Integrated skid-mounted water treatment equipment

By designing detachable mounting components and connectors, the problem of inconvenient disassembly and assembly of ultrafiltration membrane filters has been solved, enabling convenient installation and disassembly of ultrafiltration membrane filters on skid mounts and improving maintenance efficiency.

CN224226754UActive Publication Date: 2026-05-12HANGZHOU YULONG ENVIRONMENTAL TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
HANGZHOU YULONG ENVIRONMENTAL TECH CO LTD
Filing Date
2025-06-09
Publication Date
2026-05-12

AI Technical Summary

Technical Problem

The existing ultrafiltration membrane filters are inconvenient to disassemble and assemble, which affects the efficiency of inspection and maintenance.

Method used

An integrated skid-mounted water treatment device was designed, which enables convenient installation and disassembly of the ultrafiltration membrane filter through detachable mounting components and connectors. The device includes a retractable connector, a drive ring, and a gear structure, which, together with locking components, ensures stable connection and convenient assembly and disassembly of the ultrafiltration membrane filter on the skid frame.

Benefits of technology

It improves the efficiency of inspection and maintenance of ultrafiltration membrane filters, facilitates quick disassembly and assembly, and reduces maintenance difficulty.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to the technical field of water treatment equipment, in particular to integrated skid-mounted water treatment equipment, which comprises a skid-mounted frame and an ultrafiltration membrane component, a water inlet pipeline and a water outlet pipeline are arranged on the skid-mounted frame, and the ultrafiltration membrane component comprises ultrafiltration membrane filters arranged in parallel. The water inlet end of the ultrafiltration membrane filter is connected to the water inlet pipeline through a mounting assembly, and the water outlet end of the ultrafiltration membrane filter is connected to the water outlet pipeline; the mounting assembly comprises a mounting cylinder detachably connected to the water inlet pipeline, the upper end of the mounting cylinder is open, the water inlet end of the ultrafiltration membrane filter is inserted into the mounting cylinder, a telescopic plug connector is arranged on the bottom wall of the mounting cylinder, and the plug connector is used for fixing the water inlet end of the ultrafiltration membrane filter into the mounting cylinder. The lower end of the ultrafiltration membrane filter can be disassembled and assembled in the corresponding mounting cylinder through stretching and retracting of the plug connector, namely, the lower end of the ultrafiltration membrane filter can be conveniently disassembled and assembled on the skid-mounted frame, and overhauling and maintenance of the ultrafiltration membrane filter are facilitated.
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Description

Technical Field

[0001] This utility model relates to the field of water treatment equipment technology, and more specifically, to an integrated skid-mounted water treatment equipment. Background Technology

[0002] Ultrafiltration is a pressure-driven membrane separation technology. During ultrafiltration, an aqueous solution flows through the surface of the ultrafiltration membrane under pressure. Water and small solute molecules smaller than the membrane pores permeate through the membrane, becoming the purified solution. Solutes and solute clusters larger than the membrane pores are retained and discharged with the water flow, becoming the concentrated solution. Ultrafiltration is a dynamic filtration process; separation is completed under flowing conditions.

[0003] Currently, in water treatment equipment that uses ultrafiltration membranes to treat water, multiple ultrafiltration membrane filters arranged in parallel are fixedly installed on a skid-mounted frame. For example, in an ultrafiltration device disclosed in patent number CN220758697U, the main body of the ultrafiltration device is fixedly installed on the top of the bottom plate. Therefore, it is inconvenient to disassemble and assemble the ultrafiltration membrane filters, which is not conducive to the inspection and maintenance of the ultrafiltration membrane filters. Utility Model Content

[0004] The purpose of this invention is to provide an integrated skid-mounted water treatment device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An integrated skid-mounted water treatment device includes a skid frame and an ultrafiltration membrane assembly. The skid frame is provided with an inlet pipe and an outlet pipe. The ultrafiltration membrane assembly includes ultrafiltration membrane filters arranged in parallel. The inlet end of the ultrafiltration membrane filter is connected to the inlet pipe through an installation component, and the outlet end of the ultrafiltration membrane filter is connected to the outlet pipe.

