JPH05149472A - Cage type valve - Google Patents

Abstract

PURPOSE:To make a valve simple in structure and small in size as well as to facilitate processing by disposing a double multi-hole cage where an inner and an outer double side multi-hole cage are disposed in minutely spaced relation, and porous metal filled in the outer multi-hole cage, in the inside of a valve box. CONSTITUTION:High temperature and high pressure fluid flows in the inside of a valve from a valve inlet 8, its flow is controlled by a valve plug 4 and an inner multi-hole cage 1, and it then flows out of a valve outlet 9 thereafter. By the way, an outer multi-hole cage 2 is disposed at a position close to the outside of the inner multi-hole cage 1, so that a double multi-hole cage in minutely spaced relation is formed. And porous metal 3 is filled in the inside of a valve box 5 at the outside of the outer multi-hole cage 2. In this case, a space between the inner and outer multi-hole cages 1 and 2 shall be set so as to be 0.3 to 0.6 times as large as the hole diameter of the inner multi-hole cage 1. And the open area of the outer multi-hole cage 2 shall be set larger than the open area of the inner multihole cage 1 in such a way as to meet the expansion due to pressure reduction of fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage type valve applied to control and depressurize a high temperature and high pressure fluid in various plants such as a thermal power plant.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory view of the structure of various conventional valves which have been reduced in noise. In the figure, each of these valves is provided with a perforated cage-like perforated cage 01 in a valve box 05, a combination of a multi-stage plug 04 and a multi-stage seat 07, and a noise reduction mechanism such as a perforated orifice plate 09. The sudden decompression and expansion of the throttle is made gentle to prevent the generation of shock waves and cavitation, thus reducing noise.

[0003]

However, since the above-mentioned various types of valves which have been reduced in noise have a complicated structure, heat resistance and abrasion resistance due to the high temperature and high pressure of fluids in recent plants have been considered. The use of materials causes problems such as difficult processing and large size.

[0004]

The cage type valve according to the present invention is intended to solve the above-mentioned problems, and a cylindrical outer porous cage is provided outside the cylindrical inner porous cage with a minute interval. And a porous metal filled on the outside of the outer porous cage in a valve box.

The cage valve according to the present invention is characterized in that the distance between the inner and outer porous cages is 0.3 to 0.6 times the hole diameter of the inner porous cage.

Further, the cage type valve according to the present invention is characterized in that the opening area of the outer porous cage is made larger than the opening area of the inner porous cage to a size commensurate with the decompression expansion of the fluid.

Further, the cage valve according to the present invention is characterized in that the hole of the inner porous cage and the hole of the outer porous cage are provided so as not to communicate with each other.

[0008]

That is, the cage type valve according to the present invention is provided with the double perforated cage in which the tubular outer perforated cage is provided outside the tubular inner perforated cage at a minute interval in the valve box. The outer perforated cage is filled with porous metal, and the fluid expands under reduced pressure when passing through the holes of the inner perforated cage, but the shock wave due to the reduced pressure expansion occurs in the narrow part sandwiched between the double perforated cages. A large shock wave cannot be formed due to being restrained, and a strong large vortex or turbulence that causes noise is prevented. Although the fluid expands under reduced pressure when passing through the holes in the outer porous cage, the three-dimensional mesh of the porous metal filled on the outside of the outer porous cage rectifies large vortices and turbulence to prevent noise generation. To be done.

Further, in the cage type valve according to the present invention, the distance between the inner and outer porous cages is 0.
It is 3 to 0.6 times, and the shock wave due to the decompression expansion of the fluid is especially restricted in the narrow part sandwiched by the double perforated cage and a large shock wave cannot be formed, and strong vortices and turbulence that cause noise are generated. Occurrence is significantly prevented.

Further, in the cage type valve according to the present invention, the opening area of the outer porous cage is larger than the opening area of the inner porous cage by a size commensurate with the decompression expansion of the fluid, and the fluid flow is always inward. It remains choked at the holes of the multi-hole cage, and the flow rate characteristics are the same as when the pressure is reduced in one stage of the multi-hole cage.

Further, in the cage type valve according to the present invention, the holes of the inner porous cage and the holes of the outer porous cage are provided so as not to communicate with each other, and the flow passing through the holes of the inner porous cage is prevented. The non-pore portion of the outer porous cage is blocked and does not directly collide with the outer porous metal, thus avoiding erosion of the porous metal.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural explanatory view of a cage type valve according to an embodiment of the present invention, and FIGS. 2 and 3 are explanatory views of its operation.
In the figure, the cage type valve according to the present embodiment is used for control of high temperature and high pressure fluid and decompression in various plants such as thermal power plants. As shown in FIG. The sudden decompression and expansion in the gradual state is made into a gentle state to prevent the generation of shock waves and cavitation, thereby reducing noise. The high-temperature high-pressure fluid flows into the valve through the valve inlet 8, the flow is controlled by the valve plug 4 and the inner porous cage 1, and the high-temperature high-pressure fluid flows out through the valve outlet 9. An outer porous cage 2 is arranged at a position close to the outer side of the inner porous cage 1 and has a cylindrical shape.
The two porous cages form a double porous cage with a minute gap therebetween, and the inside of the valve box 5 outside the outer porous cage 2 is filled with the porous metal 3. The opening area of the outer porous cage 2 is made larger than that of the inner porous cage 1 by increasing the number of holes and the hole diameter so as to correspond to the decompression expansion of the fluid. The holes in the inner perforated cage 1 and the holes in the outer perforated cage 2 are opened at positions shifted in a staggered pattern, and the holes on both sides are arranged so as not to communicate with each other. The porous metal 3 is made of a Ni—Cr alloy, and a foamed metal having a porosity of 96% and high heat resistance is used. Other porous metal, mesh wire, sintered metal or the like may be used as the porous metal 3.

