JP2011001918A - Air lift pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air lift pump device, which performs efficient water conveyance while reducing the power required for the transfer of water to be treated from one treatment tank to the other treatment tank, the tanks being provided continuously through a barrier wall.SOLUTION: The air lift pump device 40 includes: a lift pipe 41 disposed in a second area 32 (aerobic tank 30); an air diffuser 42 disposed to face a lower opening 41a formed at the lower end of the lift pipe 41, the air diffuser releasing bubbles toward the lower opening 41a; and a water pipe 43 of substantially horizontal attitude, which transfers water to be treated lifted in the bubbles from the upper part of the lifting pipe 41 to an anoxic tank 20 adjacent to the second area 32 through the barrier wall 21. The air diffuser 42 includes an air diffusion part 42a having a plurality of diffusion ports dispersively formed in a planer manner to release fine bubbles to a range having an area substantially equal to that of the lower opening 41a. The air diffusion part 42a is disposed in parallel to the plane of the lower opening 41a of the lift pipe 41.

Description

  The present invention relates to an air lift pump device that transfers a liquid to be transferred by using an air lift effect caused by bubbles released into a pumping pipe arranged upright in the liquid to be transferred.

  Conventionally, when water to be treated is transferred from one treatment tank adjacent to the other to the other treatment tank, for example, in a sewage treatment facility, a flow rate adjustment tank, a sewage purification tank, etc., the treatment in one treatment tank Water has been pumped by a mechanical pump device installed outside or in the water and transferred to the other treatment tank.

  However, if the water level difference between one treatment tank and the other treatment tank is not large and the head is relatively low, there is no mechanical pump that can handle such a low head, so it is actually overspec. The pump must be used, and the pipe resistance increases according to the length of the transfer pipe and the total lift rises. There is also a problem that the number of parts is increased, for example, a valve is installed in the transfer pipe.

  Therefore, in order to reduce the pump power and the piping space, a pump device using an air lift pump device is often installed instead of the mechanical pump device.

  For example, as shown in FIG. 9, Patent Literature 1 discloses a configuration of an air lift pump that circulates water in a tank of a wastewater purification facility, a treated water tank, or a settling tank to an anaerobic tank. The sewage treatment facility partitions the inside of the tank with a partition wall and arranges an anaerobic tank, an aerobic tank, a treated water tank, and a disinfecting tank in this order from the upstream side, and a part of the water in the treated water tank as one treatment tank In order to stabilize the treated water quality and denitrify, the water is pumped by the air lift pump 80 and returned to the anaerobic tank as the other processing tank by the transfer pipe 81.

  In the air lift pump 80, the air 85 inserted into the air lift pump 80 from the blower 82 via the adjustment valve 83 is discharged from the lower end of the inner pipe 86, and is lifted between the outer pipe 87 and the inner pipe 86 by a driving force. The internal water 88 is pumped up, and the pumped water is configured to reach the anaerobic tank as the circulating water 89 from the transition pipe 81.

  As shown in FIG. 10, Patent Document 2 discloses, as an air lift pump 94 used in a flow rate adjustment tank and a sewage purification tank, a pumping pipe 92 having a liquid suction port 90 in the lower part and a liquid discharge port 91 in the upper part, The structure provided with the air supply pipe | tube 93 for connecting with the pipe | tube 92 and supplying air to the lower part is disclosed.

JP-A-11-104664 JP 2002-357200 A

  However, the air lift pump 80 described in Patent Document 1 described above is configured such that the treated water that has been pumped rises between the outer pipe 87 and the inner pipe 86, and therefore the inner pipe 86 itself is covered. The resistance to the flow of treated water is reduced, and the passage cross-sectional area of the treated water is reduced, resulting in an increase in pressure loss. Further, since the treated water is pumped above the water surface, the power of the blower is increased. In addition, foreign matter contained in the water to be treated is entangled with the tip of the inner pipe 86 and is blocked, and there is a possibility that the amount of pumped water is reduced.

