JPH0217760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for preventing pulsation of fluid flowing in a piping system equipped with devices such as pumps and compressors that are sources of pulsation.

[Prior Art] Conventionally, piping systems are equipped with pumps, compressors, combustion burners, flow meters, valves, and other sources of pulsation. Resonance occurs when the natural frequency of the internal fluid and the frequency of the pulsation source are extremely close, resulting in various problems such as a reduction in compressor efficiency or damage to equipment due to piping system vibration.

Conventionally, various methods have been taken to prevent pulsation. To explain this, there are two methods: (a) changing the length of the piping to make the frequency of the pulsation source different from the natural frequency of the fluid in the piping, and (b) inserting an orifice in the middle of the piping to create fluid resistance. (c) installing a tank in the middle of the piping; and (d) installing a branch pipe in the piping.

However, in (a) above, resonance occurs when the frequency of the pulsation source changes and/or when the physical properties of the fluid change, and in (b), although the orifice acts as a resistance to the pulsating waves, , it also becomes a resistance to the average flow, and the pump,
The disadvantage was that the power consumption of the compressor increased. In addition, in the case of (c), it is necessary to install a large tank, leading to an increase in the production cost of the piping system, and in the case of (d), simply installing a branch pipe has a function to prevent changes in the frequency of the pulsation source or the physical properties of the fluid. There were some drawbacks.

Therefore, the inventor of the present invention first branched a branch pipe from the piping system that should prevent pulsating waves, and installed a resistor in this branch pipe that had a small reflectance against pulsating waves and a resistance coefficient larger than that of the piping system. The company provided a pulsation prevention device equipped with
42895).

FIG. 3 is a layout diagram of the piping system and pulsation prevention device shown in Japanese Patent Application No. 56-140919. Piping 2 is connected to the reciprocating compressor 1 and reaches the tank 3. A branch pipe 4 is branched from a position a of the pipe 2 near the reciprocating compressor 1, and a resistor 5 is installed inside the branch pipe 4.

This pulsation prevention device guides pulsating waves into a branch pipe having a large resistance coefficient and prevents an increase in pulsating pressure due to resonance by damping the branch pipe, and is extremely effective. Resistor 5 used for this
Since its constituent parts are distributed throughout the branch pipe, the reflectance against pulsating waves is small, but the resistance coefficient can be made sufficiently large. in this case,
It is disclosed that if the aperture ratio of the resistor is 40% or more, the reflectance is extremely small. Further, regarding the position of the piping system where the branch pipe branches, since it is effective to place the branch pipe at a position where the pulsating pressure is large, the branch pipe is usually branched from a position close to the reciprocating compressor.

Further, as a similar technique, Japanese Patent Publication No. 57-19286 discloses a silencer in which a double pipe is provided with a resistor.

[Problem to be solved by the invention]

The conventional pulsation prevention device described above is usually branched from a position near the reciprocating compressor, but there is no place to install a branch pipe near the reciprocating compressor, and the pulsation prevention device is installed at a position away from the reciprocating compressor. Preventive devices may have to be installed. In this case, the pulsating pressure is not necessarily high at the location where the branch pipe is branched. Therefore, a plurality of branch pipes may be branched from different positions, but this method has the disadvantage that the device becomes complicated. In addition, in the case of the silencer described in Japanese Patent Publication No. 57-19286, the wavelength of the sound is short and the straight propagation due to inertia is used, so there is a tube without a resistor and a tube with a resistor. There is a drawback that they must be installed alternately.

In view of the above drawbacks, the present invention does not increase the resistance of the piping system, does not reduce the effectiveness due to changes in the frequency of the pulsation source and/or changes in the physical properties of the fluid, and has a simple and inexpensive structure. The purpose of the present invention is to provide a pulsation prevention device.

[Means to solve the problem]

The pulsation prevention device for fluid in a piping system of the present invention includes a bypass pipe connected to a piping system including a pulsation source at a plurality of locations, and components distributed within the bypass pipe,
A resistor with a low reflectance and a resistance coefficient larger than that of the piping system so as not to substantially reflect the pulsating waves passing through the bypass pipe, or between the pipes of the piping system containing the pulsation source. An outer pipe that is inserted into and connected to the outer pipe and has a larger diameter than the piping of the piping system, an inner pipe that is installed inside the outer pipe parallel to the outer pipe so as to separate the fluid passing through the outer pipe, and an outer pipe that is inserted and connected to the outer pipe. The components are distributed and installed either between the inner pipe or inside the inner pipe, and the reflectance is small and the resistance coefficient is low so as not to substantially reflect the pulsating waves passing through the installed area. The resistor has a resistance coefficient larger than the resistance coefficient of the system.

