JPH0451920Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a method for reducing organic matter contained in wastewater by the physiological action of aerobic microorganisms, which is installed at a lower position in a treatment tank such as an activated sludge treatment tank. This paper relates to improvements to air diffusers.

[Conventional technology]

In the case of an activated sludge treatment tank using aerobic microorganisms, an air diffuser is installed at a lower position within the treatment tank because it is necessary to increase the dissolved oxygen concentration in the liquid to be treated.

FIG. 4 shows an example of a conventional air diffuser installed at a lower position in a processing tank, in which 10 is an air diffuser, 11 is a support seat for the air diffuser 10, and 12 is an air diffuser. A sealing gasket is interposed between 10 and the support seat 11, and 13 indicates a bolt for fixing the diffuser member 10 to the upper surface of the support seat 11.

The conventional air diffuser 10 mainly uses a porous ceramic plate with a considerable thickness, and the pressurized gas fed by the blower is
It enters the sealed chamber 14 surrounded by the support seat 11 and the ceramic air diffuser 10, passes through the pores of the ceramic plate forming the air diffuser 10, and is dissolved into the liquid to be treated in the tank. It is something.

[Problem that the invention attempts to solve]

As mentioned above, the air diffuser 10 used in the conventional air diffuser is mainly made of ceramic and has a considerable thickness, so that the inside of the sealed chamber 14 does not enter a negative pressure state. When the process is carried out, contaminants in the liquid to be treated enter the porous pores and cause clogging, which impairs the dispersion of the pressurized gas and reduces the solubility of the gas.

Furthermore, since the resistance of the gas increases, the capacity of the blower must be improved, which is disadvantageous economically.

Furthermore, since the diffuser member 10 is made of ceramic, it is difficult to process and is easily broken, and even if it is to be fixed to the support seat 11, it must be carefully tightened to a preset torque using a torque wrench. There was also the problem that it took a lot of time and effort.

As a result of various studies to solve this problem, the inventor of the present invention found that, instead of the ceramic plate, on the upper surface of the base fabric, which has relatively coarse openings, was used as an aeration member.
The present invention was completed based on the discovery that the above-mentioned conventional problems could be solved by using a double-layered diffuser cloth made of laminated synthetic resin films with very fine pores.

[Means for solving problems]

To explain in detail the structure of the present invention for solving the problem, in an aeration device attached to a lower position in a treatment tank for treating organic wastewater, etc., the aeration member has relatively coarse mesh. This air diffuser is characterized by using a two-layered air diffuser cloth in which a synthetic resin film with very fine pores is laminated on the top surface of the base cloth.The synthetic resin film is made of polyethylene or polypropylene. , polyethylene terephthalate, fluororesin, etc., and the pore size is
It is preferable to use a material having a micropore diameter of 0.1 to 1 μm, a thickness of 10 to 30 μm, and an air permeability of 1 to 20 c.c./cm ² /sec measured by a Frazier air permeability tester.

In addition, the base fabric with relatively coarse mesh has a thickness of 0.7~
A 2.5 mm non-woven or woven fabric made of synthetic or natural fibers is used.

Since the present invention uses such a fairly thin double-layered air diffuser cloth, clogging is unlikely to occur even if the sealed chamber is under negative pressure, and its micropores make air bubbles extremely small. Since the specific surface area becomes large, the solubility in the liquid to be treated is dramatically improved. Further, it is possible to provide an air diffuser that is easy to install and manage without requiring a special torque wrench or the like when attaching to a holder.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the specific structure of this invention is demonstrated in detail based on the illustrated Example.

FIG. 1 is a sectional view showing an example of the air diffuser of the present invention;
Fig. 2 is an exploded perspective view showing an example of the aeration device of the present invention, and Fig. 3 is an enlarged sectional view showing an example of the aeration cloth used in the aeration device of the present invention. Processing tanks such as these are omitted in the drawing.

