CN221075321U

CN221075321U - Ball valve special for crystallization working condition

Info

Publication number: CN221075321U
Application number: CN202322555042.9U
Authority: CN
Inventors: 吴俊伟; 黎玉飞; 吴斌; 朱佳俊
Original assignee: Suzhou Antway Industrial Intelligent Technology Co ltd
Current assignee: Suzhou Antway Industrial Intelligent Technology Co ltd
Priority date: 2023-09-20
Filing date: 2023-09-20
Publication date: 2024-06-04
Anticipated expiration: 2033-09-20

Abstract

The utility model discloses a ball valve special for crystallization working conditions, which comprises a valve body, a bottom cover arranged at the bottom end of the valve body, a ball body arranged in the valve body and a valve cap arranged at the side of the valve body, wherein a valve seat is arranged between the ball body and the valve cap to realize gap sealing, the valve cap, the valve seat, the ball body and an inner cavity of the valve body jointly form a medium flow channel, the valve seat is arranged at one side into which a medium flows, and a gap is formed between the ball body and the valve body so that a medium accumulated liquid between the valve body and the ball body can be discharged at one side from which the medium flows; and a cladding spring for sealing is arranged between the valve seat and the valve cap, and the surfaces of the valve seat and the ball body are coated with a nano composite coating for preventing medium adhesion. The valve seat of this scheme simple structure, sealing performance is good and with low costs, can effectively solve the ball valve and produce interior hourglass because of sealed effect is poor, causes the ball valve to appear blocking and switch not in place problem because of medium hydrops crystallization.

Description

Ball valve special for crystallization working condition

[ Field of technology ]

The utility model belongs to the technical field of ball valves, and particularly relates to a ball valve special for crystallization working conditions.

[ Background Art ]

In recent years, new energy batteries develop rapidly, especially in the lithium battery industry, while the main raw material of the positive electrode of the lithium battery relates to lithium iron phosphate slurry, and in the process of producing the lithium iron phosphate slurry, as the lithium iron phosphate is thick slurry, solid scaling can occur after cooling, and the use requirement on a valve is very harsh. If a conventional double-valve-seat ball valve is used, when a ball valve switch rotates to a certain angle or the sealing performance of a valve seat is suddenly deteriorated due to uneven extrusion force of a ball body to the valve seat, lithium iron phosphate can enter a dead zone of an inner cavity of a valve body, and lithium iron phosphate cannot be discharged due to sealing of the valve seats at two sides, and the inner cavity of the valve body, the surface of the ball body, the surface of the valve seat, the surface of a ball rod and the outer surface of a transmission shaft are gradually scaled in the dead zone of the inner cavity of the valve body, so that the ball valve is blocked, and the valve is not opened or closed in place.

Besides the working condition of lithium iron phosphate slurry, the working condition of other mediums with crystallization properties can have the problems, so that the special ball valve for crystallization working conditions is urgently needed to be developed, and the stability of long-term operation of the valve is ensured.

The patent publication number is CN 219082308U discloses an anti-crystallization ball valve, designs to single disk seat structure, and the one end that the spheroid was kept away from to the disk seat is equipped with the spring holder, presses between spring holder and the disk seat to have hold-down spring, and the one end that the disk seat was kept away from to the spring holder is equipped with the baffle, and the welding has the bellows between baffle and the disk seat, and spring holder and hold-down spring are located disk seat, bellows, baffle and the cavity that the valve body encloses, and in bellows separation medium got into the spring holder, can prevent to lead to disk seat and spheroid unable normal sealing because of the crystallization in the medium got into the spring holder. Adopt single valve seat design in this scheme, can make the medium that enters into in the valve body inner chamber dead zone in time discharge, but this scheme still has following two problems:

(1) The valve seat and the valve body are sealed, a plurality of structural members such as a spring seat, a compression spring, a baffle plate and a corrugated pipe are arranged, when pressure is applied between the valve seat and the valve body, the sealing performance between the valve seat and the valve body is poor due to uneven stress, and internal leakage is caused; and a plurality of structural members are easy to adhere to the medium, so that the elastic failure is caused, and the internal leakage phenomenon is generated.

(2) The sealing effect between the valve seat and the ball body is poor due to the fact that the medium is easy to adhere to the surfaces of the valve seat and the ball body, so that the ball valve is blocked and cannot be opened or closed in place due to the fact that liquid crystals on the surface areas of the ball body and the valve seat are serious.

