Storage tank assembly type suspended ceiling

Abstract

The invention relates to a storage tank assembly type suspended ceiling which comprises a supporting beam, a suspended ceiling hanging rod, a corrugated plate laid on the supporting beam and a sealing device used for sealing the suspended ceiling and the inner wall of a storage tank, the sealing device comprises a suspended ceiling edge plate, a sealing ring plate, a sealing wall plate and an elastic blanket, the suspended ceiling edge plate is fixed to the upper portion of the outermost suspended ceiling annular beam, and the sealing ring plate is fixed to the upper portion of the sealing wall plate. The sealing ring plate is in a ring shape around the inner wall of the storage tank, the sealing ring plate is fixed to the upper portion of the suspended ceiling edge plate, the sealing ring plate is also an annular plate and partially overlaps with the suspended ceiling edge plate, the sealing ring plate is fixed to the inner side wall of the sealing wall plate, the sealing wall plate is in a vertically-open cylinder shape around the inner wall of the storage tank, and an inner tank reinforcing ring is fixed to the upper portion of the inner tank wall. The lower end of the sealing wall plate is connected with the inner tank reinforcing ring. According to the suspended ceiling, the elastic blanket can be directly seen and is easy to install, inspect and maintain, the outermost ring of the suspended ceiling is changed into a form of combining the circular suspenders and the flat steel, so that the stress of the vertical suspenders and the inclined suspenders is uniform, and the inclined suspenders are prevented from being damaged.

Description

Technical Field

[0001] The invention belongs to the field of LNG storage tanks, and in particular relates to an assembled suspended ceiling of a storage tank. Background Art

[0002] In the LNG receiving station, 220,000 m 3 A suspended ceiling needs to be installed on the top of the inner tank of the LNG storage tank to hang the glass wool cold insulation material on the top to reduce the heat transfer between the LNG stored in the inner tank and the outside world and reduce the evaporation rate of LNG. The suspended ceiling is required to be able to withstand the weight of the suspended ceiling itself, the cold insulation material, the connecting sleeve, the pressure balance port, and the construction load generated during the construction process to further ensure the safety of the personnel during the construction process.

[0003] In LNG storage tanks, the ceiling is fixed to the vault of the storage tank by ceiling hangers. The vault is composed of radially distributed vault longitudinal beams 8, vault annular beams 7 distributed from the center of the vault to the outside, steel plates (usually 6mm thick steel plates) laid on the vault longitudinal beams and annular beams, and concrete poured on the upper part of the steel plates. The ceiling is mainly composed of support beams, corrugated plates, ceiling hangers and sealing devices. Traditional corrugated plates have small cross-sectional dimensions, thin plates, poor rigidity, and many lap joints. The corrugated plate has a wave height of 80mm, a wave distance of 134mm, a plate thickness of 1.2mm, and a width of 938mm. It is easy to deform during transportation. See Figure 2 and Figure 3 . Traditional ceiling sealing devices, elastic felt installed under the ceiling edge plate, cannot be inspected and repaired, see Figure 4 The outermost ring of the suspended ceiling rods (the suspended rods are distributed in a ring on the suspended ceiling, usually 13 to 14 rings, each ring has 96 suspended rods, the ring closest to the top of the tank side wall is the outermost ring, and the diameter of this ring is the largest) are unevenly stressed. Some are more stressed, some are less stressed, and the difference is very large. The ones that are more stressed are more likely to be damaged and fail. Figure 5 .

[0004] Chinese patent CN202946922U discloses an elastic sealing structure for the top of the inner tank of a double-shell cryogenic storage tank, wherein the lower end of the baffle assembly 1 can move freely, and the upper end of the baffle assembly 1 is welded and fixed to the ceiling plate 6. It is known that when filling the elastic blanket, it must be properly compressed before filling it into the annular space. When replacing the elastic blanket, the patent requires the removal of the appropriately compressed elastic blanket, which is inconvenient to remove. The sealing wall panel is fixedly connected to the ceiling, which is complicated to manufacture and cannot guarantee the roundness and installation accuracy. Moreover, the patent does not involve improvements to the outermost ring suspension rod and the pressed corrugated plate.

