically limit as a filtration membrane, A flat membrane, a hollow fiber membrane, a ceramic membrane etc. are used. Moreover, the filtration membrane may be one in which many cylindrical ones are arranged.
[0011]
In the present invention, the reservoir is not particularly limited, but is preferably a box-shaped container having an open top.
[0012]
In the present invention, the return passage is not particularly limited as long as a flow path for returning the treated water temporarily stored in the storage portion to the first treatment tank is formed. It consists of firewood.
[0013]
In the present invention, the guide tube is preferably formed with a plurality of side holes that communicate the inside and the outside of the tube, and these side holes are within a predetermined length along the longitudinal direction of the guide tube. It is preferable to form a part of the guide flow path by forming them.
[0014]
Moreover, it is preferable that a through hole having an inner diameter smaller than the outer diameter of the float member is formed in the connection portion between the guide tube and the storage portion. When the liquid level of the second treatment tank reaches the maximum liquid level position, the float member also moves simultaneously inside the guide tube to close the through hole.
[0015]
In the present invention, the float member is not particularly limited, but the shape thereof is preferably spherical, and the inside thereof may be hollow or solid. When the inside of the float member is solid, the material constituting the float member needs to have a specific gravity lighter than water. When the inside of the float member is hollow, the material of the member constituting the float member can be made of a material whose specific gravity is heavier than water, but the float member as a whole needs to be designed to float on water. is there.
[0016]
[Action]
In the flow control device according to the present invention and the septic tank using the flow control device, when the liquid level of the second treatment tank in which the membrane separation device is disposed reaches the maximum liquid level position, the float member is placed inside the guide tube. Move to a position to close the guide channel. As a result, all of the water to be treated that enters the storage unit from the first treatment tank returns to the first treatment tank through the return passage. Further, when the liquid level of the second treatment tank reaches the minimum liquid level position, the float member moves to a position where the guide channel is opened to the maximum inside the guide pipe. As a result, most of the water to be treated entering the storage part from the first treatment tank flows into the second treatment tank through the guide channel of the guide tube.
[0017]
Therefore, even if liquid feeding means such as a pump that feeds the liquid to be treated from the first treatment tank to the reservoir is always operated, the flow control device having the float member automatically controls the liquid level of the second treatment tank. Will do. As a result, a water head pressure above a certain value is always applied to the membrane separation device in the second treatment tank, and a good membrane separation treatment can always be performed. Further, since the flow rate of the liquid to be treated is not controlled using the electric system, there are few failures and the reliability of the septic tank is improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[0019]
FIG. 1 is a schematic sectional view of a septic tank according to one embodiment of the present invention, and FIG. 2 is a partial sectional perspective view of the flow control device shown in FIG.
[0020]
As shown in FIG. 1, the septic tank 2 according to this embodiment has a septic tank body 4 made of, for example, a reaction injection molded body of a norbornene monomer. This septic tank body 4 is assembled by combining an upper septic tank body and a lower septic tank body, for example.
[0021]
In the septic tank 2, a manhole 6 necessary for maintenance of the septic tank is formed in the longitudinal direction of the septic tank body 4. A manhole cover (not shown) is attached to each manhole 6. Further, at both ends in the longitudinal direction of the septic tank body 4, an inlet 8 for introducing sewage and an outlet 10 for discharging the purified water after the treatment are formed.
[0022]
This septic tank 2 is a septic tank based on the membrane separation activated sludge method, and the inside of the septic tank main body 4 includes a plurality of treatment tanks 16, 18, 20, 22 by a plurality of partition plates 12, 13 and partition walls 14 along the longitudinal direction. It is divided into. In the present embodiment, four treatment tanks, a first treatment tank 16, a second treatment tank 18, a third treatment tank 20, and a disinfection tank 22, are formed from the upstream side where sewage is introduced.
[0023]
The first treatment tank 16 is a treatment tank into which sewage is introduced from the inlet 8, and the first treatment tank 16 supports an anaerobic filter bed to which anaerobic bacteria are attached. The sewage (liquid to be treated) that has flowed in through the anaerobic layer is subjected to anaerobic treatment when passing through the anaerobic filter bed. Although it does not specifically limit as an anaerobic bacterium, The genus Meto-pass (Meto-pus), Paramecium (Paramemeumu) (Paramecium) (Canomorpha) genus (Saprodium) (Saprodium) etc. are used. Anaerobic bacteria reduce the organic matter in wastewater to organic acids such as acetic acid and propionic acid, and these organic acids are further decomposed into methane gas and carbon dioxide gas by methane bacteria.
[0024]
A first pump 24 is disposed at the bottom of the first processing tank 16, and the liquid to be processed existing at the bottom of the first processing tank 16 is passed through the first feed pipe 26 and above the second processing tank 18. The flow is sent to the flow control device 28 arranged near the partition plate 12. The first pump 24 is always operating, and sends a certain amount of liquid to be processed to the flow control device 28.
