JPH05502283A - throttle valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] throttle valve field of invention TECHNICAL FIELD This invention generally relates to improved throttle valve designs that prevent valve surface degradation. concrete In this case, the present invention eliminates erosion and capacitance caused by sudden evaporation of liquid and subsequent implosion of bubbles. It is aimed at preventing biting.

Background of the invention Throttle valves are used for continuous blowdown sampling, high pressure exhaust, turbine drain and Chemical for a variety of high pressure drop applications including boiler feed pump bypass relief, Used in the petroleum and utility industry.

There are numerous applications for high density valves at critical service conditions. Damage conditions are , usually not permanent. They typically operate in large numbers on a daily or weekly basis during transient operation. It will be held twice. Typically such valves include high and low pressure drain and preheat valves, refill valves, Heater applications, reheater and superheater drain applications, steam turbines, stop and throttle valve drains It has been used for in- and exhaust applications.

Throttle valves are always susceptible to erosion, cavitation damage and throttling effects on critical components. has undergone more rapid deterioration. Cavitation is the process of vaporization in a rapidly moving liquid. This is the sudden generation and collapse of a Qi pocket. One of the throttle valves that minimizes such deterioration The type uses a stellite disk and cylindrical seat coated with a corrosion-resistant material. disc The fluid flowing through the annulus between the seat and the seat is smoothed until it reaches the blunt end of the disc. speed up At this time, the flow area increases at the center of the channel, and the flow area increases at the core of the channel. The resulting pressure square below is circular in a layer of non-vapor fluid flowing continuously along the wall of the seat. Evaporation occurs at the tube seat.

A frequent problem with such restrictor valves is that the pressure drop created within the valve When passing through the liquid medium, it causes evaporation and cavitation of the liquid medium. tree Cavitation often occurs at locations along the surface of the throttle valve and Occurrence at the blunt ends of the discs due to the design of the discs and seats, deteriorating their surfaces. Valve surfaces exposed to cavitation shall be coated with a wear-resistant material. No. The cost of coating surfaces with wear-resistant materials is expensive.

The inner surface of the valve housing to minimize damage caused by cavitation. Preferably, a restrictor valve is provided to expel liquid from the member.

A contour profile defined by a special exponential equation that expels material flow from the inner wall of the valve surface. It is further preferred to provide a lug on the throttle valve.

This limits the location of evaporation of the liquid medium from the valve surface and subsequent cavitation. It is an object of the present invention to provide a throttle valve specially designed for severe use. It is.

Another object of the invention is to accelerate the flow of liquid medium in a passageway of small cross-sectional area into a passageway of large cross-sectional area. As a result, evaporation and cavitation are removed from the valve surface at a defined location. The first step is to provide a throttle valve that originates from the valve surface.

Yet another object of the invention is to require only a small number of valve surfaces treated with wear-resistant coatings. The first is to provide a restrictor valve, thereby reducing the cost of manufacturing the valve.

Mixtures of gases, liquids, water and steam without eroding and damaging the seat and plug Alternatively, it is another aspect of the invention to provide a multi-purpose valve for handling liquid and abrasive slurry. It is a purpose.

Accommodates cavitation and cleaning liquids, liquids containing suspended solids, and two-phase flows. It is a further object of the present invention to provide a throttle valve that is

Summary of the invention According to the present invention, a throttle valve is disclosed that prevents deterioration of the valve surface. valve casing an inlet conduit for introducing a gas or liquid medium into the valve; having an outlet conduit for discharging from the casing and a valve opening for supporting a valve member. . An annular sealing member is located within the housing between the inlet and outlet ports. The valve is Additionally, a sliding housing within the valve to open and close fluid flow between the inlet and outlet conduits including a retractable valve member, the valve member having a compound exponential shape in sliding engagement with the sealing means; having a contour nose defined by Eq. Direct the exit flow towards. The valve of the invention has two configurations: linear and angular configurations. Ru. The straight configuration incorporates a hard coat guard plate in the exit section that is removed.

