JP5324117B2 - Water treatment facility having a diffuser and a membrane concentrator equipped with the diffuser - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an air diffuser having a plurality of air diffusers and a water treatment facility having a membrane concentrator equipped with the air diffuser, and more specifically, an air diffuser and an air diffuser that maintain the cleaning effect of each air diffuser uniformly. The present invention relates to a water treatment facility having a membrane concentrator equipped with

  Conventionally, turbidity contained in river raw water is agglomerated using a flocculant to form flocs, and then solid-liquid separation by gravity sedimentation or the like to obtain a coagulated sediment sludge, which is extracted from the bottom. Then, after further pre-concentration by gravity sedimentation or flotation separation, concentration has been performed using a mechanical concentration means such as a belt concentrator.

However, there is a limit to the concentration of sludge that can be concentrated by this method, and there is a problem that the volume of sludge cannot be made sufficiently small. Therefore, as a means for solving this, an apparatus for concentrating raw sludge using a semipermeable membrane has been developed. It was.
As a separation membrane of the sludge concentrator, a membrane module including a plurality of membranes such as a ceramic membrane, an organic hollow fiber membrane, and an organic flat membrane is immersed in the membrane concentrator and raw water is filtered. When this membrane module is subjected to sludge concentration treatment for a long time, sludge (cake) adheres to the membrane surface, and the efficiency of sludge concentration decreases. Therefore, it is necessary to provide a diffuser pipe in the sludge concentrator and perform an aeration process for cleaning the membrane surface.

  This air diffuser is provided below the membrane module immersed in the membrane concentrator. An air supply device such as a blower is connected to the air diffuser, and the air supplied from the air supply device is ejected into the tank through a plurality of holes provided in the air diffuser, and the air is treated as raw sludge. An upward flow is generated in the liquid to be treated by rising in the liquid, and the upward flow and the air flow act as a scavenging flow on the membrane surface of the membrane module provided at the upper part of the diffusion tube, and the membrane Clean the surface.

  However, when this air diffusion treatment is performed, the liquid to be treated enters and adheres to the periphery or inside of the plurality of holes provided in the air diffusion pipe, and solids such as sludge contained in the liquid to be treated are supplied to the air diffusion pipe. As a result of drying by the generated air, there arises a problem that the air is prevented from being ejected from the hole of the air diffuser by the solid matter accumulated after a certain period of time.

In order to solve this, it is only necessary to wash the inside of the air diffuser by flowing cleaning water into the air diffuser at regular intervals. To clean the inside of the air diffuser, this is an auxiliary facility for washing. Another problem arises that it is necessary to install a washing water tank and a washing pump, which is costly.
In addition, it is troublesome to operate the cleaning pump at the time of cleaning, and there is a problem that the burden of maintenance is large.

  On the other hand, an air diffuser that performs maintenance without using a cleaning pump is also known (see Patent Document 1). In this air diffuser, an exhaust port opened on the water surface at the end of the air diffuser and a valve for opening and closing the exhaust port are provided, and the valve is opened to allow the liquid to be treated to flow back into the air diffuser, At the same time, the inside of the air diffuser is washed with water by supplying air from the blower.

FIG. 9 is a perspective view for explaining an air diffuser provided with an air diffuser.
This air diffuser has an air diffuser case 58 that forms a box shape for supporting the membrane module, and an air diffuser tube 52 extends substantially vertically from one side of the air diffuser case 58 to the bottom. Further, it is bent at the bottom surface and extends substantially horizontally along the bottom surface to the opposite side surface. A plurality of holes are provided in the diffuser tube 52 portion located on the bottom surface of the diffuser case 58. Further, the flushing pipe 53 is connected to the air diffusion pipe 52 on the bottom surface of the air diffusion case 58 and extends substantially vertically upward from the bottom surface along the other side surface.

  The supply port 51 at the upper end of the air diffusion pipe 52 is connected to the air inlet side header pipe 56, and the flushing pipe 53 is connected to the air outlet side header pipe 57. A discharge port 55 and a valve 54 for opening and closing the discharge port 55 are provided at one end of the air outlet side header pipe 57.