[0005] Chinese patent CN205991324U discloses a three-layer metal wall fully contained storage tank, the purpose of which is to avoid low-temperature impact of low-temperature medium on the outer tank, shorten the evaporation gas discharge channel under accident conditions, reduce the loss of evaporation materials caused by accident conditions, and improve safety. This patent only involves the insulation of the tank wall, and does not focus on the insulation and sealing of the part connected to the ceiling and the inner tank wall.

[0006] In summary, the main problems with the existing tank ceiling include: the pressed corrugated plate has poor rigidity, many lap joints, and is difficult to transport and install; the elastic felt of the ceiling sealing device is installed under the ceiling edge plate and cannot be inspected and repaired; the outermost ring of the ceiling hanger rods is unevenly stressed and is easily damaged if it is subjected to high stress. Summary of the invention

[0007] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a new type of assembled ceiling for storage tanks. The present invention improves the sealing structure of the ceiling, and the elastic blanket can be directly seen, which is easy to install, inspect and maintain; the outermost circle of the ceiling is changed to a combination of circular hangers and flat steel, so that the stress of the vertical hangers and the oblique hangers is uniform, avoiding damage to the oblique hangers, and is also conducive to the installation of the ceiling cold insulation material.

[0008] The present invention is achieved through the following technical solutions.

[0009] A tank assembled ceiling comprises a support beam located on the top of the tank, a ceiling hanger rod fixing the support beam to the vault of the tank, a corrugated plate laid on the support beam, and a sealing device for sealing the ceiling with the inner wall of the tank.

[0010] The supporting beams include a plurality of ceiling annular beams and a plurality of ceiling longitudinal beams distributed radially from the central part of the upper part of the tank to the periphery. The ceiling annular beams and the ceiling longitudinal beams are located at the upper part of the tank (level with the highest part of the tank side wall or slightly lower than the highest part of the tank side wall, for example, 10-50cm lower) and the lower part of the vault and are arranged horizontally.

[0011] The sealing device is used to seal the natural gas in the inner tank, including a ceiling edge plate, a sealing ring plate, a sealing wall plate, and an elastic blanket. The ceiling edge plate is fixed to the upper part of the outermost ring ceiling beam, and its shape is a ring around the inner wall of the storage tank. The sealing ring plate is fixed to the upper part of the ceiling edge plate, which is also a ring plate and partially overlaps with the ceiling edge plate. The end of the sealing ring plate away from the ceiling edge plate is fixed to the inner wall of the sealing wall plate. The sealing wall plate is a cylindrical shape that is open up and down around the inner wall of the storage tank.

[0012] An inner tank reinforcement ring is fixed to the upper part of the inner tank wall, and the lower end of the sealing wall plate is connected to (or in contact with) the inner tank reinforcement ring. An annular gap is formed between the sealing wall plate and the inner tank wall, and an elastic blanket is filled in the annular gap.

[0013] The ceiling ring beams, for example, include 4-10 ring beams distributed from the inside to the outside, further 5-8 ring beams, such as 6 ring beams, the spacing between adjacent ring beams is preferably substantially equal, a plurality of ceiling longitudinal beams (e.g. 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) extend from the entire periphery of the inner ring beam to the inner side of the outermost ring beam, and a plurality of ceiling longitudinal beams (e.g. 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) extend from the second-to-last ring beam inside to the inner side of the outermost ring beam, preferably a plurality of longitudinal beams extending from the second-to-last ring beam inside (next to the innermost ring beam) are respectively located between two adjacent longitudinal beams extending from the innermost ring beam. The ceiling longitudinal beams and the ceiling ring beams are in the same horizontal plane, and the ceiling longitudinal beams are disconnected at the ceiling ring beams and welded to the ring beams.