[0007] The mounting assembly includes a mounting cylinder that is detachably connected to the inlet pipe. The mounting cylinder has an opening at the top, and the inlet end of the ultrafiltration membrane filter is inserted into the mounting cylinder. The bottom wall of the mounting cylinder is provided with a retractable connector for fixing the inlet end of the ultrafiltration membrane filter inside the mounting cylinder.

[0008] Furthermore, the inner bottom wall of the mounting cylinder is provided with an insertion ring groove along its circumference, and the water inlet end of the ultrafiltration membrane filter protrudes outward to form an insertion part that can be inserted into the insertion ring groove. The inner wall of the insertion part is provided with a positioning ring groove along its circumference.

[0009] The connector includes multiple plug blocks arranged circumferentially in the bottom wall of the mounting cylinder. One end of each plug block can extend into the plug ring groove, and the plug block extends into the positioning ring groove to fix the plug part in the plug ring groove.

[0010] Furthermore, the bottom wall of the mounting cylinder is provided with a first annular groove along its circumference, and the top wall of the first annular groove is provided with a sliding groove that connects to the insertion annular groove along its radial direction, and the insertion block is slidably disposed in the corresponding sliding groove.

[0011] The connector also includes a drive ring rotatably disposed in the first annular groove. The drive ring has a drive groove corresponding to the connector block. The connector block has a drive post that slides in the corresponding drive groove. The drive ring rotates to make the drive post slide in the drive groove, so as to realize the extension and retraction of the connector block in the sliding groove.

[0012] Furthermore, a second annular groove is provided along the circumference of the bottom wall of the mounting cylinder, and a toothed ring is provided on the lower side wall of the drive ring, extending into the second annular groove. A rotatable gear that meshes with the toothed ring is provided in the second annular groove, and a toggle shaft extending out of the bottom end of the mounting cylinder is provided on the gear. A locking member for locking the toggle shaft is provided on the bottom wall of the mounting cylinder.

[0013] Furthermore, the locking component includes a sleeve fitted over the actuating shaft, a groove on the actuating shaft located inside the sleeve, a locking block on the sleeve that slides within the groove, a nut threadedly connected to the protruding end of the actuating shaft, a spring fitted over the actuating shaft, the spring being used to push the sleeve toward the bottom wall of the mounting cylinder, a positioning pin at the upper end of the sleeve, and a positioning hole on the lower end face of the mounting cylinder, the positioning pin extending into the positioning hole to lock the sleeve.

[0014] Furthermore, a threaded connecting cylinder is provided on the bottom wall of the mounting cylinder at the middle position, the threaded connecting cylinder being used for threaded connection with the water inlet pipe.

[0015] Furthermore, the openings of the first annular groove and the second annular groove both face the bottom end of the mounting cylinder. A blocking plate is provided at the bottom end of the mounting cylinder. The threaded connecting cylinder is located at the center of the lower side of the blocking plate. The upper side of the blocking plate is provided with a stepped portion for sealing the sidewalls of the first annular groove and the second annular groove.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This invention allows the drive ring to rotate in both directions by releasing the locking member from the actuating shaft. This rotation of the actuating shaft in both directions drives the plug block to extend and retract within the sliding groove, allowing it to enter or disengage from the positioning ring groove. This facilitates the installation and removal of the lower end of the ultrafiltration membrane filter within the mounting cylinder, making installation and removal on the skid mount more convenient and facilitating the inspection and maintenance of the ultrafiltration membrane filter. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an integrated skid-mounted water treatment device according to the present invention.

[0019] Figure 2This is a schematic diagram of the structure between the ultrafiltration membrane filter and the installation components in this utility model.

[0020] Figure 3 This is a cross-sectional view of the ultrafiltration membrane filter of this utility model installed on the mounting assembly.

[0021] Figure 4 This is a schematic diagram of the mounting cylinder in this utility model.

[0022] Figure 5 This is a schematic diagram of the plug structure in this utility model.

[0023] Figure 6 This is a cross-sectional schematic diagram of the locking component in this utility model.

