Anti-blocking vacuumizing joint for LNG (Liquefied Natural Gas) storage tank

Abstract

The utility model discloses an anti-clogging vacuumizing joint for an LNG storage tank, which comprises a pipe body welded on an outer cylinder seal head of the LNG storage tank, an arc-shaped filter element is clamped in the inner side wall of the pipe body, the arc-shaped filter element comprises a fixing ring and a limiting ring, an arc-shaped hollow frame is arranged on the fixing ring, the arc-shaped hollow frame downwards extends out of the pipe body, and the limiting ring is arranged on the limiting ring. The outer side wall of the arc-shaped hollowed-out frame is coated with a layer of stainless steel filter screen, the edge of the stainless steel filter screen is laid on the fixing ring, the arc-shaped hollowed-out frame is sleeved with the limiting ring, the limiting ring abuts against the edge of the stainless steel filter screen, and the limiting ring is fixedly connected with the stainless steel filter screen and the fixing ring. The utility model has the advantages that the occurrence of blockage of the stainless steel filter screen can be effectively reduced, and the condition that the arc-shaped filter element is separated from the pipe body is avoided.

Description

Technical Field

[0001] The utility model relates to the field of high-pressure vessels, in particular to an anti-blocking vacuum pumping joint for an LNG storage tank. Background Art

[0002] When manufacturing an LNG storage tank, a vacuum pumping joint needs to be provided on the outer cylinder head, and then the interlayer between the outer cylinder and the inner cylinder is evacuated through the vacuum pumping joint. During the evacuation process, in order to prevent sundries in the interlayer from being sucked into the vacuum pump, a filter screen is provided at the air inlet end of the vacuum pumping joint. Currently, the conventional operation is to lay a layer of stainless steel filter screen on the air inlet end of the vacuum pumping joint, and then use a U-shaped retaining rod to press against the stainless steel filter screen. The two legs of the U-shaped retaining rod are respectively located on both sides of the air inlet end of the vacuum pumping joint, and then the two legs of the U-shaped retaining rod are welded to the inner wall of the outer cylinder head. The cooperation between the U-shaped retaining rod and the outer cylinder head is used to clamp the stainless steel filter screen. However, it is found during use that either the laid stainless steel filter screen is easily blocked, or under the action of the airflow generated during the evacuation process, the stainless steel filter screen falls off from the U-shaped retaining rod and cannot play a filtering role. Content of the Utility Model

[0003] The purpose of the utility model is to provide an anti-blocking vacuum pumping joint for an LNG storage tank with good filtering effect.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: an anti-blocking vacuum pumping joint for an LNG storage tank, including: a pipe body welded to the outer cylinder head of the LNG storage tank, an arc-shaped filter element is clamped in the inner side wall of the pipe body, the arc-shaped filter element includes: a fixing ring and a limiting ring, an arc-shaped hollow frame is arranged on the fixing ring, the arc-shaped hollow frame extends downward out of the pipe body, a layer of stainless steel filter screen is coated on the outer side wall of the arc-shaped hollow frame, the edge of the stainless steel filter screen is laid on the fixing ring, the limiting ring is sleeved on the outside of the arc-shaped hollow frame and abuts against the edge of the stainless steel filter screen, and the limiting ring is fixedly connected with the stainless steel filter screen and the fixing ring.

[0005] Further, for the anti-blocking vacuum pumping joint for an LNG storage tank described above, wherein, the arc-shaped hollow frame includes: arc-shaped support ribs and a connecting plate, the arc-shaped support ribs are circumferentially and evenly distributed on the fixing ring and extend downward, and each arc-shaped support rib is connected to the same connecting plate.

[0006] Further, for the anti-blocking vacuum pumping joint for an LNG storage tank described above, wherein, the connecting plate is circular in shape, each arc-shaped support rib is welded to the outer side wall of the connecting plate, and air permeation holes are formed in the connecting plate.

[0007] Further, for the anti-blocking vacuum extraction joint for LNG storage tanks mentioned above, the connection structure between the fixing ring, the limiting ring and the stainless steel filter screen is as follows: a number of upper countersunk holes are evenly distributed in a circle on the fixing ring, a number of lower countersunk holes are evenly distributed in a circle on the limiting ring, and a number of through holes are evenly distributed in a circle on the stainless steel filter screen. Each upper countersunk hole, through hole and lower countersunk hole are aligned one by one, and rivets are riveted between the aligned upper countersunk holes, through holes and lower countersunk holes. Both ends of the rivets are sunk in the upper countersunk holes and lower countersunk holes respectively.

[0008] Further, for the anti-blocking vacuum extraction joint for LNG storage tanks mentioned above, the connection structure between the pipe body and the arc-shaped filter element is as follows: an installation groove is formed on the inner bottom wall of the pipe body, an inner retaining ring is clamped in the installation groove, and the fixedly connected fixing ring and limiting ring are clamped into the installation groove. The fixing ring abuts against the inner top wall of the installation groove, and the inner retaining ring abuts against the limiting ring.

[0009] Further, for the anti-blocking vacuum extraction joint for LNG storage tanks mentioned above, a low-temperature resistant annular rubber pad is sleeved on the outer side wall of the fixing ring and the limiting ring fixed together.