It is necessary to provide a ball valve special for crystallization conditions to solve the above technical problems.

[ utility model ]

The utility model mainly aims to provide the ball valve special for the crystallization working condition, which has the advantages of simple structure, good sealing performance and low cost, and can effectively solve the problems of internal leakage of the ball valve caused by poor sealing effect, jamming and out-of-place opening and closing of the ball valve caused by medium accumulated liquid crystallization.

The utility model realizes the aim through the following technical scheme: the ball valve special for the crystallization working condition comprises a valve body, a bottom cover arranged at the bottom end of the valve body, a ball body arranged in the valve body and a valve cap arranged beside the valve body, wherein a valve seat is arranged between the ball body and the valve cap to realize gap sealing, the valve cap, the valve seat, the ball body and an inner cavity of the valve body jointly form a medium flow passage, the valve seat is arranged at one side into which a medium flows, and a gap is formed between the ball body and the valve body so that medium accumulated liquid between the valve body and the ball body can be discharged in time at one side from which the medium flows; and a cladding spring for sealing is arranged between the valve seat and the valve cap, and the surfaces of the valve seat and the ball body are coated with a nano composite coating for preventing medium adhesion.

Further, a cylindrical shaft is arranged on the bottom cover, cylindrical grooves are formed in the bottom side and the upper side of the sphere, the cylindrical shaft stretches into the grooves formed in the bottom side of the sphere, a first bearing is arranged on the outer side of the cylindrical shaft, second sealing rings are sleeved on the inner side and the outer side of the first bearing, and sealing is achieved between the bottom cover and the sphere through the second sealing rings; one end of the valve rod extends into the cylindrical groove on the upper side of the sphere, so that the valve rod and the sphere are fixedly arranged.

Further, the bottom cover and the valve body are provided with a plurality of annular step surfaces at the contact positions for matching installation, a first sealing gasket is sleeved on the step surfaces of the bottom cover, a first sealing ring is sleeved on the outer side of the cylindrical shaft, and the first sealing ring and the first sealing gasket are extruded between the bottom cover and the valve body through locking a plurality of bolts to realize sealing.

Further, the valve rod is arranged to be a step shaft, a matching surface is formed in the longitudinal direction of the step shaft, a second bearing which is arranged on the step surface of the valve body in a bearing mode is arranged on the outer side of the valve rod, graphite is arranged at the bottom end of the second bearing, a third sealing ring is arranged on the inner side and the outer side of the second bearing, and sealing is achieved between the valve rod and the valve body through the third sealing ring.

Further, a stuffing box is sleeved on the periphery of the valve rod, the stuffing box is fixed on the top of the valve body, the lower end of the stuffing box is tightly pressed on a thrust bearing, and the thrust bearing is arranged on the matching surface of the valve rod; and a packing chamber is arranged on one side of the packing box, which is close to the valve rod, and the packing chamber is filled with packing for preventing the valve rod from being worn.

Further, a second sealing gasket arranged on the step surface of the valve body is extruded between the stuffing box and the valve body through a locking bolt to realize sealing; the packing box is characterized in that a packing pressing sleeve for pressing the packing is arranged above the packing, a gland is arranged at the upper end of the packing pressing sleeve, and the packing pressing sleeve can be pressed by locking a bolt on the gland so as to press the packing, so that the tightness between the valve rod and the packing box is ensured.

Further, the valve cap comprises a first limiting surface arranged in the horizontal direction, a second limiting surface with a height difference from the first limiting surface and a third limiting surface arranged in the vertical direction; one side of the cladding spring is propped against the third limiting surface, the other side of the cladding spring is propped against one side of the valve seat, and the periphery of the cladding spring is attached to the second limiting surface; the valve seat is provided with a first sealing surface which forms a seal with the surface of the sphere, a contact surface which is abutted against the first limiting surface and is abutted against the first limiting surface, and a second sealing surface which forms a seal with the cladding spring.

Further, the contact surface is provided with a plurality of annular grooves, and stirrups are arranged in the annular grooves to tighten the valve seat.

Further, the cladding spring comprises an external wear-resistant corrosion-resistant sealing layer and an internal corrosion-resistant alloy spring, and is extruded by the third limiting surface and the second sealing surface together.

