JP2009172587A - Air diffuser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air diffuser which has pores capable of achieving a high oxygen transfer efficiency, hardly causes clogging, and enables long-term stable operation. <P>SOLUTION: The air diffuser 1 comprises: air diffusing plates 4 disposed in an aeration tank 12 and receiving pressure air supplied from diffusing air supply piping 3 to release the pressure air as air bubbles from pores 21 formed in an air diffusing surface 20; a blow water supply means 5 for supplying blow water supplied to the air diffusing plate 4 through the diffusing air supply piping 3 to be discharged from the pores; and diffusing means each having an insertion pipe 7 where its upper end communicates with the air diffusing plate 4 and its lower end is inserted into the diffusing air supply piping 3 to discharge the blow water, supplied into the diffusing air supply piping 3, from pores 21, and diffusing the blow water, supplied to the air diffusing plate 4, to the air diffusing surface 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aeration apparatus capable of removing dirt components adhering to an aeration surface of an aeration plate disposed in an aeration tank and supplying oxygen stably for a long period of time.

  In order to remove nitrogen compounds and carbon compounds in sewage at a sewage treatment facility, an activated sludge method utilizing decomposition and adsorption by microorganisms is used. In order for the microorganisms in the activated sludge to be active, it is necessary to give oxygen to the microorganisms. The air diffuser is an apparatus that is installed at the bottom of an aeration tank of a sewage treatment facility and supplies oxygen into water. There are two types of diffusers: a diffuser with a film diffuser surface (Patent Document 1) and a diffuser with a metal thin plate type diffuser surface (Patent Document 2). The thin metal plate type air diffuser has less pressure loss due to air diffused, and is excellent in durability and ease of maintenance and inspection.

  When the aeration apparatus continues aeration operation for a long period of time, the dirt component adheres to the inside and the surface of the fine holes of the film or the metal thin plate, thereby causing clogging. Many of the soil components that cause clogging are biofilms formed by microorganisms, which block the air holes. The adhesion of this biofilm is strong, and even if the gas pressure is increased, the biofilm cannot be peeled off.

  In a membrane-type diffuser, a method is disclosed in which a membrane is elongated or contracted by an air-sending operation of the diffuser to remove a biofilm derived from microorganisms attached to the inside and the surface of the micropores of the membrane (Patent Literature). 3).

  However, in the thin metal plate type air diffuser, since the air diffused surface is a rigid body having no elasticity, the above-described clogging prevention treatment cannot be performed. At present, when clogging occurs due to the growth of microorganisms in a thin metal plate type diffuser, the diffuser plate must be cleaned by lifting the diffuser onto the water surface. Management requires a lot of labor and expense.

In both the membrane type and the thin metal plate type, it is necessary to reduce the pore diameter of the diffuser surface in order to increase the oxygen transfer efficiency. However, the smaller the pore diameter, the more likely clogging occurs. Air diffusers that are prone to clogging must be lifted above the surface of the water and frequently cleaned.
JP 2003-320388 A JP 2006-61817 A JP 2004-313938 A

  Thus, the conventional diffuser has not provided a sufficient solution to the clogging problem. An object of the present invention is to provide an air diffuser that has micropores that can achieve high oxygen transfer efficiency, is less likely to be clogged, and can be operated stably for a long period of time.

In order to solve the above problems, the inventor injects water or cleaning water such as a chemical solution into the air supply pipe for air diffusion, and supplies the air to the air diffuser plate side with the pressure air for air diffusion. We considered cleaning the air plate regularly.
However, if the cleaning water is supplied from the flow channel for air diffusion, the cleaning water discharged from the supply port is likely to be concentrated and discharged from the fine holes of the air diffuser plate just above the supply port due to the inertia of the fluid. It is conceivable that uniform discharge over the entire surface of the air plate becomes difficult.
Also, the distance between the cleaning water supply port and the periphery of the diffuser plate is not always constant. For example, when the diffuser plate is rectangular, if the supply port is at the center of the diffuser plate, the four corners of the diffuser plate There is also a problem in that the cleaning water is insufficiently supplied to the four corners.
Therefore, in order to improve such a point, it was considered that the washing water supplied from the supply port is diffused to spread the washing water over the entire diffuser surface.
And as a concrete means for realizing this, it was considered to provide means for diffusing the supplied wash water.
In addition, in order to be able to automatically clean the diffuser plate by periodically supplying cleaning water to the diffuser plate even during the diffuser operation, one end communicates with the diffuser plate and the other end supplies the diffuser plate. It was considered to provide an intubation to be inserted into the air pipe.

