Low-temperature ball valve for solid phase and liquid phase of PX device

Abstract

The utility model discloses a solid-liquid two-phase low-temperature ball valve for a PX device, which mainly comprises a main valve body, an auxiliary valve body, a main valve body valve seat, an auxiliary valve body valve seat, a ball body, an upper valve rod and a lower valve rod, and is characterized in that the low-temperature ball valve adopts a valve body side-mounted two-piece bolting design, and a valve cavity has a structure with high machining precision, small clearance and no dead angle; the sealing surface of the valve seat adopts a scraper type design; the valve body and the valve seat adopt special high polymer material low-temperature-resistant sealing rings, a sealing pair adopts an explosion spraying and plasma vapor deposition hardening process, and four uniformly distributed vertical pin shaft connecting structures are adopted, so that the connecting strength and the positioning precision of the valve rod and the ball body are improved. By means of the low-temperature ball valve, the problems that a ball valve of a low-temperature solid medium-containing process pipeline needs to be frequently opened and closed, and a common low-temperature ball valve general structure cannot work normally due to the fact that freezing torque is increased abnormally in the using process are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to industrial valve field, concretely relates to a PX device solid-liquid two-phase low temperature ball valve. BACKGROUND

[0002] PX device crystallization is a new type of p-xylene crystallization separation process technology, which has the advantages of low raw material extraction production cost, less initial device investment cost and high production efficiency.

[0003] The existing technology does not consider the erosion and wear of the valve sealing pair by solid medium when the low temperature ball valve medium is clean liquid or gas (such as LNG, olefin separation, etc.). Invention Content

[0004] The utility model provides a PX device solid-liquid two-phase low temperature ball valve to solve the technical problem of not considering low temperature and solid medium condition in prior art.

[0005] To achieve the above purpose, the technical scheme of the utility model is as follows:

[0006] A PX device solid-liquid two-phase low temperature ball valve mainly comprises a main valve body, a vice valve body, a main valve body seat, a vice valve body seat, a ball body, an upper valve rod and a lower valve rod, characterized in that: the low temperature ball valve adopts a two-piece bolted design on the side of the valve body, the valve cavity has a structure with high machining precision, small gap and no dead angle, and the valve seat sealing surface adopts a scraper type design; the valve body and the valve seat adopt a special low temperature resistant sealing ring made of high polymer material, the sealing pair adopts a hardening process of explosion spraying + plasma gas deposition, and a 4 vertical pin shaft connection structure is adopted to improve the connection strength and positioning accuracy of the valve rod and the ball body.

[0007] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0008] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0009] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0010] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0011] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0012] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0013] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0014] The utility model discloses a PX device solid -liquid two -phase low temperature ball valve, and its further features are that the main valve body and the auxiliary valve body adopt the double positioning structure of guiding step positioning and sealing groove, and are connected through bolt and nut.

[0015] 1. Solve the low temperature solid medium process pipeline, and the ball valve needs to be frequently opened and closed, and the conventional low temperature ball valve general structure can not work normally in the use process because of the abnormal increase of frozen torque.

[0016] 2. Solid -liquid two -phase low temperature ball valve adopts hard sealing structure design, and the ball and valve seat sealing surface adopt the coating process of explosion spraying + plasma vapor deposition, improve the performance of solid -state medium scouring of valve whole, prolong the service life of valve whole.

[0017] 3. The guiding step positioning and sealing groove double positioning structure of the main valve body and the auxiliary valve body of the ball valve ensures the sealing reliability between the main valve body and the auxiliary valve body when the pressure boundary of the valve body bears the combined action of high-low temperature cycle and internal pressure of the pipeline.

[0018] 4. The guiding step positioning and cylindrical pin double positioning structure of the main valve body and the low-temperature extended valve cover sealing structure ensures the sealing reliability of the valve cover and the valve body.

[0019] 5. The low-temperature extended valve cover and the valve stem of the ball valve adopt the woven graphite packing sealing mode, the bolt and the nut pre-tighten the packing plate and the packing sleeve to pre-tighten the packing, and the limiting sleeve and the disc spring combined loading structure is additionally arranged, so that the disc spring will not be overloaded and failed during each compression pre-tightening.

[0020] 6. The large cylindrical surface guiding design of the lower valve stem and the main valve body sealing structure solves the sealing influence of the valve body deformation on the sealing gasket, and the spring washer is additionally arranged during screw pre-tightening, so that the relaxation of the bolt and the nut pre-tightening force can be effectively compensated during high-low temperature cycle.

[0021] 7. The machining allowance is increased during casting of the inner cavity of the ball valve, numerical control machining surface is adopted during subsequent machining of the inner cavity, the valve body and the ball body adopt a narrow gap structure design, so that the solid medium accumulation dead angle can be effectively solved, and the freezing layer adhesion rate of the medium can be reduced under low-temperature working condition.

