JP6738724B2 - Air diffuser - Google Patents

Description

The present invention relates to an air diffuser used by being immersed in a liquid such as sludge.

Conventionally, as this type of air diffuser, as shown in FIG. 25, an air storage chamber 103 for storing air is formed in a housing 101 that is immersed in a liquid 112 such as sludge and has a lower opening. There is one in which a plurality of air discharge ports 104 for discharging the air in the air storage chamber 103 are formed in the upper part of 101. A plurality of conduits 105 bent in a U shape are provided in the housing 101, one end opening 106 of each conduit 105 opens into the air storage chamber 103, and the other end opening 107 of each conduit 105 is air. It communicates with the discharge port 104.

Further, a plurality of partition plates 108 are provided in the housing 101, and the air storage chamber 103 is partitioned by the partition plate 108 for each conduit 105. A distribution pipe 109 is provided in the lower part of the housing 101, and the distribution pipe 109 is formed with a plurality of air supply ports 110 for supplying air from below the housing 101 into the air storage chamber 103. Such an air diffuser 100 is described in, for example, Patent Document 1 below.

In this configuration, by sending air to the distribution pipe 109, the air 102 in the distribution pipe 109 is ejected from the air supply port 110 and is supplied into the air storage chamber 103 from below the housing 101. In this way, as the amount of the air 102 supplied into the air storage chamber 103 increases, the liquid level 111 in the air storage chamber 103 lowers, and the liquid level 111 is higher than the height A of the bent portion 105 a in the conduit 105. When it also descends, the air in the air storage chamber 103 flows downward from the one end opening 106 of the conduit 105, passes through the bent portion 105a, flows upward and flows out from the other end opening 107, and the air outlet 104 Is discharged as bubbles into the liquid 112.

After that, since the pressure in the air storage chamber 103 decreases, the liquid 112 flows into the air storage chamber 103 from below the housing 101, the liquid level 111 in the air storage chamber 103 rises, and the liquid in the air storage chamber 103 Liquid 112 flows into conduit 105 through one end opening 106 of conduit 105, blocking conduit 105. As a result, the air in the air storage chamber 103 does not flow in the conduit 105, and the release of air from the air outlet 104 is temporarily blocked (interrupted).

After that, as the amount of air supplied into the air storage chamber 103 increases, the liquid level 111 in the air storage chamber 103 lowers, so that the air in the air storage chamber 103 is again discharged in the same manner as above. Air bubbles are emitted from 104, whereby air emission from the air emission port 104 and emission interruption are alternately repeated.

Note that this type of air diffuser is, for example, disposed below a membrane filtration device in which a plurality of membranes are vertically arranged, and is used for cleaning the membrane of the membrane filtration device by air discharged from the air diffusion device. Used for.

Special table 2013-503738 gazette

However, in the conventional air diffuser 100 shown in FIG. 25, for example, the diameter of the air supply port 110 of the distribution pipe 109 is different, and the adhered matter is accumulated around the air supply port 110. When the amount of air discharged from the air supply port 110 is different, the amount of air accumulated in each air storage chamber 103 partitioned by the partition plate 108 is also different accordingly. Therefore, each conduit 105, and hence each The amount of air discharged from the air discharge port 104 is different from each other, resulting in non-uniformity. Therefore, when the air diffuser 100 is arranged below the membrane filtration device, for example, the function of cleaning the membrane of the membrane filtration device becomes uneven.

As a method for solving such a problem, as shown in FIG. 26, it is conceivable to eliminate the partition plate 108 and allow the air storage chambers 103 to communicate with each other. According to this configuration, all the air storage chambers 103 that are communicated with each other are integrated, and even if the discharge amount of air from each air supply port 110 is different, the water surface position in each air storage chamber 103 is the same. Therefore, the air storage amount in each air storage chamber 103 can be made uniform.

