Vacuumizing filtering mechanism in low-temperature storage tank

Abstract

The utility model discloses a vacuumizing filtering mechanism in a low-temperature storage tank, which comprises an outer cylinder, a connecting pipe arranged on the outer cylinder, a vacuum valve arranged on the connecting pipe, a three-way valve connected to the vacuum valve, a first branch pipe welded on the inner side wall of the outer cylinder and communicated with the connecting pipe, a second branch pipe connected to the first branch pipe, and a third branch pipe connected to the second branch pipe, a filter screen is arranged between the first branch pipe and the second branch pipe, a plurality of elastic pieces are evenly distributed in the second branch pipe in the circumferential direction, a filter plate is arranged in the second branch pipe in an up-down sliding mode and abuts against the elastic pieces, an inner check ring is arranged in the second branch pipe in a clamped mode, and the filter plate abuts against the inner check ring under supporting of the elastic pieces. The vacuum valve has the advantages that impurities in the interlayer cannot influence the vacuum valve during vacuumizing, the probability that the filter screen is blocked can be reduced, and blockages on the filter plate can be removed when the filter plate is blocked.

Description

Technical Field

[0001] The utility model relates to the field of pressure vessels, in particular to a vacuum filtering mechanism in a low-temperature storage tank. Background Art

[0002] When producing low-temperature storage tanks, the inner cylinder is mounted on the outer cylinder to form an interlayer between the inner cylinder and the outer cylinder. In order to improve the thermal insulation performance of the low-temperature storage tank, the interlayer between the inner cylinder and the outer cylinder in the low-temperature storage tank needs to be evacuated, and then pearl sand is filled in the interlayer. During the vacuuming process, impurities in the interlayer are easily introduced into the vacuum valve along with the air, affecting the service life of the vacuum valve. During the process of filling the pearl sand, if it is found that the vacuum degree in the interlayer is insufficient, it is necessary to supplement the vacuum. During the supplementary vacuuming, the pearl sand is easily moved to the vacuum valve by the suction force of the vacuum equipment. Therefore, in order to prevent the impurities and pearl sand in the interlayer from damaging the vacuum valve during the vacuuming process, a filter is generally set on the air inlet end of the vacuum valve. Although the filter can isolate impurities and pearl sand, the filter holes of the filter are easily blocked by impurities or pearl sand, affecting the vacuuming efficiency. Utility Model Content

[0003] The utility model aims to provide a vacuum filtering mechanism in a low-temperature storage tank which can prevent a filter screen from being blocked during the vacuuming process.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a vacuum filtering mechanism in a low-temperature storage tank, comprising: an outer cylinder, a connecting pipe is arranged on the outer cylinder, a vacuum valve is arranged on the connecting pipe, a three-way valve is connected to the vacuum valve, a first branch pipe connected to the connecting pipe is welded on the inner side wall of the outer cylinder, a second branch pipe is connected to the first branch pipe, a filter screen is arranged between the first branch pipe and the second branch pipe, a plurality of elastic members are evenly distributed circumferentially in the second branch pipe, a filter plate is arranged in the second branch pipe for sliding up and down, the filter plate abuts on the elastic member, an inner retaining ring is clamped in the second branch pipe, and the filter plate abuts on the inner retaining ring under the support of the elastic member.

[0005] Furthermore, in the aforementioned vacuum filtration mechanism in the low-temperature storage tank, the connection structure between the first branch pipe and the second branch pipe is as follows: a first boss is extended on the side wall of the top of the first branch pipe, and a second boss is extended on the side wall of the bottom of the second branch pipe, and the first boss and the second boss are abutted against each other and clamped by a clamp.

[0006] Furthermore, in the aforementioned vacuum filtering mechanism in the low-temperature storage tank, a plurality of first convex rings and first concave rings are arranged at intervals on the top wall of the first boss, and a plurality of second concave rings and second convex rings are arranged at intervals on the bottom wall of the second boss, the first convex rings are aligned one by one with the second concave rings, and the first concave rings are aligned one by one with the second convex rings, and when the first boss and the second boss abut against each other, the first convex ring is inserted into the second concave ring, and the second convex ring is inserted into the first concave ring, and the filter is inserted between the first boss and the second boss.

[0007] Furthermore, in the aforementioned vacuum filtration mechanism in the low-temperature storage tank, four elastic members are evenly distributed circumferentially in the second branch pipe, and the elastic members are C-shaped spring leaves, which are vertically arranged and fixed in the second branch pipe by bolts.

[0008] Furthermore, in the aforementioned vacuum filtration mechanism in the low-temperature storage tank, a boss is provided on the inner side wall of the second branch pipe near the bottom, and the bottom of the C-shaped spring sheet abuts against the boss.

[0009] Furthermore, in the aforementioned vacuum filtration mechanism in the low-temperature storage tank, the filter mesh number of the filter is 200 mesh or 230 mesh, and the filter mesh number of the filter plate is between 160 mesh and 175 mesh.

[0010] Furthermore, in the aforementioned vacuum filtration mechanism in the low-temperature storage tank, a vacuum gauge is provided on the connecting pipe.

