阅读说明：本技术 一种铅基反应堆燃料组件锁紧结构 (Lead-based reactor fuel assembly locking structure ) 是由 刘璐 顾龙 朱彦雷 盛鑫 王大伟 李金阳 彭天骥 张璐 于锐 唐延泽 秦长平 于 2020-06-19 设计创作，主要内容包括：本发明涉及一种铅基反应堆燃料组件锁紧结构,包括：上环腔筒,其上沿与堆顶盖的下底面固定连接；上支撑板,固定连接在上环腔筒的下沿,其上形成有若干燃料组件第一定位孔,用于与上管座封头轴向接触；上支撑导向板,固定连接在上支撑板的下底面,其上形成有若干燃料组件第二定位孔,用于与上管座封头径向接触；下环腔筒,设置在上环腔筒下方且与上支撑板和上支撑导向板固定连接；上栅格板,固定连接在下环腔筒的下沿,其上形成有若干燃料组件第三定位孔,用于与上管座套管径向接触；钩爪,主体为等截面杆件,钩爪旋转后固定在上支撑导向板,完成自锁动作。本发明在保证反应堆安全性和经济性的前提下,利用重金属浮力固定燃料组件,有效避免燃料组件弹出事故。(The invention relates to a locking structure of a lead-based reactor fuel assembly, which comprises: the upper edge of the upper ring cavity cylinder is fixedly connected with the lower bottom surface of the pile top cover; the upper supporting plate is fixedly connected to the lower edge of the upper ring cavity barrel, and a plurality of first fuel assembly positioning holes are formed in the upper supporting plate and are used for being in axial contact with the upper pipe base seal head; the upper support guide plate is fixedly connected to the lower bottom surface of the upper support plate, and a plurality of second fuel assembly positioning holes are formed in the upper support guide plate and used for radially contacting with the upper pipe base sealing head; the lower ring cavity cylinder is arranged below the upper ring cavity cylinder and is fixedly connected with the upper support plate and the upper support guide plate; the upper grid plate is fixedly connected to the lower edge of the lower annular cavity cylinder, and a plurality of third fuel assembly positioning holes are formed in the upper grid plate and used for radially contacting with the upper pipe seat sleeve; the main body of the hook claw is a rod piece with a uniform cross section, and the hook claw is fixed on the upper supporting guide plate after rotating to complete self-locking action. According to the invention, on the premise of ensuring the safety and economy of the reactor, the fuel assembly is fixed by using the heavy metal buoyancy, so that the fuel assembly popping accident is effectively avoided.)

1. A lead-based reactor fuel assembly locking structure, comprising:

the upper edge of the upper ring cavity cylinder (5) is fixedly connected with the lower bottom surface of the pile top cover (1);

the upper supporting plate (8) is fixedly connected to the lower edge of the upper ring cavity barrel (5), is provided with a plurality of first positioning holes matched with the upper part of the upper tube seat end socket (41) of the fuel assembly (4) in shape, and is used for axially contacting with the upper tube seat end socket (41) to axially position the upper tube seat end socket (41);

the upper supporting guide plate (9) is fixedly connected to the lower bottom surface of the upper supporting plate (8), and a plurality of second positioning holes matched with the lower appearance of the upper tube seat end socket (41) are formed in the upper supporting guide plate and used for radially contacting the upper tube seat end socket (41) to realize radial positioning of the upper tube seat end socket (41);

the lower ring cavity cylinder (6) is arranged below the upper ring cavity cylinder (5), and the upper edge of the lower ring cavity cylinder (6) is fixedly connected with the upper support plate (8) and the upper support guide plate (9) simultaneously;

and the upper grid plate (7) is fixedly connected to the lower edge of the lower annular cavity barrel (6), is provided with a plurality of third positioning holes matched with the shape of an upper tube seat sleeve (42) of the fuel assembly (4) and is used for radially contacting the upper tube seat sleeve (42) to realize the radial positioning of the upper tube seat sleeve (42).

