JP2007105612A - Aeration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aeration device which can prevent sewage from flowing backward from an aeration tank even during the stop of aeration. <P>SOLUTION: The aeration device 10 has an aeration means comprising elastic porous bodies 21, and an air chamber 30. A ball valve 40 is movably disposed inside of the air chamber 30. The ball valve 40 opens a first air supply port 15 during air supply from an air supply pipe, and moves so as to occlude the first air supply port 15 during the stop of air supply. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air diffuser installed in an aeration tank used in an organic wastewater treatment system centering on sewage treatment.

  At present, a diffuser plate is installed in a diffuser installed in an aeration tank of many sewage treatment plants.

  A diffuser installed in a general aeration tank includes an air supply pipe and a diffuser plate, and an air chamber disposed between the air supply pipe and the diffuser plate. During the aeration, since pressurized air is sent from the air supply pipe, the air chamber is also in a pressurized state. However, since the pressure in the air chamber decreases while the aeration is stopped, the sewage in the aeration tank may flow back into the air chamber.

Patent Document 1 discloses that aeration is stopped by a valve body 8 composed of a valve plate 6, an elastic seal material (packing) 7, and a backflow prevention valve 5 composed of a valve shaft 9 provided vertically below the valve body 8. An air diffuser for closing the air supply port is disclosed.
Japanese Patent Laid-Open No. 3-165897

  Since the backflow prevention valve used in the air diffuser of Patent Document 1 is a combination of a valve body and a valve shaft, it is not sufficient in terms of durability, and there is a risk of damage due to long-term continuous use. Since the shaft is inserted into the air supply port, there is a possibility that the opening area will be narrow and the air permeability may be reduced. The valve body may be obliquely covered with the protrusion of the air supply port and the seal may be insufficient. There is room for improvement.

  An object of the present invention is to provide an air diffusing device that has high air diffusing performance and durability and can prevent the backflow of sewage from the aeration tank even when the air diffusing is stopped.

As a means for solving the problems, the present invention
An air supply means; an air diffuser means for releasing air pressurized and supplied from the air supply means; and an air chamber communicating the air supply means and the air diffuser means. A first air supply port between the air chamber and the air chamber, and a second air supply port between the air chamber and the air diffuser.
A ball valve is movably disposed inside the air chamber,
The ball valve moves so as to open the first air supply port during the supply of air from the air supply means, and close the first air supply port while the supply of air from the air supply means is stopped. A diffuser that is to do.

  The air supply means is a pipe connected to an air source (pressurized air source) or a combination of the pipe and a pressurizing device for sending pressurized air, and is the same as a known air diffuser. Can be used.

  As the air diffuser, known ones (sheet-like ones) such as ceramics, resins and rubbers having a large number of pores can be used. From the viewpoint of durability and the like, What combined with the reinforcement frame material is preferable. The second air supply port is in pressure contact with the air diffuser, and acts to supply air to the air diffuser during air diffusion, but is closed when the air diffuser is stopped.

  The air chamber is a space located between the air supply means and the air diffusion means, and the shape and size are not particularly limited. In the present invention, a cylindrical space having a diameter larger than the diameter of the ball valve is preferable in view of the movement of the ball valve.

  The ball valve functions as a backflow prevention valve, and can be floated by receiving air pressure during air diffusion and has a mass that can close the first air supply port when air diffusion is stopped. Further, a synthetic resin having a hollow structure or a non-hollow structure, rubber, wood, paper, metal, ceramics, or the like can be used. In the present invention, a non-hollow synthetic resin is preferable.

  In the air diffuser of the present invention, while the pressurized air is supplied from the air supply means connected to the external air source, and the air is diffused from the air diffuser, the ball valve floats in the air chamber by the air pressure. Therefore, the first air supply port is kept open. When the supply of pressurized air from the air supply means is stopped, the ball valve immediately falls from the floating state and is positioned on the first air supply port, so that the first air supply port is closed. At this time, since the air chamber is in a sealed state and is in a high pressure state, the sewage in the aeration tank is prevented from flowing back into the air chamber and the air supply unit through the air diffuser.

  As another means for solving the problems, the present invention provides a ball valve pedestal in the vicinity of the first air supply port in the air chamber, and the one end side opening of the ball valve pedestal has the first opening. 1. The air diffuser according to claim 1, wherein the air diffuser is located on the side of one air supply port, and the other end side opening is in contact with the ball valve.

  The ball valve pedestal is preferably cylindrical with a diameter smaller than that of the ball valve. Even when the air chamber is enlarged to increase the air supply amount, the ball valve pedestal is installed in the air chamber in this way, so that the air valve can be easily blocked by the ball valve when the air diffusion is stopped. become.