However, even in the case of such a configuration, in the conventional air diffuser 100, the conduit 105 is bent in a U shape, and the air in the air storage chamber 103 is bent from the upper end of the bent portion 105 a of the conduit 105 to the bent portion. 105a, after which the liquid level 111 rises and the liquid flows from the upper end of the bent portion 105a to the bent portion 105a, so that the inflow of liquid and the release of air from the upper end of the bent portion 105a in the conduit 105. Is a structure that ends. Therefore, in such a structure, the timing of the end of air release is different in each conduit 105, and the amount of air released from each conduit 105 becomes uneven.

In addition, in this configuration, when the air in the air storage chamber 103 increases and the liquid level 111 falls below the height A of the upper end of the bent portion 105a of the U-shaped bent conduit 105, the inside of the air storage chamber 103 is reduced. Air flows upward from the bent portion 105a of the conduit 105 and is discharged. Therefore, the height A of the upper end of the bent portion 105a of the conduit 105 may vary due to the manufacturing of the product of the conduit 105 itself, the error in the installation position, or the like. If they are different from each other, the timing of starting the discharge by flowing upward from the bent portion 105a of the conduit 105 is different, and the amount of discharge from each conduit 105 becomes uneven.

The present invention solves the above problems, and an object of the present invention is to provide an air diffuser capable of uniformly discharging a gas such as air.

In order to solve the above problems, the present invention is an air diffusing device that is immersed in a liquid and emits air bubbles, and an air diffusing case whose lower part is opened and is capable of storing gas; A gas lead-out member for releasing gas from the gas release port to the outside, the gas lead-out member being provided in the diffuser case, the first lead-out portion having an open upper portion and a closed lower portion, and a lower portion having a first portion. A second lead-out portion that is opened in the lead-out portion and discharges the gas in the diffuser case from the upper gas discharge port, and the lower ends of the plurality of second lead-out portions are located in the first lead-out portion at substantially the same height. However, a notch is formed at the lower end of the second lead-out portion . In addition, it is preferable that the shape of the cutout has a shorter cut width as it goes upward. Further, the positions of the plurality of notches may be the same angular interval with respect to the circumferential direction around the center of the second lead portion in plan view.

According to this configuration, the timing of ending the air release from each second outlet is substantially the same, and the amount of gas released from each second outlet is made uniform. Further, according to this configuration, even if the position (height) of the lower end portion of the second lead-out portion is different due to the manufacturing error of the product of the second lead-out portion, the installation position error, etc. When the air reaches the upper end of the notch, only a small amount of air flows, and the gas such as air flows upward from the lower end of each second lead-out portion, and the timing of starting discharge is almost the same. The amount of released gas such as air from the part can be made substantially uniform.

In addition, it is preferable that the plurality of second lead-out portions are provided along a straight line in the longitudinal direction of the air diffusion case, and according to this configuration, the timing of ending air release from each second lead-out portion is the same. Therefore, the amount of gas released from each second outlet is also made uniform.

Further, the membrane filtration equipment of the present invention is characterized in that the air diffuser is present in the same water tank as the membrane filtration device.

According to the air diffuser of the present invention, the gas lead-out member for releasing the gas in the air diffuser case to the outside from the gas discharge port is provided in the air diffuser case and the upper part is opened and the lower part is closed. And a second derivation part whose lower part is opened in the first derivation part and which discharges the gas in the diffuser case from the gas discharge port of the upper part, and the lower ends of the plurality of second derivation parts have substantially the same height. Since it is located inside the first outlet, the timing of the end of air release from each second outlet is the same, and the amount of air released from each second outlet can be made uniform.

Further, according to the air diffuser of the present invention, since the cutout portion is formed at the lower end of the second lead-out portion, a gas such as air flows upward from the lower end portion of each second lead-out portion to start discharging. It is possible to make the timings of the discharges uniform, and to make the amount of gas such as air discharged from the respective second outlets substantially uniform.

