High pressure differential scouring low noise stop valve

Abstract

The application belongs to the field of valves, and particularly relates to a high-pressure-difference anti-erosion low-noise stop valve, which comprises a valve body, a valve cover, a valve seat, a valve rod and a valve flap, the valve body is provided with a valve cavity, the valve body is provided with a liquid inlet channel and a liquid outlet channel which are communicated with the valve cavity, the valve seat is provided with a valve seat hole which is communicated with the liquid inlet channel, the valve sleeve is provided with a valve sleeve hole which is communicated with the valve seat hole, the valve flap is connected with the valve rod and is in sealing cooperation with the valve sleeve, one end of the valve flap is provided with a conical sealing part which is in sealing cooperation with the valve seat hole, a convex ring sealing part which is in sealing cooperation with the valve sleeve is arranged between the conical sealing part and the valve sleeve hole, the valve cavity is provided with A, B and C pressure reduction cavities which are communicated with each other, the A pressure reduction cavity is communicated with the valve sleeve hole, and the C pressure reduction cavity is communicated with the liquid outlet channel; the valve flap is provided with a double-sealing-vice structure and a three-stage pressure reduction cavity structure, the three-stage pressure reduction cavity has a sound insulation, noise reduction and shock absorption function, the erosion and abrasion of the sealing surface are reduced, and the probability of external leakage is reduced.

Description

Technical Field

[0001] This invention belongs to the field of valve technology, specifically relating to a high pressure differential anti-erosion low noise shut-off valve. Background Technology

[0002] Gate valves are among the earliest types of valves developed and applied. Their working principle involves using an operating component (such as a handwheel, speed reducer, pneumatic device, or electric device) mounted on the valve to raise or lower the valve stem, causing the closing element (valve disc) to vertically disengage from or press against the valve seat, thereby allowing or cutting off the flow of fluid media. Gate valves are commonly used for boiler blowdown. They are installed on the water-cooled wall pipes of supercritical and ultra-supercritical boilers to remove insoluble impurities such as slag, sludge, and soft sediments deposited at the bottom of the boiler, preventing scaling and corrosion.

[0003] Existing gate valves used for periodic boiler blowdown have several problems. Because the boiler blowdown water contains solid particles and is of poor quality, the heat carried away by the blowdown is minimal, accounting for only 0.1-0.5% of the evaporation, and is generally not (or difficult to) recover, resulting in direct venting. Therefore, the discharge pressure differential is large, causing severe erosion of the valve sealing surfaces. Especially at the moment of valve opening, with the valve disc at a small opening, the high-velocity medium creates an extremely high pressure differential, eroding the main sealing surfaces (i.e., the valve seat and valve disc sealing surfaces). This erosion is similar to high-pressure fluid cutting, rapidly damaging the closing components. When the valve is opened for blowdown, the high flow velocity generates extremely loud noise, severely affecting the on-site and surrounding working environment. Generally, existing gate valves used for blowdown rarely last more than 3 months; in extreme cases, they leak severely within a week, losing their sealing function and causing significant heat loss. The steam medium impacts the valve cover, causing the valve stem and valve cover sealing surfaces to fail, leading to external leakage, reduced thermal efficiency, and pollution of the working environment. Therefore, designing a high-pressure differential, erosion-resistant, and low-noise gate valve to replace conventional gate valves for boiler blowdown is essential. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and provide a high-pressure differential anti-erosion low-noise shut-off valve, which effectively solves the problems of high pressure differential, large erosion, high peak noise and easy leakage when shut-off valves are used for boiler blowdown.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A high-pressure differential anti-erosion low-noise shut-off valve includes a valve body, a valve cover, a valve seat, a valve stem, and a valve disc. The valve body has a valve cavity, and an inlet channel and an outlet channel communicating with the valve cavity are respectively provided on the valve body. The valve seat is disposed in the valve cavity, and the valve seat is provided with a valve seat hole communicating with the inlet channel. A valve sleeve is provided on the valve seat, and the valve sleeve is provided with a valve sleeve hole communicating with the valve seat hole. The valve disc is linkedly disposed on the valve stem and is sealed with the valve sleeve. One end of the valve disc has a conical sealing part that seals with the valve seat hole. A convex ring sealing part that seals with the valve sleeve hole is provided on the valve disc between the conical sealing part and the valve sleeve hole. The valve cavity has a pressure reducing chamber A, a pressure reducing chamber B, and a pressure reducing chamber C that are connected in sequence. The pressure reducing chamber A is connected with the valve sleeve hole, and the pressure reducing chamber C is connected with the outlet channel.

