JPS6199784A - High differential pressure type control valve - Google Patents

Abstract

PURPOSE:To permit the decompression with reduced noise without applying an extreme load onto the apparatus by arranging a member having at least a multihole part for fluid decompression into a valve apparatus body and adjusting the opened area of the multihole part. CONSTITUTION:High-pressure fluid flows into a fluid control part 6 from a valve box 3, and passes through a small hole 6c and further passes through a small hole 10a on a cage 10 and then flows outside. Since, in this case, the fluid is pressure-reduced in two stages in the valve body 6 and the cage 10, smooth decompression is permitted, and a part of the valve apparatus is prevented from being applied with a large load. When the valve body 6 lowers, a part of the opened port of the cage 10 is closed by the side wall of the piston part 6a of the valve body 6, and since the fluid passing part 6b lowers into a valve seat 8, the number of small holes is reduced, and the flow rate reduces.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control valve, and particularly to a high differential pressure control valve that can significantly reduce wear of a valve device and has excellent controllability.

<Prior art and its problems> Valve devices of various shapes are used for fluid control, but especially when used for high-pressure fluid, a large pressure difference occurs between the fluid inlet side and the outlet side, and various types of valve devices are used. problem occurs.

First, when high-pressure fluid flows between the valve body and the valve seat, the fluid generates severe turbulence in this gap, which causes severe wear on the valve seat and quickly reduces the closing performance of the valve device. ,
It has a big impact on the plant.

In addition, since the pressure is reduced with a large pressure difference in one stage of closing, the vibration and noise caused by the turbulent flow are intense, causing noise pollution to the surrounding area and causing severe wear. As countermeasures against this, it is necessary to apply a boat that causes great damage to the valve device, to apply a soundproofing member to the valve device, or in some cases, to house the valve device in a soundproof room, which is extremely uneconomical.

For this reason, there is a method of arranging a perforated plate downstream of the valve device and maintaining the inside of the valve device at a relatively high pressure due to the pressure loss caused by the perforated plate, thereby reducing the differential pressure between the fluid inlet and outlet of the valve device. Although this method has been proposed, it is hardly effective when the flow rate is reduced as will be described in detail later, and is also insufficient as a measure against wear.

OBJECTS OF THE INVENTION The present invention was constructed in view of the above-mentioned problems, and provides a high differential pressure valve that can appropriately control the flow rate of high-pressure fluid with low noise and has improved wear resistance. It's about doing.

Means for Solving the Problems〉 In short, the present invention is to arrange a member having - or more fluid pressure reducing porous portions in a valve device main body, and to configure the porous portions so that the opening area can be increased to alum. This device is configured to be able to appropriately reduce pressure in a wider flow range without giving any part of the device an extremely negative effect.

<Example> FIG. 1 shows a first embodiment of the invention.

Reference numeral 1 in the figure is a valve box constituting the main body, and a cage 10 is arranged and fixed within the valve box so that the upper 7 flange portion 10b is held between the bonnet 3 and the valve box 1. A large number of small holes 10& for depressurization are formed in this cage 10.

Next, reference numeral 6 denotes a valve body, which is disposed within the cage 10 and is configured to be slidable in the direction of the axis 13 of the valve body with respect to the fluid passage of the valve body.

This valve body has a piston-shaped portion 6 & having a piston-shaped upper portion, and is configured to slide in close engagement with the inner wall surface of the cage 10 by a sealing member such as a seal ring 7. Reference numeral 6b denotes a fluid passage portion formed at the lower part of the piston portion, the lower end of which is open, and a large number of small holes 6G for pressure reduction are bored in the side wall portion. This fluid passage part is formed to have a smaller diameter than the piston-shaped part (however, it is not essential that the piston-shaped part and the fluid passage part have a circular cross-sectional shape), and is shaped like a piston. The projecting lower surface of the portion 6a serves as a seat portion 9 that closely engages with the valve seat 8 formed in the valve box 3, and a recess is formed in both.

The structure is such that the engagement of the recesses improves the tightness when the valve is fully closed. Reference numeral 6d indicates a communication hole formed in the piston-shaped portion, which communicates between the fluid passage portion 6b side and the upper space of the piston-shaped portion to prevent differential pressure from occurring.
This prevents the operation of the valve body from being obstructed.

Reference numeral 5 is a valve stem for operating (elevating and lowering) the valve body 6; 1
2 is a ground backing that seals the bonnet and the valve body.

Next, the operating state of the device will be explained. Although FIG. 1 shows the valve device in a fully open state, high-pressure fluid flows into the fluid control unit 6 from, for example, the valve box 3, passes through this small hole 6G, and further passes through the small hole 10a of the cage 1o. and leak to the outside. At this time, since the pressure of the fluid is reduced in two stages at the valve body 6 and the cage 10, the pressure reduction can be performed smoothly and no large burden is placed on a part of the valve device. Furthermore, the flow rate can be adjusted by the valve body 6.
When the valve body is lowered, the opening of the cage 10 is partially blocked by the side wall of the piston portion 6a of the valve body 6, and the fluid passage portion 6b is lowered into the valve seat 8. In both cases, the number of open small holes decreases and the flow rate decreases. In other words, since the flow rate is controlled by increasing or decreasing the opening of the small hole, even when the flow rate is reduced, there is no excessive load placed on any part of the valve device, wear is kept to a minimum, and the fluid flows smoothly. Noise and vibration are significantly reduced.

