JPH11248033A - High-pressure-reducing regulating valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cabitation in a pressure-reducing regulating valve for a high-pressure fluid. SOLUTION: A pressure-reducing device installed between an inlet 10 and outlet 11 for fluid has a high-pressure reducing device 6 which decompresses a high-pressure fluid having passed between a valve seat 4 and a valve plug 3 capable of being seated on the seat 4 while the flow speed of the fluid is kept under the specified value. This high-pressure reducing device 6 is structured so that the water head energy of the fluid is lost by allowing the fluid to flow in a passage provided in the device 6 and cylindrical cages furnished with a certain requisite number of holes having a right-angle bend to generate decompression of the pressure fluid to the specified pressure level are overlapped one over another so that holes bored in each cage are in communication with holes in the adjacent cage and thereby a zigzag passage is formed. The zigzag passage is configured so that passages in the radial direction have a certain requisite number of right-angle bends independently from the inlet to outlet of the pressure-reducing device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure reducing valve for high pressure fluid. In the present specification, a fluid means a gas or a liquid containing vapor.

Heretofore, pressure reducing valves for high pressure fluids have been invented. For example, U.S. Pat. No. 3,813,079
No. etc.

[0003]

However, these inventions have a problem that cavitation may still occur. That is, the prior art is a high-pressure depressurizing mechanism (Apparatus for Effect) shown in FIG. 6 of the aforementioned US Pat. No. 3,813,079.
ting Gas FlowPresure Redu
ction) and its sectional plan view (FIG. 7), and there is a problem that cavitation may still occur. The present inventor has completed the present invention to solve this problem.

[0004]

In order to solve the above-mentioned problems, the present invention resides in a required position of a flow path between a fluid inlet 10 and a fluid outlet 11, as shown in FIGS. In the depressurizing device, a high-pressure depressurizing device 6 is configured to depressurize the high-pressure fluid that has passed between the valve seat 4 and the valve plug 3 that can be seated on the valve seat while maintaining a flow rate equal to or lower than a predetermined value. The device 6 loses the pressure head energy of the fluid by flowing the fluid through the flow path in the pressure reducing device 6,
A cylindrical cage 1 provided with a required number of holes 12 having a right-angle bend so as to reduce the pressure fluid to a predetermined pressure.
5 is inserted into each cage 15 (15a, 15b or 15c) with a hole 12 (12a, 12b, 12c or 12d, 12d).
e, 12f) communicate with the holes 12 of the adjacent cages to form a zigzag flow path 13 in the high pressure decompression control valve, wherein the zigzag flow paths 13 are each provided with a high pressure decompression device 6. The required number of channels having a right-angle bend are formed radially independently from the inlet to the outlet of the car, and the cages 15 and 15 are inserted so that the required number of them can be inserted into each other. It is fitted into the pressure balance cylinder 7. The hole 12 (12a, 1
2b, 12c or 12, 12e, 12f) is a square hole (square hole) or a round hole for practical use.

[0005] As shown in the drawing of the embodiment of FIG. 3 (section XOX 'of FIG. 4), every other hole 12 (square hole or round hole) is inserted in the direction in which the plug 3 is separated from the valve seat 4. Although they are formed continuously, since the holes 12 forming the fluid flow paths form independent flow paths 13 toward the outlet side, respectively, they are not buffered by the other flow paths 13. is there. As shown in the graph of FIG. 8, the distance between the valve seat and the plug and the area of the inlet passage to the pressure reducing device are in direct proportion. Also in this point, there is a fundamental difference from the conventional technique in which the graph curve has a step-like characteristic as shown in FIG.

[0006] The plurality of holes 12 (12a, 12b, 12c, or 12d, 12d) in the high pressure decompression device.
e, 12f) is a dimension that gradually increases or decreases its cross-sectional area depending on its position so as to form an inlet flow area to the pressure reducing device that is directly proportional to the distance (valve stroke) where the valve plug 3 separates from the valve seat 4. It is something to make.

In determining the number of right-angle bends in the flow path so as to keep the high-pressure fluid at a predetermined flow rate or less, the high flow rate generated when the fluid passing through the high-pressure decompression device 6 passes through the throttle or the orifice is determined. The number of bends is set so as not to cause a phenomenon that the fluid pressure falls below the saturation pressure.