  As another means for solving the problem, the present invention prevents movement of the ball valve toward the second air supply port between the first air supply port and the second air supply port in the air chamber. 3. A diffuser device according to claim 1 or 2, wherein a blocking means is provided.

  When the air pressure from the first air supply port at the time of air diffusion is received, the ball valve rises excessively to reach the second air supply port, and the situation where the second air supply port is closed is sufficient. Aeration performance cannot be maintained. In order to prevent such a situation from occurring, the blocking means as described above is provided. As the blocking means, in the case of a cylindrical air chamber, one having about one or two rod-shaped members spanned between the inner peripheral surfaces of the air chamber can be used.

  The present invention provides a diffuser according to any one of claims 1 to 3, wherein the ball valve pedestal is made of resin or rubber.

  When the ball valve pedestal is made of resin, it is preferable to use an O-ring made of rubber together with the O-ring at a position in contact with the ball valve in order to improve the sealing performance in the air chamber.

  According to the air diffuser of the present invention, since a means including a ball valve is used as a backflow preventing means at the time of stopping air diffusion, the durability is high, and a sufficient air flow rate can be ensured even during air diffusion. It can also be sealed in the air chamber. Therefore, a stable diffused state can be maintained over a long period of time.

  The aeration apparatus 10 of the present invention will be described with reference to FIGS.

(1) Air diffuser shown in FIGS. 1 and 2 FIG. 1 is a longitudinal sectional view of the air diffuser of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. It is a top view of a diffuser.

  The upper semi-cylindrical portion 12 and the lower semi-cylindrical portion 13 of the second support body are fitted and integrated with each other by the flange portions 12a and 13a. An air supply pipe connected to a pressurized air source (or a pressurizing device) is disposed in a space formed by the upper semicylindrical portion 12 and the lower semicylindrical portion 13.

  The second support body includes an upper semi-cylindrical portion 12 and a cylindrical portion 14 extending upward, and a screw is provided on the inner peripheral surface of the cylindrical portion 14. A first air supply port 15 is provided between the upper semi-cylindrical portion 12 and the cylindrical portion 14. The diameter of the upper semi-cylindrical portion 12 is sufficiently larger than the diameter of the first air supply port 15.

  The air diffuser is formed by combining members including the elastic porous body 21, the first support 22, the first fixing member 23, and the second fixing member 24.

  The elastic porous body 21 made of rubber and having a large number of diffused holes 29 is in close contact with a support 22 made of synthetic resin, and has an annular protrusion 26 in the vicinity of the end. A synthetic resin or metal first fixing member 23 (having a frame shape in plan view) is covered around the elastic porous body 21, and the periphery of the first fixing member 23 is shown in FIGS. As shown in FIG. 6, a plurality of synthetic resin or metal second fixing members 24 are pressed and fixed at intervals from each other.

  A synthetic resin annular plate 25 is disposed between the annular protrusions 26 of the elastic porous body 21 and the second fixing member 24, and when pressed by the second fixing member 24 from above and below, The annular protrusion 26 is crushed and brought into close contact with the annular plate 25, and the annular plate 25 and the inner lower surface of the second fixing member 24 are brought into close contact with each other, thereby being in an airtight state.

  The support 22 has a second air supply port 27 in the center, and has a leg portion 28 that extends downward from a range including the second air supply port 27. A screw is provided on the lower outer peripheral surface of the leg portion 28. The second air supply port 27 is in pressure contact with the back surface of the elastic porous body 21, but the air diffusion hole 29 is not provided in the central portion of the elastic porous body 21 that faces the second air supply port 27.

  The air chamber 30 is a cylindrical space formed by screwing the screw of the cylindrical portion 14 of the upper semi-cylindrical portion 12 and the screw of the leg portion 28 of the support 22 into which the ball valve 40 is inserted.

  In the air chamber 30, a substantially cylindrical synthetic resin ball valve pedestal 31 is installed in the vicinity of the first air supply port 15.

  The ball valve pedestal 31 has a flange portion 32 at a portion in contact with the outer peripheral surface of the upper semi-cylindrical portion 12, and an O-ring 33 is fitted into a contact portion between the flange portion 32 and the opening peripheral edge portion of the leg portion 28. ing. Further, an annular groove 34 is formed in the upper part of the ball cradle 31, and an O-ring 35 is fitted in the annular groove 34.

  Next, the operation of the air diffuser 10 will be described with reference to FIG. Prior to the operation of the air diffuser 10, the ball valve 40 is on the ball cradle 31, so the first air supply port 15 is in a closed state. The second air supply port 27 is in pressure contact with the back surface of the elastic porous body 21.

