JPH0311833B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aeration device used for sewage treatment and the like.

Aeration purification is performed as a water purification treatment for wastewater such as sewage and wastewater. That is, by sending air into the sewage stored in the sludge tank from an aeration device installed in the sludge tank, the organic matter in the sewage that has adhered to or adsorbed to the activated sludge is oxidized (decomposed), and activated bacteria are Purification is performed by absorbing it into the water. In such aeration purification, how widely and finely the air is diffused within the sludge tank is a factor that determines the quality of the treatment efficiency.

Various proposals have been made regarding this type of aeration device. For example, as shown in Fig. 1, an aeration pipe 2 connected to a pressurized air supply pipe through a joint 1 is constructed of a porous member made of synthetic resin or the like. is used. This is effective because it can perform fine aeration, but when the aeration is stopped, sewage flows into the aeration pipe, and this inflow sewage usually
It cannot be discharged without introducing pressurized air at more than double the pressure, and if you try to discharge this wastewater using air with a pressure slightly higher than that used for normal aeration, it will not only take a very long time, but also There is a problem in that it is difficult to completely discharge the waste water that has flowed into the cylinder, which worsens the aeration situation. In addition, when the aeration is stopped, the sewage flowing into the aeration pipe has a large water head, which is stored in the sludge tank, so its velocity is high, and the solid content in the sewage breaks up the flocs and enters the aeration pipe. When the wastewater that has flowed into the aeration pipe is discharged using pressurized air, the outflow speed is small, so the aeration pipe acts as a filter, and the solid content, which is the re-agglomeration of flocs in the wastewater, is absorbed by the filter effect of the aeration pipe. There is a problem in that it adheres to the inner surface and pores, causing clogging, and worsening the air diffusion situation.

For this reason, it has been impossible to use a porous member with a preferable pore size in terms of oxygen absorption efficiency.

In order to solve this problem, the present applicant closed the upper end opening of the cup-shaped container main body 3, which is opened upward, with a lid plate 4, as shown in FIG. An air chamber 5 is formed in the main body, and a connecting member 6 having a spout 6a connected to a pressure air introduction port 3a provided at the lower end of the container main body 3 is inserted into the air chamber 5 by passing through the lid plate 4. An elastic member 7 such as a disc spring is disposed between the connecting member 6 and the lid plate 4, and during aeration, the air is supplied from the pressurized air supply pipe 8 through the pressurized air inlet 3a and the connecting member 6 to the spout 6a.
Due to the pressure of the air flowing into the air chamber 5,
When the cover plate 4 is opened against the elastic force of the elastic member 7 to diffuse air into the waste water, and the pressure inside the air chamber 5 decreases when aeration is stopped, the cover plate 4 is opened by the elastic force of the elastic member 7 to open the container body. An aeration device that is seated on the upper end surface of the air chamber 5 to prevent sewage from flowing into the air chamber 5 was proposed.
It was proposed as No. 55-46520. However, it is difficult to uniformly apply the elastic force of the elastic member 7 to the entire cover plate 4, and the cover plate 4 may tilt when opened due to the pressure inside the air chamber 5, causing one-sided blowing. There is a problem that air bubbles become large and reduce the air diffusion efficiency, and there is also a problem that abnormal noise is generated when the lid plate 4 is seated.

The present invention was devised in view of the above-mentioned drawbacks of the conventional ones, and its purpose is to easily discharge sewage that has entered the air chamber of the container body through the porous diffuser into the sludge tank during aeration. The purpose of the present invention is to provide an aeration device that can perform fine aeration at all times without causing clogging, and that does not generate abnormal noise.

The gist of the present invention is to provide a container main body having an air chamber with an open upper end, an air diffuser made of a porous material attached to the upper end of the container main body and covering the opening, and an air diffuser provided in the container main body to allow air to flow through the container main body. a pressurized air inlet that communicates with the chamber and connects to a pressurized air supply pipe; an outlet for infiltrated sewage that is provided at the bottom of the container body and communicates with the air chamber; and a member that floats in the sewage and is disposed within the air chamber and The aeration device is equipped with a valve that opens and closes a discharge port for infiltrated sewage.

Hereinafter, the present invention will be specifically established based on illustrated embodiments.

3 to 5 show an embodiment of the aeration device according to the present invention. In the figures, 10 is a main pipe of a pressurized air supply pipe, one end of which is connected to a blower (not shown), and 11 is a main pipe of the main pipe 10. 12 is a branch pipe connected to the collecting pipe 11; 2 is a branch pipe connected to the collecting pipe 11;
0 is an aeration device attached to the branch pipe 12, which is usually installed in an aeration tank containing activated sludge. A detailed explanation will be given below based on FIGS. 4 and 5.

Reference numeral 21 denotes a conical container body made of synthetic resin, and includes an air chamber 22 with an open top end. A connecting portion 2 having a pressurized air inlet 23 communicating with the air chamber 22 is provided on the upper side wall of the container body 21.
4 is formed integrally with the main body 21, and by screwing the screw 24a provided at the end of the connecting portion 24 into the female screw 12a formed on the branch pipe 12 of the pressure air supply pipe, the container can be opened. The main body 21 is connected to a branch pipe of the pressurized air supply pipe. Further, a discharge port 25 communicating with the air chamber 22 is provided at the lower end of the container body 21.