[0011] The utility model has the advantages that double-layer filtration is achieved by arranging a filter plate with lower filtration accuracy and a filter screen with higher filtration accuracy. The filter plate with lower filtration accuracy can filter out impurities with larger volume in the interlayer, while the filter screen with higher filtration accuracy can filter out impurities with smaller volume in the interlayer. This can ensure that the impurities in the interlayer will not affect the vacuum valve during vacuuming and can also reduce the probability of the filter screen being blocked. Since blockage generally occurs on the filter plate that plays a coarse filtration role, when the filter plate is blocked, the environment in the first branch pipe and the second branch pipe is isolated from the environment in the interlayer. Under the action of the vacuum equipment, the pressure in the first branch pipe and the second branch pipe is lower than the pressure in the interlayer. Under the action of the negative pressure, the filter plate will apply pressure to the C-type spring sheet to elastically deform it. Then, after air is sent into the vacuum valve through the three-way valve, the filter plate collides with the inner retaining ring under the elastic force of the C-type spring sheet to form a lighter vibration, so that the blockage is bounced off and the filtering capacity is restored. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the vacuum filtration mechanism in the low-temperature storage tank described in the utility model.

[0013] Figure 2 yes Figure 1 Schematic diagram of the local enlarged structure in the A direction. DETAILED DESCRIPTION

[0014] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0015] like Figure 1 , Figure 2 As shown, the vacuum filtration mechanism in the low-temperature storage tank of the utility model comprises: an outer cylinder 1, a connecting pipe 11 is arranged on the outer cylinder 1, a vacuum gauge 12 is arranged on the connecting pipe 11, a vacuum valve 13 is arranged on the connecting pipe 11, a three-way valve 14 is arranged on the vacuum valve 13, a first branch pipe 2 connected to the connecting pipe 11 is welded on the inner side wall of the outer cylinder 1, a second branch pipe 3 is connected to the first branch pipe 2, and the connection structure between the first branch pipe 2 and the second branch pipe 3 is: a first boss 21 is extended on the side wall of the top of the first branch pipe 2, A second boss 31 is extended on the side wall at the bottom of the second branch pipe 3, the first boss 21 and the second boss 31 are abutted against each other and are clamped by the clamp 4, a plurality of first convex rings 211 and first concave rings 212 are arranged at intervals on the top wall of the first boss 21, and a plurality of second convex rings 311 and second concave rings 312 are arranged at intervals on the bottom wall of the second boss 31, the first convex ring 211 and the second concave ring 312 are aligned one by one up and down, the first concave ring 212 and the second convex ring 311 are aligned one by one up and down, a filter screen 5 is clamped between the first boss 21 and the second boss 31, and the first When the boss 21 and the second boss 31 abut against each other, the first convex ring 211 with the filter 5 is inserted into the second concave ring 312, and the second convex ring 311 with the filter 5 is inserted into the first concave ring 212, thereby improving the installation strength of the filter 5. The filter mesh number of the filter 5 is 200 mesh or 230 mesh, which can effectively filter out impurities in the interlayer. A plurality of elastic members are evenly distributed around the circumference in the second branch pipe 3. In this embodiment, four elastic members are selected for even distribution around the circumference. The elastic member is a C-shaped spring sheet 6. The C-shaped spring sheet 6 is vertically arranged and fixed in the second branch pipe 3 by bolts. A boss 32 is provided on the inner wall of the second branch pipe 3 near the bottom, and the bottom of the C-shaped spring sheet 6 abuts against the boss 32. The boss 32 can not only support the C-shaped spring sheet 6, but also limit the rotation of the C-shaped spring sheet 6. A filter plate 7 is provided in the second branch pipe 3 for sliding up and down. The filter mesh number of the filter plate 7 is between 160 mesh and 175 mesh. The filtering accuracy can filter out impurities with a larger volume. The filter plate 7 abuts against four C-shaped spring sheets 6. An inner retaining ring 33 is clamped in the second branch pipe 3. The filter plate 7 abuts against the inner retaining ring 33 under the support of the C-shaped spring sheet 6.

