JPH0671288A - Diffuser - Google Patents

Abstract

PURPOSE:To provide a diffuser capable of being assembled without variance and without the membrane rubber being detached from a holder in aeration. CONSTITUTION:The upper surface of a discoid holder 1 provided with an air ejection nozzle 2 at its center is coated with a circular membrane rubber 3 having many slits to constitute a diffuser. An annular recess 5 is formed in the peripheral end face of the rubber 3, and a metallic band 4 is engaged with the recess 5. The recess 5 is aligned with the peripheral end face of the holder 1, and the clamping force of the band 4 is exerted precisely on the holder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffuser which is installed at the bottom of an aeration tank to diffuse air into treated water.

[0002]

2. Description of the Related Art As a diffuser for air diffusion as described above, as shown in FIG. 3, a circular disk is formed on the upper surface of a synthetic resin disk-shaped holder 12 having an air jet nozzle 11 in the center. There is known a structure in which the membrane rubber 13 is covered. This membrane rubber 13 has fine slits formed all over its surface, and it is a nozzle for air ejection.
When compressed air is supplied from 11, the membrane rubber 13 swells in a dome shape, the slits are opened, and the compressed air becomes fine bubbles and is discharged into water.

However, the conventional diffuser has a structure in which the holder 12 is covered with the membrane rubber 13 in a tensioned state as shown in FIG. Occasionally, there was an accident that 13 came off holder 12.

[0004]

The present invention has been completed to solve the above-mentioned conventional problems, and to provide a diffuser in which there is no risk of the membrane rubber coming off from the holder during aeration, and variation during assembly is less likely to occur. It was done.

[0005]

DISCLOSURE OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, has a circular membrane rubber having a large number of slits on the upper surface of a disk-shaped holder having a nozzle for ejecting air in the center. In the diffuser covered with,
An annular recess is formed on the peripheral end surface of the membrane rubber so as to correspond to the width of the peripheral end surface of the holder, and a band is fitted into the annular recess.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the embodiments shown in FIGS. In these figures, 1 is a disc-shaped holder made of synthetic resin having an air ejection nozzle 2 in the center, 3 is a membrane rubber made of ethylene-propylene rubber or the like attached to the upper surface of the holder 1, and 4 is A metal band for fixing the peripheral end surface of the membrane rubber 3 to the holder 1. Compared with natural rubber, ethylene-propylene rubber has the advantages of superior water resistance and aging resistance and less variation in physical properties. Among them, if you choose a hardness of 45 degrees, you can process ethylene-propylene rubber more than other hardnesses of ethylene-propylene rubber. Excellent in performance and permanent elongation, and also excellent in product uniformity and durability.

As shown in the drawing, the peripheral end surface of the holder 1 is bent to be slightly wider than the other portions,
In the embodiment, the thickness of the main body of the holder 1 is 3 mm, while the peripheral end surface of the holder 1 has a width of 10 mm. Further, the peripheral end portion of the membrane rubber 3 is bent downward in a U-shaped cross section, and is fitted to the peripheral end face of the holder 1 from the outside by utilizing the elasticity of the rubber. An annular recess 5 is formed on the peripheral end face of the holder 3 at a position substantially corresponding to the width of the peripheral end face of the holder 1. In the embodiment, the width of the annular recess 5 is 13 mm, and the stainless steel band 4 having a width of 13 mm is fitted inside the annular recess 5.

Fine slits 6 are concentrically formed on the entire surface of the membrane rubber 3. This is to ensure that the rubber stretches during aeration evenly and at low pressure. It should be noted that when ventilation is stopped, the gap between the slits is instantly closed by the external pressure and the elasticity of the rubber itself, and the dirty water is prevented from entering the diffuser. Therefore, the length and interval of the slits 6 are set so as to exhibit this performance. Further, in this embodiment, as shown in FIG. 2, a portion without the slit 6 is formed in the central portion of the membrane rubber 3. An annular projection 7 is formed on the peripheral edge of the air jet nozzle 2 of the holder 1, and when compressed air is not supplied to the air jet nozzle 2, as shown by the solid line in FIG. When pressed, the portion of the membrane rubber 3 without the slit 6 comes into close contact with the protrusion 7,
Water is prevented from flowing backward to the air jet nozzle 2 doubly.

[0009]

The diffuser of the present invention constructed as described above is used by being attached to the bottom of an aeration tank or the like, and when compressed air is supplied from the air jet nozzle 2 of the holder 1, the membrane rubber 3 will be drawn. It is the same as in the prior art that the compressed air is bubbled from the slit 6 of the membrane rubber 3 into water as shown in FIG.

However, in the present invention, since the annular recess 5 is formed on the peripheral end face of the membrane rubber 3 so as to correspond to the width of the peripheral end face of the holder 1, and the band 4 is fitted into the annular recess 5, the band is fitted. The position of 4 is accurately determined, and there is no variation during assembly. Further, since the tightening force of the band 4 acts on the peripheral end surface of the holder 1 at a right angle, the membrane rubber 3 is not likely to come off from the holder 1 during aeration.

[0011]

As described above, in the diffuser of the present invention, the position of the band is accurately determined, so that there is no variation during assembly. Further, in the diffuser of the present invention, there is no fear that the membrane rubber will come off from the holder during aeration. Further, since the setting that the membrane rubber is slightly tensioned with respect to the holder can be maintained, it is possible to secure the foaming performance during aeration and the effect of preventing backflow of water when ventilation is stopped. Therefore, the present invention has an extremely great contribution to industrial development as a diffuser that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional diffuser.

[Explanation of symbols]

 1 Holder 2 Air Nozzle 3 Membrane Rubber 4 Band 5 Annular Recess 6 Slit

Claims (1)

[Claims] 1. A diffuser in which a circular membrane rubber having a large number of slits is covered on the upper surface of a disk-shaped holder having a nozzle for ejecting air in the center, and the peripheral end surface of the membrane rubber has the width of the peripheral end surface of the holder. The diffuser is characterized in that an annular recess is formed corresponding to the above, and a band is fitted into the annular recess.