Further, the valve cap and the valve body are provided with a plurality of annular step surfaces at the contact positions for matching installation, the step surfaces of the valve body are provided with third sealing gaskets, and the valve cap and the valve body are sealed by locking a plurality of bolts to extrude the third sealing gaskets.

Compared with the prior art, the ball valve special for the crystallization working condition has the beneficial effects that: (1) The nano composite coating for preventing the medium from being adhered is coated on the surfaces of the ball body and the valve seat, so that the phenomenon that the medium material is adhered on the surfaces of the ball body or the valve seat to generate crystallization can be prevented;

(2) When the valve seat is sealed between the ball body and the valve cap, a cladding spring which is composed of a wear-resistant and corrosion-resistant sealing layer on the outer part and a corrosion-resistant alloy spring on the inner part is adopted, and the sealing layer is used for cladding the spring, so that the phenomenon that the sealing surface of the ball valve leaks due to the fact that the spring is invalid when a medium in the spring cavity is crystallized is prevented;

(3) The valve seat is arranged between the valve bonnet and the ball body at one side where the medium flows in, and the ball body and the valve body at one side where the medium flows out are not sealed, so that the design scheme does not have a dead zone of the inner cavity of the valve body, and even if the sealing performance between the valve seat, the ball body and the valve bonnet suddenly worsens due to uneven stress to cause the medium to enter the inner cavity area of the valve body, the medium entering the inner cavity area of the valve body can be timely discharged from the other side, and the phenomenon that the medium effusion crystals cannot exist, which is caused by the medium effusion crystals in the dead zone of the inner cavity of the valve body, of the conventional ball valve double-valve design can be obviously improved;

(4) The sealing ring, the sealing gasket and the bolt are adopted for locking, so that a quadruple sealing effect is formed between the bottom cover and the valve body, between the ball body and the valve rod, between the valve rod and the stuffing box and between the valve seat and the ball body and between the valve cap and the valve cap, the tightness of the ball valve can be effectively ensured, and the phenomenon of internal leakage can not be generated.

Therefore, the ball valve provided by the scheme has a simple structure, can ensure that the valve seat, the ball body and the cladding spring cannot adhere to a medium under a crystallization working condition, and has a quadruple sealing effect by adding the inner cavity of the whole ball valve, so that good sealing performance of the ball valve is ensured, and the phenomenon of internal leakage caused by poor sealing effect is effectively solved; the ball valve adopts the design of a single valve seat at the medium inflow side, so that the dead zone of the medium effusion is not existed, the medium effusion can be discharged in time, the reliability and the safety of the operation of the ball valve under the crystallization working condition are ensured, and the problems of jamming of the ball valve, insufficient opening and closing and the like caused by crystallization of the medium effusion can be effectively solved; therefore, the whole ball valve has simple structure, good sealing performance and low cost.

[ Description of the drawings ]

FIG. 1 is a schematic diagram of a cross-sectional structure of a ball valve according to an embodiment of the utility model;

FIG. 2 is a schematic diagram of a cross-sectional structure of a ball valve seat seal in accordance with an embodiment of the present utility model;

FIG. 3 is a schematic diagram of a cross-sectional structure of a ball valve stuffing box seal according to an embodiment of the utility model;

The figures represent the numbers:

100-ball valve; 101-bolts, 102-first sealing rings, 103-first sealing gaskets, 104-nano composite coating, 105-second sealing rings, 106-first bearings, 107-second bearings, 108-third sealing rings, 109-graphite, 110-thrust bearings, 111-second sealing gaskets, 112-packing, 113-packing press jackets, 114-press covers, 115-stirrups, 116-cladding springs, 117-third sealing gaskets;

1-a bottom cover, 11-a cylindrical shaft, 2-a valve body, 3-a sphere, 4-a valve rod and 5-a stuffing box;

6-valve seat, 61-first sealing surface, 62-contact surface, 621-annular groove, 63-second sealing surface; 7-valve cap, 71-first limit surface, 72-second limit surface, 73-third limit surface.

[ Detailed description ] of the invention

Referring to fig. 1-3, the embodiment is a ball valve special for crystallization conditions, wherein the ball valve 100 comprises a valve body 2, a bottom cover 1 installed at the bottom of the valve body 2, a ball body 3 installed inside the valve body 2, a valve cap 7 installed at one side of the valve body 2, a valve rod 4 installed at the upper side of the ball body 3, a stuffing box 5 sleeved on the periphery of the valve rod 4 and fixed at the top of the valve body 2, and a valve seat 6 for realizing gap sealing between the ball body 3 and the valve cap 7.