The high-temperature high-pressure fluid expands under reduced pressure as it passes through the holes of the inner porous cage 1, but the outer porous cage 2 is arranged at a position close to the outer side of the inner porous cage 1 so that The generated shock wave is restricted by the narrow part sandwiched between the double perforated cages and a large shock wave cannot be formed, so that generation of a strong large vortex or turbulence that causes noise generation is prevented. Although the high-temperature high-pressure fluid expands under reduced pressure when passing through the holes of the outer porous cage 2, the porous metal 3 is filled inside the valve box 5 in contact with the outside of the outer porous cage 2.
The sea surface-shaped three-dimensionally fine mesh of the porous metal 3 rectifies a large vortex or turbulence and prevents noise generation. Further, the holes of the outer porous cage 2 and the holes of the inner porous cage 1 are arranged in a staggered pattern in the circumferential direction and the longitudinal direction, and the high-speed flow passing through the holes of the inner porous cage 1 is The non-hole portion of the outer porous cage 2 is blocked and does not directly collide with the outer porous metal 3, so that the erosion of the porous metal 3 is avoided. Further, the opening area of the holes in the outer porous cage 2 is larger than the opening area of the holes in the inner porous cage 1 by increasing the number of holes and the hole diameter, and the high-speed flow is choked at the holes of the inner porous cage 1. Is becoming Further, the porous metal 3 can be easily filled by opening the bonnet 6 and stacking the ring-plate-shaped porous metal 3 in the valve box 5. Further, the filled porous metal 3 is restrained by contacting the outer peripheral surface thereof with the inner periphery of the valve box 5 and is pressed and held by the bonnet 6 from above. By depressurizing the metal 3 to a pressure having sufficient strength and finally depressurizing and reducing noise, the porous metal 3 can have a simple and strong structure without requiring a special holding structure. Moreover, unlike the slit holes in the conventional cage valve as shown in FIG. 4, complicated processing is not required, and both the inner porous cage 1 and the outer porous cage 2 are easy to machine and have a simple shape and structure. In addition to being compact, it is possible to use materials with high heat resistance and wear resistance such as stellite, which makes it easy to manufacture cage type valves that have high durability and low noise.

Generally, in such a cage type valve, the high temperature and high pressure fluid is decompressed and expanded when passing through the hole of the perforated cage, and the pipe is vibrated immediately after the hole because of strong vortex and turbulence due to the shock wave. Although it generates a lot of noise, this valve has a double perforated cage in which an outer multi-perforated cage 2 is arranged in the vicinity of the outer side of the inner perforated cage 1 which determines the flow characteristics of the cage type valve. As shown in (a), when the distance L between the cages is set to be 0.3 to 0.6 times the hole diameter d of the inner porous cage 1, the generation of strong large vortices and turbulence that cause noise generation is significantly prevented. Further, the opening area of the holes in the outer porous cage 2 is larger than that in the inner porous cage 1 to correspond to the decompression expansion, and the flow of the high-temperature high-pressure fluid is always choked at the holes in the inner porous cage 1, As shown in (b), the flow rate characteristics are almost the same as when the pressure is reduced by only one stage of the porous cage.

FIG. 3 (a) shows an example of noise reduction when superheated steam having a pressure of 10 MPa or more is depressurized to the atmospheric pressure. A sound reduction of 25 dBA or more is obtained and no damage is caused to the porous metal. Has been obtained. The figure (b) shows the flow rate characteristics of this valve, and there is almost no change in the flow rate characteristics compared with the conventional valve, and this valve does not impair the flow rate characteristics and only significantly reduces noise. You can do it.

[0016]

The cage type valve according to the present invention is constructed as described above, and since the pressure reduction and noise reduction of the fluid are performed by the double-perforated cage and the porous metal, the structure is simplified and processed. It becomes easier and smaller.

[Brief description of drawings]

FIG. 1 (a) is a longitudinal sectional view of a cage type valve according to an embodiment of the present invention, and FIG. 1 (b) is bb in FIG. 1 (a).
FIG.

FIG. 2 is an explanatory view of its operation.

FIG. 3 is also an explanatory diagram of its operation.

4 (a), (c), and (d) are vertical cross-sectional views of various conventional noise-reduced valves, and FIG. 4 (b) is a cross-sectional view taken along line bb in FIG. 4 (a). It is a figure.

[Explanation of symbols]

 1 inner porous cage 2 outer porous cage 3 porous metal 4 valve plug 5 valve box 6 bonnet 7 valve seat 8 valve inlet 9 valve outlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Kojima 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi Sanhishi Heavy Industries, Ltd. Kobe Shipyard (72) Yoshihisa Manabe 5 Nishitachihana-cho, Amagasaki-shi, Hyogo No. 12-1 Toa Valve Co., Ltd.

Claims (4)

[Claims] 1. A double perforated cage in which a tubular outer porous cage is provided outside the tubular inner porous cage with a minute interval, and a porous metal filled outside the outer porous cage. A cage-type valve characterized by being equipped in a valve box. 2. The cage type valve according to claim 1, wherein the distance between the inner and outer porous cages is 0.3 to 0.6 times the hole diameter of the inner porous cage. 3. The cage-type valve according to claim 1, wherein the opening area of the outer porous cage is made larger than the opening area of the inner porous cage to a size corresponding to the decompression expansion of fluid. 4. The cage type valve according to claim 1, wherein the hole of the inner porous cage and the hole of the outer porous cage are provided so as to be displaced from each other so as not to communicate with each other.