  In the air lift pump 94 described in the above-mentioned Patent Document 2, since air is supplied from the air supply pipe 93 connected to the lower part of the pumping pipe 92 from the lateral direction, it is biased to the flow of air supplied into the pumping pipe 92. As a result, the flow of water to be treated is likely to be disturbed and the pumping efficiency is poor. In addition, similarly to the air lift pump 80 described in Patent Document 1, there is a problem that the power of the blower increases because the water to be treated is pumped above the water surface.

  In view of the above-described problems, the object of the present invention is to reduce the power required for transferring the water to be treated from one treatment tank connected to the other through the partition wall to the other treatment tank. An object of the present invention is to provide an air lift pump device that can be used.

In order to achieve the above-mentioned object, the characteristic configuration of the air lift pump device according to the present invention is as described in claim 1 of the present invention. An air diffuser is disposed below the lower opening, and the air diffuser discharges air bubbles from the air diffuser toward the lower opening and the air discharged from the air diffuser communicates with the upper opening of the pumping pipe. It has a water pipe with a substantially horizontal posture to transfer the treated water,
The diffuser is in the point of releasing fine bubbles from a range of approximately the same area as the lower opening.

  According to the above-described configuration, since the fine bubbles are discharged substantially uniformly in a state where the entire surface is aerated with respect to the lower opening, even if the flow passage cross-sectional area of the pumping pipe becomes large, the bubbles in the cross section in the pumping pipe Furthermore, since the diffuser is located below the lower opening surface of the pumping pipe, the water to be treated flows from the periphery of the lower opening to the lower opening in a balanced manner. The drift of the water to be treated can be suppressed. Further, by releasing the bubbles from below, the rising distance of the bubbles can be extended, and the amount of pumped water can be increased.

  Therefore, the pumping efficiency is improved. In addition, since the air diffuser of the air diffuser is arranged not in the pumping pipe but facing the lower opening, there is a possibility that activated sludge contained in the water to be treated may get entangled with the air diffuser and block the water pump. Disappear.

  Conventionally, the air supplied from the blower has been discharged from the pipe end into the pumping pipe, so that the size of the bubbles is more than φ10 mm, and the deviation of the bubbles in the cross section in the pumping pipe is large. Inefficient. On the other hand, a large specific surface area is ensured by dispersing and forming a plurality of minute air diffusers in the air diffuser and releasing fine air bubbles from the air diffuser, compared to conventional air bubbles with a size of φ10 mm or more. In addition, the rising speed of the bubbles in the pumping pipe is slow and the residence time is increased, the specific gravity of the apparent water to be treated becomes smaller, and the pumped amount per the same amount of air diffused can be increased. Therefore, the amount of aeration to obtain the same amount of pumped water and the power consumption of the blower can be reduced with the conventional pumped amount of bubbles. For example, the size of the fine bubbles is preferably 2 mm or less.

  In addition to the first feature configuration described above, the second feature configuration is an imaginary surface extending vertically downward from the periphery of the pumping pipe in the space of the upper surface of the lower opening and the air diffuser in addition to the first feature configuration described above. The lower opening and the diffuser upper surface are separated from each other so that the area of the imaginary plane partitioned by is equal to or larger than the area of the lower opening.

  According to the above-described configuration, when the water to be treated passes through the lower opening and the diffuser upper surface through the virtual surface extending vertically downward from the periphery of the pumping pipe, the average flow velocity when passing through the lower opening Since the average flow velocity can be reduced, the resistance when passing through the virtual surface can be reduced, and the turbulence of the water to be treated in the pumped water pipe caused by the flow passing through the virtual surface can be reduced. be able to.

  In the third characteristic configuration, as described in claim 3, in addition to the first or second characteristic configuration described above, the amount of air diffused from the air diffuser is larger in the peripheral portion than in the central portion. In the point.

  In the vicinity of the lower opening of the pumping pipe, bubbles released from the air diffuser tend to concentrate in the center of the pumping pipe due to the influence of the treated water flowing from the surroundings into the pumping pipe. The flow of water to be treated is peeled off from the inner wall surface of the pumping pipe and the pressure loss tends to increase.

