Anti-cavitation sleeve for valve and control valve

Abstract

The utility model relates to the field of valves, in particular to an anti-cavitation sleeve for a valve and a control valve. The anti-cavitation sleeve for the valve comprises a sleeve body, and the inner diameter of the sleeve body is gradually reduced in the flow direction of a medium. At least one annular groove surrounding the sleeve in the circumferential direction is formed in the circumferential wall of the sleeve. When a medium passes through the annular groove, the volume of the flowing medium is slightly increased, the pressure is slightly reduced, bubbles formed by cavitation are broken to a certain extent, corresponding energy is released and cracked, and the anti-cavitation effect is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the valve field, concretely relates to a valve is with anticavitation sleeve and control valve. BACKGROUND

[0002] In the coal chemical industry, the black ash water control valve as the key equipment is widely used in liquid, solid two-phase flow and gas, liquid or gas, liquid, solid three-phase flow and other complex working conditions. These working conditions often accompany the characteristics of high temperature, high pressure and containing solid powder or particle medium.

[0003] Under high temperature and high pressure conditions, the flow velocity in the throttling area of the valve increases sharply, and the local pressure may be lower than the saturated vapor pressure of the medium, resulting in vaporization of the liquid to form cavitation bubbles. When the bubbles enter the high pressure area with the fluid, they collapse rapidly, producing a transient high pressure shock wave and high speed microjet, which causes serious erosion and corrosion (mechanical erosion: cavitation impact causes fatigue spalling of the metal surface, forming honeycomb-shaped erosion pits; chemical corrosion: cavitation accelerates the penetration and corrosion of corrosive media such as acidic black ash water to the material), seriously affecting the safety and stability of the control valve and its service life.

[0004] Therefore, it is urgent to solve the cavitation problem of the control valve, especially the black ash water control valve in the coal chemical industry. SUMMARY

[0005] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a valve anticavitation sleeve, which can slightly increase the volume and slightly reduce the pressure of the inflowing medium when the medium passes through the annular groove, and the cavitation bubbles are broken to some extent and the corresponding energy is released, thereby playing an anticavitation role.

[0006] To solve the above technical problems, the technical scheme of the utility model is as follows: a valve anticavitation sleeve, comprising a sleeve, the inner diameter of the sleeve gradually decreases along the flow direction of the medium, wherein,

[0007] The peripheral wall of the sleeve is provided with at least one annular groove which surrounds the circumference.

[0008] Further, in order to reduce the stress concentration and the erosion damage of the parts caused by the bubble breakage, the bottom of the annular groove and each side wall are transitioned by a round corner R1, and the side wall of the annular groove on the medium outflow side and the inner wall of the sleeve are transitioned by a round corner R2.

[0009] Further, the inner peripheral wall of the sleeve is conical.

[0010] Further, the taper angle A of the inner peripheral wall of the sleeve is 4-10°.

[0011] Further, in order to improve the anti-cavitation and erosion resistance of the part, the number of annular grooves is n, the sleeve is divided into n+1 inner cone sections by all the annular grooves, and the length L of the inner cone section in the axial direction is equal to the width W of the annular groove.

[0012] Further, the depth of the annular groove is greater than the width W of the annular groove.

[0013] The utility model also relates to a control valve, including main valve body and valve anticavitation sleeve, wherein,

[0014] The main valve body has an inlet channel and a valve cavity;

[0015] The valve anticavitation sleeve is installed on the main valve body, and the channel in the valve anticavitation sleeve forms at least part of the outlet channel of the main valve body;

[0016] The inlet channel and the outlet channel are respectively communicated with the valve cavity.

[0017] Further, the control valve further comprises a valve cover, a valve core assembly, a valve seat and a venturi sleeve, wherein,

[0018] The valve seat is installed in the valve cavity;

[0019] The valve cover is covered on the main valve body, and the valve core assembly is slidingly installed on the valve cover and used for blocking and opening the outlet of the valve seat;

[0020] The valve anticavitation sleeve and the venturi sleeve are sequentially spliced along the medium flow direction and jointly form the outlet channel communicated with the outlet of the valve seat.

[0021] Further, in order to better guide the valve core assembly and maximize the volume of the valve cavity and prevent the erosion damage of the medium to the valve cover, the valve cover extends into the valve cavity, and the extending part is a conical structure.