Reference numeral 26 denotes an air diffuser that is attached to the upper end of the container body 21 and covers the opening, and is made of a porous material made of sintered or foamed synthetic resin. Flange 2
It is attached to 1a by several bolts 27 and nuts 28. Note that the diameter of the pores of the porous material constituting the air diffuser 26 is preferably about 20 μm to 0.5 μm.

Reference numeral 29 designates a ball valve disposed within the air chamber 22, which is made of a synthetic resin such as polyethylene or polypropylene that has a specific gravity smaller than that of water. When the waste water is flowing into the air chamber 22, the drain port 25 is opened by floating on the waste water. The valve 29 may be made of a material having a specific gravity greater than that of water, as long as it is made hollow and floats on the dirty water.

Reference numeral 30 denotes a check valve disposed at the lower end of the container body 21 facing the discharge port 25, one end of which is disposed at the lower end of the container body 21.
1 rotatably pivoted by a shaft 31,
Moreover, a spring 32 disposed such that one end is locked to the shaft 31 and the other end is engaged with the lower surface is always urged to rotate counterclockwise in the figure with the shaft 31 as a fulcrum, and the air is The outflow of sewage from the chamber 22 is allowed, but the inflow of sewage from the aeration tank to the air chamber 21 is blocked. Note that the check valve 30
A sealing material 30 with good sealing properties such as rubber is placed on the top surface of the
A is attached.

The present embodiment is constructed as described above, and its operation will be explained below.

When the air chamber 22 of the container body 21 is filled with air (aeration is operating), the ball valve 2
9 falls as shown in the figure and closes the discharge port 25, and when pressurized air is introduced into the air chamber 22 from the branch pipe 12 of the pressurized air supply pipe through the pressure air introduction port 23, the pressurized air is passed through the air diffuser member. Air is diffused into the sewage water in the sludge tank through 26 microscopic holes.

Next, when the aeration is stopped, the pressure in the air chamber 22 becomes approximately atmospheric pressure, so the sewage in the sludge tank enters the air chamber through the fine holes of the aeration member 26. Therefore, the ball valve 29 floats above the waste water. When aeration is started again and pressure air is introduced into the air chamber 22, the ball valve 29 is raised and the discharge port 22 is opened.
5 is open, air chamber 2 is opened by air pressure.
The sewage flowing into the sludge tank 2 is forced to open the check valve 30 against the force of the spring 32 through the discharge port 25 and flow out into the sludge tank. When the amount of sewage in the air chamber 22 becomes small, the ball valve 29 is caught up in the outflow vortex of the sewage and rapidly falls to close the discharge port 25. Therefore, the pressure in the air chamber 22 increases and the fine pores of the air diffuser 26 close. Air is diffused into the sludge tank. Note that when the waste water that has flowed into the air chamber 22 is discharged from the discharge port 25 and the ball valve 29 closes the discharge port 25, the pressure within the air chamber 22 does not act on the check valve 30.
0 rotates counterclockwise in the figure using the force of the spring 32 about the shaft 31 to close the discharge port 25 and block the inflow of waste water from the discharge port 25 into the air chamber 22.

FIG. 6 shows another embodiment of the aeration device according to the present invention, in which the same parts as in the above embodiment are given the same reference numerals.

The aeration device 20 of FIG. 6 according to the present embodiment has an inverted air inlet 23 that is connected to a pressurized air inlet 23 communicating with an air chamber 22 provided in a container body 21, and one end of which is attached to the inner surface of the container body 21 with a screw 41. A stop valve 40 is provided. The check valve 40 is made of an elastic member such as rubber, synthetic resin, or spring steel, and allows pressurized air to flow into the air chamber 22 from the pressurized air supply pipe side, but does not allow pressurized air to flow from the air chamber 22 to the pressurized air supply pipe side. It is designed to block the outflow of fluid. Therefore, air chamber 2
It is possible to prevent the wastewater that has flowed into the air tank 2 from flowing into the pressurized air supply pipe.

Further, in the aeration device 20 according to this embodiment, the aeration member 261 made of a porous material and attached to the upper end of the container body 21 is formed in a curved shape, compared to the flat aeration member 26 of the above embodiment. This has the effect of being able to diffuse air over a wide area.

FIG. 7 shows still another embodiment of the aeration device according to the present invention, in which the same parts as in the above embodiment are given the same reference numerals.