  However, according to the above-described configuration, since the water to be treated can easily flow into the lower opening from the central portion, it is possible to reduce the unevenness of bubbles, and the upward flow of the water to be treated can be smoothed inside the pumping pipe. Can be generated.

  In the fourth feature configuration, as described in claim 4, in addition to any one of the first to third feature configurations described above, the water pipe includes an enlarged portion whose cross-sectional area is enlarged toward the downstream side. The inner upper surface of the water pipe in the enlarged portion is inclined upward toward the downstream side.

  According to the above-described configuration, the bubbles released by the air diffuser and rising in the pumping pipe are separated into gas and liquid by the enlarged portion, so while quickly separating the bubbles that have finished the role of pumping in the pumping pipe, It is possible to prevent an increase in channel resistance due to a decrease in the effective cross-sectional area through which the water to be treated flows.

  The fifth characteristic configuration is that, as described in the fifth aspect, in addition to the fourth characteristic configuration described above, a water pipe is formed in a bowl shape on the downstream side of the enlarged portion.

  According to the above-described configuration, the bubbles separated from the gas and liquid at the enlarged portion are discharged to the atmosphere from the upper end portion of the bowl-shaped water channel.

  In the sixth feature configuration, as described in claim 6, in addition to the fourth or fifth feature configuration described above, the upper end portion of the pumping pipe and the base end portion of the water supply pipe communicate with each other through a curved pipe. It is in a connected point.

  According to the above-described configuration, the water to be treated that has been pumped by the pumping pipe is gently guided to the enlarged portion by the curved pipe, so that pressure loss can be reduced and the amount of air diffused can be reduced.

  As described above, according to the present invention, it is possible to provide an air lift pump device that can reduce the power required for transferring the water to be treated in the treatment tank and perform efficient water supply.

The top view explaining the sewage treatment facility which employ | adopted the air lift pump apparatus by this invention Sectional drawing explaining the sewage treatment equipment which employ | adopted the air lift pump apparatus by this invention The perspective view of the air lift pump apparatus by this invention Side view of an airlift pump device according to the present invention The front view of the air lift pump apparatus by this invention The top view of the air lift pump apparatus by this invention Side sectional view of an air lift pump device according to the present invention. (A) is a front view explaining the principal part of the air lift pump apparatus by this invention, (b) is a side view explaining the principal part of the air lift pump apparatus by this invention, (c) shows another embodiment, this invention Side view explaining the main part of the air lift pump device by Explanatory drawing of a conventional air lift pump device Explanatory drawing of a conventional air lift pump device

  Hereinafter, the case where the air lift pump device according to the present invention is applied as a pump for returning treated water in an aerobic tank of a sewage treatment facility to an anoxic tank will be described.

  As shown in FIGS. 1 and 2, the sewage treatment facility 1 is connected to an anaerobic tank 10 into which raw water that is untreated water flows, and an anaerobic microorganism connected to a downstream side of the anaerobic tank 10 via a partition wall 11. The anaerobic tank 20 for denitrifying the water to be treated and the ammonia contained in the water to be treated flowing out of the oxygen-free tank 20 through the partition wall 21 on the downstream side of the oxygen-free tank 20 is nitrified with an aerobic microorganism. An aerobic tank 30 and an air lift pump device 40 for returning a part of the water to be treated nitrified in the aerobic tank 30 to the anoxic tank 20. In addition, the broken line arrow in a figure represents the flow of to-be-processed water.

  In the anaerobic tank 10, anaerobic treatment is performed by microorganisms under anaerobic conditions, and BOD components contained in the raw water are taken into the microorganisms, and phosphorus compounds are hydrolyzed to release phosphorus as normal phosphoric acid into the liquid. The water to be treated that has been anaerobically treated in the anaerobic tank 10 is transferred to the anoxic tank 20 through the communication port 12 formed in the lower part of the partition wall 11.