2. The lead-based reactor fuel assembly locking structure of claim 1, wherein the upper tube base end enclosure (41) is a rotary shell with a truncated cone-shaped upper part and a cylindrical lower part, and a locking mechanism which can cooperate with the upper support plate (8) and the upper support guide plate (9) to complete self-locking when the fuel assembly (4) floats upwards is arranged in each upper tube base end enclosure (41).

3. The lead-based reactor fuel assembly locking structure of claim 2, wherein the locking mechanism comprises:

a float (51) having a hollow interior;

a claw rotating part (52) fixedly connected to the lower bottom surface of the float (51);

a hook claw (53) rotatably connected to the hook claw rotating member (52) such that the hook claw (53) is rotatable within a certain angular range, and the hook claw (53) is configured to complete radial fixation of the hook claw rotating member (52) when the float (51) floats;

an operating head (55) rotatably connected in the upper tube socket head (41) through a pin shaft (54) so that the operating head (55) can rotate within a certain angle range, wherein the operating head (55) is configured to be in contact with the float (51) in an initial state to limit the upward movement of the float (51), and is separated from the float (51) when the fuel assembly (4) floats to release the limitation on the upward movement of the float (51).

4. The lead-based reactor fuel assembly locking structure according to claim 3, wherein the body of the hook claw (53) is a rod with a constant section, the head of the hook claw (53) is a one-side welding anchor bar, the head of the hook claw (53) is limited in a rectangular through hole opened in the lower part of the upper tube base seal head (41), and the head of the hook claw (53) is configured not to extend out of the shell of the upper tube base seal head (41) in an initial state but to extend out of the shell of the upper tube base seal head (41) when the buoy (51) floats up; the tail part of the hook claw (53) is wedge-shaped and wedged at the rotating shaft of the hook claw rotating part (52).

5. The lead-based reactor fuel assembly locking structure according to claim 3, characterized in that the body of the operating head (55) is a rod of constant thickness, the head of the operating head (55) is an elliptical hook forming an angle with the body of the operating head (55), the head of the operating head (55) is confined in a rectangular through hole opened in the upper part of the upper tube socket head (41), and the head of the operating head (55) is configured to protrude outside the casing of the upper tube socket head (41) in an initial state; the tail of the operating head (55) is a rectangular hook which forms a certain angle with the main body of the operating head (55), and the tail of the operating head (55) is configured to contact with the upper surface of the float (51) in an initial state so as to limit the upward movement of the float (51).

6. The lead-based reactor fuel assembly locking structure as defined in claim 4, wherein a downwardly extending positioning post is provided inside the upper tube socket head (41), and a lower end surface position of the positioning post is a maximum limit of upward movement of the float (51) and at which the hook claw (53) is rotated to a horizontal position.

7. The lead-based reactor fuel assembly locking structure as defined in any one of claims 1 to 6, wherein the upper support plate (8) has an annular upper pedestal formed on an upper surface thereof, and the lower inwardly extending inner end surface of the upper ring barrel (5) is fixed to an outer side surface of the upper pedestal of the upper support plate (8); meanwhile, an annular lower column base is formed on the lower bottom surface of the upper supporting plate (8), and the diameter of the outer side surface of the lower column base of the upper supporting plate (8) is equal to the diameter of the outer end surface of the upper ring cavity barrel (5).

8. The lead-based reactor fuel assembly locking structure according to claim 7, wherein the upper support guide plate (9) is disposed within a limit of a lower column of the upper support plate (8), and an outer side surface of the upper support guide plate (9) is fixed to an inner side surface of the lower column of the upper support plate (8), and an upper surface of the upper support guide plate (9) is fixed to a lower bottom surface of the upper support plate (8); the upper edge of the lower ring cavity cylinder (6) is fixed with the lower end face of the lower column base of the upper supporting plate (8) and the lower bottom face of the upper supporting guide plate (9) at the same time, the outer diameter of the lower ring cavity cylinder (6) is equal to the diameter of the outer side face of the lower column base of the upper supporting plate (8), and the inner diameter of the lower ring cavity cylinder (6) is equal to the outer diameter of the upper grid plate (7).

