JP2001254700A - Air lift pump, flow rate regulator, and sewage purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air lift pump pumping the water highly never pumped by a conventional one-stage air lift, to provide a flow rate regulator facilitating the flow rate regulation by suppressing the pulsating flow of the water pumping, and to provide a sewage purifier using them operated stably without any troubles such as clogging. SOLUTION: This air lift pump is provided with a transfer box having the upper end projecting and opened to the inside and comprising a closed wall surface surrounding the upper end of a lifting pipe, and an air vent pipe for the transfer box, and a transfer pipe from the transfer box. The air vent pipe has one end opened to the ceiling wall of the transfer box and the other end erected upward once, bent sideways, and then released downward. The transfer pipe has one end opened to the bottom end wall of the transfer box and the other end descending right downward once, bending sideways, erected upward, and slid to the side. This air lift pump is characterized that the water level of the upper bent part of the air vent pipe is positioned higher than the water level of the upper sliding pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air lift pump for transferring treated water pumped by a pump in a place requiring flow control, such as a septic tank or a sewage treatment facility, in accordance with the capacity of the next process, and a flow control. The present invention relates to a device and a sewage purification tank using the same.

[0002]

2. Description of the Related Art Generally, in a sewage treatment tank for purifying night soil and household wastewater, etc., it is necessary to stabilize the circulating water amount and the transfer water amount of the treated water for a long time among a plurality of treatment tanks formed in the sewage treatment tank body. It has become a major factor in stabilizing treated water quality. Above all, in a small-scale septic tank, the inflow of sewage is largely fluctuated over time, and most of the inflow in the day flows in the morning and evening, and the inflow is small during the day. It is a pattern. If sewage flows into the septic tank as it is, a large amount of sewage flows at one time, so it is not possible to secure the residence time in the septic tank necessary for purifying the sewage, and it is discharged without treatment. As a result, the quality of the discharged water will be deteriorated.

[0003] In order to mitigate the time variation of the inflow of sewage, a storage tank is installed on the inflow side of the septic tank to temporarily store a large amount of sewage flowing into the tank at a time, and to store the sewage in the subsequent treatment tank. Measures have been taken to transfer sewage in a fixed amount to ensure thorough purification treatment. For example, Japanese Utility Model Publication No. 7-53756 discloses a sewage purifying tank having a flow rate adjusting function using a multi-stage air lift pump in a sewage transferring apparatus. There is disclosed a sewage purification tank in which the air source of the air lift pump is the same as that for the aeration tank, orifices are attached to each of the air pipes, and a flow regulating mass is attached to the outlet of the air lift pump.

However, in the sewage treatment tank disclosed in the above publication, as described above, the water level of the flow control tank always fluctuates due to the extreme fluctuation of the inflow of sewage, and the difference between the high water level and the low water level is 300. It is not unusual to reach ~ 500 mm. On the other hand, the air lift pump supplies air from the lower part of the pumping pipe, but since the water depth is low at low water level, the amount of air from the blower increases. The air volume decreases due to the high acupressure.

In such a state, if the air source of the air lift pump is also used for the aeration tank, the air flow rate of the air diffuser and the circulation device, which should be constant, will fluctuate depending on the water level (water pressure) of the flow control device. In this case, normal sewage treatment is hindered, for example, the good biological treatment environment is destroyed and the effluent is discharged without treatment.

[0006] In order to correct the above imbalance in the amount of air blow, there is a case where a pressure adjustment valve is attached to each air supply pipe. However, the attachment of the pressure adjustment valve complicates a piping line, and after-maintenance due to congestion of the pipe. This makes it difficult to secure a sufficient space, which is not only a problem of cost increase, but also involves technical difficulty of pressure adjustment itself. In the septic tank disclosed in the above publication, a throttle valve is used at a branch point of the pipe instead of the pressure adjusting valve.