  In the anaerobic tank 20, anaerobic treatment is performed by microorganisms under anaerobic conditions, and denitrification treatment, that is, reduction treatment of nitrate ions and nitrite ions to nitrogen gas is performed. The water to be treated that has been anaerobically treated in the anaerobic tank 20 is transferred to the aerobic tank 30 through the communication port 22 formed in the lower part of the partition wall 21.

  In the aerobic tank 30, the first region 31 that receives the treated water flowing out from the oxygen-free tank 20 and the second region 32 that guides the treated water flowing in from the first region 31 to the partition wall 22 A separation wall 34 that separates the aerobic tank 30 along the outflow direction is provided, and a plurality of air diffusers 35 that diffuse the treated water in the first region 31 are installed, and the treated water in the second region 32. A plurality of membrane separation devices 36 for solid-liquid separation are installed, and an air lift pump device 40 is installed downstream of the second region 32. The separation wall 34 is formed of a substantially vertical wall whose upper edge protrudes above the water surface, the base end side is joined to the partition wall 21, and the other end side is opened in the aerobic tank 30.

  In the first region 31, nitrification treatment is performed in which ammonium ions derived from human urine and the like contained in the water to be treated are oxidized by microorganisms and converted into nitrous acid and nitric acid under aerobic conditions by aeration by the aeration device 35. Furthermore, aerobic treatment is performed in which normal phosphoric acid in the water to be treated is taken into sludge and accumulated as polyphosphoric acid.

  In the second region 32, solid matter such as activated sludge is separated from the water to be treated by the membrane separation device 36, and the separated water to be treated is discharged to a treated water tank (not shown) in the subsequent stage through a water pipe 37. . As the separation membrane used in the membrane separation device 36, an ultrafiltration membrane, a microfiltration membrane or the like is preferably employed. As the form of the membrane, a hollow fiber membrane, a flat membrane, a tubular membrane or the like is preferably employed.

  Note that the volume of the first region 31 separated by the separation wall 34 is set to be larger than the volume of the second region 32. In particular, it is preferable to form the separation wall 34 so that the volume of the first region 31 is about twice as large as the volume of the second region 32. By comprising in this way, an aerobic process is favorably performed in the 1st area | region 31. FIG.

  An air diffuser 38 for removing and cleaning sludge adhering to the membrane surface of each membrane separator 36 is disposed below the plurality of membrane separators 36. In the second region 32, nitrification is performed by activated sludge under aerobic conditions with air supplied from the air diffuser 38. The activated sludge in the second region 32 is discharged as excess sludge through the extraction pipe 39.

  Since the water to be treated that has been subjected to the aerobic treatment in the first region 31 is configured to flow in a U shape from the open portion on the other end side of the separation wall 34 toward the second region 32, The turbulent flow of the water to be treated due to the interference between the flow of air diffused from the air device 35 and the flow of air diffused from the air diffuser 38 does not occur.

  As shown in FIGS. 3, 4, 5, 6, and 7, the air lift pump device 40 is provided at the lower end portion of the pumping pipe 41 and the pumping pipe 41 arranged upright in the second region 32 (the opportunity tank 30). An air diffuser 42 that is disposed to face the lower opening 41a and discharges air bubbles toward the lower opening 41a, and the treated water pumped up by the air bubbles is separated from the upper portion of the pumping pipe 41 through the partition wall 21. A substantially horizontal water supply pipe 43 is provided that passes through and is transferred to the anoxic tank 20 adjacent to the second region 32. In addition, the broken-line arrow in a figure represents the flow of to-be-processed water or a bubble, and the description of the partition 21 is abbreviate | omitted in FIG.

  The air diffuser 42 includes a plurality of air diffusers 42a distributed on the same plane in order to release the fine bubbles substantially evenly in a range of approximately the same area as the lower opening 41a. The pumping pipe 41 is arranged in parallel with the lower opening 41 a surface.

  Here, in order to release fine bubbles from a range of approximately the same area as the lower opening 41a using a plurality of air diffusers, the air diffuser located on the outermost side among the air diffusers arranged in a dispersed manner is used. It is preferable to be in the vicinity region including the vertically lower part of the periphery of the lower opening 41a.