[0024] The meanings of the labels in the diagram are as follows:

[0025] 100. Skid-mounted frame; 101. Inlet pipe; 102. Outlet pipe; 103. Concentrate pipe; 110. Ultrafiltration membrane filter; 111. Mounting components;

[0026] 200. Mounting sleeve; 210. Insertion part; 211. Positioning ring groove; 220. Blocking plate; 221. Threaded connecting sleeve;

[0027] 301. Insertion ring groove; 310. Sealing ring; 320. Insertion block; 330. Drive ring; 340. Gear; 341. Actuating shaft;

[0028] 401, First annular groove; 402, Sliding groove; 403, Second annular groove; 404, Mounting hole; 411, Drive groove; 412, Gear ring; 421, Drive column; 430, Sleeve;

[0029] 501, Step section; 601, Slot; 611, Block; 612, Positioning pin; 620, Nut; 630, Spring. Detailed Implementation

[0030] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are merely illustrative of this utility model and are not intended to limit it.

[0031] The following is in conjunction with the appendix Figures 1-6 This embodiment will be described in further detail.

[0032] like Figure 1As shown, an integrated skid-mounted water treatment device in this embodiment includes a skid frame 100 and an ultrafiltration membrane assembly. The skid frame 100 is provided with an inlet pipe 101, an outlet pipe 102 and a concentrate pipe 103. The ultrafiltration membrane assembly includes ultrafiltration membrane filters 110 arranged in parallel. The ultrafiltration membrane filter 110 has a conventional structure, which includes a filter cylinder with openings at both the upper and lower ends. An ultrafiltration membrane filter element is provided inside the filter cylinder. End caps are threaded to both ends of the filter cylinder. An outlet and a concentrate outlet are formed on the upper end cap, and an inlet is formed on the lower end cap.

[0033] In this embodiment, the inlet end (i.e., the lower end) of the ultrafiltration membrane filter 110 is connected to the inlet pipe 101 through the mounting assembly 111, the outlet end (i.e., the upper end) of the ultrafiltration membrane filter 110 is connected to the outlet pipe 102, and the concentrate end of the ultrafiltration membrane filter 110 is connected to the concentrate pipe 103.

[0034] Combination Figures 2-4 As shown, in this embodiment, the installation assembly 111 includes an installation cylinder 200 detachably connected to the water inlet pipe 101. The upper end of the installation cylinder 200 is open, and the water inlet end of the ultrafiltration membrane filter 110 is inserted into the installation cylinder 200. The bottom wall of the installation cylinder 200 is provided with a retractable connector, which is used to fix the water inlet end of the ultrafiltration membrane filter 110 into the installation cylinder 200.

[0035] In this embodiment, combined with Figure 1 As shown, the water inlet pipe 101 includes multiple water pipe sections and multiple T-pipes. The number of T-pipes corresponds to the number of ultrafiltration membrane filters 110. The water pipes are connected sequentially through the T-pipes to form the water inlet pipe 101. In actual use, the lower end of the mounting cylinder 200 is provided with a threaded connecting cylinder 221. The threaded connecting cylinder 221 is connected to the inside of the mounting cylinder 200. The threaded connecting cylinder 221 is threaded to one end of the T-pipe to realize the detachable installation of the mounting cylinder 200 on the water inlet pipe 101.

[0036] The connector allows the inlet of the ultrafiltration membrane filter 110 to be inserted into the mounting cylinder 200 during actual use, until it abuts against the bottom wall of the mounting cylinder 200. The bottom wall of the mounting cylinder 200 has a mounting hole 404 corresponding to the threaded connecting cylinder 221. The inlet extends into the mounting hole 404. The ultrafiltration membrane filter 110 inserted into the mounting cylinder 200 can be fixed by the connector, which facilitates the connection between the inlet of the ultrafiltration membrane filter 110 and the inlet pipe 101.

[0037] In this embodiment, after the connection of the ultrafiltration membrane filter 110 between the inlet pipe 101, the outlet pipe 102, and the concentrate pipe 103 is completed, the water to be treated enters the filter cartridge through the inlet of the inlet pipe 101. After being filtered by the ultrafiltration membrane filter element inside, the purified water enters the outlet pipe 102 through the outlet and is discharged. The concentrated water enters the concentrate pipe 103 through the concentrate outlet and is discharged, thereby completing the ultrafiltration treatment of the water.

[0038] Specifically, in order to improve the sealing performance at the water inlet, in this embodiment, a sealing ring 310 is provided between the end cap at the lower end and the inner bottom wall of the mounting cylinder 200.