In the case where the fluid is a gas, the hole 12 (12a, 12b, 12c, or 12c) is made to gradually increase (or gradually decrease) the cross-sectional area of the flow path toward the outside of the flow path.
d, 12e, 12f) are determined. (See FIGS. 2, 3 and 4). The figure shows an example in which the flow of gas is directed outward from the center, in which the depth of the flow path 13 is constant, the flow path width is gradually increased, and the flow path cross-sectional area is gradually increased. Show. As shown, W ₁ , W ₂ , W ₃ are sequentially arranged from the center side.
W ₂ / W ₁ = W ₃ / W ₂ = k> 1 + α. The value of α is defined according to the use state of the device.

FIG. 5 shows a case in which the gas flows from the outside toward the center. When the depth of the flow path 13 is constant, as shown in FIG. The hole 12 (12d, 12c,
Determine the width of 12f). As shown in FIG. 5, when W ₄ , W ₅ , and W ₆ are sequentially set from the center side, W ₅ / W ₄ = W ₆ / W ₅ = k ′ <1-β. The β value is defined according to the use condition of the device.

[0010]

The high pressure decompression device 6 according to the present invention is a decompression device located at a required position of a flow path between the fluid inlet 10 and the fluid outlet 11, and includes a valve seat 4 and a valve plug 3 that can be seated on the valve seat. A high-pressure depressurizing device 6 is configured to depressurize the high-pressure fluid that has passed through the gap while maintaining a flow rate equal to or lower than a predetermined value. Each of the cages 15 (15a, 15B or 15a or 15B or 15a, 15B or 15B) is provided with a required number of holes 12 having a right-angled bend so that the pressure head energy of the fluid is lost and the pressure fluid is reduced to a desired pressure. Hole 1 drilled in 15c)
2 (12a, 12b, 12c or 12d, 12e, 12
f) is connected to the hole 12 of the adjacent cage to form a zigzag flow path 13, wherein the zigzag flow path 13 is provided at the inlet of the high pressure decompression device 6. The required number of right-angled channels are formed radially independently from the outlet to the outlet, so that the fluid pressure is prevented from falling below the saturation pressure and cavitation is accurately generated. Is prevented.

In determining the number of right-angle bends in the flow path so as to keep the high-pressure fluid at a predetermined flow rate or less, when the fluid passing through the high-pressure decompression device 6 passes through a bend (throttle or orifice). The number of bends is set so as not to cause a phenomenon that the fluid pressure becomes lower than the saturation pressure due to the generated high-pressure fluid, in order to sufficiently enhance the above-described operation and effect.

In the case where the fluid is a gas, the cross-sectional area of the flow path 12 is directed outward as shown in FIG. 4 showing the case where the flow of the gas is directed outward from the center. The reason for gradually increasing the flow rate is to keep the flow velocity at a predetermined speed or less in response to the gas that progresses outward from the center gradually expanding as the pressure is reduced.

As shown in FIG. 5, even when the flow of the gas is directed from the outside toward the center, the flow path 12 having the flow path cross-sectional area gradually increased toward the center may be used. In order to correspond to the gradual expansion as the pressure is reduced.

[0014]

FIG. 1 is a longitudinal sectional view of a high pressure regulating valve according to the present invention. In the figure, 1 is a valve body, and the valve body is
The valve body 1 has a fluid inlet 10 and a fluid outlet 11, between which a flow path is formed. The valve body 1 can freely move up and down by applying a force from the outside to the valve shaft 5. A valve plug (3) that can be seated on a valve seat (4) is provided. As shown, a pressure balance hole 8 is formed in the valve plug 3 in a vertical direction, and a pressure balance seal ring 9 is attached to the pressure balance cylinder 7 between the valve plug 3 and the pressure balance hole 8. 2 is a valve lid (bonnet). As shown in FIG. 1, the control valve is provided with a high-pressure reducing device 6 circumscribing the valve plug 3.

The high-pressure reducing device 6 includes a cylindrical cage 15.
A hole 12 (a square hole or a round hole) having a right angle bend is formed in the inside, and the cylindrical cages 15 are superposed outward to form a required number of independent flow paths. By flowing the fluid through the flow path, the pressure head energy of the fluid is lost, and the high-pressure fluid is depressurized to a target pressure (without cavitation).