[0025]
A membrane separation device 30 is disposed inside the second treatment tank 18. In the membrane separation device 30, a large number of flat filtration membranes are arranged in parallel in an upright state, and the liquid to be treated is purified while passing through the filtration membrane. As the filtration membrane, for example, a flat membrane, a hollow fiber membrane, a disk-like membrane, a ceramic membrane or the like is used. The treatment liquid purified by passing through the filtration membrane is sent to the third treatment tank 20 through the second feed pipe 32 connected to the upper part of the membrane separation device 30. The second feed pipe 32 is equipped with a valve 33 and the like so that the flow rate setting of the treated water flowing through the second feed pipe 32 can be changed.
[0026]
An air diffuser that generates bubbles is disposed below the membrane separation device 30 and bubbles are supplied between the filtration membranes of the membrane separation device to prevent excessive adhesion of sludge to the membrane surface of the filtration membrane. While preventing, you may promote the circulation of the to-be-processed liquid in the processing tank 18. FIG.
[0027]
The third treatment tank 20 is a tank for discharging the treated liquid to the outside, and a second pump 34 is disposed at the bottom of the third treatment tank 20 and flows into the third treatment tank 20 through the second feed pipe 32. The treated liquid is then sent to the disinfection tank 22 through the third feed pipe 36. The disinfecting tank 22 is partitioned by the partition wall 14. The disinfecting tank 22 includes a medicine cylinder (not shown), and the treated liquid is sterilized with a disinfectant supplied from the medicine cylinder. It is discharged outside as purified water through the outlet 10.
[0028]
In the present embodiment, as shown in FIG. 2, the flow rate control device 28 has a storage unit 40 that can temporarily store the liquid to be processed flowing from the first processing tank 16 through the first feed pipe 26. . In the present embodiment, the storage unit 40 is a rectangular box having an open top, and the liquid to be processed temporarily stored in the storage unit 40 is returned to the first processing tank 16 on one side wall thereof. A return pipe (return passage) 42 in which a return flow path is formed is connected.
[0029]
One open end of the return pipe 42 communicates with the inside of the storage unit 40, and the other open end opens to the inside of the first processing chamber 16.
The upper end of the guide tube 44 is connected to the bottom of the reservoir 40, and the interior of the reservoir 40 and the interior of the guide tube 44 communicate with each other through a through hole 46 formed in the bottom of the reservoir 40. is there. The lower end of the guide tube 44 is opened toward the bottom of the second processing tank.
[0030]
The guide tube 44 is formed with a plurality of side holes 48 that communicate the inside and the outside of the tube. These side holes 48 are formed in a range of a predetermined length along the longitudinal direction of the guide tube 44. The predetermined length range is a range from the minimum liquid level position WL1 necessary for the membrane separation apparatus 30 in the second treatment tank 18 shown in FIG. 1 to the maximum liquid level position WL2.
[0031]
A float member 50 is mounted in the guide tube 44 so as to be movable along the axial direction of the tube. In this embodiment, the float member 50 is composed of a polyvinyl chloride sphere having a hollow inside and floats against water. The outer diameter of the float member 50 is preferably about 80 to 99% smaller than the inner diameter of the guide tube 44, and preferably 110 to 160% larger than the inner diameter of the through hole 46. The float member 50 is configured to float on the liquid surface of the water to be treated stored in the second treatment tank 18, and when the liquid surface reaches the maximum liquid surface position WL2, the through hole 46 is provided. And the flow of water to be treated from the reservoir 40 to the second treatment tank 18 is blocked. In addition, when the liquid level of the water to be treated in the second treatment tank 18 reaches the lowest liquid level WL1, the float member 50 also moves accordingly, and all the guide pipes 44 are formed. Through the side hole 48, the water to be treated sent to the inside of the storage unit 40 is guided to the second treatment tank 18.
[0032]
A stopper member that prevents the float member 50 from falling may be provided at the lower end opening of the guide tube 44. The stopper member may be any member as long as it can circulate a liquid and does not cause the float member to fall. Examples of the stopper member include a plate having a small hole and a wire mesh. By providing this stopper member, the length of the guide tube 44 can be shortened.
[0033]
In the present embodiment, the through hole 46, the internal flow path of the guide tube 44, and the side hole 48 constitute the guide flow path of the present invention.
[0034]
In the flow rate control device 28 and the septic tank 2 using the same according to the present embodiment, when the liquid level of the second treatment tank 18 in which the membrane separation device 30 is disposed reaches the maximum liquid level position WL2, the float member 50 is used. However, it moves to a position where the through hole 46 is closed inside the guide tube 44. As a result, all of the water to be treated that enters the storage unit 40 from the first treatment tank 16 returns to the first treatment tank 16 through the return pipe 42. Further, when the liquid level of the second treatment tank 18 reaches the minimum liquid level position WL1, the float member 50 moves to a position where all the side holes formed in the guide tube 44 are opened. As a result, most of the water to be treated that enters the storage section 40 from the first treatment tank 16 through the first feed pipe 26 flows into the second treatment tank 18 through the through hole 46 and the side hole 48 of the guide pipe 44.