[0014] Furthermore, in the outermost circle of hangers (i.e., the hangers supporting the outermost circle of ceiling ring beams), the oblique hangers (the upper end of one vertical circular hanger is connected to the lower end of the next vertical circular hanger through the oblique hanger, and the lower end of the next vertical circular hanger is connected to the upper end of the next vertical circular hanger through the oblique hanger, and they are connected in sequence so that the oblique hangers form a continuous V-shape in sequence) between two adjacent vertical circular hangers (i.e., the hangers that are perpendicular or substantially perpendicular to the supporting beams) are made of stainless steel flat steel (e.g., 50*8mm), and the width of the stainless steel flat steel is 50±5mm and the thickness is 8±2mm, preferably 50*8mm. The diameter of the circular hanger can remain unchanged, for example, φ16±2mm. In the non-outermost circle of ceiling ring beam hangers, the oblique hangers are also circular rods, which is the same as the existing configuration. The oblique hanger is connected to the upper and lower ends of two adjacent vertical circular hangers by connecting bolts. The vertical circular hanger is generally provided with an adjusting rod with left-hand and right-hand threads, and its function is to adjust the length or height of the vertical circular hanger. The adjusting rod is a rod with a hole in the middle and internal threads at both ends of the hole. There are also threads at the ends of the vertical circular rods connected to the adjusting rod. In this application, the stainless steel flat steel oblique hanger is connected to the upper and lower ends of the two adjacent vertical circular hangers by bolts.

[0015] Furthermore, the inner tank reinforcement ring includes a cylindrical wall and an annular plate with one end fixedly connected to the outer wall of the cylindrical wall and the other end fixedly connected to the inner tank wall.

[0016] In the present application, the elastic blanket is formed by bonding glass fibers and is shaped like a blanket.

[0017] Further, the width of the corrugated plate is increased to 1200±100mm, preferably 1200±50mm, preferably 1200±10mm, such as 1206mm, the wave height is 84±5mm, preferably 84±2mm, such as 84mm, the wave pitch is 134±20mm, preferably 134±10mm, such as 134mm, and the plate thickness is 1.4±0.2mm, preferably 1.4±0.1mm, such as 1.4mm. The length of the corrugated plate can reach 13m, such as 8-13m or 10-13m or 12-13m. The existing corrugated plate has a wave height of 80mm, a wave pitch of 134mm, a plate thickness of 1.2mm, and a width of 938mm. The cross-sectional size of the corrugated plate is small, the plate is thin, the rigidity is poor, and there are many lap joints. The corrugated plate of the present application reduces the longitudinal lap joints and the transverse lap joints, is easy to transport, has increased rigidity, and has a more solid structure, and is not easily deformed during transportation.

[0018] The corrugated plate is provided with a transverse lap joint and a longitudinal lap joint. The longitudinal lap joint is arranged at the long sides of the two corrugated plates and is used to connect the two adjacent corrugated plates. The transverse lap joint is arranged at the short sides of the two corrugated plates and is used to connect the two adjacent corrugated plates. The shape of the transverse lap joint is the edge of the corrugated plate, which is to extrude and overlap the edges of the two corrugated plates together by about half a wavelength. The longitudinal lap joint overlaps 100 mm.

[0019] In one embodiment, the ceiling edge plate is annular, with an inner radius of 42250mm, an outer radius of 42550mm, a thickness of 10mm, and is made of 304 stainless steel. The closest distance between the ceiling edge plate and the inner tank wall is about 400-600mm, and further 425mm-450mm. For example, for a 220,000 m 3 LNG storage tank, install sealing wall plate, this wall plate presses on the elastic blanket in the annular gap to achieve sealing, reduce the radius of the ceiling edge plate, the original radius is 43050mm, and the current radius is 42950mm. The lower part of the ceiling edge plate is welded to the support beam, and the upper part is connected to the sealing ring plate by bolts.

[0020] In one embodiment, the sealing ring plate is annular, has an inner radius of 42450 mm, an outer radius of 42575 mm, a thickness of 10 mm, and is made of 304 stainless steel. The sealing ring plate is used to connect with the ceiling edge plate and can be connected with 96 M16 bolts for easy installation and removal.

[0021] In one embodiment, the sealing wall plate is cylindrical, with an inner radius of 42575 mm, a height of 350 mm, a thickness of 10 mm, and is made of 304 stainless steel. The sealing wall plate is used to squeeze the elastic blanket to achieve sealing.

[0022] The elastic blanket is a compressible and expandable insulation material. The inner tank is at a low temperature of -162℃. 3For LNG storage tanks, the radius will be reduced by about 90mm after the equipment is put into operation, further compressing the elastic blanket.