The upper end of bottom 1 is provided with cylindrical shaft 11, bottom 1 and valve body 2 all set to a plurality of annular step face in contact position and carry out the adaptation installation, the outside cover of cylindrical shaft 11 is equipped with first sealing washer 102, be provided with first sealing washer 103 on the annular step face of bottom 1, extrude first sealing washer 102 and first sealing washer 103 through locking a plurality of bolt 101 between bottom 1 and the valve body 2 and realize sealedly, set to a plurality of annular step face adaptation when bottom 1 and valve body 2 are installed, can block first sealing washer 102 and first sealing washer 103 between the step face of both, make first sealing washer 102 and first sealing washer 103 be difficult for removing and skew, make the sealed effect between bottom 1 and the valve body 2 better.

The surface of the sphere 3 is coated with the nano composite coating 104 for preventing the medium from adhering, and the nano composite coating 104 is uniformly coated on the surface of the sphere 3, so that the phenomenon that the medium effusion adheres to the surface of the sphere 3 to generate crystallization can be prevented.

Cylindrical grooves are formed in the bottom side and the upper side of the ball body 3, the grooves in the bottom side of the ball body 3 are matched with a cylindrical shaft 11 at the upper end of the bottom cover 1, and the bottom cover 1 plays a role in supporting the ball body 3; the cylindrical shaft 11 on the bottom cover 1 extends into a cylindrical groove arranged on one side of the sphere 3, a first bearing 106 is arranged on the outer side of the cylindrical shaft 11, second sealing rings 105 are sleeved on the inner side and the outer side of the first bearing 106, and sealing is realized between the bottom cover 1 and the sphere 3 through the second sealing rings 105; the valve rod 4 extends into a cylindrical groove on the upper side of the sphere 3, so that the sphere 3 and the valve rod 4 are fixedly arranged. The installation of the bottom cover 1 and the ball 3 adopts the first bearing 106 and the second sealing rings 105 sleeved on the inner side and the outer side of the first bearing 106, so that the ball 3 can rotate around the cylindrical shaft 11 on the bottom cover 1, and meanwhile, as the ball 3 is sealed with the first bearing 106 and the double-layer second sealing rings 105 arranged between the first bearing 106 and the cylindrical shaft 11, the ball 3 can keep good sealing performance while rotating, and therefore, the ball 3 can keep good sealing performance with the bottom cover 1 even in the rotating process.

The surface of the valve rod 4 is provided with a step shaft, and a matching surface with a limiting function is formed in the longitudinal direction. The valve rod 4 passes through the upper end of the valve body 2 and is fixedly arranged on the ball body 3, and a plurality of annular step surfaces which play a limiting role are also arranged on the inner side of the valve body 2 close to the valve rod 4. When the valve rod 4 is installed with the valve body 2, a second bearing 107 which is supported on the step surface of the valve body 2 is arranged on the outer side of the valve rod 4, graphite 109 is arranged at the bottom end of the second bearing 107, and a third sealing ring 108 is sleeved on the inner side and the outer side of the second bearing 107; the graphite 109 plays a role in lubrication, so that the friction coefficient and the friction force of the surface of the second bearing 107 can be reduced, the bearing efficiency of the second bearing 107 is improved, and the driving system and the supporting system can operate faster and more reliably; the valve rod 4 and the valve body 2 are sealed by the third sealing ring 108, so that the valve rod 4 can be sealed by the double-layer third sealing ring 108 arranged between the valve rod 4 and the second bearing 107 and between the second bearing 107 and the valve body 2 while rotating, and therefore, the valve rod 4 can keep good sealing performance with the valve body 2 even in the rotating operation.

The packing box 5 is sleeved on the valve rod 4 and is fixed at the top of the valve body 2, a packing chamber is arranged on one side, close to the valve rod 4, of the packing box 5, packing 112 is filled in the packing chamber, sealing performance between the valve rod 4 and the packing box 5 can be guaranteed by the packing 112, meanwhile, the valve rod 4 can be protected from abrasion, and reliability and safety of operation of the ball valve 100 are guaranteed. The thrust bearing 110 is arranged on the matching surface of the step shaft of the valve rod 4, the packing box 5 is sleeved on the periphery of the valve rod 4, the lower end of the packing box 5 is tightly pressed on the thrust bearing 110, the thrust bearing 110 can bear axial load, and the axial deviation and shaking of the packing box 5 can be prevented.