[0035]
Accordingly, even if the first pump 24 that sends the liquid to be processed from the first processing tank 16 to the storage unit 40 is always operated, the flow rate control device 28 having the float member 50 is automatically in the liquid of the second processing tank 18. Will control the surface. As a result, a constant water head pressure is always applied to the membrane separation device 30 in the second treatment tank 18, and a good membrane separation treatment can always be performed. Further, since the flow rate of the liquid to be treated is not controlled using the electric system, there are few failures and the reliability of the septic tank is improved.
[0036]
The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
[0037]
For example, in the septic tank according to the embodiment described above, four tanks 16, 18, 20, and 22 are provided inside, but more tanks may be newly added. For example, a denitrification tank (activated sludge tank) may be provided between the first treatment tank 16 and the second treatment tank 18. In that case, you may arrange | position the 1st pump 24 also to a denitrification tank. In addition, the septic tank which concerns on this invention should just have the 1st processing tank 16 and the 2nd processing tank 18 at the minimum.
[0038]
In addition, the flow rate control device according to the present invention is not necessarily provided only for the second treatment tank 18, and may be provided for other tanks inside the septic tank.
[0039]
【The invention's effect】
As described above, according to the flow rate control device and the septic tank using the same according to the present invention, even if the liquid feeding means such as a pump that feeds the liquid to be treated from the first treatment tank to the storage unit is always operated, The flow control device having the float member automatically controls the liquid level of the second processing tank. As a result, a constant water head pressure is always applied to the membrane separation device in the second treatment tank, and a good membrane separation treatment can always be performed. Further, since the flow rate of the liquid to be treated is not controlled using the electric system, there are few failures and the reliability of the septic tank is improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a septic tank according to one embodiment of the present invention.
2 is a partial cross-sectional perspective view of the flow control device shown in FIG. 1. FIG.
[Explanation of symbols]
2 ... Septic tank 4 ... Septic tank body 6 ... Manhole 8 ... Inlet 10 ... Outlet 12, 13 ... Partition plate 14 ... Partition 16 ... First treatment tank 18 ... Second treatment tank 20 ... Third treatment tank 22 ... Disinfection tank 24 , 34 ... Pump 28 ... Flow rate control device 30 ... Membrane separation device 40 ... Storage part 42 ... Return pipe 44 ... Guide tube 46 ... Through hole 48 ... Side hole 50 ... Float member

Claims (3)

A first treatment tank for temporarily storing a liquid to be treated;
A second treatment tank in which a liquid to be treated stored in the first treatment tank is introduced and a membrane separation device is attached;
A septic tank having a flow rate control device for controlling the flow rate of the liquid to be treated flowing from the first treatment tank to the second treatment tank,
The flow rate control device is
A reservoir capable of temporarily storing the liquid to be treated flowing from the first treatment tank; and
A return passage that is connected to the storage section and has a return flow path for returning the liquid to be processed temporarily stored in the storage section to the first processing tank;
A guide pipe in which a guide channel for guiding the liquid to be processed flowing into the storage section into the second processing tank is formed, and the minimum liquid surface position necessary for the membrane separation device of the second processing tank A guide tube in which a plurality of side holes communicating the inside and outside of the tube are formed in a range from the maximum liquid level position to
It is mounted inside the guide tube, moves according to the liquid level position of the second processing tank, and closes the guide channel when the liquid level of the second processing tank reaches the maximum liquid level position. When the liquid level reaches the lowest liquid level position, the float is configured to move to the position where all the side holes formed in the guide tube are opened and to open the guide flow path to the maximum. A member,
A septic tank. A reservoir capable of temporarily storing the liquid to be treated flowing from the first treatment tank;
A return passage that is connected to the storage section and has a return flow path for returning the liquid to be processed temporarily stored in the storage section to the first processing tank;
A guide tube in which a guide channel for guiding the liquid to be processed flowing into the storage section into the second processing tank is formed, from the lowest liquid surface position necessary for the membrane separation device of the second processing tank A guide tube having a plurality of side holes communicating with the inside and outside of the tube in a range up to the maximum liquid level position ;
It is mounted inside the guide tube, moves according to the liquid level position of the second processing tank, and closes the guide channel when the liquid level of the second processing tank reaches the maximum liquid level position. When the liquid level reaches the lowest liquid level position, the float is configured to move to the position where all the side holes formed in the guide tube are opened and to open the guide flow path to the maximum. A member,
A flow control device for a septic tank. The guide tube has an upper end connected to a bottom portion of the storage portion, a lower end opened toward the bottom portion of the second treatment tank, and the inside of the storage portion through a through hole formed in the bottom portion of the storage portion. And the inside of the guide tube communicates with each other, and the float member closes the through hole and closes the guide channel when the liquid level reaches a maximum liquid level position . Flow control device.

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