[0022] 8. The positioning cylindrical pin is additionally arranged between the valve stem and the ball body, the main valve body and the low-temperature extended valve cover, the low-temperature extended valve cover and the bracket, and the bracket and the actuator, so that the transmission chain accuracy and position degree are ensured, and the repeated accuracy of the valve after maintenance and secondary assembly is improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a PX device solid-liquid two-phase low-temperature ball valve assembly drawing;

[0024] Figure 2 It is a main valve body and auxiliary valve body sealing structure drawing;

[0025] Figure 3 It is a main valve body and low-temperature extended valve cover sealing structure drawing;

[0026] Figure 4 It is a low-temperature extended valve cover and valve stem packing sealing structure drawing;

[0027] Figure 5 It is a lower valve stem and main valve body sealing structure drawing;

[0028] Figure 6 It is a valve body inner cavity and ball body narrow gap structure design detail drawing;

[0029] Figure 7 Figure 1 is a valve seat sealing structure diagram.

[0030] The figure shows the following reference signs: 1 - lower valve stem, 2 - lower valve stem bearing, 3 - ball, 4 - main valve body, 5 - main valve body valve seat, 6 - valve stem drive pin shaft, 7 - upper valve stem, 8 - upper valve stem bearing, 9 - valve stem anti-flying thrust pad, 10 - positioning pin shaft, 11 - low temperature elongated valve cover, 12 - packing device, 13 - packing pressure sleeve, 14 - packing plate, 15 - bracket, 16 - drive device, 17 - valve body fastening stud, 18 - valve body fastening nut, 19 - secondary valve body, 20 - secondary valve body valve seat, 21 - main secondary valve body sealing winding pad, 22 - main secondary valve body stud, nut spring pad, 23 - main valve body and valve cover sealing structure sealing winding pad, 24 - main valve body and valve cover sealing structure spring pad, 25 - main valve body and valve cover connecting nut, 26 - main valve body and valve cover connecting stud, 27 - valve cover and packing device connecting stud, 28 - packing plate limiting sleeve, 29 - packing device compression disc spring, 30 - valve cover and packing device connecting flat pad, 31 - valve cover and packing device connecting spring pad, 32 - valve cover and packing device connecting nut, 33 - lower valve stem and main valve body connecting screw, 34 - lower valve stem and main valve body connecting spring pad, 35 - lower valve stem and main valve body connecting sealing winding, 36 - valve seat sealing ring, 37 - valve seat sealing spring ring, 38 - valve seat sealing spring, 39 - valve seat sealing dustproof ring. DETAILED DESCRIPTION

[0031] The technical scheme of the utility model is further described below in combination with the drawings.

[0032] As shown in Figure 1 The utility model discloses a PX device solid -liquid two -phase low -temperature ball valve, mainly includes the main valve body 4 and secondary valve body 19 for bearing pressure, for controlling the ball 3 of valve opening and closing, for guaranteeing the main valve body sealing valve seat 5 and secondary valve body valve seat 20 of valve, for guaranteeing low -temperature working condition uses the medium of lower medium to have certain vaporization space low -temperature elongated valve cover 11, for guaranteeing the packing device 12 of valve stem sealing.

[0033] The main valve body and secondary valve body seal as shown in Figure 2 The main valve body 4 and secondary valve body 19 adopt the orientation step positioning in the sealing groove double positioning structure, guarantee the valve body pressure boundary to bear high and low temperature cycle and the internal pressure of pipe together when, do not influence the stress mode of sealing winding pad 21, and sealing is reliable, when the stud 17 and the nut 18 pre -tightening assembly, add spring pad 22, improve the pre -tightening friction, and compensate the relaxation of stud and nut pre -tightening force when high and low temperature cycle.

[0034] The main valve body and low -temperature elongated valve cover seal as shown in Figure 3As shown in the figure, the main valve body 4 and the low temperature elongated valve cover 11 sealing structure adopts guiding step positioning and double positioning structure of cylindrical pin shaft 10, which ensures that the sealing winding gasket 23 is not affected by the stress mode when the actuator operating force and the high and low temperature cycle stress act together, and the sealing is reliable, and the spring washer 24 is added during the pre-tightening assembly of the stud 26 and the nut 25, which improves the pre-tightening friction and compensates the relaxation of the stud and the nut pre-tightening force during high and low temperature cycle.