[0023] A lifting lug is fixed in the middle of the ceiling edge plate, and the function of the lifting lug is to connect with the suspension rod through a bolt, and a hole for the lifting lug to pass through is provided on the ceiling edge plate, and the lifting lug is welded to the support beam. In one embodiment, the supporting longitudinal ring beams are all I-beams, 125X125X10mm, and made of 304 steel.

[0024] The ceiling longitudinal ring beams are welded to form a frame for placing corrugated panels on the top, and fiberglass mats are laid on the corrugated panels.

[0025] In this application, the storage tank adopts a double-layer storage tank structure of inner and outer tanks, the inner and outer tanks are filled with expanded perlite and elastic felt for insulation, and a layer of concrete is laid on the surface of the outer tank.

[0026] Advantages of the present invention

[0027] The novel assembled aluminum ceiling of the present invention overcomes the shortcomings of the existing ceiling and has the following advantages:

[0028] 1. After changing the ceiling sealing structure, the elastic blanket can be directly seen, which is easy to install, inspect and maintain. The sealing ring plate is used to connect with the ceiling edge plate, which is convenient for installation and disassembly. The sealing wall plate is used to squeeze the elastic blanket to achieve excellent sealing.

[0029] 2. The outermost circle of the suspended ceiling is changed to a combination of round hangers and flat steel, so that the stress of the vertical hangers and the oblique hangers are uniform, avoiding damage to the oblique hangers, and also facilitating the installation of ceiling insulation materials.

[0030] 3. The rigidity of the pressed corrugated board is increased, the bending resistance is stronger, and it is easy to transport. The width of the corrugated board is increased to 1206, and the longitudinal lap joints are reduced; at the same time, the length of the corrugated board can reach 13 meters, and the transverse lap joints are also reduced. The reduction of lap joints can improve the installation efficiency and make the ceiling smoother after installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the prior art tank ceiling installation.

[0032] Figure 2 Schematic diagram of the overlap installation of corrugated sheet.

[0033] Figure 3 It is a schematic diagram of the cross section of the corrugated plate in the prior art.

[0034] Figure 4 It is a schematic diagram of a ceiling sealing device in the prior art.

[0035] Figure 5 It is a schematic diagram of a prior art boom.

[0036] Figure 6 Schematic diagram of the ceiling sealing device of the present invention.

[0037] Figure 7 It is a cross-sectional view of the pressed corrugated board of the present invention.

[0038] Figure 8 It is a schematic diagram of the suspension rod of the present invention.

[0039] Fig. 9 It is a schematic diagram of the support beam of the present invention.

[0040] Fig.10 It is a schematic diagram of the partial structure of the assembled ceiling of the storage tank of the present invention.

[0041] Fig.11 A schematic diagram of a suspended ceiling showing the outermost ceiling hanger rods (part A) and the non-outermost ceiling hanger rods (part B).

[0042] Fig.12 This is the stress analysis diagram of the ceiling hanger.

[0043] Fig.13 (a) and (b) are schematic diagrams showing stress measurement points of the prior art hanger solution and the hanger solution of the present application, respectively.

[0044] Fig.14 Schematic diagram of the adjustment rod.

[0045] 1: Inner tank wall; 2: Outer tank; 3: Top reinforcement ring (inner tank reinforcement ring); 4: Ceiling hanger; 401: Outermost hanger, 402: Round hanger, 403: Flat steel hanger, 404: Vertical hanger, 405: Oblique hanger; 5: Fiberglass mat; 6: Support beam; 7: Arch ring beam; 8: Arch longitudinal beam; 9: Corrugated plate; 901: Transverse lap joint; 902: Longitudinal lap joint; 11: Elastic blanket; 12: Ceiling edge plate; 13: Lifting ear; 14: Ceiling ring beam; 15: Adjustment rod of left-handed and right-handed thread; 16: Sealing wall plate; 17: Connecting bolt; 18: Sealing ring plate; 19: Ceiling longitudinal beam; 20: Longitudinal ring beam connection point; 21: M16 right-handed internal thread, 22: M16 left-handed internal thread;

[0046] R: inner tank radius, r: edge plate radius. DETAILED DESCRIPTION

[0047] The present invention is further described below with reference to the accompanying drawings.

