Axial-flow type check valve

Abstract

The utility model discloses an axial flow type check valve. The axial flow type check valve is provided with a valve clack (6), a valve shaft (1), a flow guide body (8), an inlet pipe (15), a valve chamber (12) and an outlet pipe (16). A rear lining (7) is arranged on the flow guide body, a rear sliding bearing assembly (5) is arranged in the rear lining, and the part, located in the inner cavity of the valve chamber, of the valve shaft is supported by the rear sliding bearing assembly and can move in the axial direction. A front lining (4) and a front supporting cylinder (3) are arranged in the inlet pipe, and a front sliding bearing assembly (17) is arranged in the front lining. And the front supporting cylinder is sleeved on the front bushing and is fixedly connected with the inlet pipe through a component. The valve shaft extends into the inlet pipe, and the part, located in the inlet pipe, of the valve shaft is supported by the front sliding bearing assembly and can move in the axial direction. A flow guide body opening (18) is formed in the flow guide body, and the inner cavity of the valve chamber is communicated with the inner cavity of the flow guide body through the flow guide body opening. The high-pressure hydrogenation device is mainly used in the petroleum refining industry.

Description

TECHNICAL FIELD

[0001] The utility model belongs to valve technical field, concretely relates to an axial flow check valve. BACKGROUND

[0002] In the petroleum refining industry, more and more high-pressure hydrogenation devices such as residual oil hydrodesulfurization are used, which can not only improve the light oil recovery rate, but also improve the fuel oil quality and reduce the pollution of fuel oil to the environment, thereby improving the overall economic and social benefits of the refinery. High-pressure hydrogenation devices involve high-temperature, high-pressure working conditions, complex and diverse media, and have characteristics such as erosion, hydrogen corrosion, and medium (such as residual oil) viscosity and easy coking. The existing axial flow check valve for high-pressure hydrogenation device is provided with valve clack, valve shaft, flow guide, inlet pipe, valve chamber, outlet pipe and other components, and the valve clack and valve shaft form a valve core. The flow guide is provided with a rear bushing, and the rear bushing is provided with a rear sliding bearing assembly. The part of the valve shaft located in the inner cavity of the valve chamber is supported by the rear sliding bearing assembly and can move axially. This axial flow check valve mainly has the following problems:

[0003] (1) The valve clack and valve shaft adopt a single support structure, and after long-term use, the valve clack return seat and valve core centering ability will decrease, thereby causing the sealing performance of the check valve to decrease.

[0004] (2) When the check valve is working normally, the valve clack is always open. The valve clack contacts the flow guide, and the inner cavity of the valve clack and the inner cavity of the flow guide form a closed area. The closed area forms a medium flow dead zone, and the medium is easy to coking in the gap between the valve shaft and the inner hole of the sliding bearing in the rear sliding bearing assembly, thereby causing the axial movement of the valve shaft to be blocked, and the axial flow check valve to be invalid.

[0005] (3) During the medium backflow and the closing process of the check valve, the back pressure of the backflow medium cannot act on the back of the valve clack quickly, thereby causing the valve clack to be unable to quickly return to the seat. INVENTION CONTENTS

[0006] The utility model aims at providing an axial flow check valve to solve the problems of the existing axial flow check valve used in high-pressure hydrogenation device, such as the decrease of valve clack return seat and valve core centering ability, the coking of medium causing the axial movement of the valve shaft to be blocked, and the valve clack being unable to quickly return to the seat.

[0007] The utility model discloses a technical scheme that is adopted to solve the above problems: a kind of axial flow check valve, it is equipped with valve clack, valve shaft, flow guide, inlet pipe, valve chamber, outlet pipe, and it is equipped with compression spring between valve clack inner cavity and flow guide inner cavity, flow guide is fixedly connected with outlet pipe by component, and it is equipped with rear bushing on flow guide, rear bushing is equipped with rear sliding bearing assembly, and the part of valve shaft in valve chamber inner cavity is supported by rear sliding bearing assembly and can move along axial direction, its characterized in that: it is equipped with front bushing and front supporting cylinder in inlet pipe, and it is equipped with front sliding bearing assembly in front bushing, and front supporting cylinder is sleeved on front bushing, and is fixedly connected with inlet pipe by component, and valve shaft extends to inlet pipe, and the part of valve shaft in inlet pipe is supported by front sliding bearing assembly and can move along axial direction, and it is equipped with flow guide hole on flow guide, and flow guide hole communicates valve chamber inner cavity with flow guide inner cavity.