[0007] However, if a throttle valve is used in a commonly used septic tank, the data described in the publication indicates that the aperture must be at most 2-3 mm. In such a throttle valve having a small diameter, troubles such as clogging of the valve are often caused by dust in the pipe or floating dust in the air taken in by a blower, and stable operation may be difficult. Furthermore,
In the septic tank, the air lift pump is used in two stages in order to cope with a high head. Therefore, two air supply holes are required, and the throttle valve is used at a branch point of each stage. The risk of trouble is even higher.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and realizes a high pumping water that cannot be pumped by a conventional single-stage air lift, and causes troubles such as clogging and pumping water. An object of the present invention is to provide an air lift pump, a flow control device, and a sewage purifying tank using the same, which suppress a pulsating flow to facilitate flow control and enable stable pumping in a wide range of air flow.

[0009]

According to the first aspect of the present invention, there is provided an air lift pump in which the upper end of a water pump is protruded and opened inside, and the transfer is constituted by a closed wall surrounding the upper end of the water pump. An air lift pump provided with a box, an air bleed tube of the transfer box, and a transfer tube from the transfer box, wherein the air bleed tube has one end opened in a ceiling wall of the transfer box, and the other end once stands upright. After being bent to the side and bent to the side, it is opened downward, and the transfer pipe is opened at one end to the lower end wall of the transfer box, and the other end is piped directly below and bent to the side. After that, it rises up and is laterally drawn again, and the water level of the upper bent portion of the air venting pipe is higher than the water level of the upper horizontal drawing pipe of the transfer pipe.

The air lift pump according to the second aspect of the present invention is the air lift pump according to the first aspect,
The lower end of the water pipe is opened downward to form a suction port.

An air lift pump according to a third aspect of the present invention is the air lift pump according to the first aspect of the present invention.
The lower end of the pumping pipe is folded in a U-shape, and the suction port is opened upward.

According to a fourth aspect of the present invention, there is provided a flow control device connected to the air lift pump according to the first to third aspects, wherein the control device includes a front chamber, a rear chamber connected to an overflow weir, and a control device. In the front chamber, the discharge port of the horizontal drawing pipe above the transfer pipe of the air lift pump bends downward and opens lower than the height of the overflow weir, and the rear chamber has a shutter to adjust the outflow area. The flow outlet is provided at a position lower than the height of the overflow weir, a flow meter for detecting the flow rate based on the shutter displacement amount is provided, and the control device controls the air flow rate of the air lift pump based on a signal from the flow meter. The flow rate is adjusted so as to keep the outflow constant.

According to a fifth aspect of the present invention, there is provided a flow rate adjusting device connected to the air lift pump according to the first to third aspects, comprising a front chamber and a rear chamber connected by an overflow weir. In the chamber, the discharge port of the horizontal drawing pipe above the transfer pipe of the air lift pump is bent downward and opens lower than the height of the overflow weir, and in the rear chamber, the adjustment tank is lower than the height of the overflow weir. And a sewage distribution transfer port in which the amount of effluent to the contact aeration tank is controlled according to the opening and closing of a sewage flow outlet and a shutter.

[0014] The sewage purifying tank of the invention according to claim 6 is an air lift pump or claim 1 to 3 according to claims 1 to 3.
The air lift pump described above and the flow control device according to claim 4 or 5 are used to transfer sewage from one tank to another tank.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view schematically showing the overall structure of an air lift pump according to the present invention. In FIG. 1, a pumping pipe 1 is installed in one processing tank A and a blower (not shown). Supplied air is blown from the air supply hole 21 through the air supply pipe 2, and the sewage sucked from the suction port 12 mixes with the blown bubbles to form a rising water flow of the sewage in the pumping pipe 1. Is done. The upper end opening 11 of the pumping pipe 1 is
The sewage that is provided to protrude inside the transfer box 3 and is pumped from the processing tank A by the air lift pump is supplied relatively above the transfer box 3 from the upper end opening 11 and is filled in the transfer box 3.

The transfer box 3 has a closed wall surrounding the upper end of the pumping pipe 1. The transfer box 3 is not particularly limited as long as it is excellent in corrosion resistance. For example, a transfer box 3 may be formed from a hard vinyl chloride resin plate or the like.
Any shape can be used as long as it can be compactly installed in a part of the processing tank A, such as a cylindrical shape or a rectangular tube shape.