9. The lead-based reactor fuel assembly locking structure as defined in any one of claims 1 to 6, wherein a plurality of through holes are circumferentially formed in each of the upper annular cylinder (5) and the lower annular cylinder (6), the upper portion of the upper tube seat sleeve (42) is a circular tube with an equal diameter, the lower portion of the upper tube seat sleeve (42) is a circular tube with a gradually increased diameter, and a plurality of oval through holes are circumferentially formed in the upper tube seat sleeve (42).

10. The lead-based reactor fuel assembly locking structure of claim 9, wherein the first positioning hole of the upper support plate (8) is a variable diameter through hole matching with the upper profile of the upper tube base seal head (41), the second positioning hole of the upper support guide plate (9) is an equal diameter through hole matching with the lower profile of the upper tube base seal head (41), and the third positioning hole of the upper grid plate (7) is a variable diameter through hole matching with the profile of the upper tube base sleeve (42).

Technical Field

The invention relates to a lead-based reactor fuel assembly structure, in particular to a lead-based reactor fuel assembly locking structure for fixing a fuel assembly by utilizing the buoyancy action of a heavy metal coolant.

Background

The lead-based reactor is a fast neutron reactor which takes molten metallic lead or lead-bismuth alloy as a coolant. The lead-based reactor has high neutron energy and hard energy spectrum, and has higher thorium-uranium reactivity than a conventional pressurized water reactor, so that the utilization rate of fuel is improved, and the sustainability of fuel utilization is optimized. Meanwhile, the lead-based reactor has better transmutation capability, and can incinerate minor actinides in spent fuel of the pressurized water reactor, thereby promoting the development of clean nuclear energy.

When the lead-based reactor is operated, the density of lead is 11.34g/cm³The density of the lead-bismuth alloy is 10.5g/cm³And the density of the steel material is 7.9g/cm³And the average density of the fuel assembly made of steel materials is less than that of the lead-based coolant, so that when the fuel assembly is immersed in the heavy metal lead-based coolant, the buoyancy force borne by the fuel assembly is greater than the gravity force, and the resultant force of the fuel assembly is vertically upward, so that the problem of axial fixation of the fuel assembly under the action of the buoyancy force of the heavy metal is solved.

At present, the fixing scheme of the lead-based reactor fuel assembly takes overcoming of buoyancy of the assembly as a starting point, and two specific implementation schemes are provided, namely adding of a balance weight and designing of an assembly locking mechanism. The first method is to add a counterweight in the fuel rod bundle, the material of the counterweight is usually metal tungsten and depleted uranium, and the gravity of the assembly is larger than the buoyancy by adding the counterweight, but the method greatly increases the length of the assembly, reduces the power density of the reactor core and reduces the economy of the lead-based fast reactor. The other method is to design a fuel assembly locking mechanism, the locking mechanism is used for limiting the assembly to float upwards, the stress borne by a locking component is large, and a long rod structure is arranged in a common locking mechanism to push a rod piece to complete the locking action, but the long and thin structure generates deformation problems due to the corrosion and erosion action of a lead-based coolant and the high irradiation environment of a reactor core, so that the locking component can be failed. Based on the scheme of fixing the fuel assembly by overcoming the buoyancy, the economical efficiency and the safety of the fuel assembly cannot be compatible.

In conclusion, the existing lead-based fuel assembly fixing method is difficult to bear high corrosion and high irradiation environment in the reactor, so on the premise of ensuring the safety and the economical efficiency of the reactor, the buoyancy of the heavy metal coolant is skillfully utilized, and the reasonably designed lead-based reactor core and fuel assembly structure are particularly important.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a lead-based reactor fuel assembly locking structure for fixing a fuel assembly by using buoyancy of a heavy metal coolant, which can effectively achieve the fixing and self-locking functions of the fuel assembly in a support structure on a core.

