JPH06696Y2 - Check valve for air diffuser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a check valve in an air diffuser used in a wastewater treatment aeration tank or the like.

[Conventional technology and its problems]

In a general air diffuser without a check valve, when the air supply is stopped, sewage flows back to the air diffuser and collects in the air supply pipe. When the air supply is restarted, the accumulated wastewater passes through the air diffuser in the direction opposite to the inflow direction and is discharged to the aeration tank, and then becomes in the air diffused state.

In recent air diffusers, hard porous materials with fine pores are often used, and when dirty water passes through the fine pores when the air diffuser is stopped or restarted, it acts as a filter and floats in the dirty water. As a result, clogging is promoted, and the replacement time of the hard porous material is shortened. This is a serious problem in the wastewater treatment plant because it interrupts wastewater treatment and increases replacement costs.

Therefore, an attempt has been made to provide a check valve in the air diffuser to prevent backflow of sewage when the operation is stopped, extend the life of the air diffuser, and reduce the wastewater treatment cost. However, some of the air diffusers currently on the market have a built-in check valve, but the air diffusers without a check valve are the mainstream, including those actually in operation at the wastewater treatment site.

Further, the air diffuser with a built-in check valve has a drawback that the check valve must be replaced together when the air diffuser is replaced.

[Means for Solving the Problems]

With this in mind, the present inventor aims to provide a check valve for an air diffuser that can be easily attached to an air diffuser without a check valve by a general piping method and can be improved to an air diffuser with a check valve. The present invention has been completed.

That is, according to the present invention, ventilation holes are provided on one end surface and an inner peripheral surface, and the other end of an opening of a cylindrical case having a spherical valve body inside is provided with an elastic O-ring having an inner diameter smaller than the diameter of the spherical valve body. The checker is designed to be inserted into and connected to the valve seat to integrate the cylindrical case with the valve seat, and the spherical valve body is brought into contact with the elastic O-ring to close the air supply hole.
A check valve for an air diffuser, which is inserted into an S standard nipple and fixed to an inner surface of the nipple at a valve seat portion. Here is the JIS standard nipple
Refers to JIS B2301.

The air diffuser equipped with the check valve of the present invention has an advantage that the check valve does not need to be replaced.

Since the check valve for the air diffuser according to the present invention is manufactured mainly by using a nipple, which is a JIS standard piping material that is generally commercially available, no special technique is required in the general piping method, and the air diffuser is not required. If it is possible to attach it to.

The check valve for an air diffuser according to the present invention is provided with a threaded portion on the inner surface of a JIS standard nipple that is generally commercially available, and is provided with a valve seat 7, a spherical valve body 8, a case 6, and other members as shown in FIG. The assembled chuck part is screwed into and fixed to the nipple 15 as shown in FIG.

The check valve for the air diffuser causes a pressure loss during air supply. Within the practical air supply range of the air diffuser, there will be no problem if the pressure loss does not hinder practical use, but depending on the design of the check valve, there may be a pressure loss that is more than necessary. Need to be designed. For example, in FIG. 3, the diameter of the air supply hole 11, the outer diameter of the spherical valve body 8, the diameter and position of the vent holes 9 and 9'of the case 6, and the size of the clearance 16 between the inner wall of the nipple and the case 6 are pressure loss. Since these are factors that influence the value of, it is necessary to pay attention to these points in design.

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Embodiment 1 An embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is an assembly diagram of a check valve for an air diffuser according to the present invention. As the nipple, a commercially available JIS standard octagonal nipple 15 is used. The shape and size of the nipple are determined by the pipe of the air diffuser, but 25 A size nipples are generally used, so in this example, 25 A size nipples of the same diameter were used.

The structure of the check valve for the air diffuser according to the present invention is roughly divided into (i) nipple part and (ii) check part, and the check part is further divided into (i) valve seat, (b) spherical valve body, and (c). Subdivided into cases.

Nipple part is JIS standard octagonal 25A nipple with the same diameter; Material SU
As for S 304, an M-26 fine screw 17 was cut on the inner surface on the left side in FIG. 3, and the commercially available size was modified so that the right side was φ26 mm. The M-26 fine screw 17 is for fixing the check part of FIG. 2 by screwing in, and there is a method of using an adhesive other than the screw, but there is a problem of water resistance of the adhesive, peeling due to thermal expansion / contraction, etc. However, it is preferable to fix the chuck part with a screw because of the difficulty of maintenance such as replacement of parts of the chuck part.

The modification of the inner diameter to φ26 mm on the right side is to minimize the pressure loss due to air supply, and the larger the diameter, the better, but due to the mechanical strength of the nipple, it was machined to φ26 mm.