  In the above air diffuser, when air is supplied from the air inlet side header pipe 56 to the air diffusion pipe 52 via the supply port 51 by a blower (not shown) with the valve 54 of the air outlet side header pipe 57 closed, the air flows. It ejects from the hole of the diffuser tube 52 into the tank. As described above, the air blown into the tank rises in the liquid to be processed to generate an upward flow in the liquid to be processed, and the upward flow and the air flow act on the membrane surface of the membrane module. Wash it.

  Next, when cleaning the inside of the air diffuser 52, the valve 54 is opened and the discharge port 55 is opened to depressurize the air diffuser 52, and the liquid to be treated is caused to flow backward from the air ejection hole. The liquid to be treated that has flowed into the diffuser pipe 52 becomes a gas-liquid mixed phase flow together with the air supplied from the blower, and is discharged from the discharge port 55 through the flushing pipe 53 and the air outlet side header pipe 57.

The mechanism of cleaning the diffuser tube by such a device configuration is described in detail in Patent Document 1, but the outline is as follows.
The balance between the liquid phase and the gas phase of the gas-liquid mixed phase flow in the diffuser tube 52 and the flushing tube 53 varies depending on the inflow amount of the liquid to be processed.
When the inflow amount of the liquid to be treated into the diffuser pipe 52 increases, the pressure increases. With this pressure acting, the liquid to be treated that has flowed into the air diffuser pipe 52 flows into the flushing pipe 53 and the air outlet side header pipe 57. When the gas is discharged from the discharge port 55 through the pressure, the pressure in the air diffusion pipe 52 and the flushing pipe 53 is lowered, and the water surface in the flushing pipe 53 is lowered.
Further, when the pressure in the diffuser tube 52 and the flushing tube 53 is decreased, the amount of the liquid to be processed flowing into the diffuser tube 52 is increased, and the above-described pressurization and depressurization are repeated, and the water surface in the flushing tube 53 moves up and down. Then, the inside of the air diffuser 52 is washed intermittently.

10 schematically shows an air outlet side header pipe 57 to which a plurality of flushing pipes 53 are connected, FIG. 10A is a side sectional view of the air outlet side header pipe 57, and FIG. 10B is a diagram of the air outlet side header pipe 57. It is sectional drawing.
As shown in FIG. 10A, sludge and the like flowing into the air outlet side header pipe 57 from the three flushing pipes 53 are discharged out of the pipe from the opened discharge port 55.

In this air outlet side header pipe 57, a three-phase flow of gas, liquid and solid is formed in a complicated manner, and a water surface is formed in the pipe as shown in the figure, and solid particles mainly contained in the liquid are piped. It forms a slag flow in which the gas flows in the central part of the tube attached to the wall, or forms an intermediate state.
As shown in the figure, in the state where three diffuser pipes are connected to the air outlet side header pipe 57, sludge and the like flowing into the air outlet side header pipe 57 from each flushing pipe 53 form a water surface in the pipe. It flows from the left to the right, and on the right end side in the figure, more sludge flowing in from the air diffuser is conveyed. Therefore, for example, the water level a at the position of the flushing pipe 53 at the left end in the figure and the water level b at the position of the flushing pipe 53 at the right end in the figure are not uniform, and the water level is not constant.
The difference in water level at the position of each flushing pipe 53 becomes larger as the number of the diffuser pipes constituting the diffuser increases, and when the difference in water level becomes larger, the water pressure (pressure) applied to sludge and the like flowing inside each flushing pipe 53 The difference is also increased.

In the illustrated configuration, as already described, when sludge is discharged from the flushing pipe 53 to the air outlet side header pipe 57 and the inside of the pipe is depressurized, the water level in the flushing pipe 53 is lowered and at the same time the air outlet side header pipe A phenomenon occurs in which the sludge discharged to 57 flows back into the flushing pipe 53. When this reverse flow occurs, the resistance when the water level in the flushing pipe 53 drops increases, and the lowering of the water level is prevented or the lowering speed of the water level is reduced. The effect is significant when the amount of the flushing tube 53 that is full is flowing backward.
Therefore, the amount of sludge that flows back into the flushing pipe 53 is affected by the amount of sludge that exists in the vicinity of the connection position of the flushing pipe 53. That is, if a large amount of sludge exists in the vicinity of the connection position of the flushing pipe 53 and the backflow of the sludge continues in the flushing pipe 53, the lowering of the water level is greatly hindered. If the amount of sludge existing in the vicinity of the connection position of 53 is small and the inflow to the flushing pipe 53 becomes a gas such as air shortly after the start of the backflow of sludge, the influence on the lowering of the water level becomes small.
Here, as described above, the amount of liquid such as sludge that can flow back to the flushing pipe 53 existing in the vicinity of each connection portion between the flushing pipe 53 and the header pipe 57 differs depending on the upstream side or the downstream side in the header pipe 57. Therefore, the descending speed of the water surface at the time of cleaning in each flushing pipe 53 is different. This causes a difference in the cleaning effect of each air diffuser.

