JPH0143876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a low-noise valve capable of reducing and preventing noise generated by fluid pressure reduction, high-speed fluid flow, etc.

[Prior art]

In general, when a valve provides resistance to the flow of fluid, undesirable noise may be generated due to flow turbulence occurring at the throttle portion of the valve. Second
The figure is a vertical cross-sectional view of a conventional cage valve shown to explain this noise generation. To explain this based on the figure, the valve body 1 has an upstream passage 3 and a downstream side separated by a partition wall 2. A cylindrical cage 7 and a seat ring 8 are disposed between the partition wall 2 and the top cover 6, which is fitted into the upper opening end of the top cover 6 and fixed with bolts 5. ,10
It is fitted through. On the peripheral wall of cage 7,
A plurality of windows 11 are opened to communicate the inside of the cage 7 and the upstream channel 3, and the windows 11 are formed into a substantially T-shape with a wide part and a narrow part. Further, a lower open end of the seat ring 8 is opened to the downstream flow path 4 . A valve rod 1 is slidably inserted into the inner hole of the cage 7 through the upper lid 6 via a gasket 12.
A valve plug 14 attached to the lower end of the seat ring 8 is slidably fitted, and the lower end of the valve plug 14 seats on a valve seat 15 provided at the upper end opening of the seat ring 8 when fully closed. An underwear seat portion 16 is provided. Further, a valve seat 1 formed on the inner peripheral surface of the cage 7 is provided on the outer peripheral portion of the upper end of the valve plug 14.
7 is provided with an upper seating portion 18 on which to sit when fully closed.

In such a configuration, when the valve stem 13 is moved up and down by the actuation of the drive unit by the automatic control device or by manual operation, the valve plug 14 moves together with the valve stem 13 to change the opening degree of the window 11, that is, the opening area. is changed, thereby controlling the flow rate of the controlled fluid flowing from the upstream flow path 3 through the window 11 of the cage 7 and the seat ring 8 to the downstream flow path 4.

[Problem that the invention seeks to solve]

In the flow rate control using the cage valve as described above, when fluid flows from the window 11 downward to the valve plug 14 while being depressurized as shown by the arrow, the inflowing fluid entrains the surrounding fluid and causes turbulence. As a result, high frequency noise is generated. Furthermore, this noise also propagates to the downstream piping section, so there is a drawback that it leaks outside and aggravates the situation.

Therefore, in the past, patent application No. 51-040930, patent application No. 51-040930,
No. 050614 etc., noise is reduced by filling spheres into both the upstream and downstream channels 3 and 4, inside the valve plug 14, and inside the cylindrical housing provided below the seat ring 8 to reduce the kinetic energy of the fluid. There have been proposals to prevent the occurrence of noise, but none of them can be expected to have a satisfactory silencing effect, and it is said that if the silencing part is unavoidably lengthened in order to increase the silencing effect, the entire valve will become larger. There were flaws. In addition, various low-noise valves other than those filled with spheres have been proposed, but no effective results have been obtained with these.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a low-noise valve that can reliably prevent the generation of noise.

[Means for solving problems]

In the low-noise valve according to the present invention, the flow path on the downstream side of the valve body is formed substantially concentrically with the cylindrical cage, and this flow path is partitioned by a partition plate made of a plurality of perforated plates. In between, a sound-deadening filler is filled so that the shape and size of the filler gradually increases from the upstream side to the downstream side.

[Effect]

In the present invention, since the gaps in the complicated flow path between the sound-absorbing packing bodies gradually increase from the upstream side to the downstream side, the volume of the fluid is increased,
Suppress and prevent noise generation.

Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

FIG. 1 is a longitudinal sectional view showing an embodiment of a low noise valve according to the present invention. In the figure, the valve body 22 of the low-noise valve 21 is provided with an upstream flow passage 23 that opens horizontally and is flanged to an upstream pipe line (not shown). The upper cover 24 is joined to the opening, and the bolts 25 and nuts 2 are inserted into the opening.
It is fixed at 6. A cage 27 is formed into a cylindrical shape and is fitted inside the valve body 22 below the upper lid 24. A gasket 28 is inserted between the cage 27 and the upper lid 24. Fixed. On the peripheral wall of the cage 27,
A plurality of windows 29 are opened to form a peripheral wall opening, and these windows 29 communicate the interior of the cage 27 with the upstream passage 23 surrounding the cage 27 . The lower end of a valve stem 31 is screwed into a cylindrical valve plug 30 that is slidably fitted into the inner hole of the cage 27.
It is pivotally supported by the upper lid 24 via a gasket 33 inside 2. Reference numeral 34 denotes a packing holder that presses the packing 32 against the inner bottom surface of the packing box 32. Reference numerals 35 and 36 designate upper and lower seat portions provided at the upper and lower portions of the valve plug 30 and seated on the valve seats 37 and 38 on the cage 27 side, respectively. Then, when the valve plug 30 is raised and lowered, the opening degree of the window 29 changes, and the flow from the upstream flow path 23 through the window 29 to the cage 2
The flow rate of fluid flowing into 7 is regulated.

