JPH01176893A - Water hammer absorber - Google Patents

Abstract

PURPOSE:To absorb back pressure produced upon abrupt blocking of fluid through a pressure reduction chamber by providing a restricted section at a flow path hole and communicating the restricted section with the pressure reduction chamber formed at the outside of the flow path hole. CONSTITUTION:A partially restricted flow path hole 2 is formed in a body 1 and a pressure reduction chamber 3 is formed at the outside of the flow path hole 2. The pressure reduction chamber 3 is formed around the flow path hole 2 which is enclosed air-tightly by means of an outer tube 4. A plurality of through-holes 5 are made, as a penetrating section, between the restricted section of the flow path hole 2 and the pressure reduction chamber 3 with same interval, and the flow path hole 2 and the pressure reduction chamber 3 are communicated at the restricted section.

Description

Detailed Description of the Invention (Industrial Application Field) This invention is a water hammer that is installed in a fluid flow path to prevent water hammer from occurring when the flow of fluid is abruptly interrupted. It concerns absorbers.

(Prior Art) When the flow of fluid is abruptly interrupted, an extremely large back pressure is instantaneously generated, compressing the fluid, and this compressed fluid becomes water hammer, causing water hammer. In recent years, one-touch type faucets have become popular, but in these one-touch type faucets, the fluid flow is always cut off suddenly, which tends to cause water hammer, and a solution to this problem is desired. There is.

As a means to eliminate such water hammer, a buffer tank is connected to the outside of the pipe that serves as the fluid flow path, and an air chamber partitioned with a flexible film is formed within the buffer tank, so that it can be used when the fluid flow is suddenly cut off. A system has been proposed in which the compressed fluid is released into a buffer tank to alleviate the pressure rise.

(Problem to be Solved by the Invention) In the conventional device described above, when the back pressure (static pressure) in the fluid flow path is lower than the air pressure sealed in the buffer tank, it is difficult to absorb the back pressure. could not. Furthermore, when the back pressure in the fluid flow path is greater than the air pressure, the back pressure is absorbed until the equilibrium point between the back pressure and the air pressure;
The amount exceeding the equilibrium point could not be absorbed.

(Means for Solving the Problems) The present invention provides a water hammer absorber that is installed in a fluid flow path, and a water hammer absorber that surrounds the flow path hole that constitutes a part of the fluid flow path. The above-mentioned conventional problems are solved by forming the decompression chamber in an annular shape, and by forming a through part that penetrates between the narrowed part formed in the flow passage hole and the decompression chamber.

(Operation of the Invention) In the water hammer absorber of the present invention, the flow passage hole is narrowed, and a penetrating portion with the decompression chamber is formed in the narrowed portion. Therefore, during normal fluid flow, the fluid passes through the constriction part as a high-speed flow, so suction pressure is generated and the pressure in the penetration part and the decompression chamber is reduced. Then, when the flow is abruptly interrupted while the pressure in the vacuum chamber is reduced, the compressed fluid flows into the vacuum chamber, which has been reduced in pressure to eliminate the pressure increase. Therefore, if the capacity of the decompression chamber is set to be commensurate with the pressure increase at the time of sudden shutdown, the back pressure will be almost completely absorbed by the decompression chamber, and the occurrence of water hammer will be prevented.

Embodiments of the present invention will be described below based on the drawings.

(Example 1) In FIG. 1, a partially constricted channel hole 2 inside the main body 1
is formed, and a decompression chamber 3 is formed outside the flow path hole 2. The decompression chamber 3 is formed in an annular shape so as to surround the passage hole 2, and the outside of the passage hole 2 is hermetically closed by an outer cylinder 4.

A plurality of through holes 5 are formed at equal intervals in an annular manner as penetration parts between the narrowed part of the passage hole 2 and the decompression chamber 3, and the passage hole 2 and the decompression chamber 3 communicate with each other at the contact part. ing. Further, the front and rear portions of the narrowed portion of the flow passage hole 2 are tapered toward the inflow side opening 6 and the outflow side opening 7. The taper angle α toward the outflow side opening is about 3 degrees.

In the above, the capacity of the decompression chamber 3 needs to be large enough to absorb almost all the back pressure that occurs when a sudden shutdown occurs, taking into consideration the flow rate and the diameter of the fluid flow paths (pipes) connected before and after.

When the water hammer absorber of this embodiment is inserted into a fluid flow path and fluid is allowed to flow, the fluid passes through the constriction at high speed, creating suction pressure. Further, since a through hole 5 communicating with the decompression chamber 3 is opened in the contact portion, the pressure in the decompression chamber 3 is reduced.

Next, when the faucet is suddenly shut off, back pressure is applied to the fluid, but since the pressure in the vacuum chamber 3 is low, the fluid enters the vacuum chamber 3, which is a low pressure section, regardless of the magnitude of the back pressure. Therefore, fluid compression hardly occurs and water hammer is prevented. In this way, the decompression chamber 3
The fluid that has entered will be sucked into the flow path 2 by the reduced pressure in the narrowed portion when the fluid is caused to flow next time.

By the way, the water pressure when stopped is 3 kg/cd, and the water pressure when flowing is 1°5.
kg/co! When the device of this embodiment was installed in the water flow path with a water pressure of 10 kg/aaO at the time of rapid cut-off, the water pressure at the time of sudden cut-off was 3 k.
g/aJ, and no water hammer occurred.

Here, in the above embodiment, the taper angle α of the channel hole 2 is
is about 3 degrees, but if the angle α is about 3 degrees or less, the flow passage hole 2 acts as a Venturi tube, and the pressure loss due to passage through the narrowed portion can be made as small as possible. However, the shape of the flow passage hole 2 only needs to generate suction pressure to the extent that the pressure reduction chamber can be depressurized by the narrowed portion, and the specific shape of the narrowed portion can be appropriately selected within that range.

(Embodiment 2) Next, in the embodiment shown in FIG. 2, the penetrating portion between the channel hole 2 and the decompression chamber 3 is an annular penetrating groove 8.

In addition, in the first embodiment, the water hammer absorber was constructed by combining the main body 1 and the outer cylinder 4, but in this embodiment, the outer cylinder 4 has an outlet side cylinder 9 as an example.
A water hammer absorber is constructed by fitting the inflow side cylinder 10 on the other side, and both the cylinders 9 and 10
The gap between the tips is defined as a through groove 8.

(Effects of the Invention) According to the present invention, the passage hole is provided with a narrowed part, and the narrowed part is communicated with the decompression chamber formed outside the flow passage hole. Can be automatically depressurized. The reduced pressure chamber absorbs the back pressure generated when the fluid is abruptly shut off, regardless of its magnitude.

Therefore, even in the event of sudden shutoff, the fluid is not extremely compressed, and water hammer can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of the invention, and FIG. 2 is a sectional view of a second embodiment. 1... Main body 2... Channel hole 3... Decompression chamber 4... Outer cylinder

Claims (1)

[Scope of Claims] 1. A water hammer absorber installed in a fluid flow path, which comprises: a flow path hole having a narrowed portion; a decompression chamber formed in an annular shape outside the flow path hole; The water hammer absorber 2 has a through hole that penetrates the flow path hole and the decompression chamber, and the through hole is formed in the narrowed part of the flow path hole. The water hammer absorber 3 according to claim 1 is formed into a groove, and the flow hole is tapered at an inclination angle of about 3 degrees from the narrowed portion toward the outflow side opening. Water hammer absorber as described