  The present invention has been made based on such an idea, and specifically comprises the following configuration.

(1) An air diffuser according to the present invention is disposed in an aeration tank, and discharges pressure air supplied from an air supply pipe for air diffused as fine bubbles from fine pores formed on the air diffuser surface; The blow water supply means for supplying blow water supplied to the diffuser plate via the diffuser air supply pipe and discharged from the fine pores, and the blow water supplied to the diffuser plate It is characterized by comprising diffusion means for diffusing on the diffuser surface.

(2) Further, in the above-described (1), the diffusing unit includes a guide piece radially formed from a blow water supply port to the diffuser plate, It is characterized in that it is formed so that more blow water can be guided in the direction in which the distance from the blow water supply port to the peripheral edge of the diffuser plate is long.
In this specification, the “blow water supply port” refers to a port that opens toward the diffuser plate and supplies blow water, and the “blow water supply port” refers to a peripheral portion of the blow water supply port. Say.

(3) Further, in the above-described (1) or (2), the diffuser plate is rectangular, and the guide piece has a tangent direction at a tip portion thereof to a corner portion of the diffuser plate. It is characterized by being curved.

(4) Moreover, the thing in any one of said (1)-(3) WHEREIN: The spreading | diffusion means is provided with the cover member which plugs up the micropore of the part just above the said blow water supply port part. To

(5) Further, in the above-described (4), the lid member is disposed between the blow water supply port and the air diffusion surface, and is scattered by blow water supplied from the blow water supply port. It moves to the air surface side, and closes the minute hole of the air diffusion surface corresponding to the portion directly above the blow water supply port.

(6) Further, in the above-described (5), the lid member functions as a check valve that prevents the sewage in the aeration tank from flowing into the air supply pipe for air diffusion from the blow water supply port. It consists of the spherical body which carries out.

(7) Moreover, in the thing in any one of said (1)-(6), an upper end is connected to the said diffuser board side, and a lower end is inserted in the said air supply piping for aeration, and the said aeration An internal intubation for supplying blow water supplied into the air supply pipe to the diffuser plate is provided.

  An air diffuser according to the present invention includes an air diffuser plate disposed in an aeration tank and discharging pressure air supplied from an air supply pipe for air diffused as fine bubbles from fine pores formed on the air diffuser surface, and the air diffuser. Blow water supply means for supplying blow water supplied to the diffuser plate via an air supply pipe and discharged from the fine pores, and blow water supplied to the diffuser plate on the diffuser surface Since the diffusion means for diffusing is provided, it is possible to distribute the blow water throughout the diffuser plate even if the amount of blow water supplied is small, thereby maintaining the high oxygen transfer efficiency and the eyes of the diffuser plate. Clogging can be prevented over a long period of time.

[Embodiment 1]
1. Air diffuser FIG. 1 is a schematic diagram showing an air diffuser according to the present embodiment. The air diffuser 1 according to the present embodiment includes a gas supply means 2, an air supply pipe 3 (header pipe) for introducing air supplied from the gas supply means 2 to an air diffuser plate 4, and an air supply for air diffusion. A diffuser plate 4 that receives supply of compressed air from the air pipe 3 and discharges fine bubbles, and an intubation tube 7 whose upper end communicates with the diffuser plate 4 and whose lower end is inserted into the diffuser air supply pipe 3. And a blow water supply means 5 for supplying blow water to the diffuser air supply pipe 3 via the blow water supply pipe 14.
An open / close valve 15 is provided in the air supply pipe 3 for diffusion, and an open / close valve 16 is provided in the blow water supply pipe 14.
Hereinafter, the main configuration of the air diffuser 1 will be described in detail.