[0048] like Figure 6-Figure 10 As shown, a tank assembled ceiling comprises a support beam 6 located on the top of the tank, a ceiling hanger 4 fixing the support beam (ceiling hoop beam and ceiling longitudinal beam) to the arch of the tank, a corrugated plate 9 laid on the support beam, and a sealing device for sealing the ceiling with the inner wall of the tank.

[0049] The support beam 6 includes a plurality of ceiling annular beams 14 and a plurality of ceiling longitudinal beams 19 distributed in sequence from the central part of the upper part of the tank to the periphery. The ceiling annular beams 14 and the ceiling longitudinal beams 19 are located at the upper part of the tank (level with the highest part of the tank side wall or slightly lower than the highest part of the tank side wall, for example, 10-50 cm lower) and the lower part of the arch and are arranged horizontally.

[0050] The sealing device is used to seal the natural gas in the inner tank, and includes a ceiling edge plate 12, a sealing ring plate 18, a sealing wall plate 16, and an elastic blanket 11. The ceiling edge plate 12 is fixed to the upper part of the outermost ring ceiling beam, and its shape is a ring around the inner wall of the storage tank. The sealing ring plate 18 is fixed to the upper part of the ceiling edge plate 12, and it is also an annular plate, partially overlapping with the ceiling edge plate 12. The end of the sealing ring plate 18 away from the ceiling edge plate is fixed to the inner side wall of the sealing wall plate 16, and the sealing wall plate 16 is a cylindrical shape that is open up and down around the inner tank wall 1.

[0051] An inner tank reinforcement ring (top reinforcement ring) 3 is fixed to the upper part of the inner tank wall 1, and the lower end of the sealing wall plate 16 is connected to (or in contact with) the inner tank reinforcement ring 3. An annular gap is formed between the sealing wall plate 16 and the inner tank wall 1, and an elastic blanket 11 is filled in the annular gap.

[0052] The ceiling annular beams 14, for example, include 4-10 annular beams distributed from the inside to the outside, and further 5-8 annular beams, such as 5 or 6 annular beams, forming a plurality of concentric circles, including an innermost circle, an outermost circle and one or more circles in the middle. The spacing between adjacent annular beams is preferably substantially equal. A plurality of ceiling longitudinal beams 19 (for example, 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) extend from the entire periphery of the innermost annular beam to the inner side of the outermost annular beam. A plurality of ceiling longitudinal beams 19 (for example, 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) also extend from the second-to-last annular beam in the interior to the inner side of the outermost annular beam. Preferably, the plurality of ceiling longitudinal beams extending from the second-to-last ceiling annular beam in the interior (close to the innermost annular beam) are respectively located between two adjacent longitudinal beams extending from the innermost annular beam, and are preferably located in the middle of two adjacent longitudinal beams extending from the innermost annular beam. The ceiling longitudinal beams and the ceiling circumferential beams are in the same horizontal plane. The ceiling longitudinal beams 19 are disconnected at the ceiling circumferential beams 14 and are welded to the ceiling circumferential beams. Multiple ceiling longitudinal beams connect multiple concentric ring-shaped ceiling circumferential beams together.

[0053] Furthermore, in the outermost circle of hangers 401 (the hangers of the outermost circle of ceiling ring beams), the oblique hangers between two adjacent vertical circular hangers 402 (the oblique hangers are used to connect the upper end of one of the two adjacent vertical circular hangers to the lower end of the other) are made of stainless steel flat steel, i.e., flat steel hangers 403, and the width of the stainless steel flat steel is 50±5mm and the thickness is 8±2mm, preferably 50*8mm. The diameter of the circular hanger can remain unchanged, for example, φ16±2mm. In the non-outermost circle of ceiling hangers, the oblique hangers are also made of circular rods, which is the same as the existing configuration, such as Fig.11 As shown, the cross section of part A is as follows Figure 8 As shown, the cross section of part B is Figure 5 The oblique suspension rod is connected to the upper and lower ends of two adjacent vertical circular suspension rods through connecting bolts. The vertical circular suspension rod is provided with an adjustment rod with left and right thread, which is used to adjust the length of the vertical circular suspension rod (see Fig.14 ), the adjusting rod is a rod with a hole in the middle and internal threads at both ends of the hole, and the end of the vertical circular rod is also threaded and connected to the adjusting rod. In this application, the stainless steel flat steel oblique hanger is connected to the upper and lower ends of the two adjacent vertical circular hangers by bolts respectively.