  The air diffuser 42a is connected to a blower via an air pipe. The air supplied from the blower is discharged as fine bubbles from the air diffuser 42a.

  Conventionally, the air supplied from the blower was discharged from the end of the pipe into the pumping pipe, so that the size of the bubbles was φ10 mm or more, the deviation of the bubbles in the section inside the pumping pipe was large, and the pumping efficiency was poor. On the other hand, a plurality of minute air diffusion holes are dispersedly formed in the air diffusion part 42a, and the air diffusion parts 42a are substantially uniformly distributed so as to be in a state of aeration over the entire surface. By discharging, a large specific surface area can be secured compared to conventional bubbles of about φ10 mm, the rising speed of the bubbles is slow and the residence time is long in the pumping pipe, the apparent specific gravity of the treated water is reduced, and the lower end Blower for obtaining the same pumping amount as the conventional pumping amount by reducing the unevenness of bubbles in the cross section in the opening and the pumping pipe, increasing the pumping amount per amount of diffused air. Power consumption can be reduced. For example, the size of the fine bubbles is preferably 2 mm or less.

  Here, as an air diffuser capable of discharging bubbles containing a lot of fine bubbles of φ2 mm or less at a low cost, a membrane type air diffuser that discharges bubbles from holes or slits formed through a tube or sheet having flexibility or elasticity. There is a diffuser type diffuser that discharges air bubbles from a porous plate made of a device or ceramic. There are devices that emit microbubbles, but this is not practical because of the large energy required for emission. The diffuser 42a of the diffuser 42 shown in FIGS. 3, 4, 5, and 7 is a tube-shaped membrane-type diffuser, and the outermost diffuser located below the lower opening of the lifter is the pumping pump. Four diffuser tubes are distributed at equal intervals so as to be near the vertically lower side of one side of the lower opening 41a of the tube. In this way, disposing the plurality of diffuser portions 42a in a spaced manner induces the flow of water to be treated that rises in the pumping pipe from below the diffuser portion 42a through the diffuser portions 42a. Therefore, the unevenness of the water to be treated and the flow of bubbles in the pumping pipe is preferably reduced.

  The lower opening 41a and the upper surface of the air diffuser 42a are spaced apart from each other by a predetermined distance, and the space between the lower opening 41a and the upper surface of the air diffuser 42a is partitioned by a virtual surface that divides vertically from the periphery of the pumping pipe 41. The area of the virtual surface 44 is set to be equal to or larger than the area of the lower opening 41a.

  As shown in FIGS. 8A and 8B, the predetermined distance between the lower opening 41a and the upper surface of the diffuser 42a is H, the length in the longitudinal direction of the lower opening 41a is A, and the length in the short direction. Is B. At this time, the area S1 of the lower opening 41a is S1 = A × B, the total area of the virtual surface 44 that partitions the space of the upper surface of the lower opening 41a and the diffuser portion 42a with a virtual surface extending vertically downward from the periphery of the pumping pipe 41 S2 is represented by S2 = 2 (H × A) +2 (H × B).

  That is, by setting the predetermined distance H so that S2 ≧ S1, the water to be treated is a virtual surface extending vertically downward from the periphery of the pumping pipe 41 in the space of the upper surface of the lower opening 41a and the diffuser 42a. Since the average flow velocity when passing through the partitioning virtual surface 44 is equal to or less than the average flow velocity when passing through the lower opening 41a, the resistance when passing through the virtual surface 44 can be reduced.

  Furthermore, the air lift pump device 40 includes an aeration amount adjusting mechanism that adjusts the pumping amount of the water to be treated by the amount of aeration discharged from the aeration unit 42a. The air diffusion amount adjusting mechanism is configured to control the rotational speed of a blower (not shown) and adjust the air diffusion amount.

  Further, the air diffusion amount adjusting mechanism may be a valve (not shown) provided in the middle of the path from the blower to the air diffusion part 21a.