It is a figure of the membrane filtration device provided with the air diffuser in the 1st Embodiment of this invention. FIG. 3 is a perspective view of the air diffusing equipment. FIG. 3 is a vertical cross-sectional view of the air diffuser of the air diffuser. FIG. 3 is a transverse sectional view of the air diffuser. FIG. 3 is a bottom view of the air diffuser. FIG. 3 is a partially enlarged vertical sectional view of the air diffuser. (A) is a XX arrow view in FIG. 3, (b), (c) is a XX arrow view of a modification, respectively. It is a YY arrow line view in FIG. FIG. 3 is a partially enlarged vertical sectional view of the air diffuser, showing a state in which the water surface in the air diffuser case is located above the weir body. It is a XX arrow line view in FIG. It is a YY arrow line view in FIG. FIG. 3 is a partially enlarged vertical cross-sectional view of the air diffuser, showing a state in which the water surface in the air diffuser descends between the upper end of the weir body and the lower end opening of the outlet pipe. It is a XX arrow line view in FIG. It is a YY arrow line view in FIG. FIG. 4 is a partially enlarged vertical sectional view of the air diffuser, showing a state in which the water surface in the air diffuser case has descended below the lower end opening of the outlet pipe. It is a XX arrow line view in FIG. It is a YY arrow line view in FIG. FIG. 3 is a partially enlarged vertical sectional view of the air diffuser, showing a state in which the water surface in the air diffuser case has risen. It is a XX arrow line view in FIG. It is a YY arrow line view in FIG. It is a XX arrow line view of the further modification of FIG. It is a XX arrow line view (bottom surface sectional view) of FIG. It is a longitudinal cross-sectional view of the air diffuser in the second embodiment of the present invention. It is a XX arrow line view in FIG. It is a figure of the conventional air diffuser. It is a figure of the conventional air diffuser.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
In FIG. 1, 1 is a treatment tank for treating wastewater such as sewage with activated sludge, and a membrane filtration device 2 is provided in the treatment tank 1. The membrane filtration device 2 is immersed in the water to be treated 3 (an example of a liquid) in the treatment tank 1, and the membrane case 4, the plurality of membrane elements 5 accommodated in the membrane case 4, and the membrane element 5 And an air diffuser 6 provided below the. That is, the membrane filtration equipment has the treatment tank 1, the membrane filtration device 2, and the air diffusion equipment 6, and the air diffusers 11 to 14 provided in the air diffusion equipment 6 are the same as those of the membrane filtration equipment. It is provided in the same processing tank 1 as the membrane filtration device 2.

The air diffuser 6 supplies a plurality of air diffusers 11 to 14 which are immersed in the water 3 to be treated and discharges the bubbles 10, and air (an example of gas) 15 to the air diffusers 11 to 14. It has an air supply pipe 16 (an example of a gas supply pipe), a blower device 7 that sends air 15 to the air supply pipe 16, and the like.

As shown in FIGS. 3 to 8, the air diffuser 11 has an air diffuser case 18 and an air lead-out member 19 (an example of a gas lead-out member) provided in the air diffuser case 18. The air diffuser case 18 has a ceiling plate 21, a pair of front and rear end plates 22 and 23, and a pair of left and right side plates 24 and 25, and is a rectangular case whose lower part is open. An air storage chamber 27 (an example of a gas storage chamber) capable of storing the air 15 is formed inside the air diffusion case 18.

A plurality of air discharge ports 28 (an example of gas discharge ports) for discharging the air 15 in the air storage chamber 27 are provided in the ceiling plate 21 of the air diffusion case 18, and the air 15 is supplied to the air storage chamber 27 from the air supply pipe 16. And an air supply port 29 (an example of a gas supply port) that is used to form the same. The air outlets 28 are formed at a plurality of positions in the longitudinal direction of the air diffuser case 18, and the air supply ports 29 are formed at one end of the air diffuser case 18.

The air lead-out member 19 discharges the air 15 in the air storage chamber 27 in the air diffuser case 18 to the outside from each air discharge port 28. A weir body 32 as a first lead-out portion having a descending flow path 31 in which the air 15 in the storage chamber 27 flows downward, and an ascending flow path 33 in which the air 15 flowing in the descending flow path 31 flows upward. 2 has a plurality of lead-out pipes 34 as a lead-out portion.