Further, as shown in FIG. 10B, in the structure of the conventional air diffuser in which the front end of the flushing pipe 53 is connected directly below the air outlet side header pipe 57, for example, from the flushing pipe 53 at the left end in FIG. There is also a problem that when the sludge or the like that has flowed into 57 flows to the right in the figure, it may flow back into the other flushing pipes 53 and the cleaning effect may be reduced.
Japanese Patent No. 3382926

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is to maintain a uniform cleaning effect of a plurality of air diffusers with a simple structure and prevent a backflow of sludge and the like in an air diffuser. Is to prevent.

According to the first aspect of the present invention, there is provided an air diffuser for diffusing into the tank for cleaning the membrane surface of the separation membrane immersed in the tank for storing the liquid to be treated, and supplying gas into the air diffuser An air supply means, a flushing pipe connected to the diffuser pipe, a header pipe connected to the flushing pipe, and an opening and closing means for opening and closing the header pipe, and when the opening and closing means is opened, Air diffuser having a diffuser pipe cleaning function for discharging sludge adhering to the diffuser pipe with the liquid to be treated flowing back into the diffuser pipe and the gas supplied by the air supply means from the header pipe through the outlet of the flushing pipe The flushing pipe extends upright in the header pipe from the lower side of the header pipe, and the delivery port of the flushing pipe opens the opening / closing means to clean the diffuser pipe. Case of said header tube And it is provided in a higher position than the liquid surface of the liquid to be treated containing the sludge flowing.
The invention of claim 2 is to supply a gas into the diffuser pipe, and to diffuse the diffuser pipe into the tank for cleaning the membrane surface of the separation membrane immersed in the tank for storing the liquid to be treated. An air supply means, a flushing pipe connected to the diffuser pipe, a header pipe connected to the flushing pipe, and an opening and closing means for opening and closing the header pipe, and when the opening and closing means is opened, Air diffuser having a diffuser pipe cleaning function for discharging sludge adhering to the diffuser pipe with the liquid to be treated flowing back into the diffuser pipe and the gas supplied by the air supply means from the header pipe through the outlet of the flushing pipe The flushing pipe is connected to a header pipe at a side portion of the header pipe, and the delivery port of the flushing pipe opens the opening / closing means to clean the diffuser pipe. Before flowing in the pipe Characterized in that provided at a position higher than the liquid level of the liquid to be treated containing sludge.
According to a third aspect of the present invention, in the air diffuser according to the first or second aspect , the header pipe includes a drain port for discharging the liquid to be treated and sludge, and an exhaust port for discharging the gas. characterized by comprising.
The invention according to claim 4 is a receiving well for storing raw tap water, a coagulating sedimentation basin for aggregating turbidity in the liquid to be treated flowing from the receiving well and precipitating it as floc to form sludge, and the sludge A water treatment facility having a membrane concentrating device for concentrating the gas with a separation membrane, wherein the membrane concentrating device comprises the air diffusing device according to any one of claims 1 to 3 .

  According to the present invention, in the air diffuser, since the cleaning effect of the plurality of air diffusers can be kept uniform with a simple structure, and the backflow of sludge and the like can be prevented, the air diffuser can be effectively cleaned to diffuse the air diffuser. The membrane surface of the membrane module can be stably washed with the trachea, and the adhesion of the cake to the membrane surface is suppressed, blocking between the membranes can be prevented, and the sludge can be more continuously and effectively concentrated. .

A water treatment facility having an air diffuser according to an embodiment of the present invention and a membrane concentrator equipped with the air diffuser will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram of a water treatment facility according to an embodiment of the present invention.
The water treatment facility is composed of a landing well 1, a coagulation sedimentation basin 2, a membrane concentrating device 3, and a pre-concentration tank 4, as in the prior art.

