JPH11676A - Waste water purification tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste water purification tank in which the flow rate control for in tank water pumped up from an aerobic filter bed tank or a treated water tank is not required and sludge adhered inside an airlift pump can be released and removed. SOLUTION: In a waste water tank 1, the inside of the tank is divided into partitions 17, 18, 19 and 20, and anaerobic filter bed tanks 21, 21, an aerobic filter bed tank 22, a treated water tank 23 and a disinfection tank 24 are disposed starting from the upstream side in the above order, and also an airlift pump 25 for transferring the in-tank water in the aerobic filter bed tank 22 or the treated water tank 23 to the anaerobic filter bed tanks 21, 21 and a transfer pipe 36 connected with the air lift pump 25 are provided therein, a drawing section 26 is provided on a suction hole of the airlift pump 25, and a cleaning air pipe 29 is connected with the side wall lower than an inner pipe 27 exhausting air in the airlift pump 25, and the air volume more than the air volume per unit hour exhausted from the inner pipe 27 is exhausted intermittently from the cleaning air pipe 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment tank used for purifying human wastewater and domestic wastewater.

[0002]

2. Description of the Related Art A conventional sewage purifying tank will be described with reference to FIG. 3. The inside of a sewage purifying tank 1 is partitioned by partition walls 2, 3, 4 and 5, and an anaerobic filter tank 6 is provided from the upstream side. , 6, an aerobic filter tank 7, a treated water tank 8, and a disinfecting tank 9 in this order. The treated water tank 8 has an outer pipe 1 shown in FIG.
3 and an inner pipe 11 are installed, and water in the treated water tank 8 is returned to the anaerobic filter bed tank 6 through the distribution and metering device 10 by discharging air 12 through the inner pipe 11. Such return is performed to stabilize the quality of the treated water and to remove nitrogen components from the treated water.

[0003] The dispensing and measuring device 10 will be described in detail. Part of the water in the tank pumped between the outer pipe 13 and the inner pipe 11 returns to the treated water tank 8 from the return weir 16, and the rest is measured. It is returned to the anaerobic filter bed tank 6 via the weir 15. The amount of water returned in the tank is adjusted by adjusting the height of the return weir 16, and excess water is returned from the return weir 16 to the tank that has been pumped. Excessive pumping of the water in the tank means that if only the required amount of water is to be pumped, the space between the outer pipe 13 and the inner pipe 11 must be considerably narrowed. However, it is difficult to perform a stable pumping operation because of easy blockage.

[0004]

However, in the sewage treatment tank 1 shown in FIG. 3, the entire flow of the pumped water in the tank is not returned, but the flow is adjusted and then returned. Specifically, there is a problem that sludge or the like adheres to the measuring weir 15 and the return weir 16), and the return amount gradually changes from the initial setting during long-time return. Furthermore, even if the space between the outer tube 13 and the inner tube 11 is widened to some extent,
Although it is impossible to completely prevent sludge from adhering and does not cause blockage, there is also a problem that the amount of pumped water gradually changes.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and does not use a distribution metering device 10 or the like for adjusting a flow rate by returning the entire amount of water in a pumped tank. It is an object of the present invention to provide a sewage treatment tank capable of washing to remove the wastewater.

[0006]

A first aspect of the present invention is that, as shown in FIGS. 1 and 2, partition walls 17, 18, 19, and
Partitioned at 20, the anaerobic filter bed tanks 21 and 21, an aerobic filter bed tank 22, a treatment water tank 23, and a disinfection tank 24 are arranged in this order from the upstream side, and the aerobic filter bed tank 22 or the treatment water tank 23 In the sewage purification tank 1 having an air lift pump 25 for transferring water in the tank to the anaerobic filter bed tank 21 and a transfer pipe 36 connected to the air lift pump 25, a throttle section 26 is provided at a suction port of the air lift pump 25. And a cleaning air pipe 29 is connected to a side wall below the inner pipe 27 from which the air lift pump 25 discharges air, and air per unit time discharged from the cleaning air pipe 29 from the inner pipe 27 is provided. It is characterized in that an amount of air larger than the amount is intermittently discharged.

The second aspect of the present invention is to make the function of the inner pipe 27 also serve the function of the cleaning air pipe 29.
Is removed, and the air from the cleaning air pipe 29 is discharged alternately between strong and weak.