<Air diffuser>
The diffuser plate 4 may be any form of diffuser plate such as a membrane type or a thin metal plate type. For example, when the diffuser plate 4 is a thin metal plate type, a thin metal plate having fine holes formed by machining is used as the diffuser surface. The air supplied from the gas supply means 2 is supplied from the air supply pipe 3 for air diffusion to the air diffusion plate 4 through the inner tube 7, and is discharged from a plurality of fine holes scattered on the air diffusion surface of the air diffusion plate 4. Is done.

FIG. 2 is a plan view of the diffuser plate 4, and FIG. 3 is an enlarged cross-sectional view showing an A-A cross section of the A portion circled in FIG. As shown in FIGS. 2 and 3, the diffuser surface 20 of the diffuser plate 4 is provided with a large number of fine holes 21, but as shown in FIG. 3, the diffuser surface 20 is directly above the inner tube 7. The corresponding portion 20a does not have fine holes.
In addition, as a method of forming a portion that does not have a fine hole in the air diffusion surface 20, processing is performed in which a hole is not provided at the stage of forming the fine hole 21 in a metal thin plate or the like that becomes the air diffusion surface 20. Alternatively, in the step of forming the micro holes 21, the micro holes 21 may be formed over the entire air diffusion surface 20, and only the portion 20a immediately above the inner cannula 7 may be closed later with a plate or the like.
When the fine holes are not provided in the portion 20a immediately above the diffuser surface 20, the metal thin plate itself provided with such an diffuser surface 20 corresponds to the diffusing means of the present invention. Further, when the fine holes 21 formed in the air diffusion surface 20 are closed with a plate, the plate closing the fine holes 21 corresponds to the diffusing means of the present invention.

<Intubation>
Since the air diffuser 1 according to this embodiment includes the inner intubation tube 7, water can be supplied to the air diffuser holes without filling the air diffuser air supply pipe 3 with water. Therefore, a large amount of water is not required. In particular, when an aqueous solution containing an antibacterial substance is supplied, microorganisms can be efficiently removed in a short time with a small amount of the antibacterial substance. As a result, it is not necessary to lift the air diffuser above the water surface and clean it frequently, and the air diffuser can be operated stably for a long time under the water surface.

  In addition, when there is no inner intubation 7 and it is going to supply the water for washing | cleaning the diffuser board 4, not only the air supply piping 3 for aeration needs to be filled as mentioned above but it is also filled with water. It is necessary to devise in order to drain the water. If there is no means for draining water, water remains in the air supply piping for the air diffuser to which the air diffuser plate 4 is attached, the pipe line becomes thin, and appropriate air diffusion cannot be performed. .

  FIG. 4 is a partial cross-sectional view showing an example of the inner intubation 7. The inner insertion tube 7 has an upper end communicating with the air diffusion plate 4, a lower end inserted into the air supply pipe 3 for diffusion, an inclined suction surface 8 at the lower end, and a vent hole 9 in the tube wall. have. However, the vent hole 9 provided in the intubation tube 7 is not essential, and the vent hole 9 may not be provided. As described later, the mode of pumping blow water to the intubation tube 7 differs depending on whether or not the vent hole 9 is present. .

  The intubation tube 7 is a supply path to the air diffusion plate 4 and has a function of supplying the supplied blow water to the diffusion plate 4 during the water blowing process. Therefore, the upper end opening of the inner intubation 7 becomes the blow water supply port 22.

The inner intubation 7 may be formed integrally with the air supply pipe 3 for diffusing or may be a separate member that can be attached and detached. When it is set as another member which can be attached or detached, the inner intubation tube 7 can be inserted and fixed in the insertion port previously provided in the air supply piping 3 for aeration. There is no restriction | limiting in particular in the fixing method of the intubation tube 7, All fixing methods are included. For example, the fixing tightening member 10 is pre-welded to the side surface of the inner intubation tube 7 and the mounting bracket 11 is pre-welded to the diffuser air supply piping side, so that the inner intubation tube 7 is screwed and the air supply piping for air diffusion is installed. 3 can be fixed.
Similarly, the diffuser plate 4 can be formed integrally with the inner intubation tube 7 or can be attached and detached. Moreover, there is no restriction | limiting in particular in the material of an intubation tube, Preferably, it forms from metals, such as plastic or stainless steel, titanium.