In FIG. 2, the valve seat 7 and the case 6 are made of ABS resin by machining. In this embodiment, the ABS resin is used, but other synthetic resins or metals may be used without any problem in terms of function, and the material may be determined from the difficulty of processing.

The valve seat 7 has a ventilation hole 11 penetrating through the center of the valve seat with φ11 mm,
An M-26 fine taper screw 12 for screwing and fixing in the nipple is provided on the outer circumference, and an M-20 fine screw 14 for screwing and fixing the case is provided inside.

As shown in Fig. 2, the case 6 has an opening of φ14mm on one side.
Ventilation hole 9 of φ9 mm is provided on the other end surface, four ventilation holes 9 ′ of φ9 mm are provided on the inner peripheral surface in the middle of the case, and M-20 fine screw 13 is processed on the outer circumference on the opening side. It is screwed and fixed to the valve seat 7. The vent hole 9'has an influence on the pressure loss of the blown air, and it is preferable that the vent hole 9'be larger.

Fluororesin true spheres (φ12.7 mm) were used for the spherical valve body 8, and P-11 (inner diameter 10.8 mm) was used for the sealing O-ring 10. The O-ring 10 is fitted into the valve seat 7 to form the spherical valve body 8
After inserting, the case 6 was screwed and fixed to complete the check part. The position of the vent hole 9'was set to the place where the ventilation resistance was minimized.

The completed M-26 fine taper screw 12
A normal sealing tape was wrapped around, and the chuck part was fixed by screwing it into the M-26 fine taper screw 17 of the nipple, and the check valve for the air diffuser with the piping size of 25 A of the present invention was completed.

Example 2 The check valve for the air diffuser obtained in Example 1 is attached to a scattering cylinder 4 made of a synthetic resin porous body which is generally used. As shown in FIG. A blower pipe 20 made of a transparent pipe was attached to the other end of, and the backflow state of water in the tank was observed in the test tank 19. In addition, as a comparison, the same test was performed using a normal dispersion cylinder without a check valve.

As a result, in the case of a normal diffuser cylinder without a check, when the ventilation was stopped, the water in the tank was filled from the diffuser cylinder to the point 21 of the blower pipe 20. On the other hand, in the case of the scattering cylinder 18 equipped with the check valve of the present invention, the water in the tank is scattered when the ventilation is stopped.
Although it flowed back inside, it did not penetrate into the blower pipe 20. Blast pipes in an actual wastewater treatment plant have, for example, a pipe size of 50.
Since it is about 5 m for A, the difference in the amount of backflow water will clearly appear depending on the presence or absence of the check valve, which helps prevent clogging of the scattering cylinder.

The relationship between the ventilation amount and the ventilation resistance of the check valve for the air diffuser completed in Example 1 was measured by the flow shown in FIG. That is, in FIG. 5, reference numeral 26 is a check valve, and air from the blower 22 is adjusted by the control valve 23 and the area type flow meter 24, and the instruction of the pressure gauge 25 is read to be the ventilation resistance.

The result is shown in FIG.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an air diffuser with a check valve, to which the check valve for an air diffuser of the present invention is attached, and FIG. 2 is a cross section of a check portion of the check valve for an air diffuser of the present invention. FIG. 3 is a schematic cross-sectional view of a check valve for an air diffuser of the present invention, FIG. 4 is a schematic view of an apparatus for testing the reverse flow condition of water in a tank, and FIG. FIG. 6 is a graph showing the amount of air flow and ventilation resistance for investigating the relationship between FIG. 1 ... Check valve for air diffuser according to the present invention 2 ... Holder of diffuser cylinder 3 ... Branch pipe of blower pipe 4 ... Cylinder 5 ... Blower pipe 6 ... Case 7 ... Valve seat 8 ... Spherical valve body 9, 9 '... Vent hole 10 ... O-ring 11 ... Air supply hole 12 ... Taper screw (valve seat side) 13 ... Taper screw (valve seat side) 14 ... Taper screw (case side) 15 ... Nipple 16 ... Nipple inner wall and case clearance 17 ... Taper screw (nipple side) 18… Scattering cylinder with check valve 19… Test tank 20… Air pipe 21… Water point in tank 22… Blower 23… Control valve 24… Flowmeter 25… Pressure gauge 26… Book Invented check valve

Claims (1)

[Scope of utility model registration request] 1. A ventilating hole is provided on one end surface and a circumferential surface, and the other end of an opening of a cylindrical case having a spherical valve body therein is provided with an elastic O-ring having an inner diameter smaller than the diameter of the spherical valve body. In the JIS standard nipple, there is a check part that is inserted and connected to the valve seat to integrate the cylindrical case with the valve seat, and the spherical valve body closes the air supply hole by contacting the elastic O-ring. A check valve for an air diffuser, which is inserted and fixed to the inner surface of the nipple at a valve seat portion.