[0010] Further, for the anti-blocking vacuum extraction joint for LNG storage tanks mentioned above, a positioning groove is inwardly contracted and arranged on the outer bottom wall of the pipe body. The positioning groove is adapted to the installation hole on the outer cylinder head, and the height of the positioning groove is the same as the thickness of the outer cylinder head.

[0011] Further, for the anti-blocking vacuum extraction joint for LNG storage tanks mentioned above, the filtration mesh number of the stainless steel filter screen is between 160 meshes and 170 meshes.

[0012] The advantages of the present utility model are as follows: an arc-shaped filter element is arranged at the bottom of the pipe body. Through the arc-shaped filter element, the uneven distribution of the air flow velocity during the vacuum extraction process forms fluid turbulence, which can effectively disperse the sundries in the air flow and reduce the concentrated deposition at specific points, thereby effectively reducing the occurrence of blockage. After the arc-shaped filter element is clamped in the installation groove, it is blocked by the inner retaining ring, which can prevent the arc-shaped filter element from falling off from the pipe body. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the anti-blocking vacuum extraction joint for LNG storage tanks described in the present utility model.

[0014] Figure 2 is Figure 1 a schematic structural diagram of the arc-shaped filter element in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The technical solutions described in the present utility model will be further described below with reference to the accompanying drawings and preferred embodiments.

[0016] AsFigure 1 , Figure 2 As shown in Figure 2 , the anti-blocking vacuum extraction joint for an LNG storage tank of the present utility model includes: a pipe body 2 welded to the outer cylinder head 1 of the LNG storage tank. An inwardly contracting positioning groove 21 is provided on the outer side wall of the bottom of the pipe body 2. The positioning groove 21 is adapted to the mounting hole 11 on the outer cylinder head 1, and the height of the positioning groove 21 is the same as the thickness of the outer cylinder head 1. When welding the pipe body 2 to the outer cylinder head 1, inserting the positioning groove 21 on the pipe body 2 into the mounting hole 11 of the outer cylinder head 1 can ensure the perpendicularity between the pipe body 2 and the mounting hole 11. Moreover, since the outer cylinder head 1 is arc-shaped and the top wall of the positioning groove 21 is flat, after the positioning groove 21 of the pipe body 2 abuts against the mounting hole 11 of the outer cylinder head 1, a gap will be left between the pipe body 2 and the outer cylinder head 1. When the pipe body 2 and the outer cylinder head 1 are fully welded, the pipe body 2 and the outer cylinder head 1 expand due to heat, and the gap between the pipe body 2 and the outer cylinder head 1 can reduce the stress caused by expansion, thereby improving the welding quality.

[0017] An arc-shaped filter element 3 is clamped in the inner side wall of the pipe body 2. The arc-shaped filter element 3 includes: a fixing ring 31 and a limiting ring 32. An arc-shaped hollow frame extending downward is provided on the fixing ring 31. A layer of stainless steel filter mesh 33 is coated on the outer side wall of the arc-shaped hollow frame, so that the stainless steel filter mesh 33 is arranged in an arc shape. The filtration mesh number of the stainless steel filter mesh 33 is between 160 meshes and 170 meshes. This filtration accuracy can filter out most impurities. The edge of the stainless steel filter mesh 33 is laid on the fixing ring 31. The limiting ring 32 is sleeved on the outer side of the arc-shaped hollow frame and abuts against the edge of the stainless steel filter mesh 33. The limiting ring 32 is fixedly connected to the stainless steel filter mesh 33 and the fixing ring 31. The connection structure between the fixing ring 31, the limiting ring 32 and the stainless steel filter mesh 33 is: a plurality of upper countersunk holes are evenly distributed in a circumferential direction on the fixing ring 31, a plurality of lower countersunk holes are evenly distributed in a circumferential direction on the limiting ring 32, and a plurality of through holes are evenly distributed in a circumferential direction on the stainless steel filter mesh 33. Each upper countersunk hole, through hole and lower countersunk hole are aligned with each other, and rivets 34 are riveted between the aligned upper countersunk holes, through holes and lower countersunk holes. The two ends of the rivets 34 are respectively sunk in the upper countersunk holes and the lower countersunk holes. When fixedly connecting the fixing ring 31 and the limiting ring 32, first align the upper countersunk holes on the fixing ring 31 with the lower countersunk holes on the limiting ring 32 one by one. At this time, there are no through holes on the edge of the stainless steel filter mesh 33. It is necessary to punch holes in the stainless steel filter mesh 33 between the aligned upper countersunk holes and lower countersunk holes with a drill or other tools, so as to form through holes on the stainless steel filter mesh 33 that are aligned with the upper countersunk holes and lower countersunk holes, and then pass the rivets 34 through the upper countersunk holes, through holes and lower countersunk holes for riveting.