The lower end portion of the inner intubation 7 has a suction surface 8. A plurality of diffuser plates 4 are installed in the diffuser supply pipe 3, but the diffuser supply pipe 3 is not necessarily installed horizontally, and the lower end of the intubation pipe 7 is the water surface. May not be arranged at the same height. As shown in FIG. 5, when the suction surface 8 at the lower end of the intubation tube is not inclined, the lower end portion is sucked up only from the inner tube 7 that is in contact with the water surface or under the water surface (expressed as “sucking up” in this specification). In some cases, “push-up” may be included), so that the blow water is not uniformly supplied to all the diffuser plates 4, and clogging is caused by some diffuser plates to which blow water is not supplied. There is a risk of progress.
On the other hand, as shown in FIG. 6, when the suction surface 8 at the lower end of the intubation tube is inclined, the blow water can be sucked up if the water surface is between the upper end and the lower end of the suction surface 8. Even when the lower end of the intubation is arranged up and down, suction from all the inner intubations is possible within a certain range, and uniform blow to the diffuser plate 4 is possible. Therefore, when the suction surface 8 is inclined, the allowable range of the installation accuracy in the horizontal direction of the air supply pipe 3 for air diffusion becomes large.

  In addition, as shown in FIG. 6, when the water level is between the upper end and the lower end of the suction surface 8, the air-water mixed phase is blown at a high blow speed. However, as shown in the right diagram of FIG. When it becomes higher than 8, since only water is sucked up, it becomes a water extrusion blow in which air is not mixed. On the other hand, when the vent hole 9 is provided in the tube wall of the inner intubation tube 7 as shown in the left diagram of FIG. 7, air enters from the vent hole 9 even when the water level is higher than the suction surface 8. A high-speed air-water mixed phase can be blown.

There is no restriction | limiting in particular in the shape and magnitude | size of the vent hole 9, It can be set as arbitrary shapes and magnitude | sizes. For example, when the total length of the inner intubation tube 7 is 200 mm and the inner diameter of the inner intubation tube 7 is 13 mm, the vent hole 9 can have a circular shape with a diameter of 1 mm to 10 mm, preferably 2 mm to 7 mm. The position of the vent hole 9 is not particularly limited and can be set to an arbitrary position. For example, when an intubation tube having a total length of 200 mm and an inner diameter of 13 mm is mounted in an air supply pipe for air diffusion with an inner diameter of 80 mm, and the lower end of the inner tube is in contact with the inner bottom portion of the air supply pipe for air diffusion, It can be provided at a position of 10 mm to 75 mm, preferably 30 to 70 mm from the lower end of the intubation tube.
Further, since the inside of the air supply piping for air diffusion is pressurized, the position of the vent hole 9 may be on the front side or the back side with respect to the direction of water blow and gas flow.

The lower end of the inclined suction surface 8 is located in the vicinity of the inner bottom of the air supply pipe 3 for diffusing, so that even if the water level is low, the blow water can be surely sucked into the inner tube 7. The lower end of the inclined suction surface 8 is preferably 0 to 10 mm above the inner bottom of the air supply pipe 3 for air diffusion.
Although there is no particular limitation on the inclination angle θ of the inclined suction surface 8 with respect to the vertical direction, since the intubation tube 7 is also an air supply path, the inclination angle θ is such that air can be sufficiently supplied into the intubation tube 7. It is preferable. The inclination angle θ can be, for example, 10 to 85 degrees, preferably 30 to 80 degrees.

<Blow water supply means>
The blow water supply means 5 is a device for supplying blow water to the air supply pipe 3 for air diffusion via the blow water supply pipe 14, for overcoming the air pressure of the air supply pipe 3 for air diffusion. The air supply pipe 3 can be supplied. As the blow water supply means 5, there is, for example, a water storage tank provided with a water pump.
The blow water supplied from the blow water supply means 5 flows into the air supply pipe 3 through the blow water supply pipe 14 and the pressure in the air supply pipe 3 becomes higher than a predetermined pressure. Sometimes, air is supplied from the air supply pipe 3 to the diffuser plate 4 through the inner tube 7 and discharged from a plurality of fine holes scattered on the diffuser surface of the diffuser plate 4 like air.