  When the supply of pressurized air from the air supply pipe is started, the ball valve 40 is floated in the air chamber 30 by the air pressure to flow into the air chamber 30 from the first air supply port 15 (in FIG. 1). The ball valve 40 ') indicated by a broken line.

  When the pressure in the air chamber 30 is increased by the air that has flowed in, the elastic porous body 21 is pressed from the portion of the second air supply port 27 and floats, and a gap is formed between the support 22 and the elastic porous body 21 in close contact. Then, air flows through the gap, and is discharged from the diffuser holes 29 of the elastic porous body 21 into the aeration tank.

  Then, when the supply of pressurized air from the air supply pipe is stopped, the ball valve 40 immediately drops and fits into the opening (annular groove 34) in which the O-ring 35 of the ball valve pedestal 31 is fitted. The first air supply port 15 is closed.

  At this time, since the pressure in the air chamber 30 is sufficiently high, there is not enough force to push up the elastic porous body 21, but the pressure at which the elastic porous body 21 is pressed at the portion of the second gas supply port 27 is maintained. ing. For this reason, the sewage (water to be treated) remaining between the elastic porous body 21 and the support 22 does not move in the direction of the second air supply port 27 due to the pressure in the air chamber 30.

(2) Air diffuser shown in FIGS. 3 and 4 FIG. 3 is a partially enlarged view of another form of the air diffuser shown in FIG. 1, and FIG. 4 (a) is a perspective view of one component (blocking means) in FIG. FIG. 4 and FIG. 4B are plan views of FIG.

  In the air chamber 30, a blocking means 50 for blocking the ball valve 40 from moving toward the second air supply port 27 is disposed on the ball valve pedestal 31.

  The blocking means 50 includes a cylindrical outer wall portion 51 that matches the internal shape of the air chamber 30, and a rod 52 that is spanned between opposing inner peripheral surfaces of the cylindrical outer wall portion 51. The rod 52 is stretched so as to bisect the cylindrical outer wall portion 51 in the diametrical direction, and the diametric cross-sectional areas of the two semicircular spaces are sufficiently smaller than the diameter of the ball valve 40.

  Since the blocking means 50 is thus provided, the ball valve 40 is started by the air pressure that starts to supply pressurized air from the air supply pipe and flows into the air chamber 30 from the first air supply port 15. Even when the air valve 30 is in a floating state in the air chamber 30 (ball valve 40 ′ indicated by a broken line in FIG. 3), the ball valve 40 does not move above the rod 52. For this reason, even when the air pressure in the air chamber 30 becomes excessive, the second air supply port 27 is not blocked by the ball valve 40, and a stable diffused state can be maintained.

(3) Air diffuser shown in FIG. 5 FIG. 5 is a partially enlarged view of still another embodiment of the air diffuser shown in FIG. In FIG. 5, a rubber ball valve pedestal 31 is used, which is the same as that of FIG. 1 except that the ball valve pedestal 31 does not have a notch and does not use an O-ring.

  When the ball valve pedestal 31 made of rubber is used, when the ball valve pedestal 31 and another member come into contact with each other, the ball valve pedestal 31 at the contact portion is deformed, and the other member that comes into contact by its own elasticity Therefore, the adhesion at the contact portion is ensured. For this reason, a notch part and an O-ring become unnecessary.

The longitudinal cross-sectional view of the diffuser of this invention. The elements on larger scale of FIG. The elements on larger scale of another form of the air diffusion apparatus of FIG. (A) is a perspective view of one component (blocking means) of FIG. 3, (b) is a top view. The partial expanded view of another form different from the air diffusion apparatus of FIG. The top view of one component (aeration means) of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Air diffuser 15 1st air supply port 21 Elastic porous body 27 2nd air supply port 30 Air chamber 31 Ball valve stand 40 Ball valve

Claims (4)

An air supply means, an air diffuser means for releasing air pressurized and supplied from the air supply means, and an air chamber communicating the air supply means and the air diffuser means, the air supply means A first air supply port between the air chamber and the air chamber, and a second air supply port between the air chamber and the air diffuser.
A ball valve is movably disposed inside the air chamber,
The ball valve moves so as to open the first air supply port during the supply of air from the air supply means and close the first air supply port while the supply of air from the air supply means is stopped. A diffuser that is to do.   A ball valve pedestal is installed near the first air supply port in the air chamber, one end side opening of the ball valve pedestal is located on the first air supply port side, and others The air diffuser according to claim 1, wherein an end opening is in contact with the ball valve.   A blocking means for blocking the movement of the ball valve toward the second air supply port is provided between the first air supply port and the second air supply port in the air chamber. The air diffuser according to 1 or 2. The air diffuser according to any one of claims 1 to 3, wherein the ball valve pedestal is made of resin or rubber.

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