JP3060350B2 - Pipe water hammer prevention device by air valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing occurrence of water hammer in a water supply line using an air valve.

[0002]

2. Description of the Related Art It is well known that, for example, in a pipe of a pump, an abnormal stop of a pump due to a power failure or an abrupt closure of a discharge valve causes an abnormal decrease and an abnormal rise in pressure in a pipe. When the drop pressure falls below the saturated vapor pressure, the water column separates in the pipe line (a saturated vapor pressure cavity is formed), and when the water column is recombined (the cavity is collapsed), an abnormal pressure is generated.

Conventionally, various methods have been considered in order to prevent the water hammer phenomenon. For example, there is a method using an air valve as shown in FIG. That is, as shown in FIG. 4, the water supply pipe main pipe 1 and the air valve 3 are communicated via the communication pipe 4. Reference numeral 42 denotes an intermediate valve. When a negative pressure is generated in the main pipe 1, air is sucked from the air valve 3 to prevent the generation of the negative pressure. However, in this conventional apparatus, since the air in the pipeline is discharged quickly, there is a problem that the water column is recombined and an abnormal pressure rise occurs.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method in which an intake means and an exhaust means are connected to a water supply pipe main pipe.
It is provided through a communication pipe, and the exhaust resistance value is smaller than the intake resistance value.
In a pipeline water hammer prevention device that is larger than
The intake means consists of one or more large-diameter air valves and check valves
The exhaust means consists of one or more small-diameter air valves.
In which to obtain a pipe water hammer prevention device according to the air valve, characterized in that that.

[0005]

In the device of the present invention, by increasing the resistance at the time of evacuation, the evacuation can be made slow and the pressure rise at the moment when the water flow stops can be reduced. The pressure rise is expressed by the Alivier's formula, where ΔH is the pressure rise, g is the acceleration of gravity a, the sound velocity (the sound velocity in the water may be taken if the pipe is assumed to be a rigid body), ΔV is the change in the flow velocity, It is represented by

By increasing the exhaust resistance and slowing the exhaust, ΔV can be reduced, and thereby ΔH can be reduced.

[0007]

FIG. 1 shows a first embodiment of the present invention, in which a water pipe main pipe 1, large-diameter air intake valves 21 and 22, and small-diameter exhaust air valves 31 and 32 are communicated by a communication pipe 4. Have been. 4
1 is a check valve inserted between the main pipe 1 and the large-diameter intake air valves 21 and 22, and the air valves 21 and 22 are dedicated to intake. Reference numeral 42 denotes a valve provided on the communication pipe 4.

FIG. 2 shows a second embodiment, in which a main pipe 1, intake air valves 21 and 22, and an exhaust air valve 31 are connected by a communication pipe 4 . A check valve 41 is inserted between the intake air valves 21 and 22 and the main pipe 1, and a throttle (orifice, throttle valve, etc.) is provided between the exhaust air valve 31 and the main pipe 1 to reduce the exhaust resistance. Is growing. Therefore, the air valves 21 and 22 are dedicated to intake.

In the first embodiment shown in FIG. 1, the exhaust air valve is made smaller in diameter than the intake air valve to increase the exhaust resistance. In the second embodiment shown in FIG. 2, the throttle 5 (orifice, throttle valve, etc.) is used. ) Increases the exhaust resistance. Various other means are also conceivable, such as increasing the resistance value of the pipe on the exhaust valve side of the communication pipe 4.

Although not shown, a check valve may also be attached to the air valve on the exhaust side to be dedicated to exhaust. FIG. 3 shows a construction example using the water hammer prevention device of the present invention. 1 is a main pipe of a water supply conduit, 21 is a large-diameter intake air valve 31, 32 is a small-diameter exhaust valve, 4 is a communication pipe that communicates the valves 21, 31, 32 with the main pipe 1, and 41 is an intake air valve 21 And a check valve inserted between the communication pipe 4 and the valve 21 is dedicated to intake. 42
Is a valve provided in the communication pipe 4.

[0011]

The present invention has the above-described configuration, and has an empty space.
By giving a difference in diameter of the valves, so are to increase the exhaust resistance value than the intake resistance, the exhaust is performed slowly, it is possible to suppress the speed increase of the tube lower, compared
It is possible to prevent an abnormal pressure rise with a simple configuration .

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a pipeline using the present invention.

FIG. 4 is a view showing a conventional water hammer prevention device.

[Explanation of symbols]

1 conduit present pipe 5 stop 21 intake air valve 31 the exhaust air valve 41 check valve 42 valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP 3-60690 (JP, U) JP 61-626 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 24/00 F16L 55/04

Claims (1)

(57) [Claims] 1. A pipe water hammer prevention device in which an intake means and an exhaust means are provided in a main pipe of a water supply pipe via a communication pipe and an exhaust resistance value is larger than an intake resistance value. means is composed of a 1 pc or more large diameter air valve and the check valve, the exhaust means pipeline water hammer prevention equipment by air valve, characterized in that it consists of 1 pc or more air valves small diameter.