Brief description of the drawing The foregoing description, together with the following detailed description, is best understood when read in conjunction with the accompanying drawings. It will be understood. For the purpose of illustrating the invention, the presently preferred embodiments are shown in the drawings. , the invention is not limited to the precise arrangement and apparatus shown.

FIG. 1 is a cross-sectional view over time of a preferred embodiment throttle valve in open and closed positions; be.

FIGS. 2 and 2A illustrate the profile of the nose portion of the valve plug of the preferred embodiment. It is a graph.

FIG. 3 shows the exponential formula for the plug of the preferred embodiment.

FIG. 4 is a sectional view of a second embodiment of the invention.

Description of preferred embodiments Preferred embodiments are disclosed and described with reference to the accompanying drawings. Same in this case Numbers are used where applicable. Referring to FIG. 1, an aperture according to the present invention A cross-sectional front view of valve 10 is shown in open and closed positions. The throttle valve 10 of the present invention is , has a valve body 12 made of forged or cast heat-resistant carbon. Valve configuration is angular Shape designed and manufactured according to specific industry needs. The valve body 12 is a liquid An inlet conduit 13 and a vertically arranged outlet conduit 1 for introducing and removing medium from the valve. 5. The valve body 12 is further connected to the pressure seal member by a locking nut 17. It includes a lid 14 disposed against it. The locking nut is held by port 17a. It is. The lid 14 is made from heat resistant low alloy carbon steel and is vibration free of the plug. It has a hardening guide ring 11 at the lower end providing guidance.

The axial portion of the lid 14 includes a pore 16 that retains the valve stem 18. Boa 16 The space between the upper part and the stem 18 is moved by a threaded fitting nut 21. The packing 20 is compressed by the hardened packing presser 22.

A guide bushing 23 supports the valve stem. The lid is segment ring 27 and is held in position by a support ring 25.

The lid 14 includes a cylindrical cavity 24 into which the body of the plug 26 extends when raised. nothing. An inlet conduit 13 extends from the side wall of the body 12 and is used for liquid entering the valve. Connects to media or slurry source. A mixture of water and steam or a slurry of liquid and abrasive Various types of substances, including lees, are transmitted through the valve.

An outlet conduit 15 is provided at the lower end of the valve housing through which vapor liquid is discharged. It will be done. The outlet conduit 15 is molded as a conically expanding section. conical shape The outlet conduit 15, which expands to Effective and protects against wear and tear.

The valve housing includes an annular seal 32 located between the inlet and outlet conduits. C The ring comprises an inner annular seat 32 inserted within an outer annular seat 34. Annular seat 32. 34 acts as a seal when the plug 26 is in the closed position and when the plug is in the open position. as a path through which the liquid medium is constantly accelerated in the downstream direction when drawn into the Function. The outer annular seat 34 is fused within the valve body 12 at a location adjacent to the outlet conduit. It's a close encounter. The inner annular seat 32 extends outward from one end in the upstream direction. and a second inner surface 38 extending outwardly in the downstream direction.

Inner annular seat 32 is removably displaced within outer annular seat 34 so that gap 4 0 is formed between the two respective loci. Gap 40 is a high temperature liquid medium or gas (500-1000 degrees Fahrenheit) passes through valve 10 and over inner annular seat 32. When doing so, thermal expansion of the inner annular seat 32 or distortion of the valve body 12 is allowed. Furthermore, outside When the side annular seat 34 is welded within the valve body 12, it undergoes thermal expansion caused by extremely high temperatures. Ru. Only the inner surface 36.38 is made of tungsten carbide, chromium carbide or stellite. coated with a highly wear-resistant material. During manufacturing, the two seat parts are welded together and the machine It is processed, then inserted into the valve body 12 and welded.

A preferred embodiment valve plug 26 is described below. The valve plug 26 is a liquid The media flow is directed to a specific location downstream of the inner annular seat 32. In the present invention, the valve plug 26 has a generally cylindrical body connected to the valve stem 18 at its upper end and has a nozzle. A closed section 42 is at the lower end. The valve plug slides into the lid cavity by the valve stem do. The nose portion 42 is precisely contoured with decreasing curvature relative to the central axis of the valve body 12. It has an attached arcuate wall. The contour of the valve nose is based on the graph shown in Figure 2 and It is defined by the following equation shown in FIG.