In water purification plants, raw water from rivers, etc. are sent from the landing well 1 to the coagulation sedimentation basin 2 by natural flow, and after flocculation is formed using the coagulant in the coagulation sedimentation basin 2 to form flocs, gravity Solid-liquid separation is performed by a method such as sedimentation to cause aggregation precipitation.
The supernatant liquid of the coagulation sedimentation basin 2 is sent to the subsequent processing step (filter basin 31) through the supernatant liquid delivery pipe 6 and then sent to the clean water basin 32.
On the other hand, the sludge coagulated and settled in the coagulation sedimentation basin 2 is sent from the bottom of the coagulation sedimentation tank 2 to the pre-concentration tank 4 through the feed mud pipe 5, pre-concentrated by gravity sedimentation and flotation separation, and pre-concentrated raw sludge Is sent to the membrane concentrator 3. A membrane module 7 for membrane separation of the pre-concentrated raw sludge is immersed in the membrane concentrating device 3, and the sludge concentrated in the membrane concentrating device 3 is drawn out below the membrane concentrating device 3. A concentrated sludge extraction pipe 8 is provided. The sludge extracted from the concentrated sludge extraction pipe 8 is sent to the storage tank 33.
The filtrate separated into solid and liquid by the membrane concentrator 3 is returned to the landing well 1 through the filtrate delivery pipe 9 or sent to the subsequent processing step (filter basin 31) or the clean water basin 32.

  As shown in FIG. 8, the main water treatment facility may be composed of a landing well 1, a membrane filtration device 34, a membrane concentration device 3, and a pre-concentration tank 4. In this case, the sludge generated from the membrane filtration device 34 is pretreated in the preconcentration tank 4, then sent to the membrane concentration device 3, and the membrane concentration device 3 performs the same treatment as described above. Further, the pre-concentration tank 4 may not be provided, and the sludge generated from the membrane filtration device 34 may be directly processed by the membrane concentration device 3.

FIG. 2 is an enlarged view of the air diffusing device in the membrane concentrating device 3 shown in FIG.
A plurality of membrane modules 7 are immersed in the liquid 11 to be treated inside the membrane concentrator 3. For example, ceramic membranes, organic hollow fiber membranes, organic flat membranes, and the like are used for the membrane modules 7.
The air diffuser 12 includes an air diffuser 13 for performing air diffusion in the membrane concentrator 3, a flushing pipe 14 for sending sludge in the air diffuser 13 to the air outlet side header pipe 18, and a blower (not shown). The air diffuser 13 is disposed below the membrane module 7. A supply port 15 for supplying air from the blower and a discharge port 16 for discharging sludge and air in the air diffuser 13 are respectively located on the water surface.

The supply port 15 and the discharge port 16 are connected to an air inlet side header pipe 17 and an air outlet side header pipe 18 extending in a direction perpendicular to the paper surface in the drawing.
The diffuser tube 13, the flushing tube 14, the air inlet side header tube 17 and the air outlet side header tube 18 are tubular tubes made of, for example, synthetic resin or metal, and a plurality of holes 19 for air outflow are formed on the lower surface of the diffuser tube 13. Is provided.

  When the membrane module 7 is cleaned, that is, when the air diffusion process is executed, air is supplied from the blower to the air inlet side header pipe 17 with the drain valve (not shown) of the air outlet side header pipe 18 closed. The air supplied to the air outlet side header pipe 18 is ejected from the hole 19 provided in the diffuser pipe 13 to wash the sludge and the like adhering to the membrane module 7 located above as described above. .

  As described above, when the air diffusion process is performed, the sludge that has entered from the hole 19 of the air diffusion pipe 13 adheres to the periphery of the hole 19 and the like, while supplying air from the blower to the air inlet side header pipe 17. When the drainage valve (not shown) of the air outlet side header pipe 18 is opened and the inside of the air diffuser 13 is decompressed, the pressure difference between the air diffuser 13 and the liquid to be treated (concentrated sludge) 11 is increased. The liquid 11 to be treated flows into the diffuser 13 from the hole 19. The infiltrated liquid 11 wets the solidified sludge in the air diffuser 13, and the wet sludge is discharged through the flushing pipe 14 and the air outlet side header pipe 18 together with the to-be-treated liquid 11 by the air supplied from the blower. It is discharged to the outlet 16.