2. Operation Method of Air Diffuser A normal air diffuser is operated by opening the on-off valve 15 and closing the on-off valve 16. During the air diffusion operation, the pressure air supplied from the gas supply means 2 is supplied to the air supply pipe 3 for air diffusion, and is further supplied to the air diffusion plate 4 via the inner tube 7. And in this Embodiment, since it does not have the micropore 21 in the part 20a right above the intubation tube 7 in the air diffusion surface 20, the air supplied to the diffuser board 4 from the intubation tube 7 is the inner tube 7 Without being intensively discharged from the portion directly above, it is guided to the peripheral side of the diffuser plate 4 and reaches the entire diffuser plate.

Further, at the time of the blow operation in which the air diffusion plate 4 is blown with water, the on-off valve 16 is opened and the blow water is supplied to the air supply pipe 3 for air diffusion, so that the air for air diffusion and the blow water are supplied to the inner tube 7. To the diffuser plate 4.
In the present embodiment, since there is no fine hole 21 in the portion 20a immediately above the inner intubation 7 on the air diffusion surface 20, the air is supplied from the inner intubation 7 to the air diffusion plate 4 even during this blow operation. The blow water is guided to the peripheral side of the diffuser plate 7 without being intensively discharged from the portion 20a immediately above the inner intubation tube 7, and can be effectively blown through the entire diffuser plate.

  Thus, by periodically supplying blow water from the blow water supply means 5 to the diffuser plate 4, microorganisms attached to the diffuser holes can be removed without raising the diffuser onto the water surface. In addition, although there is no restriction | limiting in particular in the supply frequency of blow water, Preferably blow water is supplied in the air supply piping 3 for aeration every several hours to several days.

As described above, the air diffuser 1 according to the present embodiment includes the inner tube 7 and can supply blow water to the air diffuser plate 4 without filling the water, so that an air supply passage is provided. Is always secured. Therefore, the air diffuser 1 is continuously operated while the blow water is regularly supplied during the air supply, and the microorganisms attached to the fine holes 21 of the air diffuser surface 20 of the air diffuser plate 4 are removed with the blow water. Can do.
Moreover, in this Embodiment, it was set as the structure which does not have the fine hole 21 in the part 20a right above the intubation tube 7 in the diffused surface 20, Therefore The diffused pressure air and blow water are diffused Thus, the diffuser plate can be prevented from being clogged for a long period of time while maintaining high oxygen transfer efficiency.

  In the above embodiment, the blow water is not particularly limited. However, the use of blow water containing a component having an effect of killing microorganisms can effectively suppress the growth of microorganisms. . The component having an effect of killing microorganisms is not particularly limited, but for example, an antibacterial substance or an oxidizing substance, more specifically, sodium hypochlorite, inverse soap, acid, alkali, ozone, or chlorine dioxide And alkali metal carbonates.

[Embodiment 2]
FIG. 8 is an explanatory diagram of the second embodiment of the present invention, and the same reference numerals are given to the same parts as those in FIG. 3 showing the first embodiment.
In the present embodiment, as shown in FIG. 8, the diffuser plate 4 has a configuration in which the fine holes 21 are not formed in the portion 20 a immediately above the inner tube 7 in the diffuser surface 20 of the diffuser plate 4. Is provided with a conical guide piece 23 projecting toward the inner intubation side. The conical guide piece 23 is preferably such that the downward extension of the apex of the cone substantially coincides with the center line of the intubation tube 7.
By providing such a guide piece 23, the flow of air or blown water supplied to the diffuser plate 4 via the inner intubation tube 7 can be smoothly turned to the peripheral side of the diffuser plate 4. Thus, it is possible to further enhance the effect of spreading the pressure air and blow water for air diffusion over the entire air diffusion plate.