Y = A ten (V l, ) / U (vll/v-Al x (U X) L#v/V-^) where A=D/2, D is the diameter of the plug at the tip.

V=SXC, U=SXC.

Here 01 is 0. It is a constant with a value of 1 to 50, and C2 is 0. Value between 5 and 50 is a constant. S is the distance between the central plug shaft and the inner seat at the point of minimum diameter be.

W=C, where C3 has a value of 0.1 to 2.0.

X=stroke, where stroke is equal to the nominal size of the valve.

The arcuate wall of the plug 26 directs the liquid medium flow in a downstream direction away from the plug surface. prevents deterioration. The plug 26 is made of ceramic material and has a profile of , coated with a very thin smooth layer of highly wear resistant tungsten carbide or chromium 41 It will be done. The seat flow path is made of surface hardened material such as 5tellite6 or Hynes25. be done. The resulting liquid flow velocity vector is directed from the plug contour. plug 26 provides a linear control characteristic with a very small dead band at the start. The linear characteristic is and hence the gap leakage rate. Exponential properties are required in applications. If required, it may be acquired by the positioner's cam or electronically.

The throttle valve 10 further includes a conically outwardly expanding outlet conduit 15 and It has a larger cross-sectional area than the inner annular seat 32. This area is characterized by evaporation and subsequent cavities. Establish a location where the tation will take place. The outlet conduit 15 has a main wall 43 and an outlet extending outwardly from the inner annular seat 32 in the direction towards the conduit 15 and It is connected to a secondary wall 44 extending parallel to the central axis of the housing. Outlet conduit 1 The walls of 5 are coated with a highly wear-resistant material similar to the first inner surface 32. inner annular seat 32 (and surfaces 36, 38) and the outlet conduit 15 due to the difference in cross-sectional area , the liquid medium moving from the inner annular seat 32 into the cavity 15 has a large Subject to sudden pressure drop. This evaporates the liquid medium at or near the saturation point. and cavitation. This phenomenon occurs when the liquid medium is inside the inner annular ring, as mentioned above. This is facilitated by the fact that it is accelerated at seat 32. As a result, cavitation The plug 26 is not a specially treated seat to prevent deterioration. Occurs at a specific location within the downstream valve housing 12.

Referring to FIG. 4, an alternative Y-shaped inline embodiment of the present invention is disclosed. Ru. In this embodiment, the inlet and outlet ports are substantially parallel and A plug and seat assembly extends across the inlet and outlet conduits. Valve body 12° are made from die forged or cast heat resistant low alloy carbon steel. Lid assembly 14° is This is the same as the first embodiment. This embodiment provides hard coating erosion protection at the exit section. Includes plate 58. The plate is held by a ring and locked by a port 17a. It is a check.

motion The operation of the invention will now be described with reference to the accompanying drawings. The throttle valve of the present invention is Under high pressure and temperature, mixtures of gases, liquids, water and steam, and liquids and abrasives Uses rally to act as a control valve for severe service. The throttle valve is Designed to protect valve surfaces from deterioration caused by corrosion and wear.

The liquid medium emanating from the source enters the throttle valve 10 through the source input and conduit port 13. Enter. In the fully closed position, the nose portion of plug 26 allows liquid to pass through valve 10. It engages an inner annular seat 32 forming a seal to prevent leakage.

Conventional actuators cause vertical upward movement of the valve stem 18 toward the open position, and Release plug 26 from inner annular seat 32 and allow liquid to flow through valve 10 . The plug retracts into the cavity of the lid 14.