[0018] When the pipe body 2 is welded to the outer cylinder head 1, the arc-shaped filter element 3 extends into the interlayer between the outer cylinder and the inner cylinder. During vacuum pumping, since the arc-shaped hollow frame supports the stainless steel filter screen 33, the stainless steel filter screen 33 can still adhere to the arc-shaped hollow frame to maintain an arc shape under the influence of negative pressure and air flow. When the stainless steel filter screen 33 is in an arc shape, the air flow velocity distribution is uneven, which will form fluid turbulence. The arc-shaped hollow frame will also affect the air flow, making the air flow velocity distribution more uneven. The combination of the two will form a strong fluid turbulence, which can effectively disperse the debris in the air flow and reduce the concentrated deposition at specific points, thus effectively reducing the occurrence of blockage.

[0019] In this embodiment, the arc-shaped hollow frame includes: arc-shaped support ribs 35 and a connecting plate 36. The arc-shaped support ribs 35 are circumferentially distributed on the fixed ring 31 and extend downward. Each arc-shaped support rib 35 is connected to the same connecting plate 36. The connecting plate 36 is circular in shape. Each arc-shaped support rib 35 is welded to the outer side wall of the connecting plate 36. Vent holes 361 are provided in the connecting plate 36. Providing vent holes 361 in the connecting plate 36 can reduce the shielding of the filtering surface of the stainless steel filter screen 33.

[0020] The connection structure between the pipe body 2 and the arc-shaped filter element 3 is as follows: an installation groove 22 is provided on the inner side wall of the bottom of the pipe body 2. An inner retaining ring 23 is clamped in the installation groove 22. The fixedly connected fixed ring 31 and the limiting ring 32 are inserted into the installation groove 22. The fixed ring 31 abuts against the inner top wall of the installation groove 22, and the inner retaining ring 23 abuts against the limiting ring 32. In order to prevent the fixed ring 31 and the limiting ring 32 from shaking with the installation groove 22 of the pipe body 2, generating noise and heat, a low-temperature-resistant annular rubber pad 37 is sleeved on the outer side wall of the fixed ring 31 and the limiting ring 32 that are fixed together.

[0021] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. Anti-blocking vacuum pumping joint for LNG storage tank, characterized in that: Comprising: A pipe body welded to the outer cylinder head of the LNG storage tank, with an arc-shaped filter element clamped in the inner side wall of the pipe body. The arc-shaped filter element includes: a fixing ring and a limiting ring. An arc-shaped hollow frame is arranged on the fixing ring, and the arc-shaped hollow frame extends downward out of the pipe body. A layer of stainless steel filter screen is coated on the outer side wall of the arc-shaped hollow frame, and the edge of the stainless steel filter screen is laid on the fixing ring. The limiting ring is sleeved on the outside of the arc-shaped hollow frame and abuts against the edge of the stainless steel filter screen, and the limiting ring is fixedly connected to the stainless steel filter screen and the fixing ring.

2. The anti-clogging vacuum extraction joint for LNG storage tanks according to claim 1, characterized in that: The arc-shaped hollow frame includes: arc-shaped support ribs and a connecting plate. The arc-shaped support ribs are circumferentially distributed on the fixing ring and extend downward, and each arc-shaped support rib is connected to the same connecting plate.

3. The anti-clogging vacuum extraction joint for LNG storage tanks according to claim 2, wherein: The connecting plate is circular in shape, and each arc-shaped support rib is welded to the outer side wall of the connecting plate, and ventilation holes are provided in the connecting plate.

4. The anti-clogging vacuum extraction joint for an LNG storage tank according to claim 1 or 2 or 3, characterized in that: The connection structure between the fixing ring, the limiting ring and the stainless steel filter screen is: a number of upper countersunk holes are circumferentially distributed on the fixing ring, a number of lower countersunk holes are circumferentially distributed on the limiting ring, and a number of through holes are circumferentially distributed on the stainless steel filter screen. Each upper countersunk hole, through hole and lower countersunk hole are aligned, and rivets are riveted between the aligned upper countersunk holes, through holes and lower countersunk holes. The two ends of the rivets are respectively sunk in the upper countersunk hole and the lower countersunk hole.

5. The anti-clogging vacuum pumping joint for an LNG storage tank according to claim 4, characterized in that: The connection structure between the pipe body and the arc-shaped filter element is: an installation groove is provided in the inner side wall at the bottom of the pipe body, an inner retaining ring is clamped in the installation groove, and the fixedly connected fixing ring and limiting ring are inserted into the installation groove. The fixing ring abuts against the inner top wall of the installation groove, and the inner retaining ring abuts against the limiting ring.

6. The anti-clogging vacuum pumping joint for LNG storage tank according to claim 5, wherein: A low-temperature resistant annular rubber pad is sleeved on the outer side wall of the fixedly connected fixing ring and limiting ring.

7. The anti-clogging vacuum extraction joint for LNG storage tank according to claim 1, wherein: A positioning groove is inwardly contracted and provided on the outer side wall at the bottom of the pipe body. The positioning groove is adapted to the installation hole on the outer cylinder head, and the height of the positioning groove is the same as the thickness of the outer cylinder head.

8. The anti-clogging vacuum pumping joint for an LNG storage tank according to claim 1, characterized in that: The filtration mesh number of the stainless steel filter screen is between 160 meshes and 170 meshes.

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