[0006] In some embodiments, the diameter of the conical sealing portion is smaller than the diameter of the convex ring sealing portion, and the valve disc has an arcuate groove corresponding to the area between the conical sealing portion and the convex ring sealing portion.

[0007] In some embodiments, a baffle is provided in the valve cavity to separate the pressure reducing chamber A and the pressure reducing chamber B, and the baffle is provided with a through hole for connecting the pressure reducing chamber A and the pressure reducing chamber B.

[0008] In some embodiments, a valve cage is provided inside the valve cavity, separating the pressure reducing chamber B and the pressure reducing chamber C, and the valve cage is provided with a plurality of valve cage holes for communicating with the pressure reducing chamber B and the pressure reducing chamber C.

[0009] In some embodiments, guide slopes are provided on both sides of the convex ring sealing portion.

[0010] In some embodiments, the valve sleeve has a guide hole through which the valve disc can pass, and the valve disc is provided with a plurality of sealing rings that seal with the valve sleeve along its axial direction.

[0011] In some embodiments, a back seal is provided between the valve stem and the valve cover, and a sealing step that cooperates with the back seal is provided on the valve stem. When the valve stem moves to the fully open position, the valve stem drives the sealing step to abut against the back seal.

[0012] In some embodiments, a layer of STL hard alloy is deposited inside the conical sealing part, the convex ring sealing part, and the valve seat hole.

[0013] In some embodiments, the valve body is provided with a flange for pressing the valve cover onto the valve body, and a sealing ring is provided between the valve body, the valve cover, and the flange.

[0014] In some embodiments, a buffer mechanism is further included in the liquid inlet channel. The buffer mechanism includes an orifice plate and an elastic element. The orifice plate is slidably disposed in the liquid inlet channel and is used to buffer the impact force of the liquid in the liquid inlet channel. The elastic element is disposed between the orifice plate and the valve seat. The elastic force of the elastic element causes the orifice plate to block the impact force of the liquid. The orifice plate is provided with a plurality of through holes for liquid to flow through.

[0015] The beneficial effects of this invention are as follows: The valve disc adopts a double-sealing pair structure and a three-stage pressure-reducing chamber structure design. The first-stage sealing pair adopts a conical sealing structure, and the second-stage sealing pair adopts a convex ring sealing structure. When the valve is opened, the high-velocity medium generated by the small opening transfers its scouring force from the first-stage sealing pair to the second-stage sealing pair, effectively reducing the pressure drop of the first-stage sealing pair at the moment of valve opening, thereby reducing the erosion of the first-stage sealing pair by the high pressure difference. The three-stage pressure-reducing chamber has sound insulation, noise reduction, and vibration damping functions; and it gradually reduces the pressure drop of the medium flowing through the valve during valve opening and sewage discharge, effectively protecting the sealing surfaces of the second-stage sealing pair, valve stem, and flap, reducing erosion and wear on the sealing surfaces, reducing the probability of external leakage, and greatly extending the service life of the gate valve when used for sewage discharge; it also reduces noise and improves the working environment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0017] Figure 1 This is a structural diagram of an embodiment of the present invention;

[0018] Figure 2 for Figure 1 Enlarged view of section A in the middle;

[0019] Figure 3 This is a schematic diagram of the structure when the valve disc opening height is h according to an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure after the valve disc is fully opened according to an embodiment of the present invention. Detailed Implementation

[0021] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings, are intended to cover non-exclusive inclusion.

[0023] The directional and positional terms used in this invention, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for illustrating and understanding this invention, and not for limiting the scope of protection of this invention.