In the figure, 1 is a rectangular box-shaped holder with an opening on the top surface, 2 is an air pipe that communicates with one side of the holder 1, 3 is a frame-shaped gasket that comes into contact with the top surface of the holder 1, and 4 is the invention of the present invention. Diffusion cloth, which forms the main part of
6 is a frame-shaped holding plate placed in contact with the upper surface of the periphery of the diffuser cloth 4, and 6 is for fixing the gasket 3, the air diffuser cloth 4, and the holding plate 5 placed on the upper surface of the holder 1 in the above-mentioned order. This is a set screw. Further, 7 is a sealed chamber formed when the upper opening of the holder 1 is covered with the air diffuser cloth 4.

The diffuser cloth 4, which forms the main part of the present invention, has a double structure in which a synthetic resin film 9 having very fine pores with a pore diameter of 0.1 to 1 μm is laminated on the upper surface of a base cloth 8 having relatively coarse openings. It is becoming.

The base fabric 8 has flexibility, and may be a synthetic resin monofilament cloth, a synthetic resin multifilament cloth, a blended fabric of a synthetic resin monofilament and a synthetic resin multifilament cloth, a natural fiber cloth, felt, a nonwoven fabric, Alternatively, a material with a wire mesh enclosed therein for reinforcement is suitable, and a material having a thickness of about 0.7 to 2.5 mm is suitably used. As mentioned above, the synthetic resin film 9 is made of polyethylene, polypropylene,
Made of fluororesin, polyethylene terephthalate resin, etc., with a thickness of 10 to 30μ and an air permeability of 1 to 1.
20 c.c./cm ² /sec is preferably used.

The upper opening of the holder 1 is closed by the air diffuser cloth 4, and the pressurized gas sent through the air pipe 2 flows into the sealed chamber 7 below the air diffuser cloth 4.
As the pressure increases, the flow passes through the base cloth 8 forming the diffuser cloth 4, and reaches the synthetic resin film 9 attached to the upper surface while being divided, and is further finely divided by the fine pores of the film 9. As a result, it dissolves in the liquid to be treated in the treatment tank.

[Effect of idea]

Therefore, according to the present invention, the micropore diameter of the film in the aeration member that comes into contact with the liquid to be treated is 0.1.
Because it is extremely small at ~1μ, it is almost impossible for pollutants in the liquid to be treated to enter the micropores and cause clogging.Also, the material of the diffuser cloth is flexible, and it is much more flexible than conventional methods. Since it is thin, it is easy to handle, and it does not require a conventional torque wrench or the like to fix it to a holder, making it an easy-to-assemble and install air diffuser.

Furthermore, in the case of conventional ceramic diffuser members,
There was a problem in that the fixing bolts gradually loosened due to vibrations caused by the air blowing pressure, reducing the sealing performance, but according to the device of the present invention, the fixing screws loosen because the diffuser cloth has a certain degree of elasticity. This inconvenience can be resolved.

The diffuser cloth used in the present invention air diffuser is characterized by a double structure in which a synthetic resin film is laminated on the upper surface of the base cloth. This makes it possible to improve the solubility of gas in the liquid to be treated by several orders of magnitude.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the air diffuser of the present invention;
Figure 2 is an exploded perspective view showing an example of the air diffuser of the present invention, Figure 3 is an enlarged sectional view of an example of the diffuser cloth used in the air diffuser of the invention, and Figure 4 is an example of a conventional air diffuser. FIG. DESCRIPTION OF SYMBOLS 1... Holder, 2... Air pipe, 3... Packing, 4... Diffusion cloth, 5... Holding plate, 6... Set screw, 7... Sealed chamber, 8... Base fabric, 9... Synthetic resin film.

Claims (1)

[Scope of utility model registration request] In an aeration device attached to a lower position in a treatment tank for treating organic wastewater, etc., holes with a diameter of 0.1 to
This air diffuser is characterized by using a two-layer air diffuser cloth made of laminated synthetic resin films with very fine pores of 1μ.