(First embodiment)
FIG. 3 is a schematic view of the air outlet side header pipe 18 to which a plurality of flushing pipes are connected in the air diffuser according to the first embodiment, and FIG. 3A is a side sectional view of the air outlet side header pipe 18. FIG. 3B is a cross-sectional view of the air outlet side header pipe 18.
In the air diffusing device according to the present embodiment, the tip (outlet 14a) of each flushing pipe 14 connected to the air outlet side header pipe 18 is in the air outlet side header pipe 18 to which each flushing pipe 14 is connected. When the liquid level is higher than the liquid level (water surface) when the liquid level is formed, and the liquid containing mainly solid particles adheres to the tube wall and forms a slag flow in which gas flows in the central part of the tube The thickness of the liquid layer attached to the tube wall is larger than the thickness of the liquid layer. Here, if the amount of liquid such as sludge is the same, the depth when forming the liquid surface (header) rather than the thickness of the liquid layer adhering to the tube wall when forming the slag flow The distance from the bottom of the tube 18 to the liquid level is considered to be greater.
By configuring the connecting portion between the flushing pipe 14 and the header pipe 18 in this way, there is a difference in the amount of sludge between the flushing pipes 14 and in the vicinity of the connecting portion of the header pipe 18 in the header pipe 18 on the air outlet side. Even if it occurs, the amount of flushing water is not affected, and sludge discharged into the air outlet side header pipe 18 (liquid to be treated including sludge) can be prevented from flowing back to the flushing pipe 14.

  That is, in this embodiment, as shown in FIG. 3A, three flushing pipes 14 are connected to the lower surface of the air outlet side header pipe 18, and the other end side of the discharge port 16 is closed by a lid 21. Therefore, the liquid to be treated including sludge discharged from each flushing pipe 14 into the air outlet side header pipe 18 flows from the left to the right in the figure, and is opened by opening the drain valve 20 which is an opening / closing means of the discharge port 18a. It is discharged from the discharge port 18a.

Here, since the outlet 14a of each flushing pipe 14 is at a position higher than the liquid level of the liquid to be treated including sludge flowing in the air outlet side header pipe 18, the inside of the air outlet side header pipe 18 from each flushing pipe 14 When the sludge etc. flows, the liquid level of the sludge etc. in each flushing pipe 14 becomes a free liquid level unrelated to the above flow, and is not affected by the sludge.
The connection between the air outlet side header pipe 18 and the flushing pipe 14 is not easily disconnected, and any connection method may be used as long as sludge flowing in the air outlet side header pipe 18 does not leak from the connection portion. .

  Further, as shown in FIG. 3B, the diameter of the air outlet side header pipe 18 is set such that sludge once discharged into the air outlet side header pipe 18 does not flow back into another flushing pipe 14. It is set so that a sufficient capacity can be obtained so that the water level is always lower than the height of the outlet 14 a of each flushing pipe 14.

(Second embodiment)
In the air diffuser according to the first embodiment, when the number of flushing pipes 14 connected to the air outlet side header pipe 18 increases, the amount of sludge and the like discharged into the air outlet side header pipe 18 increases. Therefore, it is necessary to increase the diameter of the air outlet header pipe 18 accordingly.
In that case, since the drain valve 20 is the same size as the diameter of the air outlet side header pipe 18, there is a problem that the larger the diameter of the air outlet side header pipe 18, the larger the drain valve 20 and the higher the cost.
Therefore, the air diffuser according to the second embodiment is made to solve this problem, and can determine the diameter of the drain valve regardless of the diameter of the header pipe 18 on the air outlet side. It is possible to suppress this.

4 is a schematic view of the air outlet side header pipe 18 to which a plurality of flushing pipes are connected in the air diffuser according to the second embodiment, FIG. 4A is a side sectional view of the air outlet side header pipe 18, and FIG. 4 is a cross-sectional view of an air outlet side header pipe 18. FIG.
As shown in FIG. 4A, the left and right ends of the air outlet side header pipe 18 in the air diffuser according to the second embodiment are closed by lids 21 and 22. A drain pipe 25 is provided.
The exhaust pipe 23 is for exhausting the air in the air outlet side header pipe 18 and is opened and closed by an exhaust valve 24. The drain pipe 25 is for discharging sludge and the like in the air outlet side header pipe 18 and is opened and closed by a drain valve 26.