The upper end of each outlet pipe 34 is connected to each air outlet 28. Further, each outlet pipe 34 has an opening 35 at the lower end. The weir body 32 has a pair of front and rear end walls 37a, 37b, a pair of left and right side walls 38a, 38b, and a bottom plate 39. The upper part of the weir body 32 is opened in the air storage chamber 27, and the front, rear, left and right sides are surrounded by the wall surfaces of the end walls 37a, 37b and the side walls 38a, 38b, and the bottom part (lower part) is closed by the bottom plate 39. The weir body 32 is supported between the side plates 24 and 25 of the air diffusion case 18 by a plurality of support members 41.

Each lead-out pipe 34 is inserted into the weir body 32 from above, and the lower ends of the plurality of lead-out pipes 34 are located at substantially the same height in the weir body 32 as the first lead-out portion. Further, in this embodiment, a plurality of outlet pipes 34 are provided in a straight line in the longitudinal direction of the air diffusion case 18. The lower end opening 35 of each outlet pipe 34 is set lower than the upper end of the weir body 32. In addition, in the air storage chamber 27 and the descending flow path space 36 that is the space of the descending flow path, the space between the outlet pipes 34 (between the outlet pipes 34 and 34) is not partitioned, and a continuous air reservoir chamber is provided. 27 and a continuous descending flow path space 36 are formed.

As shown in FIGS. 7A to 7C, a cutout portion (so-called notch) 42 is formed in the lower end of each outlet pipe 34 inserted into the descending flow path space 36 in the weir body 32. The notch 42 is formed such that the cut width becomes shorter (smaller) as it goes upward. For example, as shown in FIG. 7A, the notch shape may be formed in a straight line of an inverted V shape so that the cut width becomes shorter (smaller) as it goes upward, but the present invention is not limited to this. As shown in FIG. 7(b), the notch shape of the notch portion 42 is formed so as to be curved obliquely downward, or as shown in FIG. 7(c), the notch shape of the notch portion 42 is obliquely upward. It may be formed to be curved. Further, it is preferable that the notches are evenly cut out in the left-right direction with respect to the circumferential direction around the uppermost end position, but the present invention is not limited to this, and for example, one may extend upward and the other may have an inclined shape. The shape may be such that the cut width becomes shorter (smaller) as it goes upward.

Although the air diffuser 11 has the above-described configuration, the other air diffusers 12 to 14 also have the same configuration as the air diffuser 11. The air supply pipe 16 supplies the air 15 to the air storage chamber 27 of each air diffuser 11-14, and is connected to the air supply port 29 of each air diffuser 11-14.

The operation of the above configuration will be described below.
By driving the blower device 7 to send the air 15 to the air supply pipe 16, the air 15 in the air supply pipe 16 is supplied to the air storage chamber 27 through the air supply ports 29 of the air diffusers 11 to 14. To be done. As the amount of the air 15 in the air storage chamber 27 increases, the water surface 45 in the air storage chamber 27 lowers as shown in FIGS. 9 to 11, and the water level in the air storage chamber 27 as shown in FIGS. The air 15 flows downward (increases) in the weir body 32.

As shown in FIGS. 15 to 17, the water surface 45 has a predetermined height H (that is, the height of the lower end opening 35, more specifically, the upper end of the notch 42 provided in the lower end opening 35). When descending further, the air 15 in the weir body 32 flows into the lead-out pipe 34 from the lower end opening 35 of each lead-out pipe 34, flows upward in the lead-out pipe 34, and becomes air bubbles 10 from each air discharge port 28. And is discharged into the water 3 to be treated in the treatment tank 1.

Due to the release of the air 15 as described above, the pressure in the air storage chamber 27 decreases, so that the water 3 to be treated flows into the air storage chamber 27 from below the air diffusion case 18, and as shown in FIGS. Then, the water surface 45 in the air storage chamber 27 rises. As shown in FIGS. 9 to 11, when the water surface 45 in the air storage chamber 27 rises above the upper end of the weir body 32, the water to be treated 3 in the air storage chamber 27 flows into the weir body 32 and is led out. The inside of the pipe 34 is closed with the water 3 to be treated. As a result, the air 15 in the air storage chamber 27 does not flow in each outlet pipe 34, and the release of the air 15 from each air outlet 28 is temporarily interrupted (interrupted).