The installation position of the transfer box 3 depends on the capacity of the air lift pump, but the higher the installation position in the treatment tank A is above the sewage surface water level, the higher the pumping water.
It is determined based on requirements such as the space in the processing tank A and desired pumping. For example, the height of an air vent tube 5 described later is 150 to
If the transfer box 3 is installed at a position 200 mm higher than the surface water level of the sewage, if the transfer box 3 is installed at a position 200 mm higher than the surface level of the sewage, the transfer box 3 is 300 mm higher than the sewage water level of the anaerobic filter bed tank as the flow control tank.
It can pump water up to a height higher by mm.

The air release pipe 4 is connected to the pumping pipe 1 of the transfer box 3.
Is opened on the ceiling wall 31 immediately above the opening, the other end is piped upright, and is bent laterally and laterally drawn 41,
For example, it is opened downward in a U-shaped tube, and overflow water is returned to the original tank 4 together with pumping air.
The space between the upper end opening 11 of the pumping pipe 1 and the opening of the transfer box 3 ceiling wall 31 of the air vent pipe 4 is preferably provided as close as possible to smooth the pumping of the sewage and pulsate the sewage to be pumped. Is suppressed. The above interval is
Preferably about 10 to 50 mm, more preferably about 10 to 50 mm
It is about 30 mm.

On the other hand, the transfer pipe 5 is opened to the bottom wall 32 of the transfer box 3, and the other end is piped directly below, bent 51 to the side, and then rises up in a U-shaped tubular shape. Lateral pulling 52 is performed laterally, and the water is pumped to another tank B. The sewage pumped into the transfer pipe 5 is trapped in the transfer box 3 and then drawn out from the bottom of the transfer box 3, so that the intake of pumping air is small and the pulsation of the transferred sewage is reduced.

A laterally drawn tube 41 is provided on the upper side of the air vent tube 4.
Is different from the water level of the horizontal drawing pipe 52 above the transfer pipe 5,
The larger, the larger the original tank 4 together with the pumping air from the air vent 4
The amount of sewage returned to the storage pipe decreases, and the amount of pumped sewage to the transfer pipe 5 increases. Therefore, if there is no fluctuation in the water level and the supply amount of the pumping air is constant, the pumping amount of the sewage to the transfer pipe 5 can be controlled by adjusting the water level difference.

The difference between the water level of the horizontal drawing pipe 41 above the air vent pipe 4 and the water level of the horizontal drawing pipe 52 above the transfer pipe 6 depends on the head and the supply amount of pumping air to be used. , 1
It is set at 00 to 250 mm.

The above-mentioned pumping amount and head tend to increase or increase as the water depth at the position of the supply hole 21 of the pumping air supplied to the pumping pipe 1 increases, and the diameter of the pumping pipe 1 also decreases. Tend to increase or increase.

As described above, a purification tank for transferring sewage from a processing tank A to another processing tank B using an air lift pump provided with a transfer box 3 having an air vent pipe 4 and a transfer pipe 5 is manufactured. For example, as shown in FIG. 1, the suction port 12 of the pumping pipe 1 is placed 50 mm above the bottom of the processing tank A.
And a blower of 20 liters / min.
The air is supplied to the air supply pipe 2 so that the amount of air is supplied to the air supply pump, and the air lift pump is operated to pump the wastewater from the anaerobic filter bed tank as the processing tank A to the aeration tank as the processing tank B.

The suction port 12 of the air lift pump may be of a type that opens toward the bottom of the processing tank A as shown in FIG. 1; however, as shown in FIG. 1 may be of a type in which the lower end is folded in a U-shape and opens toward the surface of the sewage water of the treatment tank. When the air lift pump is installed in an anaerobic filter bed tank, an enclosure may be formed by a blocking wall as a scum baffle and a cleaning port so that scum or the like is sucked and the suction port 12 is not closed. The air lift pump may be connected to a flow control device at a sewage discharge port of the transfer pipe 5.

FIG. 2 is an explanatory view showing an outline of the entire structure of one example of the flow rate adjusting device 7 connected to the air lift pump of the present invention. In FIG.
Reference numeral 72 denotes a rear chamber, both of which are connected via an overflow weir 73. In the front chamber 71, the drain port 55 of the transfer pipe 5 of the air lift pump is bent downward, and the height of the overflow weir 73 is increased. It is opened at a lower water level, trapped in the sewage water of the front chamber 71, and is U-shaped from the bottom of the transfer box 3 immediately before, and furthermore,
A double trap is formed together with the S-shaped primary trap connected to the drain port 55, and can greatly contribute to suppressing the pulsating flow of wastewater pumped by the air lift pump.