[0022] Further, in order to continue to release bubbles after the medium flows out of the venturi sleeve, the valve anticavitation sleeve further comprises a secondary valve body, wherein,

[0023] The secondary valve body is installed on the main valve body, is sleeved outside the anticavitation sleeve and the venturi sleeve, and outwardly exceeds the venturi sleeve along the medium flow direction;

[0024] The secondary valve body has a conical inner peripheral wall, and the taper angle of the inner peripheral wall is greater than the taper angle of the inner peripheral wall of the medium outlet end of the venturi sleeve.

[0025] The inner diameter of the sleeve gradually decreases along the flow direction of the medium, the annular groove is designed to slightly increase the volume of the medium and slightly reduce the pressure when the medium flows through the annular groove, the cavitation bubbles are broken to a certain extent and the corresponding energy is released, then the medium flows to the flow channel with a reduced inner diameter, the volume of the medium is reduced again, and the cavitation bubbles stop breaking. When a plurality of annular grooves are arranged, the cavitation bubbles can be released and broken multiple times, and the cavitation erosion degree of the medium is gradually reduced, so that the anti-cavitation effect of the anti-cavitation sleeve for the valve is similar to multi-stage pressure reduction, thereby playing a good anti-cavitation effect and improving the safety stability and service life of the control valve. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A structure diagram of the anti-cavitation sleeve for the valve of the utility model;

[0027] Figure 2 A structure diagram of the control valve of the utility model;

[0028] In the figure, 1, sleeve; 11, annular groove; 12, inner tapered section; 2, main valve body; 21, inlet flow channel; 22, valve cavity; 3, valve cover; 4, valve core assembly; 5, valve seat; 6, venturi sleeve; 7, auxiliary valve body; 8, outlet flow channel. DETAILED DESCRIPTION

[0029] In order to make the content of the utility model more easily and clearly understood, the utility model will be further described in detail below according to specific embodiments and in combination with the drawings.

[0030] As shown in Figure 1 and Figure 2 , an anti-cavitation sleeve for a valve comprises a sleeve 1, and the inner diameter of the sleeve 1 gradually decreases along the flow direction of the medium; wherein,

[0031] The peripheral wall of the sleeve 1 is provided with at least one annular groove 11 which surrounds in the circumferential direction.

[0032] Specifically, the inner diameter of the sleeve 1 gradually decreases along the flow direction of the medium, the annular groove 11 is designed to slightly increase the volume of the medium and slightly reduce the pressure when the medium flows through the annular groove 11, the cavitation bubbles are broken to a certain extent and the corresponding energy is released, thereby playing an anti-cavitation effect, then the medium flows to the flow channel with a reduced inner diameter, the volume of the medium is reduced again, and the cavitation bubbles stop breaking. When a plurality of annular grooves 11 are arranged, the cavitation bubbles can be released and broken multiple times, and the cavitation erosion degree of the medium is gradually reduced, so that the anti-cavitation effect of the anti-cavitation sleeve for the valve is similar to multi-stage pressure reduction, thereby playing a good anti-cavitation effect and improving the safety stability and service life of the control valve.

[0033] The number of the annular grooves 11 is set according to the pressure difference, and the number is preferably greater than or equal to 3.

[0034] More preferably, according to the working principle of multi-stage pressure reduction throttling, the pressure drop of each stage of throttling decreases in geometric progression, that is:

[0035]

[0036] The saturation vapor pressure Pv of the medium (such as water) at the inlet temperature T1 of the control valve is calculated or looked up, and ΔP represents the total pressure drop, and ΔP1=P v , and we have:

[0037]

[0038] The value of m calculated according to the above formula usually has decimal places, so it must be rounded off by using the rounding method to obtain the final minimum pressure reduction stage number n min , and according to the actual process conditions, the actual pressure reduction stage number n≥n min +1.

[0039] In one embodiment, as shown in Figure 1 and Figure 2 , the bottom of the annular groove 11 and each side wall are transitioned with a round corner R1, and the side wall of the annular groove 11 located on the medium outflow side is transitioned with a round corner R2 between the inner wall of the sleeve 1.