[0054] Furthermore, the inner tank reinforcement ring 3 includes a cylindrical wall and an annular plate having one end fixedly connected to the outer wall of the cylindrical wall and the other end fixedly connected to the inner tank wall.

[0055] In the present application, the elastic blanket 11 is formed by bonding glass fibers and is shaped like a blanket.

[0056] Further, the width of the corrugated plate 9 is or increases to 1200±100mm, preferably 1200±50mm, preferably 1200±10mm, for example 1206mm, the wave height is 84±5mm, preferably 84±2mm, such as 84mm, the wave pitch is 134±20mm, preferably 134±10mm, for example 134mm, and the plate thickness is 1.4±0.2mm, preferably 1.4±0.1mm, for example 1.4mm. The length of the corrugated plate 9 can reach 13m, for example 8-13m or 10-13m or 12-13m. Compared with the existing corrugated plate with a wave height of 80mm, a wave pitch of 134mm, a plate thickness of 1.2mm, and a width of 938mm, the corrugated plate of the present application reduces the longitudinal lap joints 902 and the transverse lap joints 901, is easy to transport, has a more solid structure, and is not easily deformed during transportation.

[0057] The corrugated plate is provided with a transverse lap joint 901 and a longitudinal lap joint 902. The longitudinal lap joint is arranged at the long sides of the two corrugated plates for connecting the two adjacent corrugated plates. The transverse lap joint is arranged at the short sides of the two corrugated plates for connecting the two adjacent corrugated plates. The shape of the transverse lap joint is the edge of the corrugated plate, which is to extrude and overlap the edges of the two corrugated plates together by about half a wavelength. The longitudinal lap joint overlaps 100mm.

[0058] In one embodiment, the ceiling edge plate 12 is annular, for example, with an inner radius of 42250mm, an outer radius of 42550mm, a thickness of 10mm, and is made of 304 stainless steel. The closest distance between the ceiling edge plate 12 and the inner tank wall is about 400-600mm, and further 425mm-450mm. For example, for a 220,000 m 3 LNG storage tank, install sealing wall plate, this wall plate presses on the elastic blanket in the annular gap to achieve sealing, reduce the radius of the ceiling edge plate, the original radius is 43050mm, and the current radius is 42950mm. The lower part of the ceiling edge plate is welded to the support beam, and the upper part is connected to the sealing ring plate through the connecting bolt 17.

[0059] In one embodiment, the sealing ring plate 18 is annular, has an inner radius of 42450 mm, an outer radius of 42575 mm, a thickness of 10 mm, and is made of 304 stainless steel. The sealing ring plate 18 is used to connect with the ceiling edge plate 12, and can be connected with 96 M16 bolts for easy installation and removal.

[0060] In one embodiment, the sealing wall plate 16 is cylindrical, with an inner radius of 42575 mm, a height of 350 mm, a thickness of 10 mm, and is made of 304 stainless steel. The sealing wall plate 16 is used to squeeze the elastic blanket to achieve sealing.

[0061] Elastic blanket 11 is a compressible and expandable insulation material. The inner tank is at a low temperature of -162℃. 3 For LNG storage tanks, the radius will be reduced by about 90mm after the equipment is put into operation, further compressing the elastic blanket.

[0062] A lifting lug 13 is fixed in the middle of the ceiling edge plate. The lifting lug 13 is connected to the suspension rod through a bolt. A hole for the lifting lug to pass through is provided on the ceiling edge plate 12. The lifting lug is welded to the support beam. In one embodiment, the supporting longitudinal ring beams are all I-beams, 125×125×10mm, and made of 304 steel.

[0063] The longitudinal ring beams of the suspended ceiling are welded to form a frame for placing a corrugated plate 9 on the upper part. A glass fiber mat 10 is laid on the corrugated plate 9.

[0064] Example 1

[0065] A tank assembled ceiling comprises a support beam 6 located on the top of the tank, a ceiling suspension rod 4 fixing the support beam to the vault of the tank, a corrugated plate 9 laid on the support beam, and a sealing device for sealing the ceiling with the inner wall of the tank.