When the fluid is a gas, the volume increases as the pressure is reduced, and it is necessary to gradually increase the flow path area in order to keep the flow rate below a predetermined value. FIGS. 2, 3 and 4 show specific examples thereof, in which the cross-sectional area of the flow path is made larger as going outward. The channel cross-sectional area can be expanded by a method of increasing the width of the flow channel while keeping the depth constant, or a method of increasing the depth while keeping the width of the flow channel constant. The embodiment shown in FIGS. 2, 3 and 4 is the former. In FIGS. 1 and 4, which are the embodiments, the arrow indicating the flow path direction is directed outward from the center, but the direction of the flow path opposite to this flow path direction may be the same as in the embodiment of FIG. There is no change in the operation and effect of the present invention.

[0017]

As described above, according to the device of the present invention, the fluid passing through the high-pressure depressurizing device has such a phenomenon that the fluid pressure becomes less than the saturation pressure due to the high-speed flow generated when passing through the general valve or the orifice. Since there is no cavitation, quiet decompression without cavitation and no gas decompression noise is possible. The cavitation does not occur, so that the valve seat, the valve plug, the fluid passage inside the valve, and the like are not damaged.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a high-pressure pressure-reducing control valve according to the present invention;

FIG. 2 is a cross-sectional view of the high-pressure reducing control valve taken along line AA of FIG.

FIG. 3 is an enlarged cross-sectional view of the high-pressure decompression device,

FIG. 4 is a cross-sectional view of the same high-pressure reducing control valve taken along a line YABY ′;

FIG. 5 is a partially cut-away cross-sectional view of a high-pressure reducing device according to another embodiment of the present invention;

FIG. 6 is a front view showing a partially cutaway cross section of a high-pressure decompression device according to the related art;

FIG. 7 is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 8 is a graph showing a state of a change in a flow path area with respect to a distance between a valve seat and a plug according to the present invention;

FIG. 9 is a graph showing a state of a change in a flow path area with respect to a distance between a valve seat and a plug according to the related art;

[Explanation of symbols]

 1. Valve body 2. 2. Bonnet (valve lid) Valve plug 4. Valve seat 5. Valve shaft 6. High pressure decompression device 7. 7. Pressure balance cylinder Pressure balance hole 9. Pressure balance sealing 10. Fluid inlet 11. Fluid outlet 12. Hole 13. 14. Zigzag flow path Cylindrical cage

Claims (4)

[Claims] A high-pressure fluid passing between a valve seat and a valve plug that can be seated on the valve seat is depressurized at a predetermined position in a flow path between a fluid inlet and a fluid outlet. A high-pressure decompression device that reduces the pressure while maintaining the pressure, the high-pressure decompression device loses the pressure head energy of the fluid by flowing the fluid through a flow path in the decompression device, and pressurizes the pressure fluid at a predetermined pressure. A cylindrical cage provided with a required number of holes having a right-angled bend so that the pressure is reduced to a maximum, and a hole formed in each cage communicates with a hole of an adjacent cage to form a zigzag flow path. In the high-pressure depressurizing control valve overlapped as described above, the zigzag flow path has a required number of right-angled bends independently formed radially from an inlet to an outlet of the high-pressure depressurizing device. High pressure Power reducing valve. 2. The high-pressure reducing valve according to claim 1, wherein a cross-sectional area of the plurality of holes in the high-pressure reducing device is directly proportional to a distance of a valve plug from a valve seat, that is, a valve stroke. A high-pressure decompression control valve having a size that gradually increases or decreases depending on its position so as to form an inlet flow path area to the pressure reducing device. 3. The high-pressure depressurizing control valve according to claim 1, wherein the number of right-angle bends in the flow path is determined so as to keep the high-pressure fluid at a flow rate or less. A high-pressure reducing valve, wherein the number of bends does not cause cavitation or abnormal noise due to a high-speed flow and a saturation pressure or less. 4. The high-pressure reducing valve according to claim 1, wherein, in the case where the fluid is a gas, the cross-sectional area of the flow path is gradually increased each time the hole in the high-pressure reducing device repeats bending. A high-pressure pressure-reducing control valve characterized in that it is dimensioned to be large.