Liquid flowing through input port 13 is directed to inner annular seat 32 by the nose of the plug. is directed downwards, and its contour is defined by the following exponential equation:

Y=A0(V-A)/U”””’x　(U-X)””’-^)Here, A=D/2 , D is the diameter of the plug at the tip.

v==sxcl;U=SXCz Here, C7 is 0.1 to 5. is a constant with a value of 0, and C2 is 0. 5~5゜0 is a constant value of . S is the distance between the central plug axis and the inner seat at the point of minimum diameter It's far away.

W=C3, where C8 is a value between 0.1 and 2.0.

X=stroke, where stroke is equal to the nominal size of the valve.

When the liquid flows on the first inner surface 36 of the inner annular seat 32, the cross-sectional area at the inner surface 36 is Continuously accelerated to continuously decrease. The velocity of the liquid medium is determined by the inner annular seat 3 The maximum is reached when the start of the second inner surface 38 of 2 is reached. The cross-sectional area at the second inner surface 38 is It suddenly increases in size as it connects to the oral canal 15. of the first and second inner surfaces 36.38; Due to the sudden change in the cross-sectional area between the In its vicinity it causes evaporation of the liquid medium and subsequent cavitation. nose The profile of portion 42 directs liquid flow and resulting cavitation to the surface of nose 42. downwardly toward the cavity 46.

The bubbles formed as a result of cavitation implode within the cavity 46 and its walls is coated to prevent deterioration. The liquid and gas mixture is then passed through the output port. is released.

In this embodiment, flanges 54 and 56 are inserted into the socket as shown in FIG. It is provided in the mouth conduit 13 and the outlet conduit 15 and serves to connect the throttle valve. There is. However, depending on the system in which the valve is used, proper installation may require You will find that it is also good.

The plug and seat assembly operates in a similar manner in alternative embodiments. . However, the wear-resistant mounting plate 58 protects the valve body from cavitation liquid. There is.

Changes may be made to the above-described embodiments of the invention without departing from the broader inventive concept. That will be recognized by those skilled in the art. Therefore, this invention discloses without being limited to the particular embodiments described, but as defined by the appended claims. As such, it is intended to embrace all modifications that fall within the scope and spirit of the invention.

■ Procedural amendment February 17, 1992

Claims (11)