[0040] In one embodiment, as shown in Figure 1 and Figure 2 , the inner peripheral wall of the sleeve 1 is conical. The taper angle A of the inner peripheral wall of the sleeve 1 is preferably 4-10°.

[0041] In one embodiment, as shown in Figure 1 and Figure 2 , the number of annular grooves 11 is n, and the sleeve 1 is divided into n+1 inner conical segments 12 by all the annular grooves 11. The length L of the inner conical segment 12 in the axial direction is equal to the width W of the annular groove 11. The depth of the annular groove 11 is slightly greater than the width W of the annular groove 11.

[0042] In this way, the anti-cavitation and erosion resistance of the entire valve anti-cavitation sleeve can be improved.

[0043] Generally, after determining the total size H of the sleeve 1 in the axial direction according to the space, the width W of the annular groove 11 can be calculated according to the formula H=(2*n+1)*W.

[0044] In one specific example, the parameters of the valve anti-cavitation sleeve are as follows:

[0045] W H A R1 R2 D1 12 ~ 40 mm (2*n + 1)W 4°～10° 2 ~ 10 mm 2 ~ 5 mm 2*H*tanA / 2 + D2

[0046] Wherein, R1 is the radius of the round corner R1, R2 is the radius of the round corner R2, D1 is the inner diameter of the large end face of the sleeve 1, and D2 is the inner diameter of the small end face of the sleeve 1.

[0047] As shown in Figure 2 , a control valve comprises a main valve body 2 and the anti-cavitation sleeve for valve in any of the above embodiments; wherein,

[0048] The main valve body 2 has an inlet channel 21 and a valve cavity 22;

[0049] The anti-cavitation sleeve for valve is installed in the main valve body 2, and the channel in the anti-cavitation sleeve forms at least part of the outlet channel 8 of the main valve body 2;

[0050] The inlet channel 21 and the outlet channel 8 are respectively communicated with the valve cavity 22.

[0051] In an embodiment, as shown in Figure 2 , the control valve further comprises a valve cover 3, a valve core assembly 4, a valve seat 5 and a Venturi sleeve 6; wherein,

[0052] The valve seat 5 is installed in the valve cavity 22;

[0053] The valve cover 3 is installed on the main valve body 2, and the valve core assembly 4 is slidingly installed on the valve cover 3 for blocking and opening the outlet of the valve seat 5;

[0054] The anti-cavitation sleeve for valve and the Venturi sleeve 6 are sequentially spliced along the medium flow direction to jointly form the outlet channel 8 communicated with the outlet of the valve seat 5, and the outlet channel 8 is perpendicular to or close to perpendicular to the inlet channel 21.

[0055] In the embodiment, as shown in Figure 2 , the valve cavity 22 has a spherical structure, which can make the pressure distribution of the medium on the main valve body 2 more uniform, and the inner wall of the main valve body 2 can be sprayed with a hardening process. The center of the inlet channel 21 is higher than the center of the valve cavity 22 and the upper end surface of the valve seat 5, and the medium entering from the inlet channel 21 points to a slightly higher position of the upper end surface of the valve seat 5. After the medium fills the larger spherical valve cavity 22, it flows out from the smaller space between the valve core assembly and the valve seat 5, which weakens the erosion damage to the inner wall of the main valve body 2. In addition, the inner wall of the main valve body 2 is sprayed with a hardening process, and the service life of the main valve body 2 can reach more than 24 months. In addition, the Venturi sleeve 6 is provided to gradually increase the volume of the medium in the Venturi sleeve 6 and make the cavitation bubbles gradually break along the flow channel, and the uniform distribution of the destruction energy on the entire Venturi cone surface can greatly prolong the service life of the entire machine.

[0056] In an embodiment, as shown in Figure 2 , in order to enhance the guiding effect on the valve core assembly 4, the valve cover 3 extends into the valve cavity 22, the extending part has a conical structure, and a spraying hardening process is adopted for protection, which can maximize the volume of the valve cavity 22 and prevent the erosion damage of the medium to the valve cover 3.

[0057] In an embodiment, as shown in Figure 2 , the control valve further comprises a secondary valve body 7; wherein,

[0058] The auxiliary valve body 7 is installed on the main valve body 2, is sleeved outside the anti-cavitation sleeve and the Venturi sleeve 6, and extends outward beyond the Venturi sleeve 6 along the medium flow direction;

[0059] The auxiliary valve body 7 has a conical inner wall, and the conical angle of the inner wall is greater than the conical angle of the inner wall of the medium outflow end of the Venturi sleeve 6.