[0066] The supporting beams include a plurality of ceiling annular beams 14 and a plurality of ceiling longitudinal beams 19 distributed radially from the central part of the upper part of the storage tank to the outer periphery. The ceiling annular beams 14 and the ceiling longitudinal beams 19 are located at the upper part of the storage tank and the lower part of the vault and are arranged horizontally.

[0067] The sealing device is used to seal the natural gas in the inner tank, and includes a ceiling edge plate 12, a sealing ring plate 18, a sealing wall plate 16, and an elastic blanket 11. The ceiling edge plate 12 is fixed to the upper part of the outermost ring ceiling beam, and its shape is a ring around the inner wall of the storage tank. The sealing ring plate 18 is fixed to the upper part of the ceiling edge plate 12, and it is also an annular plate, partially overlapping with the ceiling edge plate 12. The end of the sealing ring plate 18 away from the ceiling edge plate is fixed to the inner side wall of the sealing wall plate 16, and the sealing wall plate 16 is a cylindrical shape that is open up and down around the inner tank wall 1.

[0068] An inner tank reinforcement ring (top reinforcement ring) 3 is fixed to the upper part of the inner tank wall 1, and the lower end of the sealing wall plate 16 is connected to the inner tank reinforcement ring 3. An annular gap is formed between the sealing wall plate 16 and the inner tank wall 1, and an elastic blanket 11 is filled in the annular gap.

[0069] The ceiling ring beam 14 includes 6 ring beams distributed from the inside to the outside, and the spacing between adjacent ring beams is preferably substantially equal. Eight ceiling longitudinal beams 19 extend from the entire periphery of the innermost ceiling ring beam to the inner side of the outermost ring beam, and eight ceiling longitudinal beams 19 also extend from the second-to-last ceiling ring beam inside to the inner side of the outermost ring beam. The multiple ceiling longitudinal beams extending from the second-to-last ceiling ring beam inside (next to the innermost ceiling ring beam) are respectively located between two adjacent longitudinal beams extending from the innermost ring beam. The ceiling longitudinal beams and the ceiling ring beams are in the same horizontal plane, and the ceiling longitudinal beams 19 are disconnected at the ceiling ring beam 14 and welded to the ceiling ring beam.

[0070] In the outermost circle of hangers 401, the oblique hanger connecting the two adjacent circular hangers 402 (the oblique hanger is used to connect the upper end of one of the two adjacent circular hangers to the lower end of the other) is made of stainless steel flat steel, that is, flat steel hanger 403, and the specification of the stainless steel flat steel is 50*8mm. The diameter of the circular hanger remains unchanged at φ16mm. The oblique hanger is respectively connected to the upper and lower ends of the two adjacent vertical circular hangers by connecting bolts. The vertical circular hanger is provided with an adjustment rod with left and right threaded threads, and its function is to adjust the length of the vertical circular hanger. The adjustment rod is a rod with a hole in the middle and internal threads at both ends of the hole. There is also a thread at the end of the vertical circular rod connected to the adjustment rod. In this application, the stainless steel flat steel oblique hanger is connected to the upper and lower ends of the two adjacent vertical circular hangers by bolts.

[0071] The inner tank reinforcement ring 3 comprises a cylindrical wall and an annular plate having one end fixedly connected to the outer wall of the cylindrical wall and the other end fixedly connected to the inner tank wall.

[0072] The elastic blanket 11 is formed by bonding glass fibers and is shaped like a blanket.

[0073] The width of the corrugated plate 9 is increased to 1206 mm, the wave height is 84 mm, the wave distance is 134 mm, the plate thickness is 1.4 mm, and the length of the corrugated plate 9 is 13 m.

[0074] The corrugated plate is provided with a transverse lap joint 901 and a longitudinal lap joint 902. The longitudinal lap joint is arranged at the long sides of the two corrugated plates for connecting the two adjacent corrugated plates. The transverse lap joint is arranged at the short sides of the two corrugated plates for connecting the two adjacent corrugated plates. The shape of the transverse lap joint is the edge of the corrugated plate, which is to extrude and overlap the edges of the two corrugated plates together by about half a wavelength. The longitudinal lap joint overlaps 100mm.

