Cavitation-resistant low-noise three-eccentric center butterfly valve

Abstract

The invention discloses an anti-cavitation low-noise three-eccentric center butterfly valve, and belongs to the technical field of industrial valves.The valve body disclosed by the invention has an anti-cavitation design, so that valve internals can be protected, frequent damage of parts is avoided, and the service life of the valve is prolonged; the anti-cavitation holes can effectively reduce noise generated in the working process of the valve; the three-eccentric butterfly valve is provided with three eccentric points, so that excellent control performance and sealing capability can be provided; the self-compensation design is adopted to adapt to abrasion and temperature changes, the excellent temperature performance and abrasion resistance of the valve are ensured, the front face and the back face of the butterfly plate are each provided with a fan-shaped spherical surface, a plurality of small holes are evenly distributed in the surfaces of the spherical surfaces, and the small holes can decompose large jet fluid into a plurality of small flow beams; concentrated single total energy is decomposed into a plurality of small energy units, the pressure drop flowing through the valve is controlled not to be lower than the vaporization pressure of a fluid medium, bubbles cannot be generated, cavitation is avoided, and the metal surface of a valve internal part is protected.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial valves, and in particular relates to a cavitation-resistant, low-noise triple-eccentric butterfly valve. Background Art

[0002] In the field of industrial valves, triple eccentric butterfly valves, as a key control component, have a unique structural design and are widely used in various fluid delivery systems. Compared with ordinary butterfly valves, triple eccentric butterfly valves have three key eccentric designs in their structure: one is the eccentricity between the valve stem axis and the center of the butterfly plate sealing surface, the second is the eccentricity between the valve stem axis and the center line of the valve body, and the third is the eccentricity between the center line of the valve body and the center line of the butterfly plate. This triple eccentric structure gives the triple eccentric butterfly valve many excellent properties, enabling it to achieve better sealing effects, higher adjustment accuracy, and adapt to more complex working conditions.

[0003] Traditional three-eccentric butterfly valves have many problems in long-term use. When in a small opening condition, the internal fluid channel is narrow, the medium flow rate increases sharply, and the valve internal parts, such as the valve seat, the edge of the butterfly plate and the sealing parts, are violently impacted, causing mechanical vibration. Long-term accumulation will cause the parts to loosen and deform, affecting the mechanical performance and sealing reliability.

[0004] At the same time, the turbulent flow of the fluid causes uneven pressure. According to the principles of fluid mechanics, the local pressure drops below the saturated vapor pressure of the medium, causing vaporization and the generation of a large number of bubbles. After flowing to the pressure recovery area, the bubbles burst instantly due to the high pressure, generating impact force and local high temperature, causing pits, pitting and other damage to the metal surface of the valve trim, which is cavitation. This will cause the seal to fail and leak, resulting in the valve being unable to work normally, greatly increasing the risk of failure in the fluid delivery system.

[0005] In addition, cavitation is also accompanied by strong noise. The energy of bubble burst is transmitted in the form of sound waves, which overlap and interfere with each other to form a high-intensity noise field, which interferes with communication at the industrial production site and damages the hearing of operators. Cavitation also causes abnormal fluid resistance, requiring additional energy to maintain the system, increasing corporate costs and energy consumption, and deviating from the concept of energy conservation and emission reduction.

[0006] In summary, cavitation and its derivative problems at small opening of traditional three-eccentric butterfly valve restrict its application in high-precision fluid control systems. Therefore, there is an urgent need for a low-noise three-eccentric butterfly valve that is resistant to cavitation. Summary of the invention

[0007] In view of the above situation, in order to overcome the defects of the prior art, the present invention is based on preventing the occurrence of cavitation, providing users with a direct anti-cavitation function when in use, which can effectively reduce the bubbles generated when the fluid flows inside the valve with a small opening, and prevent these bubbles from suddenly bursting in the pressure recovery area and causing damage to the valve. At the same time, the small hole design can greatly suppress the noise generated during the working process, and the pressure drop is relatively reduced, thereby reducing energy consumption and improving the efficiency of the system.

[0008] In order to achieve the above-mentioned purpose, the following technical scheme is adopted: the present invention provides a cavitation-resistant, low-noise three-eccentric butterfly valve, comprising a valve body, a butterfly plate, and a valve stem, the butterfly plate being located in the center of the valve body, the butterfly plate being connected to the valve body through the valve stem, a sealing gasket and an elastic sealing ring being placed on the front of the valve body, the sealing gasket and the elastic sealing ring being pressed against the valve body by a pressure ring, the upper and lower parts of the valve body being sealed by a stuffing box assembly and a bottom cover respectively, a semi-ring being embedded in the groove at the lower end of the valve stem, a fan-shaped spherical surface being respectively arranged on the front and back sides of the butterfly plate, and a plurality of small holes being evenly distributed on the fan-shaped spherical surface.