[0024] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments:

[0025] like Figure 1-3As shown, a high-pressure differential anti-erosion low-noise shut-off valve includes a valve body 1, a valve cover 2, a valve seat 3, a valve stem 4, and a valve disc 5. The valve body 1 has a valve cavity 100, and an inlet channel 101 and an outlet channel 102 communicating with the valve cavity 100 are respectively provided on the valve body 1. The valve seat 3 is disposed in the valve cavity 100, and the valve seat 3 is provided with a valve seat hole 31 communicating with the inlet channel 101. A valve sleeve 6 is provided on the valve seat 3, and the valve sleeve 6 is provided with a valve sleeve hole 61 communicating with the valve seat hole 31. The valve disc 5 is linked to the valve stem 4 and is sealed with the valve sleeve 6. One end of the valve disc 5 has a conical sealing part 51 that seals with the valve seat hole 31. A convex ring sealing part 52 that seals with the valve sleeve 6 is provided on the valve disc 5 between the conical sealing part 51 and the valve sleeve hole 61. The valve cavity 100 has a pressure reducing chamber A 103, a pressure reducing chamber B 104, and a pressure reducing chamber C 105 that are connected in sequence. Pressure reducing chamber A 103 is connected to valve sleeve hole 61, and pressure reducing chamber C 105 is connected to liquid outlet channel 102. The diameter of the conical sealing part 51 is smaller than the diameter of the convex ring sealing part 52, and the valve disc 5 has an arc-shaped groove 53 corresponding to the area between the conical sealing part 51 and the convex ring sealing part 52. The arc-shaped groove can guide the flow of medium, avoid impurities from accumulating at the interface of the sealing surface, and reduce the risk of jamming or scratching the sealing surface. When the valve is opened and closed, the medium flowing through the groove will generate local eddies, which will play a self-cleaning role at the interface of the sealing surface. This will help extend the sealing service life of the gate valve. A baffle 7 is provided in the valve cavity 100, separating pressure reducing chamber A 103 and pressure reducing chamber B 104. The baffle 7 is provided with a through hole 71 for connecting pressure reducing chamber A 103 and pressure reducing chamber B 104. The through hole of the baffle can throttle and reduce the flow rate and pressure, avoid high-speed erosion of the sealing surface, and thus help extend the sealing service life of the gate valve. A valve cage 8 is disposed within the valve chamber 100, separating the pressure-reducing chamber B 104 and the pressure-reducing chamber C 105. The valve cage 8 is provided with multiple valve cage holes 81 for connecting the pressure-reducing chambers B 104 and C 105. The valve cage has multiple regularly arranged valve cage holes, which divide the medium into multiple fine streams as it passes through them. This gradual throttling reduces the flow velocity and pressure, preventing cavitation, flashing, or high-speed erosion under high pressure differentials. This helps extend the sealing life of the gate valve.

[0026] like Figure 2-4As shown, guide ramps 521 are provided on both sides of the convex ring sealing part 52. The guide ramps can guide the valve disc to fit more accurately with the sealing surface during the closing process, avoiding poor sealing or local wear caused by positional misalignment, and can meet the requirements of high pressure differential or frequent operation conditions. The valve sleeve 6 has a guide hole 62 through which the valve disc 5 can pass, and multiple sealing rings 54 are respectively provided on the valve disc 5 along its axial direction to seal with the valve sleeve 6. The valve disc achieves axial sealing with the valve sleeve through multiple sealing rings, which helps to improve the sealing performance between the valve disc and the valve sleeve. A reverse seal 21 is provided between the valve stem 4 and the valve cover 2. A sealing step 41 that cooperates with the reverse seal 21 is provided on the valve stem 4. When the valve stem 4 moves to the fully open position, the valve stem 4 drives the sealing step 41 to abut against the reverse seal 21. When the valve is fully open, the valve stem is pressed against the reverse seal by the sealing step, which can effectively improve the sealing performance between the valve stem and the valve cover and prevent leakage. A layer of STL hard alloy is overlaid in the conical sealing part 51, the convex ring sealing part 52, and the valve seat hole 31. The STL overlay structure design in the conical sealing part, the convex ring sealing part, and the valve seat hole can effectively improve the wear resistance, corrosion resistance, high temperature stability, and sealing performance of the sealing surfaces of the conical sealing part, the convex ring sealing part, and the valve seat hole, thereby effectively resisting media erosion and particle wear, and extending the service life of the valve sealing surface.