[0035] The low temperature elongated valve cover and the valve stem packing seal as shown in the figure Figure 4 As shown in the figure, the low temperature elongated valve cover and the valve stem sealing adopts woven graphite packing sealing, and the stud 27 and the nut 32 are used to pre-tighten the packing plate 14 and the packing sleeve 13 to implement the pre-tightening force operation on the packing, and the utility model adds the structure of the limiting sleeve 28 and the disc spring 29 combination loading on this basis, and the advantage is that the deformation pre-tightening force of the disc spring is better, and the deformation amount is 0.75xh, and directly using the nut to load the disc spring is easy to cause the deformation overload phenomenon, and then causes the sealing failure. The advantage of loading the limiting sleeve 28 is that the limiting sleeve 28 and the stud 27 adopt shaft hole guiding cooperation, so that the threads on the stud do not interfere with the packing plate, and the stability of the packing dynamic load is ensured, and the limiting sleeve and the packing plate adopt compression step limiting, and the limiting distance X≤n×0.75×h (n is the number of disc springs) is designed, so that the disc spring will not overload failure during each compression pre-tightening.

[0036] The lower valve stem and the main valve body sealing as shown in the figure Figure 5 As shown in the figure, the lower valve stem 1 and the main valve body 4 adopt large cylindrical surface guiding design, which solves the sealing influence of the valve body deformation on the sealing winding gasket 35, and the spring washer 34 is added during the pre-tightening of the screw 33, which improves the pre-tightening friction and compensates the relaxation of the stud and the nut pre-tightening force during high and low temperature cycle of the medium.

[0037] The ball valve adopts the method of increasing the machining allowance in the inner cavity casting as shown in the figure Figure 6 After the casting blank is finished, the numerical control machining surface design is adopted, the roughness after machining is Ra1.6, and due to the high machining precision, the valve body and the ball surface adopt narrow gap structure design (the gap is 1.5-3mm quality inspection), the valve body overall inner cavity and the ball body present spherical fitting surface, there is no dead angle of solid medium accumulation, and due to the high smoothness of the ball surface and the valve body inner cavity surface, the adhesion rate of the frozen layer is reduced, the medium speed flushing and the scraper type design of the ball valve sealing pair can be used when the ball valve is opened and closed, so that the operation performance and the sealing performance of the valve are ensured under the low temperature solid containing condition.

[0038] The ball valve adopts hard sealing structure design, and uses explosion spraying + plasma vapor deposition coating process to prepare sealing pair coating Cr2C3 / NiCr, coating bonding force is increased from 68-70MPa of prior art to 140-145MPa, coating porosity is reduced from 3% of prior art to 0.5%, hardness value is increased from HRC70 of prior art to HRC85, the performance of solid-state medium scouring of the whole valve equipment is improved, and the service life of the whole valve is prolonged.

[0039] The ball valve is additionally provided with a positioning cylindrical pin shaft between the upper valve rod 7, the lower valve rod 1 and the ball body 3, the main valve body 4 and the low-temperature lengthened valve cover 11, the low-temperature lengthened valve cover 11 and the support 15, the support 15 and the driving device 16, the transmission chain precision and position degree are ensured, and the reassembly precision after valve maintenance is improved.

[0040] The above is only a typical embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements or substitutions can be made, and these improvements or substitutions should also be considered as the protection scope of the present application.

Claims

1. PX device solid-liquid two-phase low-temperature ball valve, mainly comprising a main valve body, a secondary valve body, a main valve body valve seat, a secondary valve body valve seat, a ball body, an upper valve rod and a lower valve rod, characterized in that: The low-temperature ball valve adopts two-piece bolted design of side-mounted valve body, the valve cavity has the structure of high machining precision, small gap and no dead angle, the valve seat sealing surface adopts scraper type design; the valve body and the valve seat adopt special high-molecular material low-temperature-resistant sealing ring, the sealing pair adopts hardening process of explosion spraying + plasma vapor deposition, the 4 vertical pin shaft connection structure with uniform distribution is adopted, and the connection strength and positioning precision of the valve rod and the ball body are improved.

2. The PX device low temperature ball valve for solid-liquid two-phase according to claim 1, characterized in that: The main valve body and the auxiliary valve body adopt the double positioning structure of the guide step positioning and the sealing groove, and are connected through bolts and nuts.

3. The PX device low temperature ball valve for solid-liquid two-phase according to claim 1, characterized in that: The main valve body and the low-temperature elongated valve cover sealing structure adopt the double positioning structure of the guide step positioning and the cylindrical pin shaft, and are connected through bolts and nuts.

4. The PX device low temperature ball valve for solid-liquid two-phase according to claim 1, characterized in that: The valve rod and the main valve body sealing structure adopt large cylindrical surface guide design, and a spring washer is additionally arranged when the screw is pre-tightened.

5. The PX device low temperature ball valve for solid-liquid two-phase according to claim 1, characterized in that: The valve body inner cavity adopts numerical control machining surface design, and the valve body and the ball body surface adopt 1.5-3mm narrow gap structure design.

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