[0009] Furthermore, the pressure ring is fixed to the valve body by screws.

[0010] Furthermore, the half ring is clamped on the lower end of the valve body to limit the axial movement of the valve stem.

[0011] Furthermore, two fan-shaped spherical surfaces are provided, and the fan-shaped spherical surfaces are centrally symmetrical with the center line of the valve stem as the axis.

[0012] The beneficial effects of the present invention are as follows: the valve body disclosed in the present invention has an anti-cavitation design, which can protect the valve internals, avoid frequent damage to parts, and extend the service life of the valve; the anti-cavitation holes can effectively reduce the noise generated by the valve during operation; the three-eccentric butterfly valve design has three eccentric points, which can provide excellent control performance and sealing ability; the self-compensation design can adapt to wear and temperature changes, ensuring the excellent temperature performance and wear resistance of the valve. The front and back sides of the butterfly plate have a fan-shaped spherical design, and many small holes are evenly distributed on the surface of these spherical surfaces. These small holes can decompose larger jet fluids into many small streams, thereby decomposing the concentrated single total energy into many small energy units, controlling the pressure drop flowing through the valve to be not lower than the vaporization pressure of the fluid medium, so that bubbles cannot be generated, thereby avoiding cavitation and protecting the metal surface of the valve internals. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an overall structural diagram of a low-noise, cavitation-resistant triple-eccentric butterfly valve of the present invention;

[0014] Figure 2 It is a top view of a low-noise, cavitation-resistant triple-eccentric butterfly valve of the present invention when the opening degree is 20°;

[0015] Figure 3 This is a top view of a low-noise, cavitation-resistant triple-eccentric butterfly valve of the present invention when the opening angle is 60°.

[0016] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0017] Legend: 1. Valve body; 2. Butterfly plate; 3. Valve stem; 4. Sealing gasket; 5. Elastic sealing ring; 6. Pressing ring; 7. Stuffing box assembly; 8. Bottom cover; 9. Half ring; 10. Sector spherical surface; 11. Small hole. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0020] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0021] Reference Figure 1-3 The present invention provides an embodiment: a low-noise three-eccentric butterfly valve with anti-cavitation, which has an ingenious overall structural design and various components cooperate with each other to play a unique function. The butterfly valve mainly includes several key components: valve body, butterfly plate and valve stem.

[0022] The butterfly plate is located in the center of the valve body. This position setting makes it the core component that controls whether the fluid medium flows and the flow rate. The butterfly plate is connected to the valve body through the valve stem. The valve stem plays a transmission role and can drive the butterfly plate to rotate according to the predetermined requirements, thereby achieving precise adjustment of the valve opening.

[0023] There are sealing gaskets and elastic sealing rings placed on the front of the valve body, and the existence of these two plays a vital role in ensuring the sealing of the valve. The sealing gasket and the elastic sealing ring are pressed against the valve body by a pressure ring, and the pressure ring is fixed to the valve body by screws. This fixing method allows the sealing gasket and the elastic sealing ring to be firmly in the working position, effectively preventing the fluid from leaking from the front of the valve body. Even under the influence of factors such as pressure changes and vibrations under long-term use and different working conditions, it can still maintain good sealing performance.

[0024] The upper and lower parts of the valve body are sealed by the stuffing box assembly and the bottom cover respectively. The stuffing box assembly can well seal the gap between the valve stem and the valve body to prevent the medium from leaking out of this part. At the same time, it can also play a certain supporting and limiting role on the valve stem to ensure the stability of the valve stem during operation; the bottom cover further improves the sealing structure of the lower part of the valve body, and together with other components constructs a relatively closed and reliable internal space to ensure that the fluid flows inside the valve according to the predetermined flow channel.

[0025] A half ring is embedded in the groove at the lower end of the valve stem, and the half ring is stuck in the lower end of the valve body to limit the axial movement of the valve stem. This design detail can accurately control the movement range of the valve stem and prevent abnormal situations such as excessive axial movement during operation, thereby ensuring the accurate rotation angle of the butterfly plate, thereby achieving precise control of the fluid flow rate, and also helping to extend the service life of the entire valve and reduce problems such as component wear that may be caused by abnormal displacement of the valve stem.