[0039] In this embodiment, an insertion ring groove 301 is provided circumferentially on the inner bottom wall of the mounting cylinder 200, and the water inlet end of the ultrafiltration membrane filter 110 protrudes outward to form an insertion part 210 that can be inserted into the insertion ring groove 301. Specifically, as shown in the figure... Figure 2 As shown, a plug-in portion 210 extends downward from the outer edge of the end cap located on the lower side, and a positioning annular groove 211 is provided on the inner wall of the plug-in portion 210 along its circumference.

[0040] The connector includes a plurality of plug blocks 320 arranged circumferentially in the bottom wall of the mounting cylinder 200. One end of the plug block 320 can extend into the plug ring groove 301, and the plug block 320 extends into the positioning ring groove 211 so that the plug part 210 is fixed in the plug ring groove 301.

[0041] In this embodiment, when the inlet end of the ultrafiltration membrane filter 110 is inserted into the mounting cylinder 200 and abuts against the inner bottom wall of the mounting cylinder 200, the insertion part 210 is inserted into the insertion ring groove 301. At this time, one end of the insertion block 320 extends into the positioning ring groove 211 so that the insertion part 210 is fixed in the insertion ring groove 301, thereby realizing the installation of the ultrafiltration membrane filter 110 in the mounting cylinder 200. When it is necessary to remove the ultrafiltration membrane filter 110 from the mounting cylinder 200, the insertion block 320 is retracted to disengage it from the positioning ring groove 211, thereby releasing the fixation of the ultrafiltration membrane filter 110. At this time, the outlet pipe 102 and the concentrate pipe 103 are removed from the skid frame 100 so that the ultrafiltration membrane filter 110, the outlet pipe 102, and the concentrate pipe 103 are removed from the skid frame 100 as a whole, thereby facilitating the inspection and maintenance of the ultrafiltration membrane filter 110.

[0042] In this embodiment, the bottom wall of the mounting cylinder 200 is provided with a first annular groove 401 along its circumference, and the top wall of the first annular groove 401 is provided with a sliding groove 402 that connects to the insertion annular groove 301 along its radial direction. The insertion block 320 is slidably disposed in the corresponding sliding groove 402.

[0043] The connector also includes a drive ring 330 rotatably disposed in the first annular groove 401. The drive ring 330 is provided with a drive groove 411 corresponding to the connector 320. The connector 320 is provided with a drive post 421 that slides in the corresponding drive groove 411. The drive ring 330 rotates in both directions to make the drive post 421 slide in the drive groove 411, so as to realize the extension and retraction of the connector 320 in the sliding groove 402.

[0044] In this embodiment, to achieve forward and reverse rotation of the drive ring 330, a second annular groove 403 is provided circumferentially inside the bottom wall of the mounting cylinder 200. The second annular groove 403 is located below the first annular groove 401 and communicates with it. A toothed ring 412 extending into the second annular groove 403 is provided on the lower side wall of the drive ring 330. A rotatable gear 340 meshing with the toothed ring 412 is provided in the second annular groove 403. The gear 340 is provided with a toggle shaft 341 extending out of the bottom end of the mounting cylinder 200. To achieve forward and reverse rotation of the drive ring 330, a toggle shaft 341 is provided on the gear 340. 40 is rotatably installed in the second annular groove 403. In this embodiment, the two ends of the actuating shaft 341 pass through the gear 340. The top wall of the second annular groove 403 is provided with a groove for the upper end of the actuating shaft 341 to extend into. The lower end of the actuating shaft 341 extends through the bottom end of the mounting cylinder 200, thereby realizing the rotatable installation of the gear 340. In actual use, the gear 340 can be driven to rotate by rotating the extended end of the actuating shaft 341 in both directions, thereby realizing the forward and reverse rotation of the drive ring 330 and performing synchronous extension and retraction adjustment of multiple plug-in blocks 320.

[0045] In order to prevent the actuating shaft 341 from being rotated erroneously and thus affecting the installation of the inlet end of the ultrafiltration membrane filter 110 in the mounting cylinder 200, in this embodiment, a locking member for locking the actuating shaft 341 is provided on the bottom wall of the mounting cylinder 200.