[0008] The axial flow check valve further has the following features: the flow guide hole is a circular hole with a diameter of 10-50 mm, and there are 3-4 holes evenly distributed around the center line of the flow guide.

[0009] The axial flow check valve further has the following features: the end region of the front bushing close to the inlet of the axial flow check valve is connected with a flow straightener.

[0010] The axial flow check valve further has the following features: the outer surface of the main body of the flow straightener is a surface of revolution, and the diameter of the meridian circle on the surface of revolution gradually increases in the direction from the inlet to the outlet of the axial flow check valve.

[0011] The utility model has the following advantages:

[0012] (1) the part of the valve shaft in the valve chamber inner cavity is supported by the rear sliding bearing assembly, and the part of the valve shaft in the inlet pipe is supported by the front sliding bearing assembly. Since the valve clack and the valve shaft adopt a double-bearing structure, the valve clack reseating and valve core centering ability will not decrease after long-term use, and the sealing performance of the check valve will not decrease, so that the check valve can maintain excellent sealing performance.

[0013] (2) when the check valve is in normal operation, part of the medium in the valve chamber inner cavity enters the area composed of the flow guide inner cavity and the valve clack inner cavity through the flow guide hole, and part of the medium in the area also enters the valve chamber inner cavity through the flow guide hole, so that the flowability of the medium in the area is improved, and the medium flow dead zone is reduced. The medium is not easy to be deposited in the gap between the valve shaft and the inner hole of the sliding bearing in the rear sliding bearing assembly on the valve shaft in the area, and the valve shaft will not be blocked in axial direction, so that the check valve can be used normally.

[0014] (3) In the process of medium backflow and check valve closing, the back pressure of part of the backflow medium can be transmitted to the medium in the inner cavity of the flow guide, the space between the valve disc and the flow guide, and the inner cavity of the valve disc through the opening of the flow guide, and acts on the back of the valve disc, so that the valve disc can be quickly seated, thereby improving the closing response capability and reliability of the check valve.

[0015] The utility model mainly is used in high pressure hydrogenation device (for example, residual oil hydrogenation desulfurization device) in petroleum refining industry. Other industrial devices of processing high temperature, high pressure, easy coking medium can also use the utility model.

[0016] The utility model will be explained further in detail in combination with the drawings and specific embodiments. The drawings and specific embodiments do not limit the range of the utility model claimed. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the structural diagram of the axial flow check valve of the utility model;

[0018] Figure 2 It is Figure 1 A-A enlarged sectional view in the middle of the utility model;

[0019] Figure 3 It is Figure 1 The enlarged right view of the stop washer 11 in the middle of the utility model, and the bendable piece of the stop washer is not bent.

[0020] The reference signs shown in the figure are: 1-valve shaft; 2-flow straightener; 3-front support cylinder; 4-front bushing; 5-rear sliding bearing assembly; 6-valve disc; rear bushing 7; flow guide 8; compression spring 9; stop ring 10; stop washer 11; valve chamber 12; valve disc sealing surface 13; valve seat sealing surface 14; inlet pipe 15; outlet pipe 16; front sliding bearing assembly 17; flow guide opening 18; rib plate 19; connecting plate 20; support ring 21; flow straightener groove 22. DETAILED DESCRIPTION