  Then, for example, the rotation speed of the blower is set so as to increase or decrease the amount of treated water returned from the second region 32 (aerobic tank 30) to the anoxic tank 20 in proportion to the increase or decrease of the inflow amount of raw water. By increasing or decreasing the amount, the sewage treatment can be performed stably.

  A water supply pipe 43 having an enlarged portion 43a whose cross-sectional area is enlarged toward the downstream side is connected to the upper end side of the pumping pipe 41, and the upper surface of the base end portion of the enlarged portion 43a is higher than the highest water level HWL of the water surface WL of the water to be treated. It arrange | positions so that it may be located below.

  By comprising in this way, since to-be-processed water is not transferred above the minimum water level LWL of the water surface WL, since a head can be made low, the motive power of a blower can be reduced.

  The enlarged portion 43a is configured so that the water to be treated transferred by the pumping pipe 41 and the bubbles released by the diffuser pipe 42 are separated from each other, and the inner upper surface of the water supply pipe 43 in the enlarged portion 43a is on the downstream side. It is comprised so that it may incline upwards.

  Since it is possible to prevent all the bubbles released by the air diffuser 42 from being returned to the oxygen-free tank 20 as they are, the concentration of dissolved oxygen in the oxygen-free tank 20 becomes high, and the possibility that the denitrification efficiency is lowered can be reduced. it can.

  The water supply pipe 43 is formed in a bowl shape on the downstream side of the enlarged portion 43a, and the upper end portion 43c of the bowl-shaped water supply passage 43b is configured to be located above the water surface WL of the water to be treated.

  By configuring in this way, the water to be treated in the anoxic tank 20 can be prevented from overflowing to the second region 32 through the upper part of the water supply path 43b of the air lift pump device 40. It can prevent that the to-be-processed water in which the aerobic process is not fully performed by 31 circulates in the anoxic tank 20 and the 2nd area | region 32. Note that the air-liquid-separated air bubbles in the enlarged portion 43a are discharged to the atmosphere from the upper end portion 43c of the bowl-shaped water supply channel 43b.

  Further, the upper end portion of the pumped water pipe 41 and the proximal end portion of the enlarged portion 43 a are connected in communication via a curved pipe 46. By configuring in this way, the treated water pumped by the pumping pipe 41 is gently guided to the enlarged portion 43a by the curved pipe 46, so that the upper end of the pumped pipe 41 and the base end of the enlarged portion 43a are The pressure loss can be reduced and the amount of diffused air, that is, the power of the blower can be reduced as compared with the case of connecting at right angles.

  The pumping pipe 41 is supported by a gantry 45, and the air lift pump device 40 is installed at an appropriate position near the partition wall 21. In addition, when there exists a ceiling with the tank installed, you may support the water pipe 43 with the support part suspended from the ceiling.

  The water to be treated that has been nitrified in the aerobic tank 30 is returned to the upstream side of the anoxic tank 20 by the air lift pump device 40 configured as described above. As a result, nitrate ions and nitrite ions contained in the water to be treated are circulated to the anaerobic tank 20 by the nitrification treatment of the aerobic tank 30 to perform the denitrification treatment.

  By disposing the air lift pump device 40 in the vicinity of the partition wall 21 and shortening the water supply path 43, that is, shortening the total head, it is possible to reduce the amount of aeration necessary for water supply of the water to be treated, that is, the power of the blower. Moreover, since it can prevent that the to-be-processed water with high dissolved oxygen concentration flows into the anoxic tank 20 by reducing the amount of aeration, the possibility of reducing the denitrification efficiency of the anoxic tank 20 can be reduced. .

  Furthermore, part of the water to be treated returned to the anoxic tank 20 via the air lift pump device 40 is returned to the anaerobic tank 10 via the water supply path 23. Microorganisms in the membrane separation tank 30 having taken in phosphorus are circulated to the anaerobic tank 10 through the water supply channel 23, and phosphorus is released into the liquid as normal phosphoric acid.

