JPS59194194A - Pressure pulsation absorber for piping system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a device for absorbing pressure pulsations in a piping system.

[Background of the invention]

In general, when pressure pulsations generated by driving a fluid machine such as a pump are transmitted to a piping system, the piping system and noise are generated. For example, in pump equipment, water pressure pulsations occur when the impeller blades pass through the discharge volute inlet, that is, pulsations with a frequency equal to the number of blades x rotation speed, and this pulsation propagates through the water column in the piping and It makes the whole thing vibrate and makes noise.

Various types of pulsation absorbing devices are used to deal with the occurrence of pulsation as described above. For example, installing a branch pipe with a wavelength 174 times the pressure pulsation generated in the piping system in the middle of the piping, or attaching a flexible material such as rubber to a part of the inner surface of the piping.
There are methods of absorbing pulsation by vibration of this part. By the way, as a pressure pulsation absorbing device, it is desirable to have a compact device that does not require a large installation space, and that is made of strong materials and structure and has excellent durability.

The conventional pressure pulsation absorbing device will be explained with reference to FIG.
A closed chamber 2 is connected to the middle of the piping 1, and the chamber 2 and the piping 1 are connected to a connecting portion 3 having a length L1 and a cross-sectional area a.
are connected via. When this chamber 2 is filled with the liquid in the pipe 1, the eigenvalue fII of the pressure pulsation in the chamber 2 is as follows. Here, C is the indoor compliance, K is the cross-sectional area of the connection, ■ is the volume of the chamber, and L/ is the length of the connection including the terminal correction.

When the above-mentioned eigenvalue fn matches the frequency of pressure pulsations transmitted through the piping system, the interior of the room resonates, and the pressure pulsations transmitted through the piping system are significantly reduced. A pressure pulsation absorbing device based on this principle has been put into practice for air piping systems, but it is not suitable for liquid piping systems that transport clean liquids. This is room 2 and pipe 1
Since the cross-sectional area of the connecting portion 3 of 8 is small, there is a problem that the liquid in the chamber 2 stagnates for a long period of time and deteriorates in quality.

For example, if the above-mentioned pulsation absorbing device is installed in pump piping for waterworks or chemical liquids, it is undesirable for the liquid that has been stagnant inside for a long time to flow out into the piping due to hygiene reasons or problems with chemical fishing force. It is something.

[Purpose of the invention]

The object of the invention is to prevent the flow member from becoming lodged in a closed chamber which absorbs pressure pulsations and which is connected to the piping via a capillary.

[Summary of the invention]

This invention is constructed by arranging at least two capillary tubes in the direction of fluid flow in the entire piping that connects the closed chamber and the piping so that a pressure difference is created between each capillary tube, thereby closing off fresh liquid constantly flowing inside the piping. By supplying the liquid to the chamber, the problem of liquid stagnation and deterioration in the chamber is eliminated.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 2 to 4.

In FIG. 2, the closed chamber 2 is a thin tube 3a.

It is connected to the outside of the pipe 1 via 3b4. The thin tubes 3a and 3b are arranged to be inclined in different directions with respect to the flow direction of the fluid in the pipe 1.

In the figure, the angle θa between the thin tube 3a and the fluid flow direction of the pipe 1 is θa + 90°, and the angle θb between the thin tube 3b and the fluid flow direction of the pipe 1 is θb>90°. . Therefore, when fluid is flowing in the direction of the arrow in the pipe 1, the pressure at point A of the pipe 3a is higher than the pressure at point B of the thin tube 3b. Therefore, the fluid at point A flows into the closed chamber 2, and the same amount of fluid flows out to point B. Therefore, the fluid in the closed chamber 2 does not stagnate but always flows due to the pressure difference.

As a result, fresh fluid in the pipe 1 is constantly guided to the closed chamber 2, thereby preventing the fluid from corroding or deteriorating due to stagnation.

FIG. 3 shows another embodiment of the invention. In this case, a closed chamber 2 is arranged around the outer periphery of the pipe 1, and thin tubes 3a and 3b are provided to protrude from the inner surface of the pipe 1, and the protruding ends C and C' of the thin tubes 3a and 3b are are inclined in different directions with respect to the flow direction of the fluid within. That is, the angle θ1 between the normal direction of the end surface C of the thin tube 3a and the flow direction of the fluid in the pipe 1 is θa - 90°, and the angle θ1 between the normal direction of the end surface C' of the thin tube 3b and the flow direction of the fluid in the pipe 1 is The angle θb formed with the flow direction is θb)90', and the same effect as in the embodiment shown in FIG. 2 can be achieved.

Further, FIG. 4 shows still another embodiment of the present invention.

In this case, as in the embodiment shown in FIG. 3, a closed chamber 2 is arranged around the outer periphery of the pipe 1 and communicated with the pipe 1 through thin tubes 3a and 3b. Protrusions are provided on the downstream side of the thin tube 3a and the upstream side of the thin tube 3b of the piping 1, respectively. As a result, when the fluid in the pipe 1 flows in the direction of the arrow, a pressure difference can be created in which the pressure at point A of the thin tube 3a is higher than the pressure at point B of the thin tube, as shown in FIGS. 2 and 3. Almost the same effect as the example can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, at least two thin tubes connecting the closed chamber that absorbs pressure pulsations and the piping are arranged in the direction of fluid flow in the piping, so the liquid in the closed chamber is always fresh. Corrosion or deterioration of fluid due to stagnation can be prevented.

[Brief explanation of drawings]

FIG. 1 is a front view showing a conventional pressure pulsation absorbing device, and FIGS. 2 to 4 are partially sectional front views showing the pressure pulsation absorbing device of the present invention. 1...Piping, 2...Room, 3...Connection. Agent Patent Attorney Akio Takahashi (7) No. 18 Fig. 2 Fig. 3 ■ Fig. 4

Claims (1)

[Scope of Claims] 1. In a pressure pulsation absorbing device for a piping system in which a closed chamber for absorbing pressure pulsations is connected to piping via a thin tube, a thin tube that connects the closed chamber to the entire piping is connected to the piping. Absorbing pressure pulsations in a piping system, characterized in that at least two thin tubes are arranged in the fluid flow direction so that a pressure difference is created between each thin tube, and the fluid in the closed chamber is circulated through the piping. Device. 2. At least two thin tubes connected to the piping are inclined in different directions with respect to the flow direction of the fluid in the piping to create a pressure difference between them and the thin tubes. The pressure pulsation absorbing device for a piping system according to item 1. 3. The end surfaces of at least two capillary tubes connected to the piping are provided to protrude into the piping, and the end surfaces of the capillary tubes are inclined in different directions with respect to the flow direction of the fluid in the piping, so that the end surfaces of the capillary tubes are connected to the piping. The pressure pulsation absorbing device for a piping system according to claim 1, characterized in that a pressure difference is generated between the piping system. 4. The piping according to claim 1, characterized in that a projection is provided at the upstream or downstream portion of the inner surface of the pipe of at least two thin tube openings connected to the pipe to create a pressure difference between the thin tubes. System pressure pulsation absorber.