As shown in FIG. 4B, the outlet 14 a of each flushing pipe 14 is connected to a position on the side surface of the air outlet side header pipe 18 higher than the liquid level in the air outlet side header pipe 18.
With this configuration, as in the first embodiment, when sludge or the like flows from the respective flushing pipes 14 into the air outlet side header pipes 18, the outlets 14 a of the respective flushing pipes 14 are opened to the gas phase, and are once air outlets. It is also possible to prevent the sludge discharged into the side header pipe 18 from flowing backward.
The connection position of the flushing pipe 14 may be applied to the first embodiment, or the connection position of the flushing pipe 14 in the first embodiment may be applied to the second embodiment.

As described above, according to the aeration apparatus and the sludge concentration apparatus according to the embodiment of the present invention, the amount of flushing water from each flushing pipe 14 is not affected by the water level difference in the air outlet side header pipe 18 with a simple structure. Since the sludge and the like once discharged into the air outlet header pipe 18 can be prevented from flowing back to the respective flushing pipes 14, the air diffusion pipe 13 stabilizes the membrane module 7. Thus, the concentrated sludge treatment can be performed more efficiently.
In addition, according to the aeration apparatus and the membrane treatment apparatus according to the second embodiment, since it is not necessary to match the size of the drain valve of the discharge port for discharging sludge and the like with the diameter of the air outlet side header pipe 18, The drainage valve can be used and the cost can be reduced.
In addition, the aeration apparatus demonstrated above is applicable also in an activated sludge processing apparatus, and at that time, raw | natural sludge turns into activated sludge.

(Example)
An embodiment of the present invention will be described below.
FIG. 5 is a schematic side view of an air outlet side header pipe connected with a plurality of flushing pipes in the air diffuser according to the present embodiment.
5 to 7 described below are all in millimeters (hereinafter, mm).
The air outlet side header pipe 18 according to the present embodiment has a total length of 2010 mm and a pipe diameter of 200 mm, both left and right ends are closed by the lids 21 and 22, and is 280 mm away from the lid 22 in the longitudinal direction of the pipe. An exhaust pipe 23 is connected to the upper surface of the position, and a drain pipe 25 is connected to the lower surface, and an exhaust valve 24 and a drain valve 26 are provided respectively.
The drain pipe 25 is bent and extends in the front direction of the drawing in the drawing.

  At a position 250 mm away from the drain pipe 25 toward the longitudinal lid 21 side of the pipe, a total of five flushing pipes 14 are provided at intervals of 300 mm, extending 120 mm from the lower side of the air outlet side header pipe 18 into the air outlet side header pipe 18. The lower ends of the respective flushing pipes 14 are connected to a diffuser pipe (not shown), and sludge and the like are discharged into the air outlet side header pipe 18 through the flushing pipe 14 when the diffuser pipe is cleaned.

FIG. 6 is a cross-sectional view of the air outlet side header pipe 18 as viewed in the direction of arrows aa shown in FIG.
As shown in the figure, an exhaust pipe 23 having a pipe diameter of 50 mm is connected to the upper surface of the header pipe 18 on the air outlet side, and a drain pipe 25 having a pipe diameter of 65 mm is connected to the lower face, and an exhaust valve 24 and a drain valve 26 are provided respectively. ing.
Further, the drain pipe 25 is bent in the left direction in the figure, and sludge and the like in the air outlet side header pipe 18 are discharged out of the pipe from the end thereof.

FIG. 7 is a cross-sectional view of the air outlet side header pipe 18 as viewed in the direction of arrows bb shown in FIG.
FIG. 7 shows a portion where the flushing pipe 14 extends from the lower side of the air outlet side header pipe 18 into the air outlet side header pipe 18 and is connected. As described above, the flushing pipe 14 is connected to the air outlet side. The side header pipe 18 is connected by extending 120 mm.
The flushing pipe 14 has a pipe diameter of 40 mm, and the water depth of sludge and the like in the air outlet side header pipe 18 is 93 mm.
Table 1 shows the specifications of this example.

  When the air diffuser was cleaned in the air diffuser according to the specifications of the present embodiment, the water level in the air outlet side header pipe 18 was always kept lower than the height of the outlet 14a of each flushing pipe 14, and each flushing pipe 14 The end portion was opened to the gas phase, and the backflow of sludge to each flushing tube 14 was suppressed, and a uniform cleaning effect could be obtained.