  Since the water to be treated containing activated sludge is returned from the aerobic tank 30 to the anaerobic tank 20 and the water to be treated is returned from the anoxic tank 20 to the anaerobic tank 10, The water to be treated which is denitrified and does not contain nitrate nitrogen and nitrite nitrogen and consumes oxygen is returned to the anaerobic tank 10, and the NOx and oxygen-free conditions that are the conditions for releasing phosphorus in the anaerobic tank 10 Can be maintained.

  Therefore, in the anaerobic tank 10, the phosphorus compound is efficiently released as normal phosphoric acid, and the released normal phosphoric acid is taken into the activated sludge more than the amount released in the anaerobic tank 10 in the subsequent aerobic tank 30, It becomes possible to remove phosphorus from treated water to a high degree.

  Although not described in detail in the above-described embodiment, the anaerobic tank 10 and the oxygen-free tank 20 are provided with a stirring mechanism that stirs the water to be treated so that each process is performed uniformly.

  With the above configuration, the power of the air lift pump device 40 required for returning from the aerobic tank 30 to the anoxic tank 20 can be reduced, and the water to be treated can be efficiently transferred.

  In particular, in sludge treatment facilities, there are many cases where a plurality of treatment paths for the water to be treated including the anaerobic tank 20 and the aerobic tank 30 as treatment tanks are arranged in parallel, and the installation space of the piping is limited. Therefore, the water to be treated is sucked through the branch pipe from the most downstream side of each aerobic tank by a single on-site pump installed outside the tank, and the water is sent to the upstream side of the anaerobic tank through one junction pipe. Pumps that are returned to each anaerobic tank via branch pipes are provided, but each anaerobic tank is mixed with water to be treated having a different degree of aerobic treatment for each treatment system in the junction pipe. As a result, there is a problem that the purification process varies in each processing path, and the purification process efficiency may be reduced.

  However, according to the air lift pump device of the present invention, each aerobic tank is provided even when a plurality of treatment paths for the water to be treated including the anaerobic tank 20 and the aerobic tank 30 are arranged in parallel. Since it can be configured to be returned to each oxygen-free tank 20 by an air lift pump device provided with 30 water to be treated, the processing efficiency in the processing path of each oxygen-free tank 20 and aerobic tank 30 It does not decrease

  Next, another embodiment according to the present invention will be described.

  In the above-described embodiment, the diffuser tube 42 has been described as having a structure in which fine bubbles are evenly released in a range of approximately the same area as the lower opening 41a. However, as shown in FIG. The installation interval of the trachea 42 does not need to be uniform, and the amount of air diffused from the air diffuser 42a is greater than the central portion of the lower opening 41a so that a more uniform overall aeration is achieved in the lower opening. The air diffuser 42 may be arranged so as to be biased toward the peripheral side so that the surrounding area is increased.

  In the vicinity of the lower opening 41a of the pumping pipe 41, the bubbles discharged from the air diffuser 42 are likely to concentrate on the central part of the pumping pipe 41 due to the treatment to flow into the pumping pipe 41 from the surroundings. The flow of water to be treated is peeled off from the inner wall surface of the pumping pipe 41 and the pressure loss tends to increase.

  However, according to the above-described configuration, since the water to be treated can easily flow into the lower opening 41a from the central portion, it is possible to reduce the unevenness of bubbles and the upward flow of the water to be treated inside the pumping pipe 41. Can be generated smoothly.

  In the above-described embodiment, the plurality of diffuser tubes 42 are arranged in a distributed manner, but a plurality of disk-shaped membrane-type diffuser devices and diffuser-type diffuser devices may be arranged in a dispersed manner, and the panel shape Such a membrane type air diffuser may be provided with one air diffuser 42a.

  In embodiment mentioned above, the air lift pump apparatus 40 which returns the to-be-processed water in the 2nd area | region 32 to the anaerobic tank 20, and the water supply path 23 which returns the to-be-processed water in the anoxic tank 20 to the anaerobic tank 10 are provided. However, the water to be treated in the anaerobic tank 20 may be returned to the anaerobic tank 10 by the air lift pump device 40 instead of the water supply path 23. Moreover, you may comprise so that the to-be-processed water of the 2nd area | region 32 sent with the one air lift pump apparatus 40 may be returned to each of the anaerobic tank 20 and the anaerobic tank 10 by predetermined amount. It is preferable from the viewpoint of processing efficiency that the amount of water returned from the machine tank 30 to the anaerobic tank 20 is 3Q and the amount of water returned from the anaerobic tank 20 to the anaerobic tank 10 is Q with respect to the inflow amount Q.