  The shape of the guide piece 23 is not limited to a conical shape, and the flow of air or blow water supplied to the diffuser plate 4 is smoothly turned to the peripheral side of the diffuser plate 4. For example, a shape such as a pyramid or a shape in which a circumferential surface of a cone is curved may be used.

[Embodiment 3]
9 to 13 are explanatory diagrams of Embodiment 3 of the present invention.
9 to 13 are explanatory views of the air diffuser plate 4 and the inner intubate tube 7 when the inner intubation tube 7 and the air diffuser plate 4 are integrally formed, FIG. 9 is a front view, and FIG. 10 is a longitudinal section of FIG. FIG. 11 is an enlarged view of a portion B surrounded by a circle in FIG. 10, FIG. 12 is a perspective view of the portion B surrounded by a circle in FIG. 10, and FIG. 13 illustrates the operation of this embodiment. It is explanatory drawing to do.
Hereinafter, the air diffusing device according to the present embodiment will be described with reference to FIGS. 9 to 13.

  The diffuser plate 4 according to the third embodiment has a rectangular shape, and includes a bottomed frame 4a formed integrally with the intubation tube 7, a metal thin plate constituting the diffuser surface 20, and a bottomed frame 4a. A frame body 4b is provided so as to sandwich a thin metal plate around the periphery. And the four curved guide blades 24 are radially provided in the upper-end periphery part (blow water supply port part 28) of the inner tube 7 in the bottomed frame 4a, as shown in FIG. 11, FIG. Yes. Each guide vane 24 is arranged so that the tangential direction of its tip end faces each of the four corners. The guide vane 24 configured in this manner functions as a diffusing means for diffusing the blow water supplied through the inner intubation 7 over the entire air diffusion surface 20.

  The function of the guide blade 24 will be described with reference to FIG. The blow water supplied through the inner intubation 7 collides with the air diffusion surface 20 and tries to spread in the circumferential direction of the air diffusion surface 20. At this time, more blow water flows along the side wall of the guide vane 24, and as shown by the arrows in FIG. 13, the blow water easily flows toward the four corners of the air diffusion surface 20, and is far from the blow water supply port. It becomes possible to supply up to a distance, and as a result, the blow water can be diffused over the entire diffuser surface 20. That is, since the air diffusing surface 20 has a rectangular shape, the four corners of the air diffusing surface 20 are located farthest from the upper end of the inner tube 7 that serves as a blow water supply port. Since it is guided and easily flows in the four corner directions, the blow water can be diffused over the entire air diffusion surface 20 including the four corners.

Since an experiment for confirming the blow water diffusion effect of the guide vanes 24 provided on the diffuser plate 4 was performed, this experiment will be described below. The experimental method is to install guide vanes 24 (φ55 mm) on a 250 mm square diffuser plate, and to check the diffusion status by flowing blow water. As shown in FIG. 14, the guide blades 24 used in the experiment are of the four-blade type in which the length of each guide blade 24 is the same as that of the four-blade type shown in FIG. This is an eight-blade type in which one short guide vane 240 is arranged between each of the four guide vanes 24.
For the four-blade type, two types of experiments were conducted, one with a lid (φ55 mm) above the inner cannula 7 and the other without a lid. For the eight-blade type, intubation was performed. An experiment with a lid above 7 was performed.
The results of the experiment are shown in Table 1.

  As shown in Table 1, it was confirmed that the four-blade type lid had the highest diffusion effect. Further, as can be seen from a comparison between Experiment No. 1 and Experiment No. 2, Experiment No. 1 with a lid has a higher diffusion effect, so the lid is placed above the inner intubation 7 and blow water is discharged from above the inner intubation 7. It was confirmed that it was effective for the diffusion of blow water. Further, as can be seen from comparison between Experiment No. 1 and Experiment No. 3, in this example, the four-blade type was found to have a higher blow water diffusion effect than the eight-blade type.

  In addition, the aspect which installs another member in the bottomed frame 4a may be sufficient as the guide blade | wing 24, and when manufacturing the bottomed frame 4a with a resin molded product, even if it integrally molds with the bottomed frame 4a. Good.