The sewage transferred into the sewage basin in the front chamber 71 overflows the overflow weir 73 into the rear chamber 72, and
The shutter 72 adjusts the outflow area of the outlet 721.
2, a flow meter 723 for detecting the displacement amount of the adjustment shutter 722 is provided at a water level lower than the height of the overflow weir 73.

The shape of the opening of the outlet 721 of the rear chamber 72 constituting the flow meter 723 is not particularly limited. For example, a V-shaped groove is provided at the center of a flat weir, and a shutter is provided. A method of increasing or decreasing the outflow area by 722 in the V-shaped groove may be used.

The flow rate measuring method using the V-shaped groove further facilitates the detection of the magnitude of the pulsation of the sewage passing through the V-shaped groove. It can be input to a control device described later.
The degree of opening / closing of the V-shaped groove by the shutter 722 is set in advance to an opening degree corresponding to a human tank, and the degree of opening / closing provided on the outer wall of the rear chamber 72 is roughly set by a manual lever. (Not shown).

FIG. 3 is an explanatory diagram showing the configuration of an example of a sewage purification tank using the flow rate adjusting device 7 shown in FIG. In FIG. 3, the sewage treatment tank is
An anaerobic filter tank first 81, an anaerobic filter tank second 82, a contact aeration tank 83, a sedimentation tank 84, and a disinfection tank 85 are provided. The anaerobic filter tank second 82 has a flow control device shown in FIG. Is installed in a section surrounded by a blocking wall, and irrespective of the amount of inflow of sewage, only sewage of an amount corresponding to the treatment capacity is always pumped and transferred to the contact aeration tank 83 in the next step. It has been made like that.

FIG. 4 is a partially cutaway perspective view showing another example of the flow control device of the present invention. In FIG. 4, the flow control device 70 includes a front chamber 74 and a rear chamber 75,
The drainage port 55 of the transfer pipe 5 of the air lift pump is bent downward in the front chamber 74 so as to open to a lower water level than the height of the overflow weir 76.
Transfer box 3 immediately before being trapped in the sewage masquerade 4
It is the same as the flow control device 7 shown in FIG. 2 in that a double trap is configured together with a U-shaped primary trap from the bottom of the, and an S-shaped primary trap connected to the drain port 55.

In the present embodiment, the sewage overflowing the overflow weir 76 into the rear chamber 75 is supplied to the sewage outlet 2 to the regulating tank.
74 is provided so as to open at a water level lower than the height of the overflow weir 76. Further, a shutter 725 is attached to the sewage outlet 274, and the sewage outlet 274 is connected to the contact aeration tank according to the opening and closing of the shutter 725. Is provided with a sewage distribution port.

Although the adjusting tank is not particularly limited, for example, an anaerobic filter bed tank may be used as in the previous embodiment. A contact aeration tank may be provided.

The installation position of the distribution transfer port is not particularly limited. For example, as shown in FIG.
It may be formed on one side of the side wall of the sewage basin defined by the overflow weir 76 and the sewage outlet 274 of the rear chamber 75, and a shutter capable of adjusting the area of the outlet at the sewage outlet 274 is provided. The sewage distribution and transfer port whose outflow amount is controlled may be provided to be branched from the sewage transfer pipe 9.

The form of the distribution transfer port is not particularly limited as long as it can control the transfer amount of sewage to the contact aeration tank. For example, as shown in FIG. A transfer port and a shutter that moves in the height direction of the trapezoid, the opening degree of the distribution transfer port is set by the movement of the shutter, and the transfer amount of the sewage to the contact aeration tank can be manually controlled. The flow rate of the sewage outlet 274 is measured by a flow meter, and an automatic control method according to a programmed scheme is adopted using a sewage distribution device such as an automatic distribution valve. You may.

The manual control type dispensing transfer port shown in FIG. 4 has a sewage outlet 27 in the rear chamber 75 shown in FIG.
As shown in the cross-sectional view taken along the line V-V in FIG. Since it is generally grasped empirically, it is preferable to provide and display a human tank display based on this, and to set the opening degree of the distribution transfer port using the human tank display as a guide.