[0027] like Figure 1 and 2 As shown, a flange 11 is provided on the valve body 1 to press the valve cover 2 onto the valve body 1. A sealing ring 12 is provided between the valve body 1, the valve cover 2, and the flange 11. The sealing ring is pressed between the valve body and the valve cover by the flange, which helps to improve the sealing performance of the valve body and the valve cover. A buffer mechanism 9 is also included in the inlet channel 101. The buffer mechanism 9 includes an orifice plate 91 and an elastic element 92. The orifice plate 91 is slidably disposed in the inlet channel 101 to buffer the impact force of the liquid in the inlet channel. The elastic element 92 is disposed between the orifice plate 91 and the valve seat 3. The elastic force of the elastic element 92 causes the orifice plate 91 to block the impact force of the liquid. The orifice plate 91 is provided with multiple through holes 911 for liquid flow. The buffer mechanism adopts an elastic structure design, and the orifice plate can effectively reduce the impact force of the liquid in the inlet channel, thereby helping to extend the sealing life of the valve. A sliding guide groove is provided within the liquid inlet channel 101, and the orifice plate 91 is slidably disposed within the sliding guide groove. The elastic element 92 is a spring, with one end of the spring abutting against the positioning groove of the orifice plate 91 and the other end abutting against the valve seat 3. The sliding guide groove within the liquid inlet channel allows the orifice plate to slide reliably, ensuring that the orifice plate can reliably operate within the sliding guide groove. The buffer mechanism adopts a spring structure design, which plays a buffering role, effectively reducing the scouring force of high-velocity media and helping to extend the valve's sealing life.

[0028] The valve disc adopts a double-sealing pair structure and a three-stage pressure-reducing chamber structure. The first-stage sealing pair uses a conical sealing structure, and the second-stage sealing pair uses a convex ring sealing structure. When the valve is opened, the high-velocity medium generated at a small opening transfers its scouring force from the first-stage sealing pair to the second-stage sealing pair, effectively reducing the pressure drop of the first-stage sealing pair at the moment of valve opening, thereby reducing the erosion of the first-stage sealing pair by the high pressure differential. The three-stage pressure-reducing chamber has sound insulation, noise reduction, and vibration damping functions; and it progressively reduces the pressure drop of the medium flowing through the valve during valve opening and sewage discharge, effectively protecting the sealing surfaces of the second-stage sealing pair, valve stem, and flap, reducing erosion and wear on the sealing surfaces, reducing the probability of external leakage, greatly extending the service life of the gate valve when used for sewage discharge; reducing noise and improving the working environment.

[0029] When the main sealing pair of the valve is closed to achieve a seal, the sealing height of the second sealing pair is h (e.g., Figure 2 When the valve is opened (as shown in Figure 3), the valve stem moves the valve disc upwards. When the opening height reaches h, sealing pair II is at the critical opening / closing position, while sealing pair I has formed an annular channel with a width of δ. If the valve continues to open to a smaller degree (>h), at sealing pair II, the convex ring seal of the valve disc disengages from the valve sleeve hole. As the opening increases, the increase in channel area at sealing pair I is much greater than the increase in channel area at sealing pair II; that is, the medium velocity V2 at sealing pair II is much greater than the medium velocity V1 at sealing pair I. According to Bernoulli's equation, the medium pressure drop ΔP = ρV 2 / 2. Therefore, the pressure drop at sealing pairs II and I is ΔPII > ΔPI. Thus, under small opening conditions, the location of most severe medium erosion changes from sealing pair I to sealing pair II, significantly reducing the erosion of the valve seat and valve disc sealing surfaces by the high pressure difference and extending the valve's sealing lifespan.