[0060] Specifically, after the medium flows out of the Venturi sleeve 6 and enters the auxiliary valve body 7, the inner wall of the auxiliary valve body 7 is a larger-angle conical surface, on the one hand, the volume suddenly increases, the bubbles formed by cavitation in the medium are broken here, and the energy is released far away from the inner wall of the auxiliary valve body 7, and on the other hand, the larger angle of the conical surface prevents the medium sprayed by the Venturi sleeve 6 from being sprayed to the inner conical surface, thereby protecting the inner wall of the auxiliary valve body 7 and greatly prolonging the service life.

[0061] In summary, the entire control valve, the anti-cavitation sleeve, the main valve body 2, the Venturi sleeve 6, and the auxiliary valve body 7 are all designed with anti-cavitation, thereby prolonging the service life of each component and achieving the purpose of prolonging the service life of the entire control valve.

[0062] With the above ideal embodiments of the present application as inspiration, through the above description, relevant personnel can certainly make various changes and modifications without deviating from the technical concept of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of the claims.

Claims

1. An anti-cavitation sleeve for valve, characterized in that, it comprises a sleeve (1) whose inner diameter gradually decreases along the direction of medium flow; wherein, a circumferential wall of the sleeve (1) is provided with at least one circumferential annular groove (11).

2. The anti-cavitation sleeve for valve according to claim 1, characterized in that, a transition between the groove bottom and each side wall of the annular groove (11) is rounded with a radius R1, and a transition between the side wall on the medium outflow side of the annular groove (11) and the inner wall of the sleeve (1) is rounded with a radius R2.

3. The anti-cavitation sleeve for valve according to claim 1, characterized in that, the inner circumferential wall of the sleeve (1) is conical.

4. The anti-cavitation sleeve for valve according to claim 3, characterized in that, the taper angle A of the inner circumferential wall of the sleeve (1) is 4-10°.

5. The anti-cavitation sleeve for valve according to claim 3, characterized in that, the number of annular grooves (11) is n, the sleeve (1) is divided into n+1 inner conical sections (12) by all the annular grooves (11), and the length L of the inner conical section (12) in the axial direction is equal to the width W of the annular groove (11).

6. The anti-cavitation sleeve for valve according to claim 1, characterized in that, the depth of the annular groove (11) is greater than the width W of the annular groove (11).

7. A control valve, characterized in that, it comprises a main valve body (2) and the anti-cavitation sleeve for valve according to any one of claims 1-6; wherein, the main valve body (2) has an inflow passage (21) and a valve cavity (22); the anti-cavitation sleeve for valve is mounted on the main valve body (2), and the passage in it forms at least part of the outflow passage (8) of the main valve body (2); the inflow passage (21) and the outflow passage (8) respectively communicate with the valve cavity (22).

8. The control valve according to claim 7, characterized in that, it further comprises a valve cover (3), a valve core assembly (4), a valve seat (5) and a Venturi sleeve (6); wherein, the valve seat (5) is mounted in the valve cavity (22); the valve cover (3) is mounted on the main valve body (2), and the valve core assembly (4) is slidingly mounted on the valve cover (3) for blocking and opening the outflow port of the valve seat (5); the anti-cavitation sleeve for valve and the Venturi sleeve (6) are sequentially spliced along the direction of medium flow to jointly form the outflow passage (8) that communicates with the outflow port of the valve seat (5).

9. The control valve according to claim 8, characterized in that, the valve cover (3) extends into the valve cavity (22), and the extended part is conical.

10. The control valve according to claim 8, characterized in that, it further comprises a secondary valve body (7); wherein, the secondary valve body (7) is mounted on the main valve body (2) and is sleeved outside the anti-cavitation sleeve and the Venturi sleeve (6) and outwardly beyond the Venturi sleeve (6) along the direction of medium flow; the secondary valve body (7) has a conical inner circumferential wall, and the taper angle of the inner circumferential wall is greater than the taper angle of the inner circumferential wall of the medium outflow end of the Venturi sleeve (6).

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