(Embodiment 1) As shown in FIG. 1, a pump pipe 1 (30 mm in diameter, air supply pipe 2) of an air lift pump
Is provided with an upper end opening 11 of a hard vinyl chloride resin tube with a nominal diameter of 13 protruding 110 mm inside the transfer box 3, and sewage pumped from one tank A by an air lift pump is supplied to the transfer box 3. Pipes are supplied relatively above the

The transfer box 3 is made of a hard vinyl chloride resin plate and has an inner capacity of 110 mm long × 110 mm wide × 130 mm high. Vent tube 5
Is opened to the ceiling wall 31 immediately above the pumping pipe 1 of the transfer box 3 and the other end is piped upright, bent to the side, then opened downward in a U-shaped tube, and overflowed. Is returned to the original tank 4 together with the pumping air. The distance between the upper end opening 11 of the pumping pipe 1 and the opening of the transfer box 3 ceiling wall 31 of the air vent pipe 5 is about 20 mm.

On the other hand, the transfer pipe 6 is opened to the bottom wall 32 of the transfer box 3, and the other end thereof is piped so as to be directed downward. It is drawn to the side and pumped to another tank 4. The difference between the water level of the pipe bent to the side above the air vent pipe 5 and the water level of the horizontal drawing pipe above the transfer pipe 6 was set to 150 mm.

As described above, the air lift pump provided with the transfer box 3 having the air bleeding pipe 5 and the transfer pipe 6 is moved upward by 50 mm from the bottom of the tank 4 into the suction pipe 1 as shown in FIG. Installed so that mouth 12 or opening,
Using a blower with an air flow rate of 20 liters / minute, the branch portion is blown to the air supply pipe 2 using a valve so that the air flow rate is about 10 liters / minute, and the air lift pump is operated to discharge the wastewater shown below. A pumping test was performed.

The amount of air blown by the valve is adjusted by changing the head, so that the amount of air blow also changes and the amount of pumped water changes. The amount of air is blown so that it can be stably used for other devices, for example, for an air diffuser of an aeration tank.

(Comparative Example) A conventional one without the transfer box 3, the air vent tube 5, and the transfer tube used in the first embodiment.
A step-type air lift pump was installed in the tank 4 as in Example 1, and a pumping test of sewage was performed as in Example 1.

In the above pumping test, as shown in Table 1, the head (difference between the surface water level of the sewage tank 4 and the water level of the horizontal drawing pipe above the transfer pipe 6) was set to three levels of 230 mm, 350 mm and 430 mm. The pumping rate was measured at five levels near 10 liters / minute in the range of 5 to 14.5 liters / minute. The test results are shown in Table 1.

[0044]

[Table 1]

As is evident from Table 1, the air lift pump of Example 1 has a head of 230 mm, a blowing rate of 9.5 liter / min or more, and a substantially stable high pumping rate of 12 liter / min. While the head was 230 mm and the blowing rate was 13 liters / min or more, the pumping amount was almost stable and a high pumping amount of 10 liters / min was shown.
30 mm, air flow rate of 13 liters / min or more, pumping rate 1
Except for 0 liter / min, all of them showed only a very small pumping rate, indicating that stable operation was not expected. In addition, when the head was 430 mm, water could not be pumped at all in the comparative example, but even with the air lift pump of Example 1, the pumping amount was significantly reduced.

(Embodiment 2) As shown in FIG. 2, the lower end of a water pumping pipe 1 (having a diameter of 30 mm) of an air lift pump is
It is folded back in the shape of a letter, the end is opened upward, a suction port is formed, the virtual water surface including the suction port 13 is a lower sewage management water surface (abbreviated as LWL), and the sewage surface is Upper sewage management water surface (abbreviated as HWL).

The transfer box 30 and the air bleeding pipe 40 connected to the water pumping pipe 1 of the air lift pump are the same as those in the first embodiment. Bend the front chamber 71 of the flow control device 7
The same thing as in Example 1 was used except that it was buried and opened in a sewage water tank.