After that, as the amount of the air 15 in the air storage chamber 27 increases, the water surface 45 in the air storage chamber 27 descends as shown in FIGS. 12 to 14, and the water surface 45 becomes predetermined as shown in FIGS. 15 to 17. When the height is lower than the height H, the air 15 in the air storage chamber 27 is again discharged as bubbles 10 from each air discharge port 28, as described above. As a result, the discharge of the air 15 from each air discharge port 28 and the blocking of the discharge are alternately repeated.

Here, according to the above configuration, the air lead-out member 19 for discharging the air in the air diffuser case 18 to the outside from the air discharge port 28 is provided in the air diffuser case 18, and the upper portion is opened and the lower portion is closed. It has a weir body 32 as a first lead-out portion, and a lead-out pipe 34 as a second lead-out portion whose lower portion is opened in the weir body 32 and which discharges the air in the air diffuser case 18 from the air outlet 28 in the upper portion. By arranging the lower ends of the plurality of outlet pipes 34 in the weir body 32 at substantially the same height, the end timing of air release from each outlet pipe 34 becomes the same, and the amount of air released from each outlet pipe 34 is changed. It can be made uniform. Further, the descending flow path space 36 in the weir body 32 into which the lower end of the outlet pipe 34 is inserted is not partitioned between the outlet pipes 34 (between the outlet pipes 34 and 34) and is continuously formed. Therefore, the liquid surface of the descending flow path space 36 is of course the same, and as a result, the timing of the end of air release of each outlet pipe 34 is the same, and therefore the amount of air released from each outlet pipe 34 is also the same. Be homogenized.

Further, in the conventional air diffuser 100 as shown in FIGS. 23 and 24, the conduit 105 is bent in a U shape, and the air in the air storage chamber 103 is bent from the upper end of the bent portion 105 a of the conduit 105. The liquid flows into the portion 105a, and then the liquid surface 111 rises and the liquid flows from the upper end of the bent portion 105a to the bent portion 105a. The structure is such that the release is completed. In this case, when the cross-sectional area from the upper end of the bent portion 105a in the conduit 105 to the bent portion 105a is small and the amount of air injected into the air storage chamber 103 is large, the air is not intermittently released. , There was a case of continuous emission (aeration).

On the other hand, in the air diffuser 11 (12 to 14), the descending flow path space 36 in the weir 32 into which the lower end of the outlet pipe 34 is inserted is located between the outlet pipes 34 (the outlet pipe 34 and the outlet pipe 34). Since it is not partitioned off by (between) and is continuously formed, the cross-sectional area of the descending flow path becomes extremely large, and even if the amount of air injected into the air storage chamber 27 is large, the air is reliably intermittently supplied. Can be released.

In addition, in the air diffuser 11 (12 to 14), a cutout portion (so-called notch) 42 having a smaller cut width toward the upper side is formed in the lower end openings 35 of the plurality of outlet pipes 34 (the lower end portions of the second outlet portions). Has been done. Therefore, the positions (heights) of the lower end openings 35 of the plurality of lead-out pipes 34 (more specifically, the upper end positions of the notches 42) are different from each other due to the manufacturing error of the product of the lead-out pipes 34 or the error in the installation position. For example, even if the water surface reaches the upper ends of the cutouts 42 in some of the lead-out pipes 34 even if they are different, a small amount of air flows. The timing at which the gas such as air flows upward and starts to be discharged becomes substantially the same, and the amount of discharge of the gas such as air from each outlet pipe 34 can be made substantially uniform.

Therefore, when the air diffusers 11 to 14 are arranged below the membrane filtration device 2, the membrane element 5 of the membrane filtration device 2 can be uniformly washed, and the air diffusion devices 11 to 14 and the air diffusers can be washed. The reliability of the equipment 6 can be improved.