The packing box 5 and the valve body 2 are sealed by pressing a second sealing gasket 111 arranged on the step surface of the valve body 2 through the locking bolt 101, and the sealing effect between the packing box 5 and the valve body 2 and between the packing box and the valve rod 4 can be enhanced by pressing the packing 112 and the second sealing gasket 111 through the locking bolt 101.

A packing pressing sleeve 113 for pressing the packing 112 is arranged above the packing 112, a pressing cover 114 is arranged at the upper end of the packing pressing sleeve 113, the packing pressing sleeve 113 can be pressed by locking the bolt 101 on the pressing cover 114 so as to press the packing 112, and the tightness between the valve rod 4 and the packing box 5 is ensured.

The surface of the valve seat 6 is coated with the nano composite coating 104 for preventing the medium from being adhered, and the nano composite coating 104 is uniformly coated on the surface of the valve seat 6, so that the crystallization phenomenon caused by the adhesion of the medium material on the surface of the valve seat 6 can be prevented.

The valve seat 6 is arranged between the valve cap 7 and the ball body 3, namely, on the side where the medium flows in, and the valve seat 6 is not arranged between the ball body 3 and the valve body 2, namely, on the side where the medium flows out, so that the medium can be discharged from the valve seat in time, namely, no dead zone in the inner cavity of the valve body exists in the design scheme; even when the sealing performance between the valve seat 6 and the ball body 3 and the valve cap 7 suddenly worsens due to uneven stress or other acting forces to cause that a medium enters the inner cavity area of the valve body, the medium entering the inner cavity area of the valve body can be timely discharged from the position because the valve seat is not arranged between the valve body 2 and the ball body 3, so that the phenomenon that the ball valve is blocked and cannot be opened due to the medium effusion crystallization in the dead zone of the inner cavity of the valve body in the conventional ball valve double-valve-seat design can be obviously improved.

The valve cap 7 comprises a first limiting surface 71 which is horizontally arranged, a second limiting surface 72 which has a height difference with the first limiting surface 71 and a third limiting surface 73 which is vertically arranged at a position close to the contact position with the valve seat 6; the cladding spring 116 is extruded by three sides, one side of the cladding spring 116 is propped against the third limiting surface 73, the other side is propped against one side of the valve seat 6, and the periphery is propped against the second limiting surface 72; the valve seat 6 is provided with a first sealing surface 61 which forms a seal with the surface of the ball 3, a contact surface 62 which is abutted against the first limit surface 71 of the valve cap 7, and a second sealing surface 63 which forms a seal against the cladding spring 116; the first sealing surface 61 coated with the nano composite coating 104 for preventing the medium from adhering is contoured with the surface of the sphere 3 coated with the nano composite coating 104 for preventing the medium from adhering, when the first sealing surface 61 is extruded by the sphere 3, the first sealing surface 61 generates a sealing effect, so that good sealing performance is realized between the valve seat 6 and the sphere 3; the contact surface 62 is provided with a plurality of annular grooves 621, stirrups 115 are arranged in the annular grooves 621, the stirrups 115 are sleeved on the periphery of the valve seat 6, and the stirrups 115 have a longitudinal tightening effect on the valve seat 6 and prevent the valve seat 6 from being longitudinally deviated and deformed; the cladding spring 116 is subjected to co-extrusion of the second limiting surface 72 and the second sealing surface 63, so that pretightening force is added to the sealing of the second sealing surface 63 of the valve seat 6, and the tightness between the valve seat 6 and the valve cap 7 can be enhanced; the wrap spring 116 comprises an outer wear-resistant corrosion-resistant sealing layer and an inner corrosion-resistant alloy spring, and the spring is wrapped by the sealing layer, so that the phenomenon that the sealing surface of the ball valve 100 leaks due to spring failure caused by crystallization of medium entering the spring cavity can be prevented.