[Embodiment 4]
FIG. 16 is an explanatory diagram of the fourth embodiment of the present invention, and is a cross-sectional view of the vicinity of the upper end portion of the intubation tube 7.
In the fourth embodiment, the air diffused between the upper end of the intubation tube 7 and the diffuser surface 20 is moved to the diffuser surface 20 side by the pressure air and / or blow water supplied through the inner intubator 7. A spherical body 25 is provided on the surface 20 to close the minute hole of the portion 20a corresponding to the portion directly above the inner tube 7.

  When air diffused or blown water is supplied to the intubation tube 7, the spherical body 25 moves upward as shown in FIG. 16 (b) to supply air or blown water. While not obstructing, the micropores of the portion 20a immediately above the inner intubation 7 on the air diffusing surface 20 are blocked, and air and blow water are intensively discharged from the portion 20a immediately above the inner intubation 7 on the air diffusing surface 20. To prevent.

  When the spherical body 25 moves to the diffuser surface 20 side, the spherical body 25 is brought into contact with the peripheral surface of the spherical body 25 so that the spherical body 25 is held at the position corresponding to the portion 20 immediately above the inner intubation tube 7. It is preferable to provide a holding piece 26 for holding. Furthermore, by making the outer peripheral surface of the holding piece 26 into an inclined surface 26 a that inclines toward the outer peripheral edge side of the air diffusion surface 20, air for air diffusion or blow water supplied to the air diffusion plate 4 side via the inner intubation 7. This is more preferable because the flow can be smoothly turned to the peripheral side of the diffuser plate 4 and the effect of spreading the diffused pressure air and blow water over the entire diffuser plate can be further enhanced.

  When the supply of air for blown air or blow water is stopped, the spherical body 25 is seated on a valve seat 7a formed on the upper end surface of the inner intubation 7, thereby preventing the backflow of sewage to the inner intubation 7 side. Functions as a check valve. By the spherical body 25 functioning as a check valve, sewage or activated sludge flows backward to the inside of the diffuser plate 4 even when the operation of the gas supply means 2 is stopped due to a power failure or management operation. The clogging of the air diffusing surface 20 due to the backflowed sewage or the like can be prevented.

[Embodiment 5]
FIG. 17 is an explanatory diagram of Embodiment 5 of the present invention, and is a cross-sectional view of the vicinity of the upper end portion of the internal intubation 7. In the fifth embodiment, a check valve including the spherical body 25 described in the fourth embodiment is further provided in addition to the guide blade 24 described in the third embodiment. In this case, the base end portion 24 a of the guide blade 24 is disposed on the upper part of the inner intubation 7, and the base end portion 24 a functions as a guide for the vertical movement of the spherical body 25.

  In the fifth embodiment, when blow water is supplied from the intubation tube 7, the fine holes of the air diffusing surface 20 are blocked by the floating of the spherical body 25, and further, the guide vanes 24 move to the periphery of the air diffusing surface 20. Since it is diffused, it has a function of diffusing blow water in addition to the function of a check valve.

  In the description of the above fourth and fifth embodiments, the pressure air and / or blow water supplied via the inner intubation 7 moves to the air diffusion surface 20 side and corresponds to the upper surface of the inner intubation 7 on the air diffusion surface 20. Although the example in which the spherical body 25 is provided as a member that closes the fine hole of the portion 20a has been shown, the shape of the member of the present invention is not limited to the spherical body. For example, a disk-shaped member may be used instead of the spherical body 25. It may be provided.

  In the above description of each embodiment, the diffuser plate 4 is provided with the inner intubation tube 7. However, even if the diffuser plate 4 is not provided with the inner intubator tube 7, the diffuser air supply pipe 3. If the inside is filled with water, it is possible to blow the diffuser plate 4 with blow water. Even in that case, the blow water can be diffused over the entire diffuser surface 20 by providing the diffuser plate 4 with the diffusion means described in the above embodiments. That is, the diffusing means has an effect even on an air diffuser that does not include the inner intubation 7. In addition, when water blow is performed when the inner intubation pipe 7 is not provided, a drain remover for removing blow water in the air supply piping 3 is provided, and after the water blow is finished, air diffused from the drain remover. The blow water stored in the supply air pipe 3 may be discharged.