  In the above-described embodiment, the case where the air lift pump device is configured by a rectangular pumping pipe and a water feeding pipe has been described. However, the pumping pipe and the water feeding pipe are not limited to a rectangular shape, and may be a round pipe. Further, the shape of the lower opening and the discharge port of the water to be treated may be a bell mouth shape.

  In the above-described embodiment, the material of the pumping pipe and the water supply pipe constituting the air lift pump device was not specified, but depending on the property of the water to be treated in the treatment tank in which the air lift pump device according to the present invention is installed, chemical resistance, corrosion resistance An appropriate material may be used in consideration of the properties and the like.

  In the above-described embodiment, the air lift pump device according to the present invention returns a part of the water to be treated in the machine tank of the sludge treatment facility adopting the membrane separation type activated sludge method equipped with the membrane separation device to the anoxic tank. However, it may be installed so that a part of the water to be treated in the oxygen-free tank is returned to the anaerobic tank.

  Furthermore, the air lift pump device according to the present invention is not limited to a case where it is provided in a sludge treatment facility that employs a membrane separation type activated sludge method, and a nitrification liquid circulation activated sludge method or a biological circulation type anaerobic method that does not employ a membrane separation type activated sludge method. It can be applied as a pump device when water to be treated is transferred from one treatment tank installed through a partition wall to sludge treatment equipment, flow rate adjustment tank, sewage septic tank, etc. adopting the aerobic method Further, there is no limitation on the type of water to be transferred, the transfer source, and the transfer destination.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. Needless to say.

1: Sewage treatment facility 10: Anaerobic tank 11: Partition 12: Communication port 20: Anoxic tank 21: Partition 22: Communication port 23: Water supply channel 30: Aerobic tank 31: First region 32: Second region 34: Separation Wall 35: Air diffuser 36: Membrane separator 37: Water supply pipe 38: Air diffuser 39: Extraction pipe 40: Air lift pump device 41: Water pump 41a: Lower opening 42: Air diffuser 42a: Air diffuser 43: Water pipe 43a: Enlarged part 43b: bowl-shaped water supply channel 43c upper end 44: virtual surface 45: mount 46: curved pipe 47: air supply pipe

Claims (6)

A pumping pipe arranged upright in the treated water, an air diffuser in which an air diffuser is disposed below the lower opening of the pumped pipe, and air bubbles are discharged from the air diffuser toward the lower opening, and the water pump A water pipe having a substantially horizontal posture for transferring the water to be treated pumped up by air bubbles communicated with the upper opening of the air diffuser,
An air lift pump device in which a diffuser discharges fine bubbles from a range of approximately the same area as the lower opening.   The lower opening and the upper surface of the air diffuser are separated so that the area of the virtual surface that divides the space between the lower opening and the upper surface of the air diffuser with a virtual surface extending vertically downward from the periphery of the pumping pipe is equal to or greater than the area of the lower opening. 2. The air lift pump device according to claim 1, wherein the air lift pump device is disposed.   The air lift pump device according to claim 1 or 2, wherein the amount of air diffused from the air diffuser is greater in the peripheral part than in the central part.   The air lift pump device according to any one of claims 1 to 3, wherein the water supply pipe includes an enlarged portion whose cross-sectional area is enlarged toward the downstream side, and an inner upper surface of the water supply pipe in the enlarged portion is inclined upward toward the downstream side.   The air lift pump device according to claim 4, wherein the water supply pipe is formed in a bowl shape downstream of the enlarged portion.   The air lift pump device according to claim 4 or 5, wherein the upper end portion of the pumping pipe and the proximal end portion of the water supply pipe are connected in communication via a curved pipe.

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