The first sealing surface 61 of the valve seat 6 is extruded by the ball 3, the contact surface 62 of the valve seat 6 is propped against the first limiting surface 71 of the valve cap 7, the second sealing surface 63 of the valve seat 6 extrudes the cladding spring 116 on the second limiting surface 72 and the third limiting surface 73 of the valve cap 7, both the valve seat 6 and the cladding spring 116 are extruded and deformed, meanwhile, the cladding spring 116 can provide the pre-pressing force of the valve seat 6 to enable the valve seat 6 to keep good sealing effect with the valve cap 7 and the ball 3, and meanwhile, the stirrup 115 can clamp the valve seat 6 to enable the first sealing surface 61 to keep good sealing effect with the ball 3, so that the valve seat 6 can keep good sealing effect between the valve cap 7 and the ball 3.

The valve cap 7 and the valve body 2 are all set to a plurality of annular step face in the position of contact and carry out the adaptation installation, seal is realized to the third sealing gasket 117 that sets up on the step face of valve body 2 through locking a plurality of bolt 101 between valve cap 7 and the valve body 2, and valve body 2 and valve cap 7 set to a plurality of annular step face adaptation, can be with third sealing gasket 117 card between the step face of both, makes the difficult removal of third sealing gasket 117 and skew, makes the sealed effect between valve body 2 and the valve cap 7 better.

The ball valve special for crystallization conditions provided by the scheme is characterized in that (1) the surfaces of the ball body 3 and the valve seat 6 are coated with the nano composite coating 104 for preventing medium adhesion, so that the phenomenon that a medium material is adhered to the surface of the ball body 3 or the valve seat 6 to generate crystallization can be prevented; (2) When the valve seat 6 is sealed between the ball body 3 and the valve cap 7, a cladding spring 116 which is composed of a wear-resistant and corrosion-resistant sealing layer outside and an alloy spring with corrosion resistance inside is adopted, and the spring is clad by the sealing layer, so that the phenomenon that the sealing surface of the ball valve 100 is leaked due to the fact that the spring is invalid caused by the fact that a medium in a spring cavity is crystallized is prevented; (3) The valve seat 6 is arranged between the valve 7 cap and the ball body 3 on the side where the medium flows in, and the ball body 3 and the valve body 2 on the side where the medium flows out are not sealed, namely, the design scheme does not have a dead zone of the inner cavity of the valve body, even when the sealing performance between the valve seat 6, the ball body 3 and the valve cap 7 suddenly worsens due to uneven stress to cause the medium to enter the inner cavity area of the valve body, the medium entering the inner cavity area of the valve body can be timely discharged from the other side, and the phenomenon that the conventional double valve seat design of the ball valve is blocked and cannot be opened due to the medium effusion crystallization in the dead zone of the inner cavity of the valve body can be obviously improved; (4) Adopt sealing washer, sealing washer and bolt locking's mode, make between bottom 1 and the valve body 2, spheroid 3, between valve body 2 and the valve rod 4, between valve rod 4 and the stuffing box 5 and between disk seat 6 and spheroid 3, the valve bonnet 7 form the quadruple seal effect, can effectually guarantee ball valve 100's leakproofness, and can not produce the phenomenon of interior hourglass. Therefore, the ball valve 100 provided by the scheme has a simple structure, can ensure that the valve seat 6, the ball body 3 and the coating spring 116 are not adhered with medium under the crystallization working condition, and has a quadruple sealing effect by adding the inner cavity of the whole ball valve 100, so that good sealing performance of the ball valve 100 is ensured, and the phenomenon of internal leakage caused by poor sealing effect is effectively solved; the ball valve 100 adopts a single valve seat design at the medium inflow side, so that a dead zone of medium effusion does not exist, the medium effusion can be discharged in time, the reliability and the safety of the operation of the ball valve 100 under the crystallization working condition are ensured, and the problems of jamming, insufficient switching and the like of the ball valve caused by crystallization of the medium effusion can be effectively solved; therefore, the whole ball valve 100 is simple in structure, good in sealing performance and low in cost.

What has been described above is merely some embodiments of the present utility model. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the inventive concept.