[0046] Combination Figure 6As shown, in this embodiment, the locking component includes a sleeve 430 fitted over the actuating shaft 341. The lower end of the sleeve 430 is open, and a plug is threaded onto the opening to facilitate the assembly of the internal components. Specifically, the upper end of the sleeve 430 has a through hole for the actuating shaft 341 to extend into. The actuating shaft 341 inside the sleeve 430 has a groove 601, and the sleeve 430 has a locking block 611 that slides within the groove 601. The locking block 611 is fixedly installed within the through hole, thus forming a keyway fit between the sleeve 430 and the actuating shaft 341. This means that rotation of the sleeve 430 can drive rotation of the actuating shaft 341, and the sleeve 430 can move axially along the actuating shaft 341. A nut 620 is threaded onto the protruding end of the actuating shaft 341, and a spring 630 is fitted over the actuating shaft 341. The lower end of the sleeve 430 abuts against the nut 620, and the upper end abuts against the upper end of the sleeve 430, so that the spring 630 always pushes the sleeve 430 to move towards the bottom wall of the mounting cylinder 200. The upper end of the sleeve 430 is provided with a positioning pin 612, and the lower end face of the mounting cylinder 200 is provided with a positioning hole. The positioning pin 612 extends into the positioning hole to lock the sleeve 430, that is, to lock the actuating shaft 341 to prevent it from rotating accidentally. Thus, in actual use, when it is necessary to rotate the actuating shaft 341, the operator pulls down the sleeve 430 to make the positioning pin 612 disengage from the positioning hole. At this time, rotating the sleeve 430 in both directions can drive the actuating shaft 341 to rotate in both directions to adjust the extension and retraction of the plug block 320. After the rotation is completed, the sleeve 430 is released, so that it moves upward under the action of the spring 630, so that the positioning pin 612 extends into the corresponding positioning hole.

[0047] It should be noted that in this embodiment, there are two positioning holes. One is set when the plug-in block 320 extends into the plug-in ring groove 301, and the other is set when the plug-in block 320 retracts into the sliding groove 402. That is, the positioning pin 612 extends into the corresponding positioning hole to keep the plug-in block 320 in the extended or retracted state for actual use.

[0048] Specifically, in order to reduce the wobbling of the spring 630 inside the sleeve 430, in this embodiment, rubber pads are provided at both ends of the spring 630 to abut against the nut 620 or the upper end of the sleeve 430.

[0049] In this embodiment, in order to achieve the assembly of the connector within the bottom wall of the mounting cylinder 200, combined with Figure 5As shown, in this embodiment, the openings of the first annular groove 401 and the second annular groove 403 both face the bottom end of the mounting cylinder 200. A blocking plate 220 is provided at the bottom end of the mounting cylinder 200. The threaded connecting cylinder 221 is located at the center of the lower side of the blocking plate 220. The upper side of the blocking plate 220 is provided with a stepped portion 501 for sealing the side walls of the first annular groove 401 and the second annular groove 403. A through hole is provided in the stepped portion 501 corresponding to the threaded connecting cylinder 221. The blocking plate 220 is welded and installed at the bottom end of the mounting cylinder 200. At this time, the stepped portion 501 extends into the mounting hole 404 in the bottom wall of the mounting cylinder 200 to seal the sliding groove 402, the first annular groove 401 and the second annular groove 403, thereby facilitating the assembly of the connector in the bottom wall of the mounting cylinder 200.

[0050] Specifically, in order to make the installation of the blocking plate 220 at the lower end of the mounting cylinder 200 more stable, in this embodiment, the end face of the step portion 501 extending into the mounting hole 404 is welded to the side wall of the mounting hole 404, so as to make the connection between the blocking plate 220 and the mounting cylinder 200 more stable.

[0051] In summary, the above description is only a preferred embodiment of the present utility model. All equivalent changes and modifications made within the scope of the patent application of the present utility model shall fall within the scope of the patent of the present utility model.

