JP3791639B2 - Wastewater septic tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewage septic tank used for purifying human wastewater and domestic wastewater.
[0002]
[Prior art]
A conventional sewage septic tank will be described with reference to FIG. 3. The sewage septic tank 1 is partitioned by partition walls 2, 3, 4, and 5, and anaerobic filter bed tanks 6, 6, aerobic from the upstream side. The filter bed tank 7, the treated water tank 8, and the disinfection tank 9 are arranged in this order. The treated water tank 8 is provided with an outer pipe 13 and an inner pipe 11 shown in FIG. 4, and by discharging air 12 through the inner pipe 11, the water in the treated water tank 8 passes through the distribution metering device 10. It is returned to the anaerobic filter bed tank 6. Such return is performed in order to stabilize the quality of the treated water and to remove nitrogen components from the treated water.
[0003]
The distribution metering device 10 will be described in detail. A part of the water in the tank pumped through the outer pipe 13 and the inner pipe 11 returns to the treated water tank 8 from the return weir 16 and the rest passes the measuring weir 15. And returned to the anaerobic filter bed tank 6. The amount of water returned in the tank is adjusted by adjusting the height of the return weir 16, and excess water is overflowed from the return weir 16 and returned to the pumped water tank. The excessive pumping of the water in the tank requires that the space between the outer pipe 13 and the inner pipe 11 be considerably narrowed when only the necessary amount of water is to be pumped. This is because they are easily clogged and stable pumping cannot be performed.
[0004]
[Problems to be solved by the invention]
However, in the sewage septic tank 1 shown in FIG. 3, the entire amount of the pumped water is not returned, but is returned after the flow rate is adjusted. There was a problem that sludge and the like adhered to the weir 16) and the return amount gradually changed from the initial setting while returning for a long time. Furthermore, even if the space between the outer pipe 13 and the inner pipe 11 is widened to some extent, it is impossible to completely prevent the sludge from adhering, and although there is no blockage, there is a problem that the pumping amount gradually changes. is there.
[0005]
The present invention has been made in view of the above-described problems, and returns sludge in the air lift pump without using the distribution metering device 10 that adjusts the flow rate by returning the entire amount of the pumped tank water. The object is to provide a septic tank that can be washed.
[0006]
[Means for Solving the Problems]
1 and 2, the inside of the tank is partitioned by partition walls 17, 18, 19, and 20, and the anaerobic filter bed tanks 21 and 21 and the aerobic filter bed tank 22 from the upstream side. An air lift pump 25 for transferring the aerobic filter bed tank 22 or the water in the treated water tank 23 to the anaerobic filter bed tank 21; In the sewage septic tank 1 having a transition pipe 36 connected to the pump 25, a throttle part 26 is provided at the suction port of the air lift pump 25 and the side wall below the inner pipe 27 that discharges air from the air lift pump 25 is washed. An air pipe 29 is connected, and an air quantity larger than the air quantity per unit time discharged from the inner pipe 27 is intermittently discharged from the cleaning air pipe 29.
[0007]
The second aspect of the present invention is to share the function of the internal officer 27 with the function of the cleaning air pipe 29. The inside of the tank is partitioned by a partition wall, and the anaerobic filter bed tank and the aerobic filter from the upstream side. It is arranged in the order of a floor tank, a treated water tank, and a disinfection tank, and is connected to the air lift pump for transferring the aerobic filter bed tank or the water in the treated water tank to the anaerobic filter bed tank. In the sewage septic tank having a transition pipe, a throttle portion is provided at the suction port of the air lift pump, and an air pipe is connected to a side wall of the air lift pump, and the mounting position of the air pipe can be cleaned by the entire air lift pump. near the and with throttle portion is a septic tank for discharging air from the air tube strength alternately.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The pumping amount of the air lift pump is determined by the depth, pipe diameter, lifting head (pumping height from the water surface) and the amount of air, and the amount of pumping required in the present invention is extremely small. Therefore, it is necessary to pump more than necessary to perform stable pumping. Therefore, in the present invention, the air lift pump 25 itself has an excessive pumping capacity, and the throttle part 26 is provided at the suction port, so that the pumped amount can be reduced and only the target water volume can be pumped stably. Yes.