Claims

1. A ball valve special for crystallization conditions is characterized in that: the valve comprises a valve body, a bottom cover arranged at the bottom end of the valve body, a ball body arranged in the valve body, and a valve cap arranged beside the valve body, wherein a valve seat is arranged between the ball body and the valve cap to realize gap sealing, the valve cap, the valve seat, the ball body and an inner cavity of the valve body jointly form a medium flow channel, the valve seat is arranged at one side of medium inflow, and a gap is formed between the ball body and the valve body so that medium accumulated liquid between the valve body and the ball body can be discharged in time at one side of medium outflow; and a cladding spring for sealing is arranged between the valve seat and the valve cap, and the surfaces of the valve seat and the ball body are coated with a nano composite coating for preventing medium adhesion.

2. The ball valve special for crystallization conditions according to claim 1, wherein: the bottom cover is provided with a cylindrical shaft, the bottom side and the upper side of the sphere are both provided with cylindrical grooves, the cylindrical shaft stretches into the grooves arranged on the bottom side of the sphere, the outer side of the cylindrical shaft is provided with a first bearing, the inner side and the outer side of the first bearing are respectively sleeved with a second sealing ring, and the bottom cover and the sphere are sealed through the second sealing rings; one end of the valve rod extends into the cylindrical groove on the upper side of the sphere, so that the valve rod and the sphere are fixedly arranged.

3. The ball valve special for crystallization conditions according to claim 2, wherein: the bottom cover and the valve body are provided with a plurality of annular step surfaces at the contact position for matching installation, a first sealing gasket is sleeved on the step surface of the bottom cover, a first sealing ring is sleeved on the outer side of the cylindrical shaft, and the first sealing ring and the first sealing gasket are sealed by locking a plurality of bolts to extrude between the bottom cover and the valve body.

4. A ball valve dedicated to crystallization conditions as defined in claim 3, wherein: the valve rod is arranged to be a step shaft, a matching surface is formed in the longitudinal direction of the step shaft, a second bearing which is arranged on the step surface of the valve body in a bearing mode is arranged on the outer side of the valve rod, graphite is arranged at the bottom end of the second bearing, a third sealing ring is arranged on the inner side and the outer side of the second bearing, and sealing is achieved between the valve rod and the valve body through the third sealing ring.

5. The ball valve special for crystallization conditions according to claim 4, wherein: the periphery of the valve rod is sleeved with a stuffing box, the stuffing box is fixed at the top of the valve body, the lower end of the stuffing box is tightly pressed on a thrust bearing, and the thrust bearing is arranged on the matching surface of the valve rod; and a packing chamber is arranged on one side of the packing box, which is close to the valve rod, and the packing chamber is filled with packing for preventing the valve rod from being worn.

6. The ball valve special for crystallization conditions according to claim 5, wherein: the second sealing gasket arranged on the step surface of the valve body is extruded between the stuffing box and the valve body through the locking bolt to realize sealing; the packing box is characterized in that a packing pressing sleeve for pressing the packing is arranged above the packing, a gland is arranged at the upper end of the packing pressing sleeve, and the packing pressing sleeve can be pressed by locking a bolt on the gland so as to press the packing, so that the tightness between the valve rod and the packing box is ensured.

7. The ball valve special for crystallization conditions according to claim 1, wherein: the valve cap comprises a first limiting surface arranged in the horizontal direction, a second limiting surface with a height difference from the first limiting surface and a third limiting surface arranged in the vertical direction; one side of the cladding spring is propped against the third limiting surface, the other side of the cladding spring is propped against one side of the valve seat, and the periphery of the cladding spring is attached to the second limiting surface; the valve seat is provided with a first sealing surface which forms a seal with the surface of the sphere, a contact surface which is abutted against the first limiting surface and is abutted against the first limiting surface, and a second sealing surface which forms a seal with the cladding spring.

8. The ball valve special for crystallization conditions according to claim 7, wherein: the contact surface is provided with a plurality of annular grooves, and stirrups are arranged in the annular grooves to tighten the valve seat.

9. The ball valve special for crystallization conditions according to claim 7, wherein: the cladding spring comprises an external wear-resistant corrosion-resistant sealing layer and an internal corrosion-resistant alloy spring, and is extruded by the third limiting surface and the two surfaces of the second sealing surface.

10. The ball valve special for crystallization conditions according to claim 1, wherein: the valve cap with the valve body is provided with a plurality of annular step faces in the position of contact and is installed in a matched mode, a third sealing gasket is arranged on the step faces of the valve body, and the valve cap and the valve body are sealed by locking a plurality of bolts to extrude the third sealing gasket.