The valve body 22 has a downstream flow path 40 formed substantially orthogonal to the upstream flow path 23 and concentrically with the cage 27.
The lower end flange portion 41 is connected to a downstream pipe line (not shown). This downstream flow path 40 is formed in a truncated conical shape whose diameter gradually increases in the direction of fluid flow, and is formed in the cage 27.
It communicates with the inside of the cage 27 through small holes 43 in a partition plate 42 made of a perforated plate attached to the lower end opening of the cage 27 . Further, the downstream flow path 40 is partitioned by partition plates 44, 45, 46, and 47 made of a plurality of (four in this embodiment) perforated plates welded to the inner circumferential wall of the flow path 40, thereby forming four inner chambers. 48,49,5
0 and 51, and each of these inner chambers is closely filled with steel balls 54, which are shown as an example of a noise-reducing filler and have a gap between them for fluid passage. The diameters of the steel balls 54 in each inner chamber are different and are set to increase successively from the upstream side, that is, the uppermost inner chamber 48, to the downstream side, that is, the lowermost inner chamber 51.

The operation of the low noise valve configured as above will be explained. When the valve stem 31 is moved up and down by the actuation of the drive unit by an automatic control device or by manual operation, the valve plug 30 moves together with the valve plug 30, and the opening degree, that is, the opening area of the window 29 changes. Thus, the flow rate of fluid flowing from the upstream flow path 23 through the window 29 of the cage 27 to the downstream flow path 40 is controlled. The fluid then flows through the gaps between the steel balls 54 in the downstream flow path 40 .

When the fluid continues to flow from the upstream flow path 23 to the downstream flow path 40 while the flow rate is controlled in this way, the fluid flowing in from the window 29 while being depressurized entrains the surrounding fluid and becomes turbulent. As a result, high-frequency noise is generated. This noise tries to propagate to the outside through the downstream flow path 40, but since each inner chamber of the downstream flow path 40 is densely filled with a large number of steel balls 54, the downstream flow path The fluid flowing into the steel balls 54 has its kinetic energy greatly reduced as it flows downward through the complicated flow paths between the steel balls 54, and the complicated flow paths between the steel balls 54 gradually become larger as it reaches downstream. This promotes volume expansion, and as a result, the effect of reducing or preventing noise generation can be obtained.

FIG. 3 is a diagram illustrating the desired pressure drop of fluid through downstream flow path 40. In this case, the partition plate 4
It is obvious that the pressure drop curve can be freely changed by changing the spacing and number of the steel balls 2, 44 to 47, the diameter of the steel balls 54, etc.

FIG. 4 is a perspective view of a sound-deadening filling body showing another embodiment of the present invention, and in this embodiment, the steel balls 54 of the above embodiment are used as the filling body to be filled in the inner chamber of the downstream flow path 40. Instead, a short and small tube piece 60 shown in the figure is used. This tube piece 60 is made by cutting a stainless steel pipe into small pieces, and when filled with it, a gap is formed between them for fluid to pass between them, similar to a steel ball, so it has a fluid flowing function and a noise damping effect, and also has a hollow Since it is made of steel, its weight is significantly reduced compared to steel balls, making the entire valve lighter.

[Effects of the Invention] As is clear from the above description, according to the present invention, in a low-noise valve, the flow path on the downstream side of the valve body is formed substantially concentrically with the cylindrical cage, and the flow path is crossed by the flow path on the downstream side of the valve body. A plurality of porous partition plates are provided, and a plurality of sound-deadening fillers are filled between each partition plate so that the shape and dimensions gradually increase from the upstream side to the downstream side, and the gaps between the fillers are filled. Since the fluid passes through the packing bodies to form a fluid flow path, the operating energy is greatly reduced when the fluid flows down the complicated flow path between these packing bodies, and the gaps in the complicated flow path gradually increase. The volume is also expanded and decompressed in multiple stages. Therefore, a sound reduction effect and a noise prevention effect are obtained, quiet operation is realized, and the environment is improved.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a low-noise valve according to the present invention, FIG. 2 is a vertical cross-sectional view showing an example of a conventional cage valve, and FIG. 3 is a pressure drop of the low-noise valve according to the present invention. FIG. 4 is a perspective view of a sound-deadening filling body showing another embodiment of the present invention. 21...Low noise valve, 27...Cage, 29...
Window, 40...Downstream channel, 42, 44, 45, 4
6, 47... Porous partition plate, 54... Steel ball, 60...
...Tube body.

Claims (1)

[Claims] 1. A downstream flow path of the valve body through which the fluid flowing in from the peripheral wall opening of the cylindrical cage passes toward the downstream pipe path is formed approximately concentrically with the cage, and this flow path is formed with a plurality of porous holes. 1. A low-noise valve, characterized in that the valve is partitioned by partition plates made of plates, and a noise-reducing filler is filled between the partition plates so that the shape and dimensions thereof become larger sequentially from the upstream side to the downstream side.