[0030] After the valve is fully opened (as shown in Figure 4), the valve stem sealing step presses against the back seal, and the back seal functions. The medium flows inside the valve, passing through the valve seat hole and valve sleeve hole in sequence to pressure reducing chambers A, B, and C (the pressure in pressure reducing chamber A is ΔPa, the pressure in pressure reducing chamber B is ΔPb, and the pressure in pressure reducing chamber C is ΔPc), and finally flows out from the valve body outlet channel. The valve's working pressure is P, reaching a maximum of Pmax = 32MPa, and the valve outlet pressure is Po. During drainage, Po is generally close to atmospheric pressure. The pressure drop ΔP flowing through the valve decreases sequentially to ΔPa, ΔPb, and ΔPc, where ΔP = P - Po = ΔPa + ΔPb + ΔPc. Therefore, the pressure drop between the valve seat and valve disc sealing pair decreases from ΔP to ΔPa, thereby reducing erosion and wear on the valve disc and valve seat sealing surfaces. When the valve is at a small opening, the high-velocity medium is sound-insulated through cavity B and its noise is reduced by the cover side of cavity C, which greatly reduces the noise generated by the medium flowing through the valve and reduces the vibration during valve operation.

[0031] The above description is merely one embodiment of the present invention and is not intended to limit the scope of protection of the present invention; the scope of protection of the present invention is defined by the claims in the claims, and all equivalent changes and modifications made in accordance with the invention are within the scope of protection of the present invention patent.

Claims

1. A high-pressure differential anti-erosion low-noise shut-off valve, comprising a valve body, a valve cover, a valve seat, a valve stem, and a valve disc, characterized in that: The valve body has a valve cavity, and the valve body is respectively provided with an inlet channel and an outlet channel communicating with the valve cavity. The valve seat is disposed in the valve cavity, and the valve seat is provided with a valve seat hole communicating with the inlet channel. The valve seat is provided with a valve sleeve, and the valve sleeve is provided with a valve sleeve hole communicating with the valve seat hole. The valve disc is linkedly disposed on the valve stem and is sealed with the valve sleeve. One end of the valve disc has a conical sealing part that seals with the valve seat hole. A convex ring sealing part is provided on the valve disc between the conical sealing part and the valve sleeve hole, and is sealed with the valve sleeve. The valve cavity has a pressure reducing chamber A, a pressure reducing chamber B, and a pressure reducing chamber C that are connected in sequence. The pressure reducing chamber A is connected with the valve sleeve hole, and the pressure reducing chamber C is connected with the outlet channel. The valve cavity is provided with a baffle separating the pressure reducing chamber A and the pressure reducing chamber B, and the baffle is provided with a through hole for connecting the pressure reducing chamber A and the pressure reducing chamber B. The valve cavity is provided with a valve cage separating the pressure reducing chamber B and the pressure reducing chamber C. The valve cage is provided with multiple valve cage holes for connecting the pressure reducing chamber B and the pressure reducing chamber C.

2. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: The diameter of the conical sealing part is smaller than the diameter of the convex ring sealing part, and the valve disc has an arc-shaped groove between the conical sealing part and the convex ring sealing part.

3. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1 or 2, characterized in that: The convex ring sealing part is provided with guide slopes on both sides.

4. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: The valve sleeve has a guide hole through which the valve disc can pass, and the valve disc is provided with a plurality of sealing rings that seal with the valve sleeve along its axial direction.

5. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: A back seal is provided between the valve stem and the valve cover. A sealing step that cooperates with the back seal is provided on the valve stem. When the valve stem moves to the fully open position, the valve stem drives the sealing step to abut against the back seal.

6. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: The conical sealing part, the convex ring sealing part, and the valve seat hole are all welded with a layer of STL hard alloy.

7. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: The valve body is provided with a flange for pressing the valve cover onto the valve body, and a sealing ring is provided between the valve body, the valve cover, and the flange.

8. The high-pressure differential anti-erosion low-noise shut-off valve according to claim 1, characterized in that: It also includes a buffer mechanism installed in the liquid inlet channel. The buffer mechanism includes an orifice plate and an elastic element. The orifice plate is slidably installed in the liquid inlet channel and is used to buffer the impact force of the liquid in the liquid inlet channel. The elastic element is installed between the orifice plate and the valve seat. The elastic force of the elastic element causes the orifice plate to block the impact force of the liquid. The orifice plate is provided with multiple through holes for liquid to flow through.

Images