It is a schematic diagram of the air diffusion apparatus which concerns on Embodiment 1 of this invention. It is a top view of the diffuser plate which concerns on Embodiment 1 of this invention. It is an expanded sectional view which expands and shows a part of FIG. It is sectional drawing of the intubation which concerns on Embodiment 1 of this invention. It is a figure which shows the one aspect | mode of the intubation tube concerning Embodiment 1 of this invention, and is a schematic diagram in case the suction surface is not inclined. It is a figure which shows the other aspect of the intubation tube concerning Embodiment 1 of this invention, and is a schematic diagram in case the suction surface inclines. It is explanatory drawing of the intubation in Embodiment 1 of this invention, and is a schematic diagram which shows the effect of the vent provided in the intubation. It is a partially expanded sectional view of the aeration apparatus concerning Embodiment 2 of the present invention. It is a side view of the diffuser plate which concerns on Embodiment 3 of this invention. It is an end elevation of the state made into the longitudinal section of the diffuser plate concerning Embodiment 3 of the present invention. It is an enlarged view of the end surface of the state made into the longitudinal section of the diffuser plate concerning Embodiment 3 of this invention. It is a perspective view which expands and shows a part of diffuser plate which concerns on Embodiment 3 of this invention. It is explanatory drawing explaining the effect | action of the diffuser plate which concerns on Embodiment 3 of this invention. It is explanatory drawing of the experiment which confirms the effect of the diffuser plate which concerns on Embodiment 3 of this invention. It is explanatory drawing of the experiment which confirms the effect of the diffuser plate which concerns on Embodiment 3 of this invention. It is explanatory drawing of Embodiment 4 of this invention. It is explanatory drawing of Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air diffuser 2 Gas supply means 3 Air supply piping for diffuser 4 Air diffuser plate 5 Blow water supply means 7 Inner intubation 7a Valve seat 8 Suction surface 9 Vent hole 10 Fixing member 11 Mounting bracket 12 Aeration tank 14 Blow water Supply pipes 15 and 16 On-off valve 20 Air diffuser surface 20a Equivalent portion directly above the inner tube 7 21 Fine hole 22 Blow water supply port 23 Guide piece 24, 240 Guide vane 24a Base end portion 25 Spherical body 26 Holding piece 26a Inclined surface 28 Blow Water supply port θ Inclination angle

Claims (7)

A diffuser plate that is arranged in the aeration tank and discharges the pressure air supplied from the air supply pipe for the air diffused as fine bubbles from the fine pores formed on the air diffusion surface, and the air supply pipe for the air diffuser. Blow water supply means for supplying blow water supplied to the diffuser plate and discharged from the fine pores, and diffusing means for diffusing the blow water supplied to the diffuser plate on the diffuser surface. A diffuser characterized by that. The diffusion means includes a guide piece formed radially from the blow water supply port to the diffuser plate, and the guide piece is a distance from the blow water supply port to the peripheral edge of the diffuser plate. The air diffuser according to claim 1, wherein the air diffuser is formed so that more blow water can be guided in a long direction. The diffuser plate according to claim 1 or 2, wherein the diffuser plate has a rectangular shape, and the guide piece is curved so that a tangential direction of a tip portion thereof is in a direction of a corner portion of the diffuser plate. Qi device. The air diffusing device according to any one of claims 1 to 3, wherein the diffusing unit includes a lid member that closes a minute hole corresponding to a portion immediately above the blow water supply port. The lid member is disposed between the blow water supply port and the air diffuser surface, and moves to the air diffuser surface side by blow water supplied from the blow water supply port, and the blow water on the air diffuser surface. The air diffuser according to claim 4, wherein a minute hole corresponding to a portion immediately above the supply port is closed. The said cover member consists of a spherical body which functions as a non-return valve which prevents that the sewage in the said aeration tank flows in into the air supply piping for aeration from a blow water supply port. Air diffuser. An inner tube is provided that has an upper end communicating with the diffuser plate side and a lower end inserted into the diffuser air supply pipe to supply blow water supplied into the diffuser air supply pipe to the diffuser plate. The air diffuser according to any one of claims 1 to 6, wherein

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