In the above embodiment, two cutouts (so-called notches) 42 are formed in the lower end of the outlet pipe 34 in the circumferential direction (that is, they are formed at 180° intervals in the circumferential direction. However, the present invention is not limited to this, and one or three or more notches may be formed at the lower end of the outlet pipe 34. When a plurality of cutouts 42 are formed, the cutouts 42 are formed at the same angle intervals with respect to the circumferential direction with the center of the drawout tube 34 as the center when the leadout tube 34 is viewed in plan. (For example, when three cutouts 42 are provided, the centers of the cutouts 42 are formed at 120° intervals, and when four cutouts 42 are provided, the cutouts 42 are formed. Are formed so that the centers of the lead tubes are spaced by 90 degrees) (in FIGS. 21 and 22, the case where four cutouts 42 are provided at the lower end of the outlet tube 34 is shown), It is not limited to this.

(Second embodiment)
In the first embodiment described above, as shown in FIGS. 4 and 7, the weir body 32 and the outlet pipe 34 are arranged in the central portion between the pair of side plates 24 and 25 of the air diffusion case 18. However, in the second embodiment described below, as shown in FIGS. 21 and 22, the weir body 32 and the outlet pipe 34 are arranged close to one of the side plates 24 of the air diffuser case 18. Has been done.

That is, the lead-out pipe 34 is a half-split pipe and is attached to the inner surface of one side plate 24. Further, one side plate 24 also serves as one side wall 38a (see FIGS. 4 and 7) of the weir body 32.

According to this, the same operation and effect as those of the first embodiment described above can be obtained.
In the second embodiment, the weir body 32 and the outlet pipe 34 are arranged close to the one side plate 24 of the air diffusion case 18, but are arranged close to the other side plate 25 on the opposite side. You may.

In each of the above-described embodiments, as shown in FIG. 1, the air diffuser 6 has four air diffusers 11 to 14, but the number of air diffusers is not limited to four. Further, in each of the above embodiments, the air 15 is emitted from the air diffusers 11 to 14, but a gas other than the air 15 may be emitted.

In each of the above-described embodiments, the weir body 32 (an example of the first lead-out portion) and the lead-out pipe 34 (an example of the second lead-out portion) are individually manufactured by different parts. 34 and 34 may be integrally formed.

2 Membrane filtration device 3 Water to be treated (liquid)
6 Air diffuser 10 Bubble 11-14 Air diffuser 15 Air (gas)
16 Air supply pipe (gas supply pipe)
18 Air diffusion case 19 Air derivation member (gas derivation member)
21 ceiling plate 27 air storage chamber (gas storage chamber)
28 Air outlet (gas outlet)
29 Air supply port (gas supply port)
31 descending flow path 32 weir body (first lead-out section)
33 ascending flow path 34 outlet pipe (second outlet portion)
35 (Lower End) Opening 36 Downward Flow Path Space 42 Notch (Notch)
45 water surface

Claims (5)

An air diffuser that emits air bubbles when immersed in a liquid,
An air diffuser case whose lower part is opened and capable of storing gas, and a gas lead-out member for discharging the gas in the air diffuser case to the outside from the gas discharge port,
The gas lead-out portion is provided in the air diffusion case and has a first lead-out portion whose upper portion is open and whose lower portion is closed; and a gas lead-out portion whose lower portion is opened in the first lead-out portion and which is in the upper portion of the air diffuser case. And a second derivation part for discharging from
The lower ends of the plurality of second lead-out portions are located at substantially the same height in the first lead- out portion,
A diffusing device characterized in that a notch is formed at the lower end of the second lead-out portion . The air diffuser according to claim 1, wherein the plurality of second lead-out portions are provided in a line along the longitudinal direction of the air diffuser case. The air diffuser according to claim 1 or 2 , wherein the shape of the cutout portion is such that the cutout width becomes shorter toward the upper side. The air diffuser according to any one of claims 1 to 3, wherein the positions of the plurality of cutout portions are the same angular intervals with respect to the circumferential direction around the center of the second lead portion in a plan view. .. A membrane filtration facility comprising the air diffuser according to any one of claims 1 to 4 ,
Membrane filtration equipment, wherein the air diffuser is provided in the same treatment tank as the membrane filtration equipment of the membrane filtration equipment.

Images