[0026] In particular, the front and back sides of the butterfly plate are each provided with a sector-shaped spherical surface, and there are two sector-shaped spherical surfaces, and the sector-shaped spherical surfaces are centrally symmetrical with the center line of the valve stem as the axis. This symmetrical design enables the butterfly plate to exert corresponding functional characteristics in different rotation directions and when facing fluids of different flow directions. More importantly, there are a number of small holes evenly distributed on the sector-shaped spherical surface. These small holes have unique functions and design significance, and are the key to achieving many excellent properties of the butterfly valve, such as anti-cavitation and low noise.

[0027] How it works

[0028] like Figure 2 , Figure 3 As shown, when the butterfly plate rotates to a small opening, the traditional three-eccentric butterfly valve is prone to cavitation and produces a lot of noise. In this state, the butterfly valve of the present invention changes the flow state of the fluid due to the presence of the small holes when the fluid medium flows through the cavitation holes (i.e., the small holes on the fan-shaped spherical surface). The originally concentrated fluid jet with high energy is decomposed into many small streams by these small holes. From an energy perspective, the concentrated single total energy is decomposed into many small energy units. In this way, part of the energy can be effectively attenuated, thereby greatly reducing the noise generated by cavitation during operation.

[0029] When the medium enters the three-eccentric butterfly valve, it first reaches the slit between the butterfly plate and the elastic sealing ring. The butterfly plate rotates to gradually open or close the slit, thereby achieving flow control of the medium. In this process, due to the unique design of the butterfly plate, especially the fan-shaped spherical surface and the small holes on it, the fluid can avoid the problem of strong impact of the fluid medium on the valve trim at a small opening when flowing through the valve, which is like the traditional valve, and then bubbles are generated during internal flow, and the bubbles suddenly burst in the pressure recovery area to cause cavitation.

[0030] The valve design of the present invention is intended to control the pressure drop flowing through the valve to be no less than the vaporization pressure of the fluid medium. Through the synergistic effect of multiple factors such as the above-mentioned small hole design and the reasonable flow channel structure inside the entire valve, bubbles cannot be generated at all, thereby avoiding cavitation, protecting the metal surface of the valve internal parts from irreversible damage, preventing sealing failure and leakage caused by cavitation, and ensuring the overall reliability and sealing of the valve.

[0031] The present invention is a valve designed for the industrial field. It can be widely used in multiple working scenarios including offshore platforms, refineries, power plants, liquefied natural gas storage and transportation, urea, ammonia and fertilizer production, etc. It can be applied to seawater lift pump back pressure control, ballast water flow control, hydrocarbon gas flow control, fire main pipe bypass control, torch gas control, metering flow balance, steam control, cooling water flow and back pressure control, cooling tower deicing, loading and unloading flow control, liquefied natural gas circulation control, liquefied natural gas tank flow control, etc. The valve is precisely designed with three eccentric points in the design, which can provide excellent control performance and sealing ability. The design is designed to provide the most accurate, reliable and rugged service capabilities to help achieve safe operation and minimize downtime.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0033] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A low-noise, cavitation-resistant triple-eccentric butterfly valve, characterized in that: It includes a valve body, a butterfly plate and a valve stem. The butterfly plate is located in the center of the valve body. The butterfly plate is connected to the valve body through the valve stem. A sealing gasket and an elastic sealing ring are placed on the front of the valve body. The sealing gasket and the elastic sealing ring are pressed on the valve body through a pressure ring. The upper and lower parts of the valve body are sealed by a stuffing box assembly and a bottom cover respectively. A semi-ring is embedded in the groove at the lower end of the valve stem. A fan-shaped spherical surface is respectively arranged on the front and back sides of the butterfly plate, and a plurality of small holes are evenly distributed on the fan-shaped spherical surface.

2. The anti-cavitation low-noise triple-eccentric butterfly valve according to claim 1 is characterized in that: The pressing ring is fixed on the valve body by screws.

3. The anti-cavitation low-noise triple-eccentric butterfly valve according to claim 2 is characterized in that: The half ring is clamped at the lower end of the valve body to limit the axial movement of the valve stem.

4. The anti-cavitation low-noise triple-eccentric butterfly valve according to claim 3 is characterized by: There are two sector-shaped spherical surfaces, and the sector-shaped spherical surfaces are centrally symmetrical with the center line of the valve stem as the axis.

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