Claims

1. An integrated skid-mounted water treatment device, comprising a skid frame (100) and an ultrafiltration membrane assembly, characterized in that: The skid-mounted frame (100) is provided with an inlet pipe (101) and an outlet pipe (102). The ultrafiltration membrane assembly includes an ultrafiltration membrane filter (110) arranged in parallel. The inlet end of the ultrafiltration membrane filter (110) is connected to the inlet pipe (101) through the mounting assembly (111), and the outlet end of the ultrafiltration membrane filter (110) is connected to the outlet pipe (102). The mounting assembly (111) includes a mounting cylinder (200) detachably connected to the water inlet pipe (101). The mounting cylinder (200) has an opening at its upper end. The water inlet end of the ultrafiltration membrane filter (110) is inserted into the mounting cylinder (200). The bottom wall of the mounting cylinder (200) is provided with a retractable connector for fixing the water inlet end of the ultrafiltration membrane filter (110) into the mounting cylinder (200).

2. The integrated skid-mounted water treatment equipment according to claim 1, characterized in that: The inner bottom wall of the mounting cylinder (200) is provided with a circumferential insertion groove (301), and the water inlet end of the ultrafiltration membrane filter (110) protrudes outward to form a insertion part (210) that can be inserted into the insertion groove (301). The inner wall of the insertion part (210) is provided with a positioning groove (211) along its circumferential direction. The connector includes a plurality of plug blocks (320) arranged circumferentially in the bottom wall of the mounting cylinder (200). One end of the plug block (320) can extend into the plug ring groove (301), and the plug block (320) extends into the positioning ring groove (211) so that the plug part (210) is fixed in the plug ring groove (301).

3. The integrated skid-mounted water treatment equipment according to claim 2, characterized in that: The bottom wall of the mounting cylinder (200) is provided with a first annular groove (401) along its circumference, and the top wall of the first annular groove (401) is provided with a sliding groove (402) that connects to the insertion annular groove (301) along its radial direction. The insertion block (320) is slidably disposed in the corresponding sliding groove (402). The connector also includes a drive ring (330) rotatably disposed in the first annular groove (401). The drive ring (330) is provided with a drive groove (411) corresponding to the connector block (320). The connector block (320) is provided with a drive post (421) that slides in the corresponding drive groove (411). The drive ring (330) rotates to make the drive post (421) slide in the drive groove (411) so as to realize the extension and retraction of the connector block (320) in the sliding groove (402).

4. The integrated skid-mounted water treatment equipment according to claim 3, characterized in that: The bottom wall of the mounting cylinder (200) is provided with a second annular groove (403) along its circumference. The lower side wall of the drive ring (330) is provided with a toothed ring (412) extending into the second annular groove (403). The second annular groove (403) is provided with a rotatable gear (340) that meshes with the toothed ring (412). The gear (340) is provided with a toggle shaft (341) extending out of the bottom end of the mounting cylinder (200). The bottom wall of the mounting cylinder (200) is provided with a locking member for locking the toggle shaft (341).

5. The integrated skid-mounted water treatment equipment according to claim 4, characterized in that: The locking component includes a sleeve (430) fitted over the actuating shaft (341). The actuating shaft (341) located inside the sleeve (430) has a groove (601). The sleeve (430) has a locking block (611) that slides within the groove (601). The protruding end of the actuating shaft (341) is threaded with a nut (620). The actuating shaft (341) is fitted with a spring (630). The spring (630) is used to push the sleeve (430) to move towards the bottom wall of the mounting cylinder (200). The upper end of the sleeve (430) is provided with a positioning pin (612). The lower end face of the mounting cylinder (200) is provided with a positioning hole. The positioning pin (612) extends into the positioning hole to lock the sleeve (430).

6. The integrated skid-mounted water treatment equipment according to claim 2, characterized in that: A threaded connecting sleeve (221) is provided on the bottom wall of the mounting sleeve (200) at the middle position. The threaded connecting sleeve (221) is used to connect to the water inlet pipe (101) by thread.

7. The integrated skid-mounted water treatment equipment according to claim 6, characterized in that: The openings of the first annular groove (401) and the second annular groove (403) both face the bottom end of the mounting cylinder (200). A blocking plate (220) is provided at the bottom end of the mounting cylinder (200). The threaded connecting cylinder (221) is located at the center of the lower side of the blocking plate (220). The upper side of the blocking plate (220) is provided with a stepped portion (501) for sealing the side walls of the first annular groove (401) and the second annular groove (403).