In order to achieve the purpose, the invention adopts the following technical scheme: a lead-based reactor fuel assembly locking structure comprising: the upper edge of the upper ring cavity cylinder is fixedly connected with the lower bottom surface of the pile top cover; the upper supporting plate is fixedly connected to the lower edge of the upper ring cavity barrel, is provided with a plurality of first positioning holes matched with the upper appearance of the upper pipe seat seal head of the fuel assembly and is used for axially contacting the upper pipe seat seal head to axially position the upper pipe seat seal head; the upper support guide plate is fixedly connected to the lower bottom surface of the upper support plate, is provided with a plurality of second positioning holes matched with the appearance of the lower part of the upper pipe seat seal head, and is used for radially contacting the upper pipe seat seal head to realize radial positioning of the upper pipe seat seal head; the lower ring cavity cylinder is arranged below the upper ring cavity cylinder, and the upper edge of the lower ring cavity cylinder is fixedly connected with the upper support plate and the upper support guide plate simultaneously; and the upper grid plate is fixedly connected to the lower edge of the lower annular cavity barrel, is provided with a plurality of third positioning holes matched with the appearance of an upper tube seat sleeve of the fuel assembly, and is used for radially contacting with the upper tube seat sleeve to realize radial positioning of the upper tube seat sleeve.

Preferably, the upper tube base end socket is a rotary shell with the upper part in a circular truncated cone shape and the lower part in a cylindrical shape, and each upper tube base end socket is internally provided with a locking mechanism which can cooperate with the upper support plate and the upper support guide plate to complete self-locking when the fuel assembly floats upwards.

The lead-based reactor fuel assembly locking structure preferably comprises: the interior of the buoy is hollow; the claw rotating part is fixedly connected to the lower bottom surface of the buoy; a finger rotatably coupled to the finger rotating member such that the finger is rotatable within a range of angles, the finger configured to complete radial securement of the finger rotating member while the buoy floats; the operating head is rotatably connected in the upper tube seat end socket through a pin shaft so as to enable the operating head to rotate within a certain angle range, is configured to be in contact with the float in an initial state so as to limit the upward movement of the float, and is separated from the float when the fuel assembly floats upwards so as to remove the limitation on the upward movement of the float.

In the lead-based reactor fuel assembly locking structure, preferably, the main body of the hook is a rod piece with a uniform cross section, the head of the hook is a rectangular through hole with one side being attached with a welding anchor bar, the head of the hook is limited in the rectangular through hole arranged at the lower part of the upper tube base seal head, and the head of the hook is configured not to extend out of the shell of the upper tube base seal head in an initial state but to extend out of the shell of the upper tube base seal head when the buoy floats upwards; the tail part of the hook claw is a wedge which is wedged into the rotating shaft of the hook claw rotating part.

The lead-based reactor fuel assembly locking structure is characterized in that preferably, the main body of the operating head is a rod piece with equal thickness, the head of the operating head is an elliptical hook forming a certain angle with the main body of the operating head, the head of the operating head is limited in a rectangular through hole formed in the upper part of the upper tube socket end socket, and the head of the operating head is configured to extend out of a shell of the upper tube socket end socket in an initial state; the tail of the operating head is a rectangular hook angled from the main body of the operating head, and the tail of the operating head is configured to contact the upper surface of the float in an initial state to limit upward movement of the float.

Preferably, a positioning column extending downwards is arranged inside the upper tube seat end socket, the position of the lower end face of the positioning column is the maximum limit of the upward movement of the float, and the claw is rotated to the horizontal position at the position.