[0010]
The sludge adhering between the inner pipe 27 and the outer pipe 28 is cleaned by the air 37 ejected from the cleaning air pipe 29 connected to the side wall of the air lift pump 25 and the air ejected from the inner pipe 27. That is, during normal operation, air is only ejected from the inner pipe 27, but when the air lift pump 25 is cleaned, air is also discharged from the cleaning air pipe 29, so that the inner pipe 27 and the outer pipe 27 are discharged. More air than normal operation is passed between the pipes 28 to separate the sludge. As another method, the discharge of air from the inner pipe 27 is stopped once, and then an air quantity larger than the air quantity per unit time (hereinafter simply referred to as air quantity) ejected from the inner pipe 27 is used for the cleaning air pipe. 29 may be discharged. The time interval for passing the air 37 through the cleaning air pipe 29 is arbitrarily set. However, the sludge can be sufficiently peeled off if it is performed at a frequency of about once / day for about 10 minutes. . The connection position of the cleaning air pipe 29 is not particularly limited as long as it is below the lowermost part of the inner pipe 27. As shown in FIG. 1, the connection between the throttle part 26 and the lowermost part of the inner pipe 27 is not limited. Alternatively, it may be under the diaphragm 26 as shown in FIG.
[0011]
The cleaning air pipe 29 used in the present invention can be replaced with an inner pipe corresponding to the inner pipe and a common pipe 39 of the cleaning air pipe (see FIG. 7A). Conversely, the inner pipe 27 is used for cleaning. The air pipe 29 can be substituted (see FIG. 7B). However, as described above, when a single pipe is also used, it is necessary to increase the amount of air to be discharged for a predetermined time (while the air lift pump 25 is being cleaned) compared to the normal time. Further, when the cleaning air pipe 29 is also used as the function of the inner pipe 27, it is preferable that the mounting position of the cleaning air pipe 29 is in the vicinity of the throttle portion 26. This is because the entire air lift pump 25 is cleaned.
[0012]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view of the sewage purification tank 1 showing an embodiment of the present invention. The inside of the tank is partitioned by partition walls 17, 18, 19 and 20, and the anaerobic filter bed tanks 21, 21 and the like are arranged from the upstream side. An air filtration bed tank 22, a treated water tank 23, and a disinfection tank 24 are arranged. The anaerobic filter bed 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 22 is provided with a microorganism adherent 31 for aerobic treatment with aerobic microorganisms. The treated 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.
[0013]
Explaining the flow of sewage, the sewage 33 flowing in from the inflow port 32 flows into the anaerobic filter bed tank 21 and after anaerobic treatment, is transferred to the aerobic filter bed tank 22. The sewage that has undergone the aerobic treatment in the aerobic filter bed tank 22 is subjected to solid-liquid separation in the treatment water tank 23, and then most of the sewage is discharged as treated water 34 from the outlet 35 after being disinfected in the disinfection tank 24. The A 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 through the transition pipe 36.
[0014]
The air lift pump 25 will be described in detail with reference to FIG. 1. During normal operation, sewage is sucked from the throttle portion by the air discharged from the inner pipe 27 and passes between the inner pipe 27 and the outer pipe 28. Flow into the transition pipe 36. When cleaning between the inner tube 27 and the outer tube 28, the air discharge from the inner tube 27 is once terminated, and the amount of air discharged from the inner tube 27 from the cleaning air tube 29 connected to the air lift pump 25. Air is discharged with a larger amount of air, and the attached sludge is peeled off.