[0016] When in use, a vacuum device is connected to one air inlet end of the three-way valve 14, and the other air inlet end of the three-way valve 14 is connected to the external environment. The three-way valve 14 is switched to the air inlet passage connected to the vacuum device, and the vacuum valve 13 is opened. The vacuum device is started to vacuum the interlayer. During the vacuum process, the filter plate 7 plays a coarse filtering role, and the filter screen 5 plays a fine filtering role. If the reading of the vacuum gauge 12 suddenly stops decreasing or the decreasing speed slows down significantly during the vacuum process, it means that blockage has occurred. Since the filter plate 7 plays a coarse filtering role, Blockage generally occurs on the filter plate 7. When the filter plate 7 is blocked, the blocked filter plate 7 will isolate the environment in the first branch pipe 2 and the second branch pipe 3 from the environment in the interlayer. The vacuum equipment continues to vacuumize, generating negative pressure in the first branch pipe 2 and the second branch pipe 3. When the pressure value in the environment of the first branch pipe 2 and the second branch pipe 3 is lower than the pressure value in the interlayer environment, the pressure in the interlayer will generate pressure on the blocked filter plate 7, forcing the blocked filter plate 7 to apply pressure to the C-type spring sheet 6. After being subjected to a large pressure, the C-type spring sheet 6 will produce elastic deformation. The vacuum pumping device stops vacuuming and switches the three-way valve 14 to the air inlet passage connected to the external environment. The external air will quickly enter the first branch pipe 2 and the second branch pipe 3 under the action of negative pressure to be pressurized. After the pressure in the first branch pipe 2 and the second branch pipe 3 is greater than or equal to the pressure in the interlayer, the blocked filter plate 7 is no longer affected by the negative pressure in the first branch pipe 2 and the second branch pipe 3, and no longer applies pressure to the C-type spring sheet 6. The C-type spring sheet 6 is reset under the action of elastic force and quickly pushes the blocked filter plate 7. The blocked filter plate 7 will quickly move and contact the inner block. The filter plate 7 collides with the inner retaining ring 33, and the blocked filter plate 7 vibrates after colliding with the inner retaining ring 33, thereby bouncing off the blocked impurities, and the filter plate 7 recovers its filtering capacity. Then the three-way valve 14 is switched back to the air inlet passage connected to the vacuum equipment. After switching to the air inlet passage connected to the external environment, it generally lasts for 2s to 3s. Too long a time will affect the vacuum state in the interlayer. After the three-way valve 14 is switched back to the air inlet passage connected to the vacuum equipment, vacuuming can continue. If blockage occurs again during the vacuuming process, the three-way valve 14 can be switched repeatedly.

[0017] When filling the pearl sand after completing the vacuuming, first close the vacuum valve 13, and switch the three-way valve 14 to the air intake passage connected to the vacuuming equipment. A nitrogen gas source is connected to the air intake end of the three-way valve 14 connected to the external environment. If it is observed through the vacuum gauge 12 that the vacuum degree in the interlayer is insufficient, open the vacuum valve 13 and the vacuuming equipment to perform vacuuming. If the filter plate 7 is blocked by the pearl sand during the vacuuming process, switch the three-way valve 14 to the air intake passage connected to the nitrogen gas source, and the nitrogen enters the first branch pipe 2 and the second branch pipe 3 for pressurization, so that the filter plate 7 rebounds to bounce off the blocked pearl sand, and then switch back to the air intake passage connected to the vacuuming equipment to perform vacuuming until the vacuum degree in the interlayer meets the requirements.

[0018] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. The vacuum filtration mechanism in the cryogenic storage tank includes: An outer cylinder body is provided with a connecting pipe on the outer cylinder body, and a vacuum valve is provided on the connecting pipe. The invention is characterized in that: a three-way valve is connected to the vacuum valve, a first branch pipe connected to the connecting pipe is welded on the inner wall of the outer cylinder body, a second branch pipe is connected to the first branch pipe, a filter screen is provided between the first branch pipe and the second branch pipe, a plurality of elastic members are evenly distributed circumferentially in the second branch pipe, a filter plate is provided in the second branch pipe to slide up and down, the filter plate abuts on the elastic member, an inner retaining ring is clamped in the second branch pipe, and the filter plate abuts on the inner retaining ring under the support of the elastic member.

2. The vacuum filtration mechanism in the cryogenic storage tank according to claim 1, characterized in that: The connection structure between the first branch pipe and the second branch pipe is as follows: a first boss is extended on the side wall of the top of the first branch pipe, and a second boss is extended on the side wall of the bottom of the second branch pipe. The first boss and the second boss are abutted against each other and are fastened by a clamp.

3. The vacuum filtration mechanism in the cryogenic storage tank according to claim 2, characterized in that: A plurality of first convex rings and first concave rings are arranged at intervals on the top wall of the first boss, and a plurality of second concave rings and second convex rings are arranged at intervals on the bottom wall of the second boss. The first convex rings are aligned one by one with the second concave rings, and the first concave rings are aligned one by one with the second convex rings. When the first boss and the second boss abut against each other, the first convex ring is inserted into the second concave ring, and the second convex ring is inserted into the first concave ring, and the filter is inserted between the first boss and the second boss.

4. The vacuum filtration mechanism in the cryogenic storage tank according to claim 1, characterized in that: Four elastic members are evenly distributed around the circumference of the second branch pipe. The elastic members are C-shaped spring sheets, which are vertically arranged and fixed in the second branch pipe by bolts.

5. The vacuum filtration mechanism in the cryogenic storage tank according to claim 4, characterized in that: A convex shoulder is arranged on the inner side wall of the second branch pipe near the bottom, and the bottom of the C-shaped spring sheet abuts against the convex shoulder.

6. The vacuum filtration mechanism in the cryogenic storage tank according to claim 1, characterized in that: The filter mesh number of the filter is 200 mesh or 230 mesh, and the filter mesh number of the filter plate is between 160 mesh and 175 mesh.

7. The vacuum filtration mechanism in the cryogenic storage tank according to claim 1, characterized in that: A vacuum gauge is provided on the connecting pipe.

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