[0021] As shown in the drawings Figure 1 , Figure 2 and the drawings Figure 3As shown, the axial flow check valve (referred to as check valve) of the utility model is equipped with valve clack 6, valve shaft 1, flow guide 8, inlet pipe 15, valve chamber 12, outlet pipe 16, inlet pipe 15, valve chamber 12, outlet pipe 16 constitute axial flow check valve shell, valve clack 6 and valve shaft 1 constitute integrated valve core. The inner cavity of valve clack 6 is equipped with compression spring 9 between the inner cavity of flow guide 8, which is generally cylindrical helical spring. The outer surface of valve clack 6 faces inlet pipe 15. Flow guide 8 is located in the inner cavity of valve chamber 12, and is fixedly connected with outlet pipe 16 through connecting plate 20, supporting ring 21 and baffle ring 10. Flow guide 8 is equipped with rear bushing 7, and flow guide 8 is fixedly connected with rear bushing 7. Rear bushing 7 is equipped with rear sliding bearing assembly 5, and the part of valve shaft 1 located in the inner cavity of valve chamber 12 is supported by rear sliding bearing assembly 5 and can move along the axial direction.

[0022] The outer surface of the main part of flow guide 8 is a rotary surface, and the diameter of the weft line circle on the rotary surface gradually decreases in the direction from the inlet to the outlet of the axial flow check valve. The outer surface of valve clack 6 is a rotary surface, and the diameter of the weft line circle on the rotary surface gradually increases in the direction from the inlet to the outlet of the axial flow check valve.

[0023] Inlet pipe 15 is equipped with front bushing 4 and front supporting cylinder 3, and front sliding bearing assembly 17 is arranged in front bushing 4. Front supporting cylinder 3 is sleeved on front bushing 4 and is fixedly connected with inlet pipe 15 through component rib plate 19. Front supporting cylinder 3 and front bushing 4 are fixedly connected through interference fit and are equipped with anti-rotation screws. Valve shaft 1 extends into inlet pipe 15, and the part of valve shaft 1 located in inlet pipe 15 is supported by front sliding bearing assembly 17 and can move along the axial direction. Flow guide 8 is equipped with flow guide opening 18, and flow guide opening 18 communicates the inner cavity of valve chamber 12 with the inner cavity of flow guide 8. Figure 1 It can be seen that flow guide opening 18 is arranged on the plate of flow guide 8.

[0024] Flow guide opening 18 is generally a circular hole. The size of flow guide opening 18 is determined according to the diameter of the check valve, and there is a positive correlation relationship. For the check valve with a nominal diameter of DN50-350mm, the diameter of flow guide opening 18 is generally 10-50mm. The number of flow guide openings 18 is generally 3-4, which are uniformly distributed around the center line of flow guide 8.

[0025] Generally, the end region of front bushing 4 close to the inlet of the axial flow check valve is connected with a fairing 2. The outer surface of the main part of the fairing 2 is generally a rotary surface, and the diameter of the weft line circle on the rotary surface gradually increases in the direction from the inlet to the outlet of the axial flow check valve.

[0026] The front support cylinder 3, the front bushing 4 (excluding the end area near the inlet of the axial flow check valve), the rear bushing 7, the inlet pipe 15, the outlet pipe 16, and the support ring 21 all have annular cross-sectional shapes. The valve shaft 1, the rectifier 2, the front support cylinder 3, the front bushing 4, the rear sliding bearing assembly 5, the valve disc 6, the rear bushing 7, the guide fluid 8, the compression spring 9, the retaining ring 10, the anti-reverse gasket 11, the inlet pipe 15, the outlet pipe 16, the front sliding bearing assembly 17, and the support ring 21 are coaxially arranged.

[0027] In a preferred embodiment of this invention, the end region of the front bushing 4 near the inlet of the axial flow check valve has a flat circular semi-threaded (external thread) structure, and the end region of the rectifier 2 near the valve chamber 12 has an internal thread and an external rectifier groove 22. The internal thread is screwed into the flat circular semi-threaded structure. A backlash gasket 11 with an elongated hole is provided between the rectifier 2 and the front support cylinder 3, and the backlash gasket 11 is sleeved on the flat circular semi-threaded structure. The bendable piece of the backlash gasket 11 is mechanically bent and embedded into the rectifier groove 22 to prevent the rectifier 2 from rotating or falling off.

[0028] As attached Figure 1 Appendix Figure 2 As shown, multiple baffles can be provided on the outside of the fairing 2, and fairing grooves 22 are formed between adjacent baffles. There are multiple fairing grooves 22, which are evenly distributed around the center line of the fairing 2.