[Claims] 1. In a throttle valve that prevents deterioration of the valve surface, it is a casing that allows the liquid medium to an inlet conduit for introducing into the valve and a cone for discharging liquid from said casing. and a valve port for supporting a retractable valve member. an annular casing located within the housing between the inlet and outlet ports; A retractable valve plug for opening and closing the flow between the sealing member and the inlet suction outlet conduit. the valve has a contoured nose for sliding engagement with the sealing means; , contoured to direct liquid flow toward the center of the outlet conduit, thereby Evaporation and cavitation of the liquid occurs through a retractable valve from the wall of the outlet conduit. A throttle valve comprising a plug. 2. The sealing means connects an outer annular seat and an inner annular seat inserted within the outer annular seat. A throttle valve according to claim 1, comprising: 3. 3. The throttle valve of claim 2, wherein the outer annular seat is welded to the housing. 4. The contour of the nose is defined by the exponential equation Y=A+(VA-A)/U(WU/V-A)× (U-X) (WU/V-A) where A=D/2, D is the diameter of the plug at the tip , V=S×C1; U=S×C2 Here, C1 is a constant with a value of 0.1 to 5.0, and C2 is a constant with a value of 0.5 to 5.0. is a constant of S is the distance between the central plug axis and the inner seat at the point of minimum diameter, W = C3 , where C3 is a value between 0.1 and 2.0, X=stroke, where stroke is the valve's public 3. Throttle valve according to claim 2, defined by: equal to the nominal size. 5. A throttle valve according to claim 1, wherein the valve plug is coated with a highly wear-resistant material. 6. Claim 5, wherein the highly wear-resistant material is tungsten carbide or chromium. throttle valve. 7. In a throttle valve that prevents deterioration of the valve surface, it is a casing that allows the liquid medium to A generally cylindrical inlet conduit for introducing into the valve and for discharging liquid from said casing. a conically expanding outlet conduit for receiving and retaining a retractable valve member; a casing having a valve port; an annular sealing member attached to the housing between the inlet and outlet ports; a retractable valve member extending through the valve port; the material has a contoured nose portion for sliding engagement with the annular sealing means; Equation, Y=A+(V-A)/U(WU/V-A)×(U-X)(WU/V-A) where A=D/2, D is the diameter of the plug at the tip, V=S×C1; U=S×C 2 Here, C1 is a constant with a value of 0.1 to 5.0, and C2 is a constant with a value of 0.5 to 5.0. is a constant of S is the distance between the central plug axis and the inner seat at the point of minimum diameter, W = C3 , where C3 is a value between 0.1 and 2.0, X=stroke, where stroke is the valve's public equal to the nominal size of the ring to direct the flow toward the center of the outlet port. The evaporation and cavitation of the liquid is reduced between the contoured nose area and the corresponding area. Throttle valve originating from the conically expanding wall of the outlet conduit. 8. In a throttle valve that prevents deterioration of the valve surface, it is a casing that allows the liquid medium to an inlet conduit for introducing the liquid medium into the valve; and an inlet conduit for discharging the liquid medium; an outlet conduit extending vertically and having a conically expanding inner wall; a casing and the inlet conduit to form a seal between the inlet and outlet conduits; an annular sealing means attached to the casing between the outlet conduit and a retractable valve plug; a lid attached to the casing having a groove for retaining the lugs; a retractable valve plug retained within the lid and between the inlet and outlet conduits; a contoured nose portion for sliding engagement with the sealing means for opening and closing the flow of the liquid medium; and the contoured nose portion directs fluid toward the center of the conically expanding outlet conduit. evaporation and cavitation of the liquid are directed towards the outflow of the cone. A throttle valve comprising a retractable valve plug emanating from the wall of the outlet conduit that expands into the . 9. The contour nose part is expressed by the equation Y=A+(V-A)/U(WU/V-A)×(U-X)(WU/V-A) where A=D/2, D is the diameter of the plug at the tip, V=S×C1; U=S×C 2 Here, C1 is a constant with a value of 0.1 to 5.0, and C2 is a constant with a value of 0.5 to 5.0. is a constant of S is the distance between the central plug axis and the inner seat at the point of minimum diameter, W = C3 , where C3 is a value between 0.1 and 2.0, X=stroke, where stroke is the valve's public 9. Throttle valve according to claim 8, defined by: equal to the nominal size. 10. In throttle valves that prevent deterioration of the valve surface, it is the casing that prevents the liquid medium from flowing. an inlet conduit for introducing the liquid into the valve; and a substantially inlet conduit for discharging the liquid. an outlet conduit extending parallel to the the inlet conduit and the outlet conduit to form a seal between the inlet conduit and the outlet conduit. an annular sealing means attached to the casing between the outlet conduit; a cap attached to the inlet and outlet conduits and extending substantially across the inlet and outlet conduits; a lid having a groove for holding a retractable valve plug; a retractable valve plug retained within the lid and between the inlet and outlet conduits; a contoured nose portion for sliding engagement with the sealing means for opening and closing the flow of the liquid medium; and the contoured nose portion directs fluid toward the center of the conically expanding outlet selection tube. directing the flow, which prevents evaporation and cavitation of the liquid from expanding into the cone. a retractable valve plug that emanates from the wall of the outlet conduit; a removable erosion protection located in the outlet portion opposite the plug and the annular sealing means; A throttle valve comprising a plate. 11. The contour nose part is expressed by the equation Y=A+(V-A)/U(WU/V-A)×(U-X)(WU/V-A) where A=D/2, D is the diameter of the plug at the tip, V=SxC1; U=SxC 2 Here, C1 is a constant with a value of 0.1 to 5.0, and C2 is a constant with a value of 0.5 to 5.0. is a constant of S is the distance between the central plug axis and the inner seat at the point of minimum diameter, W = C3 , where C3 is a value between 0.1 and 2.0, X=stroke, where stroke is the valve's public 11. Throttle valve according to claim 10, defined by: equal to the nominal size.