In the lead-based reactor fuel assembly locking structure, preferably, an annular upper column base is formed on the upper surface of the upper support plate, and an inner end surface of the lower part of the upper ring cavity cylinder, which extends inwards, is fixed to the outer side surface of the upper column base of the upper support plate; meanwhile, an annular lower column base is formed on the lower bottom surface of the upper supporting plate, and the diameter of the outer side surface of the lower column base of the upper supporting plate is equal to the diameter of the outer end surface of the upper ring cavity cylinder.

In the lead-based reactor fuel assembly locking structure, preferably, the upper support guide plate is arranged within the limit range of the lower column base of the upper support plate, the outer side surface of the upper support guide plate is fixed with the inner side surface of the lower column base of the upper support plate, and the upper surface of the upper support guide plate is fixed with the lower bottom surface of the upper support plate; the upper edge of the lower ring cavity cylinder is fixed with the lower end surface of the lower column base of the upper supporting plate and the lower bottom surface of the upper supporting guide plate, the outer diameter of the lower ring cavity cylinder is equal to the diameter of the outer side surface of the lower column base of the upper supporting plate, and the inner diameter of the lower ring cavity cylinder is equal to the outer diameter of the upper grid plate.

The locking structure of the fuel assembly of the lead-based reactor is characterized in that preferably, a plurality of through holes are formed in the upper ring cavity barrel and the lower ring cavity barrel along the circumferential direction, the upper portion of the upper tube seat sleeve is a circular tube with the same diameter, the lower portion of the upper tube seat sleeve is a circular tube with the variable diameter, the diameter of the circular tube is gradually increased, and a plurality of oval through holes are formed in the upper tube seat sleeve along the circumferential direction.

Preferably, the first positioning hole on the upper support plate is a variable-diameter through hole matched with the shape of the upper part of the upper tube seat sealing head, the second positioning hole on the upper support guide plate is an equal-diameter through hole matched with the shape of the lower part of the upper tube seat sealing head, and the third positioning hole on the upper grid plate is a variable-diameter through hole matched with the shape of the upper tube seat sleeve.

Due to the adoption of the technical scheme, the invention has the following advantages: 1. based on the characteristic of high density of the heavy metal lead-based coolant, the fuel assembly fixing device fully utilizes the characteristic that the buoyancy of the fuel assembly is larger than the gravity and the resultant force borne by the fuel assembly is vertically upward, breaks through the conventional fuel assembly arrangement scheme, inserts the fuel assembly into a grid structure on a reactor core upward, completes the fuel assembly fixing by utilizing the upward resultant force, does not balance the buoyancy in a mode of increasing a counterweight, and avoids the consequence of the reduction of the assembly economy caused by the increase of the assembly length. 2. The invention utilizes the buoyancy floating in the heavy metal coolant to rotate the hook claw, so that the hook claw is fixed on the lower end surface of the upper support guide plate to complete buoyancy self-locking, the structure is exquisite, a slender push rod is avoided, and the assembly pop-up accident caused by the failure of a locking structure due to the corrosion and erosion of heavy metal and the irradiation embrittlement of structural materials is effectively avoided. 3. The upper support plate, the upper support guide plate and the hook claw structure can axially fix the fuel assembly, the upper support guide plate, the upper support plate and the upper grid plate can radially fix the fuel assembly, and the multiple structures together complete the fixing function of the fuel assembly, so that the serious consequence that the fuel assembly pops up due to the failure of a single structure under the extreme working condition of a reactor is effectively avoided. On the premise of ensuring the economy of the reactor, the invention can more effectively avoid the fuel assembly ejection accident caused by high corrosion and high irradiation environment of the reactor, thereby ensuring the safe operation of the reactor.

Drawings

FIG. 1 is a cross-sectional view of the present invention;

FIG. 2 is a partial cross-sectional view of the present invention;

FIG. 3 is an initial state diagram of the locking mechanism of the present invention;

FIG. 4 is a state diagram of the locking mechanism of the present invention completing the self-locking action.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

In the description of the present invention, it is to be understood that the terms "axial," "radial," "upper," "lower," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings, which are used for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the scope of the present invention.