[0029] The cross-sectional shape of the stiffening plate 19 is generally elliptical, with its major axis parallel to the centerline of the front support cylinder 3, which reduces resistance to the medium. There are generally 3 to 4 stiffening plates 19, evenly distributed around the centerline of the front support cylinder 3. The stiffening plates 19 are generally welded to the front support cylinder 3 and the inlet pipe 15. The cross-sectional shape of the connecting plate 20 is generally rectangular, and there are generally 3 to 4 connecting plates 20, evenly distributed around the centerline of the guide fluid 8. The connecting plate 20 is generally welded to the guide fluid 8 and the support ring 21. The retaining ring 10 clamps the support ring 21 onto the outlet pipe 16; the retaining ring 10 can be, for example, a three-ring.

[0030] The front sliding bearing assembly 17 and the rear sliding bearing assembly 5 have the same structure, both including sliding bearings, retaining rings, nuts, and other parts, and are assembled using conventional methods; detailed descriptions and drawings are omitted. The front sliding bearing assembly 17 and the rear sliding bearing assembly 5 should be resistant to media corrosion and high temperatures. The sliding bearing has an inner bore into which the valve shaft 1 can be inserted or passed, with a clearance between the valve shaft 1 and the inner bore. Graphite sliding bearings are preferred.

[0031] The valve disc 6 has a valve disc sealing surface 13, and the axial flow check valve body has a valve seat sealing surface 14. During normal operation, the valve disc 6 opens, and the valve disc sealing surface 13 and the valve seat sealing surface 14 separate (as shown in the attached diagram). Figure 1When the check valve is in the sealing state, the valve clack sealing surface 13 and the valve seat sealing surface 14 are in contact.

[0032] As shown in Figure 1 The valve clack 6 and the valve shaft 1 are simultaneously connected by threads and welded. In this way, the occurrence of the situation that the valve clack sealing surface 13 is eccentric to the valve shaft 1 after the corrosion of the threads by the hydrogen-containing medium can be avoided, the reliability of the check valve sealing is ensured, and the service life of the check valve is increased.

[0033] The utility model is described through some specific embodiments. Those skilled in the art know that various changes or equivalent replacements can be made to these specific embodiments without departing from the spirit and scope of the utility model to adapt to specific conditions. Therefore, the utility model is not limited by the disclosed specific embodiments. All changes or equivalent replacements falling within the scope of claims of the present application belong to the protection scope of the utility model.

Claims

1. A axial flow check valve, it is equipped with valve clapper (6), valve shaft (1), flow guide (8), inlet pipe (15), valve chamber (12), outlet pipe (16), the inner chamber between valve clapper (6) and the inner chamber of flow guide (8) is equipped with compression spring (9), flow guide (8) is fixedly connected with outlet pipe (16) through component, flow guide (8) is equipped with rear bushing (7), rear bushing (7) is equipped with rear sliding bearing assembly (5) in, the part of valve shaft (1) in the inner chamber of valve chamber (12) is supported by rear sliding bearing assembly (5) and can move along the axial direction, it is characterized in that: The front bushing (4) is internally provided with a front sliding bearing assembly (17), and the front supporting cylinder (3) is sleeved on the front bushing (4) and is fixedly connected with the inlet pipe (15) through a component.

2. The axial flow check valve of claim 1, wherein: The flow guide body opening (18) is a circular hole with a diameter of 10-50 mm, and the number of the flow guide body openings (18) is 3-4, which are uniformly distributed around the center line of the flow guide body (8).

3. The axial flow check valve of claim 1 or 2, wherein: The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2).

4. The axial flow check valve of claim 3, wherein: The outer surface of the main part of the fairing (2) is a surface of revolution, and the diameter of the latitudinal circle on the surface of revolution gradually increases in the direction from the inlet to the outlet of the axial flow check valve.

5. The axial flow check valve of claim 4, wherein: The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2).

6. The axial flow check valve of claim 1, wherein: The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2). The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2). The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2). The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2). The end region of the front bushing (4) near the inlet of the axial flow check valve is connected with a fairing (2).

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