A third aspect of the present invention is that a partition wall 1 is formed in the tank.
The anaerobic filter tanks 21 and 21, an aerobic filter tank 22, a treatment water tank 23, and a disinfection tank 24 are arranged in this order from the upstream side. Alternatively, an air lift pump 25 for transferring water in the treatment water tank 23 to the anaerobic filter bed tank 21 and the air lift pump 2
In the sewage treatment tank 1 having the transfer pipe 36 connected to the air purifier 5, the throttle section 26 is provided at the suction port of the air lift pump 25, and air is discharged from the inner pipe 27 built in the air lift pump 25 per unit time. The amount is set to be larger than that during normal operation only for a predetermined time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The amount of water pumped by an air lift pump is determined by the depth at which the suction port is installed, the pipe diameter, the head (pumping height from the water surface), and the amount of air. Since the amount of water to be pumped is extremely small, it is necessary to perform more than necessary pumping in order to perform stable water pumping. Therefore, in the present invention, the air lift pump 25 itself is provided with an excessive water pumping capacity, and the throttle port 26 is provided at the suction port to reduce the pumping amount and stably pump only the target water amount. I have.

The sludge adhering between the inner pipe 27 and the outer pipe 28 is washed by the air 37 jetted from the cleaning air pipe 29 connected to the side wall of the air lift pump 25 and the air jetted from the inner pipe 27. . That is, in the normal operation, only air is blown out from the inner pipe 27. However, when the air lift pump 25 is washed, the cleaning air pipe 2 is used.
By discharging the air from the pipe 9 as well, more air is passed between the inner pipe 27 and the outer pipe 28 than in the normal operation to separate sludge. Further, as another method, the air discharge from the inner pipe 27 is temporarily stopped, and then the amount of air larger than the amount of air ejected from the inner pipe 27 per unit time (hereinafter simply referred to as “air amount”) is reduced. 29 may be discharged. The interval of time for passing the air 37 through the cleaning air pipe 29 is arbitrarily set, but it is possible to sufficiently remove the sludge if it is performed about once per day for about 10 minutes. . The connection position of the cleaning air pipe 29 is the inner pipe 2
7 is not particularly limited as long as it is below the lowermost portion of the inner tube 27, as shown in FIG. May be underneath.

The cleaning air pipe 29 used in the present invention is:
The inner pipe corresponding to the inner pipe and the common pipe 39 of the cleaning air pipe can be substituted (see FIG. 7A), and the inner pipe 27 can be substituted by the cleaning air pipe 29 (FIG. 7B ))). However, when one pipe is also used as described above, it is necessary to increase the amount of air to be discharged for a predetermined time (during the cleaning of the air lift pump 25) as compared with the normal time. Furthermore, when the function of the inner pipe 27 is also used for the cleaning air pipe 29, it is preferable that the mounting position of the cleaning air pipe 29 be near the throttle unit 26. This is for cleaning the entire air lift pump 25.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view of the sewage treatment tank 1 showing one embodiment of the present invention, and the inside of the tank is partitioned by partitions 17, 18, 19 and 20.
The anaerobic filter bed tanks 21 and 21, the aerobic filter bed tank 22, the treated water tank 23, and the disinfection tank 24 are arranged from the upstream side. The anaerobic filter tanks 21 and 21 are provided with a filter bed 30 for anaerobic treatment with anaerobic microorganisms and removal of large solids. The aerobic filter bed tank 22 is provided with a microorganism adhering body 31, and is subjected to aerobic treatment by aerobic microorganisms. The treatment water tank 23 is provided with an air lift pump 25 shown in FIG. 1 so that a part of the water in the tank can be returned to the anaerobic filter bed tank 21.

To explain the flow of sewage, sewage 33 flowing from an inlet 32 flows into an anaerobic filter tank 21, performs anaerobic treatment, and then flows to an aerobic filter tank 22. The sewage that has been subjected to aerobic treatment in the aerobic filter bed tank 22 is subjected to solid-liquid separation in a treatment water tank 23, and after that, most of the sewage is disinfected in a disinfection tank 24 and then discharged as treated water 34 from an outlet 35. You. Part of the water in the treated water tank 23 is pumped by the air lift pump 25 shown in FIG. 1 and returned to the anaerobic filter bed tank 21 via the transfer pipe 36.

The air lift pump 25 will be described in detail with reference to FIG.
The sewage is sucked in from the throttle by the air discharged from 7, and flows into the transition pipe 36 through between the inner pipe 27 and the outer pipe 28. When cleaning the space between the inner pipe 27 and the outer pipe 28, the air discharge from the inner pipe 27 is once stopped, and the inner pipe 2 is connected to the cleaning air pipe 29 connected to the air lift pump 25.
Air is discharged with an air amount larger than the air amount discharged from 7 to separate the attached sludge.