As shown in fig. 1 and fig. 2, the lead-based reactor fuel assembly locking structure provided by the invention comprises: the upper edge of the upper ring cavity cylinder 5 is fixedly connected with the lower bottom surface of the pile top cover 1; the upper supporting plate 8 is fixedly connected to the lower edge of the upper cavity barrel 5, is provided with a plurality of first positioning holes matched with the upper appearance of the upper pipe seat seal head 41 of the fuel assembly 4, and is used for axially contacting the upper pipe seat seal head 41 to axially position the upper pipe seat seal head 41; the upper supporting guide plate 9 is fixedly connected to the lower bottom surface of the upper supporting plate 8, is provided with a plurality of second positioning holes matched with the lower appearance of the upper pipe seat seal 41 of the fuel assembly 4, and is used for radially contacting the upper pipe seat seal 41 to realize the radial positioning of the upper pipe seat seal 41; the lower ring cavity cylinder 6 is coaxially arranged below the upper ring cavity cylinder 5, and the upper edge of the lower ring cavity cylinder 6 is fixedly connected with the upper support plate 8 and the upper support guide plate 9; and the upper grid plate 7 is fixedly connected to the lower edge of the lower annular cavity barrel 6, is provided with a plurality of third positioning holes matched with the shape of the upper tube seat sleeve 42 of the fuel assembly 4, and is used for radially contacting the upper tube seat sleeve 42 to realize the radial positioning of the upper tube seat sleeve 42.

In the above embodiment, the upper tube base sealing head 41 is preferably a revolving shell with a truncated cone-shaped upper part and a cylindrical lower part, and a locking mechanism which can cooperate with the upper support plate 8 and the upper support guide plate 9 to complete self-locking when the fuel assembly 4 floats is arranged in each upper tube base sealing head 41.

In the above embodiment, preferably, as shown in fig. 3 and 4, the locking mechanism includes: a float 51 having a hollow interior; a hook rotating member 52 fixedly connected to a lower bottom surface of the float 51; a hook 53 rotatably connected to the hook rotating member 52 such that the hook 53 is rotatable within a certain angular range, and the hook 53 is configured to complete radial fixation of the hook rotating member 52 when the float 51 floats up; and an operating head 55 rotatably connected in the upper tube socket head 41 by a pin 54 so that the operating head 55 can rotate within a certain angle range, and the operating head 55 is configured to contact the float 51 in an initial state to restrict the upward movement of the float 51 and to be separated from the float 51 to release the restriction of the upward movement of the float 51 when the fuel assembly 4 floats.

In the above embodiment, preferably, the body of the hook 53 is a rod with a uniform cross section, the head of the hook 53 is a one-side welding anchor, the head of the hook 53 is limited in a rectangular through hole opened at the lower part of the upper tube socket head 41, and the head of the hook 53 is configured not to extend out of the housing of the upper tube socket head 41 in the initial state, but to extend out of the housing of the upper tube socket head 41 when the float 51 floats upwards; the tail of the hook claw 53 is wedge-shaped and wedged at the rotating shaft of the hook claw rotating part 52.

In the above embodiment, preferably, the main body of the operating head 55 is a rod with equal thickness, the head of the operating head 55 is an elliptical hook forming a certain angle with the main body of the operating head 55, the head of the operating head 55 is limited in a rectangular through hole opened in the upper part of the upper socket head 41, and the head of the operating head 55 is configured to extend out of the housing of the upper socket head 41 in an initial state; the tail of the operating head 55 is a rectangular hook that forms an angle with the main body of the operating head 55, and the tail of the operating head 55 is configured to contact the upper surface of the float 51 in an initial state to restrict the upward movement of the float 51.