FIG. 2 shows a second embodiment. In this embodiment, the fluid passage portion and the valve body are separated, and the fluid passage portion is formed in a fixed manner. That is, reference numeral 14 indicates a fluid passage portion, which is fixed to the valve box 1 by screwing or other means, and has a fluid passage portion main body 15 formed with a large number of small holes 15a in its upper part. 16 is the cage 10 and the fluid passage main body 15
It is a valve body disposed so as to be able to rise and fall in a space between
The seat portion 9' is formed so as to closely engage with the sheet portion 9'. In this embodiment, since the valve body can be made simple and lightweight, the valve body can be operated quickly with less power. Note that the flow rate is controlled by raising and lowering the valve body to adjust the number of openings of the small holes, as in the previous embodiment.

FIG. 3 shows a third embodiment. In the embodiment described above, the small hole forming member, which is the pressure reducing part formed in two stages, that is, the cage, and the fluid passage part are arranged concentrically, but in this embodiment, they are arranged in series, that is, the valve body. They are connected in the axial direction.

That is, the hollow valve body 26 is partitioned by a blind plate 17c to form upper and lower chambers 2.
7a and 27b are formed. This valve body has small holes divided into two groups, 26& in the upper chamber 27& and 26b in the lower chamber 27b, as shown in the figure.

This lower chamber 2? In b, there are small holes lea and 17 in two groups.
A plurality of holes b (which form a group of small fluid exit holes) are formed. Further, the seven rung portions 26c of the valve body 26 and the seven rung portions 17c of the blind plate member F are designed to engage and come into close contact with the valve seat 18, and the valve seat 19, respectively. In the illustrated case, the valve is almost fully closed, but when the valve body 26 is raised by the valve body, fluid flows into the valve body from the small hole 26&, and 26b to the outside of the valve body, and further through the small hole 17.
It flows into the connecting member 17 from a, and is finally discharged from i & 17b. In this embodiment, the pressure is reduced in four stages through the small holes, so that the pressure can be reduced more smoothly and effectively.

Next, the performance of the device according to the present invention will be explained in comparison with a conventional device. Note that FIG. 4 is a diagram showing the performance of a conventional device, and FIG. 5 is a diagram showing the performance of the device according to the present invention.

First, let's look at the conventional device shown in FIG. 4, in which a perforated plate is formed at the outlet of the valve device. A first stage of pressure reduction is performed by adjusting the opening degree of the valve seat and valve body, and a second stage of pressure reduction is performed by a perforated plate at the valve outlet. For example, when the flow rate is 100%, assume that the pressure is reduced to about 1 at the valve seat to lower the pressure from P□ to P8, and then further reduced to about 1 of P by a perforated plate to reduce the pressure to the rated pressure P4. . Next, when the flow rate is reduced to 50%, most of the pressure loss will shift to the valve seat side because the opening area of the perforated plate itself remains unchanged, and the valve seat side will bear about 80% of the pressure reduction part. Then, the pressure is reduced to P, and the perforated plate almost no longer functions. As a result, severe erosion occurs around the valve seat.

FIG. 5 shows the case of the present invention. Since the number of openings of the small holes is variable, there is almost no difference in the reduced pressure state between 100% flow rate and 50% flow rate, and a part of the valve device , it does not cause a large burden.

Effects> According to the present invention, the flow rate of high-pressure fluid can be adjusted smoothly with low noise and low vibration, and erosion of the device can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a valve device showing a first embodiment of the present invention;
Fig. 2 is a sectional view of a valve device showing a second embodiment, Fig. 3 is a sectional view of a valve device showing a third embodiment, and Figs. 4 and 5 are internal fluid pressures in various parts of the valve device. FIG. 1... Valve box 't 16, 26... Valve body 17... Blind plate 6a... Piston shaped part 6b... Fluid passage Part 6c, lo
a, 15a, 17a, 17b, 26a, 26
b-...Small hole for fluid pressure reduction 8. B: 1B, 1
9... Valve seat 2nd diagram c o? ' a” dry ζ

Claims (1)

[Claims] 1. By arranging one or more members having a plurality of small holes for fluid passage in the valve box and adjusting the number of openings of the small holes in these members, the pressure of the fluid can be reduced and the flow rate can be adjusted. A high differential pressure type control valve that is characterized by: 2. A cage is placed in the valve box, a valve body is slidably placed in the cage, and one group of small holes is formed in the side wall of the cage, and another group of small holes is formed in the fluid passage portion of the valve body. The number of openings of the small holes on the cage side is determined by the elevation of the piston-shaped part of the valve body, and the number of openings of the small holes on the fluid passage side is similarly determined by the amount of entry of the fluid passage part into the valve seat opening due to the elevation and descent of the valve body. A high differential pressure type control valve according to claim 1, characterized in that the control valve is configured to adjust the pressure. 3. A tube having a group of small holes for fluid passage is positioned and fixed in a cylindrical portion located within a certain space within the valve box, and the valve body is slid in the space between the two cylindrical portions. 2. The high differential pressure type control valve according to claim 1, wherein the control valve is configured to adjust the number of small holes that can be arranged and opened. 4. A blind partition member is provided in the middle of the first hollow cylindrical valve body to form two chambers, with multiple small holes in the side wall of each chamber, and multiple small holes in the bottom of the lower chamber. A patent claim characterized in that a hole is provided, and the valve body is configured to protrude from the inner wall of the valve box so as to correspond to the groups of small holes in the upper and lower chambers, surround the valve body, and control the opening number of the small holes by the vertical movement of the valve body. The high differential pressure type control valve according to item 1.