The aeration device 20 according to this embodiment has a container body 21
A pressurized air introduction pipe connecting part 210 is formed downwardly and has a screw hole 210a on the inner periphery, and is integrally formed with the main body 21, and a pressurized air introducing pipe 90 is formed on the outer periphery of the screw hole 210a of the connecting part 210. male screw 9
0a and the upper end is the air chamber 22 of the container body 21.
It is mounted so that it is located at the top of the The pressurized air introduction pipe 90 has a road 91 in the center,
A pressure air introduction port 91a communicating with the passage 91 is provided at its upper end, and the pressure air introduction port 91a includes:
Cup-shaped check valve 4 made of an accessible member such as rubber
01 is attached, and its upper end is fixed by a tightening ring 402. The check valve 401 is connected to the pressure air inlet 9
When pressurized air is introduced into the air chamber 22 from 1a, its lower end is expanded to allow the inflow of the pressurized air into the air chamber 22, but the fluid does not flow out from the air chamber 22 to the pressurized air introduction pipe 90 side. This prevents the wastewater that has flowed into the air chamber 22 from flowing into the pressurized air introduction pipe 90. Further, the lower end of the pressurized air introduction pipe 90 is attached so as to protrude downward from a connecting portion 210 formed on the container body 21, and its position relative to the connecting portion 210 is fixed by a lock nut 92.
The aeration device 20 can be attached to the pressurized air supply pipe by screwing the lower end thereof onto the pressurized air supply pipe. Therefore, according to this embodiment, the pressurized air introduction pipe 90 attached to the container body 21 can be attached by screwing together from above the pressurized air supply pipe, so that the attachment is easy and the operation at the time of attachment is easy. This has advantages such as easy positioning (positioning is free).

In addition, the aeration device 20 according to this embodiment is equipped with a check valve 301 made of an accessible member such as rubber at the outlet 25 provided at the bottom of the container body 21. A plurality of openings 301a are provided at positions that do not face the discharge port 25, and when the pressure of pressurized air acts on the waste water in the air chamber 22, the check valve 301 is pushed and bent (opened) to open the discharge port 25.
The check valve 301 communicates with the opening 301a to allow sewage to flow into the sludge tank, but to block the flow of sewage from the sludge tank into the air chamber 22.
The check valve 30 has a simpler structure and is easier to assemble than the check valve 30 shown in the above embodiment.

The present invention has been described above based on the illustrated embodiments. According to the first invention, an air diffuser made of a porous material is attached to the upper end of the container body having an air chamber with an open upper end, Pressurized air is introduced into the air chamber through the pressure air introduction port connected to the supply pipe, and is diffused through the fine holes in the diffuser member, allowing for uniform and efficient aeration. be able to. In addition, a discharge port is provided at the bottom of the container body, and a valve made of a member that floats in the waste water is installed in the air chamber, so that the waste water that has entered through the aeration member during the aeration stop will be discharged during the next aeration. Since it is discharged through the outlet, the wastewater that has flowed into the air chamber can be discharged in a very short period of time, and since the wastewater that has flowed into the air chamber is not discharged from the air diffuser, clogging of the air diffuser can be prevented. This allows for good aeration over a long period of time.

Further, according to the second invention, a check valve that allows wastewater to flow out from the air chamber but blocks wastewater from flowing into the air chamber is disposed at the discharge port provided in the container body. The check valve shuts off the discharge port except when discharging the sewage that has flowed into the room, preventing sewage from flowing into the air chamber from the discharge port.
Unfiltered wastewater does not flow into the air chamber as it is, and dirt and clogging of the air chamber and the air diffuser can be prevented.

According to the third invention, a check valve is provided in the pressurized air inlet provided in the container body to allow the inflow of pressurized air into the air chamber, but to block the outflow of sewage from the air chamber to the pressurized air supply pipe side. Because of this arrangement, it is possible to prevent sewage that has flowed into the air chamber from flowing back into the pressurized air supply pipe.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an example of a conventionally used aeration device, Fig. 2 is a broken perspective view showing another example of a conventionally proposed aeration device, and Fig. 3 is a cutaway perspective view showing another example of a conventionally proposed aeration device.
4 is a sectional view showing an embodiment of the aeration device according to the present invention, FIG. 5 is a sectional view taken along line V-V in FIG. 4, and FIG. 7 are sectional views showing other embodiments of the present invention. 20... Aeration device, 21... Container body, 22...
...Air chamber, 23...Pressure air inlet, 25...Exhaust port, 26...Diffusing member, 29...Ball valve, 30
...Check valve, 40...Check valve.

Claims (1)

[Scope of Claims] 1. A container body having an air chamber with an open upper end, an air diffuser made of a porous material attached to the upper end of the container body and covering the opening, and an air diffuser provided in the container body and having an air chamber. a pressurized air inlet that communicates with the pressurized air supply pipe; an outlet for infiltrated sewage that is provided at the bottom of the container body and communicates with the air chamber; and an outlet that is disposed within the air chamber and is made of a member that floats in the sewage. An aeration device equipped with a valve that opens and closes. 2. In the aeration device according to claim 1, a check valve is provided at the discharge port provided in the container body and allows sewage to flow out from the air chamber but blocks sewage from flowing into the air chamber. Aeration equipment with. 3. In the aeration device according to claim 1 or 2, the aeration device is arranged at a pressurized air introduction port provided in the container body and allows pressurized air to flow into the air chamber, but does not allow pressurized air to flow from the air chamber to the pressurized air supply pipe side. Aeration equipment equipped with a check valve to shut off the flow of sewage.