Fig. 3 shows a state diagram when the upper tube base sealing head 41 is not inserted into the upper support plate 8, at this time, the float 51 does not float upward, the head of the operating head 55 extends out of the shell of the upper tube base sealing head 41, and the tail of the operating head 55 is in a horizontal position, so as to limit the upward movement of the float 51; meanwhile, the hook rotating part 52 pulls the tail part of the hook 53 downwards, the head part of the hook 53 does not extend out of the shell of the upper tube seat seal head 41, and the whole fuel assembly 4 can pass through the third positioning hole of the upper grid plate 7 and the second positioning hole of the upper support guide plate 9.

Fig. 4 shows a state diagram when the upper tube seat sealing head 41 is inserted into the upper support plate 8, because the first positioning hole of the upper support plate 8 is matched with the upper part of the upper tube seat sealing head 41, the upper support plate 8 pushes the extended operating head 55, so that the operating head 55 rotates clockwise, the limitation on the upward movement of the float 51 is removed after the tail part of the operating head 55 rotates, at this time, the float 51 floats upwards under the action of heavy metal lead-based coolant, and then the claw rotating part 52 is pulled to move upwards, the claw rotating part 52 drives the claw 53 to rotate anticlockwise, the head part of the claw 53 extends out of the shell of the upper tube seat sealing head 41, when the claw 53 rotates to a horizontal position, the upper end surface of the head part of the claw 53 and the lower bottom surface of the upper support guide plate 9 complete rigid fixation, and thereby completing the buoyancy self-locking action.

In the above embodiment, it is preferable that a positioning column extending downward is provided inside the upper tube socket head 41, and a position of a lower end surface of the positioning column is a maximum limit of upward movement of the float 51, and the hook claw 53 is rotated to a horizontal position at the position.

In the above embodiment, preferably, the upper surface of the upper support plate 8 is formed with an annular upper pillar base, and the inner end surface of the lower part of the upper cavity tube 5 extending inwards is fixed with the outer side surface of the upper pillar base of the upper support plate 8; meanwhile, the lower bottom surface of the upper supporting plate 8 is formed with an annular lower column base, and the diameter of the outer side surface of the lower column base of the upper supporting plate 8 is equal to the diameter of the outer end surface of the upper ring cavity cylinder 5.

In the above embodiment, preferably, the upper support guide plate 9 is disposed within the range limited by the lower pillar of the upper support plate 8, and the outer side surface of the upper support guide plate 9 is fixed to the inner side surface of the lower pillar of the upper support plate 8, and the upper surface of the upper support guide plate 9 is fixed to the lower bottom surface of the upper support plate 8; the upper edge of the lower ring cavity cylinder 6 is simultaneously fixed with the lower end surface of the lower column base of the upper supporting plate 8 and the lower bottom surface of the upper supporting guide plate 9, the outer diameter of the lower ring cavity cylinder 6 is equal to the diameter of the outer side surface of the lower column base of the upper supporting plate 8, and the inner diameter of the lower ring cavity cylinder 6 is equal to the outer diameter of the upper grid plate 7.

In the above embodiment, preferably, the upper ring cavity cylinder 5 and the lower ring cavity cylinder 6 are both provided with a plurality of through holes along the circumferential direction, the upper portion of the upper tube seat sleeve 42 is a circular tube with an equal diameter, the lower portion of the upper tube seat sleeve 42 is a circular tube with a gradually increasing diameter, and the upper tube seat sleeve 42 is provided with a plurality of oval through holes along the circumferential direction.

In the above embodiment, preferably, the first positioning hole of the upper support plate 8 is a variable diameter through hole matching with the upper outer shape of the upper tube seat seal 41, the second positioning hole of the upper support guide plate 9 is an equal diameter through hole matching with the lower outer shape of the upper tube seat seal 41, and the third positioning hole of the upper grid plate 7 is a variable diameter through hole matching with the outer shape of the upper tube seat sleeve 42.

In the description of the present invention, it should be understood that the terms "first", "second", "third", etc. are used to define the components, and are used only for the convenience of distinguishing the components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present invention.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.