[Effect]

In those having a bypass pipe, since there is resistance within the bypass pipe, the average flow of the fluid mainly passes through the pipes of the piping system. However, since the reflectance of the bypass pipe is low, the pulsating waves are also introduced into the bypass pipe and are attenuated by the resistance of the resistor, thereby suppressing the pulsation. In addition, even in the case where the inner tube and resistor are provided in the outer tube, the average flow of the fluid mainly passes through the flow path without the resistor, but the pulsating waves are also introduced to the part where the resistor is present and are attenuated. .

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a pulsation prevention device for fluid in a piping system according to the present invention.

A reciprocating compressor 1 and a tank 3 are connected by a pipe 2. The bypass 6 is connected to the positions b, b', and b'' of the pipe 2. A resistor 5 is installed in the bypass pipe. This resistor 5 is the same as described above. Each constituent part is installed in a distributed manner as shown in Figure 1, and the aperture ratio of each cross section of the resistor is made sufficiently large so as not to reflect pulsating waves (approximately 40% aperture ratio). However, since each part of the resistor 5 is distributed and installed in multiple stages, the resistance coefficient can be freely increased compared to that of the pipe 2. Also, b, b Both positions ′ and b″ are reciprocating compressor 1
are located far from, and all positions b,
Although the pulsating pressure is not necessarily large at positions b' and b'', it may be assumed that the pulsating pressure is large at any one of positions b, b', and b''.

Since a resistor 5 is installed inside the bypass pipe 6, most of the average flow flows through the pipe 2, but a small amount of the average flow also flows inside the bypass pipe 6. This means that there is no stagnation of gas in the bypass pipe 6, and the bypass pipe 6 is strong against corrosive gases.

Furthermore, since the pulsating waves are introduced into the bypass pipe 6 from any of the positions b, b', and b'' and are attenuated by the resistor 5, the pulsating pressure in the piping system will not increase due to resonance. do not have.

FIG. 2 is a block diagram showing another embodiment of the pulsation prevention device of the present invention.

Piping 2 and Piping 2 are between the reciprocating compressor 1 and tank 3.
They are connected by an outer tube 12 that connects between them. The outer tube 12 has a larger inner and outer diameter than the pipe 2, and the inner tube 7 is installed inside. Inside the inner tube 7, there is a resistor 5 whose constituent parts are distributed.

In this case, the characteristics of the inner tube 7, outer tube 12, and resistor 5 at position C are substantially equivalent to the characteristics at position b viewed from the reciprocating compressor 1 side in FIG. It can be said that this embodiment incorporates the bypass pipe 6 shown in FIG. 1 into the outer pipe 12. As disclosed in Japanese Patent Application No. 56-140919, the length of the inner tube 7 is set to be 1/16 or more of the pulsating wave whose pulsation is to be prevented.

Further, the functions and effects of this embodiment are the same as those shown in FIG. 2, but the external structure is simple, so there is an advantage that it can be easily kept warm and cold.

〔Effect of the invention〕

As explained above, in the present invention, a flow path is provided in the piping system that branches the main flow in addition to the main flow, and resistors having a low reflectance to pulsating waves and a large resistance coefficient are distributed in the flow path, so that the resistance The resistance of the resistor has the effect of preventing pulsation without causing the reflection of pulsating waves due to insertion of the body, and if the location where the resistor is installed is constructed with a double tube, in addition to the above effects, it is easy to keep warm and cold. It also has certain effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a pulsation prevention device for fluid in a piping system according to the present invention, and FIG.
FIG. 3 is a block diagram showing two embodiments of a pulsation prevention device, and FIG. 3 is a block diagram showing a conventional example. 1... Reciprocating compressor, 2... Piping, 3... Tank, 5... Resistor, 6... Bypass pipe, 7... Inner pipe, 12... Outer pipe.

Claims (1)

[Scope of Claims] 1. A bypass pipe connected to a piping system including a pulsation source at a plurality of points, and constituent parts distributed within the bypass pipe to reflect the pulsating waves passing through the bypass pipe so as not to be substantially reflected. A pulsation prevention device for a fluid in a piping system, which has a resistor having a small resistance coefficient and a resistance coefficient larger than the resistance coefficient of the piping system. 2 An outer pipe that is inserted between the pipes of the piping system that includes the pulsation source and has a larger diameter than the pipes of the piping system, and a Components are distributed between the inner pipe installed inside, the outer pipe and the inner pipe, or only inside the inner pipe, so that the pulsating waves passing through the installed area are not substantially reflected. A device for preventing pulsation of fluid in a piping system, which has a resistor having a small reflectance and a resistance coefficient larger than that of the piping system.