It is a block diagram of the water treatment facility which concerns on embodiment of this invention. It is a figure which shows the diffuser in a film concentration apparatus. It is the schematic of the air outlet side header pipe | tube which connected the several flushing pipe | tube in the diffuser which concerns on 1st embodiment. It is the schematic of the air outlet side header pipe | tube which connected the several flushing pipe | tube in the diffuser which concerns on 2nd embodiment. It is a schematic side view of the air outlet side header pipe which connected a plurality of flushing pipes in the diffuser concerning this example. It is a cross-sectional view of the air outlet side header tube viewed in the direction of arrows aa. It is a cross-sectional view of the air outlet side header pipe viewed in the direction of arrow bb. It is a block diagram of the water treatment facility which concerns on another embodiment of this invention. It is a perspective view for demonstrating the diffuser provided with the diffuser tube. It is the schematic of the air outlet side header pipe | tube which connected the several flushing pipe | tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Water well, 2 ... Coagulation sedimentation basin, 3 ... Membrane concentrator, 4 ... Pre-concentration tank, 5 ... Mud supply pipe, 6 ... Supernatant liquid delivery pipe, 7. ..Membrane module, 8 ... concentrated sludge extraction pipe, 9 ... filtrate delivery pipe, 11 ... liquid to be treated (concentrated sludge), 12 ... aeration device, 13 ... aeration pipe, 14 ... Flushing pipe, 14a ... Delivery port, 15 ... Supply port, 16 ... Discharge port, 17 ... Air inlet side header pipe, 18 ... Air outlet side header pipe, 18a ..Discharge port, 19 ... hole, 20 ... drain valve, 21,22 ... lid, 23 ... exhaust pipe, 24 ... exhaust valve, 25 ... drain pipe, 26 ... -Drain valve, 31 ... Filtration pond, 32 ... Clean water basin, 33 ... Reservoir, 34 ... Membrane filtration device, 51 ... Supply port, 52 ... Air diffuser, 53 ...・Lashing pipe, 54 ... valve, 55 ... outlet, 56 ... air inlet side header pipe, 57 ... air outlet header pipe, 58 ... air diffuser case.

Claims (4)

A diffuser pipe for aeration in the tank for cleaning the membrane surface of the separation membrane immersed in the tank for storing the liquid to be treated, an air supply means for supplying gas into the diffusion pipe, and A flushing pipe connected to the air diffusion pipe; a header pipe connected to the flushing pipe; and an opening / closing means for opening and closing the header pipe; and when the opening / closing means is opened, the gas flows backward into the air diffusion pipe. An air diffuser equipped with an air diffuser cleaning function for discharging the sludge adhering to the air diffuser with the gas to be treated and the air supply means from the header pipe through the outlet of the flushing pipe,
The flushing pipe extends upright in the header pipe from the lower side of the header pipe, and the outlet of the flushing pipe opens the opening / closing means to clean the diffuser pipe. An air diffuser characterized by being provided at a position higher than the liquid level of the liquid to be treated containing the sludge flowing in the water. A diffuser pipe for aeration in the tank for cleaning the membrane surface of the separation membrane immersed in the tank for storing the liquid to be treated, an air supply means for supplying gas into the diffusion pipe, and A flushing pipe connected to the air diffusion pipe; a header pipe connected to the flushing pipe; and an opening / closing means for opening and closing the header pipe; and when the opening / closing means is opened, the gas flows backward into the air diffusion pipe. An air diffuser equipped with an air diffuser cleaning function for discharging the sludge adhering to the air diffuser with the gas to be treated and the air supply means from the header pipe through the outlet of the flushing pipe,
The flushing pipe is connected to the header pipe at the side of the header pipe, and the sludge that flows in the header pipe when the outlet of the flushing pipe opens the opening / closing means to clean the diffuser pipe A diffuser provided at a position higher than the liquid level of the liquid to be treated . In the aeration apparatus according to claim 1 or 2 ,
An air diffuser characterized in that the header pipe includes a drain port for discharging the liquid to be treated and sludge and an exhaust port for discharging the gas . A landing well for storing raw tap water, a coagulation sedimentation basin for aggregating the turbidity in the liquid to be treated flowing from the landing well and precipitating it as a floc to form sludge, and concentrating the sludge in a separation membrane A water treatment facility having a membrane concentrator,
A water treatment facility, wherein the membrane concentrating device comprises the air diffusing device according to any one of claims 1 to 3 .

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