The flow control device 7 is manufactured using a rigid vinyl chloride resin plate and a tube. The front chamber 71 is made of sewage which traps sewage and suppresses pulsation of transferred sewage. An overflow weir 73 is formed between the and the rear chamber 72 by cutting out the central part of the upright wall that partitions the square into a square, and the rear chamber 72 is provided with a flow rate of the sewage that overflows the overflow weir 73. A metering chamber is provided with an outlet having a V-shaped groove in the center of a flat weir and a flow meter which can be detected by the displacement of an adjustment shutter 722 for adjusting the outflow area of the outlet. Have been.

With respect to the sewage purification tank equipped as described above, a purification test of simulated household wastewater was performed. The test results show that the head is operated at a head of 230 mm and the air flow rate is about 9.5 liter / min. When the inflow of sewage increases rapidly, the temporary storage in the sewage control tank is stabilized at a high pumping rate of 10 liter / min or more. Biological treatment was performed.

(Embodiment 3) Pumping pipe 1 of air lift pump
The transfer box 30 and the air vent tube 40 connected to
The transfer pipe 50 is formed by bending the drain port 55 of the upper horizontal drawing pipe 42 downward, and
The same thing as in Example 1 was used except that it was buried and opened in the sewage sewage of the front chamber 71.

The flow control device 70 is manufactured using a rigid vinyl chloride resin plate and a tube, and as shown in FIG.
The tip of the transfer pipe 5 is bent downward and trapped in the sewage in the front chamber 74 to suppress the pulsation of the transferred sewage. Also, an overflow weir 76 is formed between the front chamber 74 and the rear chamber 75 by cutting off the center of the upright wall that separates it into a square. The rear chamber 75 is a measuring chamber for the flow rate of the sewage flowing out of the overflow weir 76. As shown in FIG. 5, an outlet 724 having a V-shaped groove is provided at the center of the flat weir. On the side wall of the outlet 724, an average outflow amount for each human tub, which is empirically grasped, is displayed as a human tub display.

On the side wall of the rear chamber 75, that is, the side wall 77 between the overflow weir 76 and the weir of the outlet 724, an inverted base having an upper bottom on the front chamber 74 side and a lower bottom on the outlet 724 side. A sewage distribution transfer port 78 having a shape is provided near the bottom surface of the outlet 724. The delivery port 78 has a shutter 7
9 is provided so as to be openable and closable, and can be fixed at an arbitrary position from the upper bottom to the lower bottom of the trapezoidal distribution transfer port 78.

The opening and closing of the shutter 79 is shown in FIG. 5 by the knob of the shutter 79 shown in FIG.
It is managed manually based on the above-mentioned human tank display. The sewage distributed from the distribution transfer port 78 preferentially transfers sewage having a substantially constant flow rate to the contact aeration tank, and the aerobic treatment is sufficiently performed. At this time, surplus wastewater is transferred from the outlet 724 to the second anaerobic filter bed tank (adjustment tank) by the transfer pipe (hard vinyl chloride resin pipe VU nominal diameter 50) 9.

With respect to the sewage purification tank equipped as described above, a purification test of simulated household wastewater was performed. The test results show that the operation is performed at a head of 350 mm and an air flow rate of 13 liter / min. When the inflow of sewage increases rapidly, the temporary storage in the sewage control tank is stabilized and the biological treatment is stably performed at a high pumping rate of 10 liter / min or more. Was made.

[0055]

Since the air lift pump according to the first aspect of the present invention is constructed as described above, it realizes high pumping water which cannot be pumped by a conventional single-stage air lift pump, and has a throttle valve. This enables stable pumping over a wide range of air flow without troubles such as clogging.

Since the air lift pump according to the second aspect of the present invention is configured as described above, the air lift pump according to the second aspect of the present invention can exert the effects described in the previous aspect as a means for pumping and transferring sewage in a contact aeration tank or the like. is there.

Since the air lift pump according to the third aspect of the present invention is configured as described above, in particular, pumping and transferring of sewage in an anaerobic filter bed tank or the like used as an adjusting tank for reducing fluctuations of inflow sewage. As a means, the effect described for the air lift pump according to the first aspect of the invention can be remarkably exhibited.