An experiment described below was performed to confirm the cleaning effect of the air lift pump 25 of the present invention. The entire structure is an air lift pump 25 shown in FIG.
The diameter of the inner tube 27 is 13 mm, the diameter of the narrowed portion 26 is 10 mm, the air supply to the inner tube 27 is about 6 liters / minute on average, and the air supply to the cleaning air pipe 29 is about 15 liters. / Min., Installed in a sewage purification tank 1 for five persons (see FIG. 2). From the treated water tank 23 to the anaerobic filter bed tank 21
The amount of sewage flowing into the sewage treatment tank 1 is set at 4
(Circulation ratio 4), and the control range was set to a circulation ratio of 3 to 5. The air supply to the cleaning air pipe is 10 times / day.
Minutes.

FIG. 5 shows a change in the return amount when the air lift pump 25 is cleaned and when the air lift pump 25 is not cleaned. When the cleaning is performed, the return amount decreases to about 90 days. Although it was stable within the control range, when the cleaning was not performed, the return amount was reduced even after 120 days, and the return amount was out of the control range.

[0017]

According to the present invention, the provision of the restricting portion makes it possible to return all the water to be pumped, and eliminates the need for adjusting the flow rate of the distribution metering device or the like. Further, by attaching a cleaning air pipe or by using both an inner pipe and a cleaning air pipe, it has become possible to perform stable return in a long term.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an air lift pump used in the present invention.

FIG. 2 is a longitudinal sectional view of a sewage treatment tank showing an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a conventional sewage purification tank.

FIG. 4 is a perspective view of a conventional distribution / metering apparatus using a sewage purification tank.

FIG. 5 is a graph showing a daily change of a return amount.

FIG. 6 is a longitudinal sectional view showing an air lift pump used in the present invention.

FIGS. 7A and 7B are longitudinal sectional views showing an air lift pump used in the present invention. FIG. 7A is a view using a common pipe of an inner pipe and a cleaning air pipe, and FIG. It is connected with an air pipe.

[Explanation of symbols]

1. Sewage septic tank 2. Partition wall 3. Partition wall 4. Partition wall 5. Partition wall 6. Anaerobic filter bed tank 7. 7. Aerobic filter bed tank
Treatment water tank 9. Disinfection tank 10. Dispensing and weighing device 11. Inner tube 12. Air 13. Outer tube 14. Tank water 15. Measuring weir 16. Return weir 17. Partition wall 18. Partition wall 1
9. Partition wall 20. Partition wall 21. Anaerobic filter bed tank 22.
Aerobic filter bed tank 23. Treated water tank 24. Disinfection tank 25. Air lift pump 26. Restrictor 27. Inner tube 28. Outer tube 29. Cleaning air tube 30. Filter bed 31. Microbial adherent 32. Inlet 33. Sewage 34. Treated water 3
5. Outlet 36. Transition tube 37. Air 38. Tank water 39. Inner pipe, common pipe for cleaning air pipe

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nobuyoshi Katagai 1250 Shimoedori, Shimodate-shi, Ibaraki Pref.Hitachi Kasei Kogyo Co., Ltd. Seiki Kogyo Co., Ltd.

Claims (3)

[Claims] 1. An aerobic filter bed tank, an aerobic filter bed tank, a treatment water tank, and a disinfection tank are arranged in this order from an upstream side, and the aerobic filter bed tank or the treatment water tank is arranged. An air lift pump for transferring water in the tank to the anaerobic filter bed tank, and a sewage purification tank having a transition pipe connected to the air lift pump, wherein a throttle portion is provided at a suction port of the air lift pump and the air lift pump is provided. A sewage treatment tank wherein a cleaning air pipe is connected to a side wall below an inner pipe for discharging air from a pump, and air is intermittently discharged from the cleaning air pipe. 2. The sewage purification tank according to claim 1, wherein the inner pipe is removed, and air from the cleaning air pipe is alternately discharged intensely and weakly. 3. An aerobic filter bed tank, an aerobic filter bed tank, a treatment water tank, and a disinfection tank are arranged in this order from an upstream side, and the aerobic filter bed tank or the treatment water tank is arranged. An air lift pump for transferring water in the tank to the anaerobic filter bed tank, and a sewage purification tank having a transition pipe connected to the air lift pump, wherein a throttle portion is provided at a suction port of the air lift pump and the air lift pump is provided. A sewage treatment tank characterized in that an amount of air discharged per unit time from an inner pipe incorporated in a pump is increased only for a predetermined time period compared with a normal operation.