[0015]
In order to confirm the cleaning effect of the air lift pump 25 of the present invention, the following experiment was conducted. The overall structure is the same as the air lift pump 25 shown in FIG. 1, the diameter of the outer tube 28 is 30 mm, the diameter of the inner tube 27 is 13 mm, the opening diameter of the throttle 26 is 10 mm, and the air supply to the inner tube 27 is about 6 on average. The air supply to the cleaning air pipe 29 was about 15 liters / minute and was installed in the sewage septic tank 1 (see FIG. 2) for 5 persons. The amount of return from the treated water tank 23 to the anaerobic filter bed tank 21 was set to 4 times the amount of sewage flowing into the sewage purification tank 1 (circulation ratio 4), and the management range was set to 3 to 5 circulation ratios. Air supply to the cleaning air tube was performed once / day for 10 minutes.
[0016]
When the air lift pump 25 is cleaned and when it is not returned, the return amount changes as shown in FIG. 5. When the cleaning is performed, the return amount decreases until about 90 days, and is within the management range. However, when cleaning was not performed, the return amount decreased even after 120 days, and the return amount was out of the management range.
[0017]
【The invention's effect】
In the present invention, since the throttle portion is provided, all the water to be pumped can be returned, and the flow rate adjustment of the distribution metering device or the like is not necessary. Furthermore, it becomes possible to perform stable return over a long period of time by attaching a cleaning air pipe or by using both the inner pipe and the cleaning air pipe.
[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 septic tank showing an embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a conventional sewage septic tank.
FIG. 4 is a perspective view of a distribution metering device using a conventional sewage septic tank.
FIG. 5 is a graph showing the daily change of the return amount.
FIG. 6 is a longitudinal sectional view showing an air lift pump used in the present invention.
FIG. 7 is a longitudinal sectional view showing an air lift pump used in the present invention, (a) using a common pipe for an inner pipe and a cleaning air pipe, and (b) for cleaning by removing the inner pipe. This is a connection of an air pipe for use.
[Explanation of symbols]
1. Wastewater septic tank Partition wall Partition wall 4. Partition wall 5. Partition wall 6. Anaerobic filter bed 7. Aerobic filter bed 8. 8. Treated water tank Disinfection tank 10. 10. Dispensing metering device Inner pipe 12. Air 13. Outer tube 14. Tank water 15. Weighing weir 16. Return weir 17. Partition wall 18. Partition wall 19. Partition wall 20. Partition wall 21. Anaerobic filter bed 22. Aerobic filter bed 23. Treated water tank 24. Disinfection tank 25. Air lift pump 26. Diaphragm part 27. Inner pipe 28. Outer tube 29. Air tube for cleaning 30. Filter bed 31. Microbial adherent 32. Inlet 33. Wastewater 34. Treated water 35. Outlet 36. Transition tube 37. Air 38. Water in tank 39. Inner pipe, joint pipe for cleaning air pipe

Claims (2)

  The inside of the tank is partitioned by a partition wall, and an anaerobic filter bed tank, an aerobic filter bed tank, a treated water tank and a disinfecting tank are arranged in this order from the upstream side, and the water in the tank of the aerobic filter bed tank or the treated water tank is In the sewage purification tank having an air lift pump for transferring to the anaerobic filter bed tank and a transition pipe connected to the air lift pump, a throttle portion is provided at the suction port of the air lift pump, and air discharge of the air lift pump is performed. A sewage septic tank, wherein a cleaning air pipe is connected to a side wall below the inner pipe to be performed, and air is intermittently discharged from the cleaning air pipe. The inside of the tank is partitioned by a partition wall, and an anaerobic filter bed tank, an aerobic filter bed tank, a treated water tank and a disinfecting tank are arranged in this order from the upstream side, and the water in the aerobic filter bed tank or the treated water tank is In the sewage purification tank having an air lift pump for transferring to the anaerobic filter bed tank and a transition pipe connected to the air lift pump, a throttle portion is provided at the suction port of the air lift pump, and air is provided on the side wall of the air lift pump. the tube was attached, dirty water septic tank the entire air lift pump the mounting position of the air tube and near with the narrowed portion washable to eject air from the air tube strength alternately.

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