Since the flow rate adjusting device according to the fourth aspect of the present invention is configured as described above, in addition to the effects described in the preceding sections, it suppresses the pulsating flow of the pumping water, and makes the pumping smooth and efficient. In addition to reducing wastewater, fluctuations of inflow sewage can be reduced, and sewage can be reliably purified at a flow rate corresponding to the treatment capacity of the sewage treatment tank.

Since the flow regulating device according to the fifth aspect of the present invention is configured as described above, in addition to the effects described in the preceding items, the pulsating flow of the pumped water is suppressed, and the smoothness and efficiency of the pumped water are improved. In addition to the purification, the sewage purification can be surely performed at a flow rate corresponding to the processing capacity of the sewage purification tank.

The sewage purifying tank of the invention according to claim 6 is constructed as described above, so that it has the effects described in the preceding paragraphs, and reliably utilizes the biological activity of the sewage purifying tank. Can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an air lift pump of the present invention.

FIG. 2 is an explanatory view showing an example of a flow rate adjusting device of the present invention.

FIG. 3 is an explanatory view showing an example of a sewage purification tank of the present invention.

FIG. 4 is a perspective view showing another example of the flow control device of the present invention.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pumping pipe 11 Upper end opening part 12,13 Suction port 2 Air supply pipe 21 Air supply hole 3,30 Transfer box 31 Ceiling wall 32,41,42,52,53 Horizontal draw pipe 33 Bottom wall 4,40 Air vent pipe 5, 50, 9 Transfer pipe 51 Bending 54, 55 Drain port 6 Blocking wall 7, 70 Flow control device 71, 74 Front room 72, 75 Rear room 721, 724 Outflow port 722, 725, 79 Shutter 723 Flow meter 73, 76 Overflow Weir 77 Side wall 78 Distribution transfer port 81 Anaerobic filter bed tank first 82 Anaerobic filter bed tank second 83 Contact aeration tank 84 Precipitation tank 85 Disinfection tank A Treatment tank (1) B Treatment tank (2)

Claims (6)

[Claims] 1. An upper end of a pumping pipe protrudes inside and opens,
An air lift pump provided with a transfer box composed of a closed wall surrounding the upper end portion of the pumping pipe, an air bleed pipe of the transfer box, and a transfer pipe from the transfer box. One end is opened in the ceiling wall of the box, the other end is piped upright once, bent sideways, and then opened downward, and the transfer pipe is opened at the lower end wall of the transfer box. , The other end is piped directly below, bent sideways, then erected upright, laterally drawn again, and the water level of the upper bent portion of the air vent is above the transfer pipe. An air lift pump characterized by being located higher than the water level of the horizontal draw pipe. 2. The air lift pump according to claim 1, wherein a lower end of the pumping pipe is opened downward to form a suction port. 3. The air lift pump according to claim 1, wherein a lower end of the water pipe is folded back in a U-shape, and a suction port is opened upward. 4. A flow control device connected to the air lift pump according to claim 1, comprising a front room, a rear room, and a control device connected by an overflow weir, and transferring the air lift pump to the front room. The discharge port of the horizontal draw pipe above the pipe is bent downward and opens lower than the height of the overflow weir, and an outlet with a shutter for adjusting the outflow area is provided in the rear chamber of the overflow weir. A flow meter that is provided at a lower position than the height and detects a flow rate with the shutter displacement amount is provided, and the control device adjusts the blowing amount of the air lift pump by a signal from the flow meter,
A flow control device characterized in that an outflow amount is kept constant. 5. A flow control device connected to the air lift pump according to claim 1, comprising a front chamber and a rear chamber connected by an overflow weir, wherein the front chamber is provided above a transfer pipe of the air lift pump. The outlet of the horizontal draw pipe is bent downward and opens at a level lower than the height of the overflow weir, and the rear chamber has a level lower than the height of the overflow weir to open and close the sewage discharge outlet and shutter to the regulating tank. A flow control device, comprising: a sewage distribution transfer port whose discharge amount to a contact aeration tank is controlled accordingly. 6. An air lift pump according to claims 1 to 3, or an air lift pump according to claims 1 to 3 and a flow control device according to claim 4 or 5, for transferring sewage from one tank to another tank. A sewage septic tank characterized by being made as described above.