[0075] The ceiling edge plate 12 is annular, with an inner radius of 42250mm, an outer radius of 42550mm, a thickness of 10mm, and is made of 304 stainless steel. The closest distance between the ceiling edge plate 12 and the inner tank wall is about 425mm. 3 LNG storage tank, install sealing wall plate, this wall plate presses on the elastic blanket in the annular gap to achieve sealing, reduce the radius of the ceiling edge plate, the original radius is 43050mm, and the current radius is 42950mm. The lower part of the ceiling edge plate is welded to the support beam, and the upper part is connected to the sealing ring plate through the connecting bolt 17.

[0076] The sealing ring plate 18 is annular, with an inner radius of 42450mm, an outer radius of 42575mm, a thickness of 10mm, and is made of 304 stainless steel. The sealing ring plate 18 is used to connect with the ceiling edge plate, and is connected with 96 M16 bolts for easy installation and removal.

[0077] The sealing wall plate 16 is cylindrical, with an inner radius of 42575 mm, a height of 350 mm, a thickness of 10 mm, and is made of 304 stainless steel. The sealing wall plate 16 is used to squeeze the elastic blanket to achieve sealing.

[0078] Elastic blanket 11 is a compressible and expandable insulation material. The inner tank is at a low temperature of -162℃. 3 For LNG storage tanks, the radius will be reduced by about 90mm after the equipment is put into operation, further compressing the elastic blanket.

[0079] A lifting lug 13 is fixed in the middle of the ceiling edge plate. The lifting lug 13 is connected to the suspension rod through bolts. A hole for the lifting lug to pass through is provided on the ceiling edge plate 12. The lifting lug is welded to the support beam. The supporting longitudinal ring beams are all I-beams, 125X125X10mm, and made of 304 steel.

[0080] The ceiling longitudinal ring beams are welded to form a frame for placing corrugated plates 9 on the upper part. Glass fiber mats 10 are laid on the corrugated plates 9.

[0081] The ceiling sealing structure of the present application has an elastic blanket that can be directly seen, and is easy to install, inspect and maintain. The sealing ring plate is used to connect with the ceiling edge plate, which is convenient for installation and disassembly. The sealing wall plate is used to extrude the elastic blanket to achieve excellent sealing.

[0082] The outermost circle of the suspended ceiling is changed to a combination of round hangers and flat steel, so that the stress of the vertical hangers and the oblique hangers are uniform, avoiding damage to the oblique hangers, and also facilitating the installation of ceiling insulation materials.

[0083] The rigidity of the pressed corrugated board has been increased, the bending resistance is stronger, and it is easy to transport. The width of the corrugated board has been increased to 1206, which reduces the longitudinal lap joints; at the same time, the length of the corrugated board can reach 13 meters, which also reduces the transverse lap joints. Reducing the lap joints can improve the installation efficiency and make the ceiling smoother after installation.

[0084] Comparative Example 1

[0085] like Figure 1-5 As shown, the radius of the ceiling edge plate is 43050mm, covering the entire inner wall of the tank. The elastic felt is installed under the ceiling edge plate, which is not easy to install, inspect and maintain.

[0086] Circular hangers are used all the time, and the force on the outermost hangers of the suspended ceiling is uneven, some are subjected to greater force, some are less, and the difference is very large. The ones subjected to greater force are more likely to be damaged and fail.

[0087] The corrugated plate has a wave height of 80mm, a wave distance of 134mm, a plate thickness of 1.2mm and a width of 938mm. The corrugated plate has a small cross-sectional size, a thin plate, poor rigidity, many lap joints, and is easily deformed during transportation.

[0088] test

[0089] The suspended ceiling is required to be able to bear the weight of the suspended ceiling itself, the cold insulation material, the pipe sleeve, the pressure balance port, and the construction load generated during the construction process to further ensure the safety of the personnel during the construction process. The outermost ring of the suspended ceiling is unevenly stressed, and the structure of the outermost ring of the suspended ceiling needs to be improved to prevent the suspension from being damaged and failing.

[0090] (1) Force theory analysis

[0091] At 220,000 m 3 In the LNG storage tank, there are 13 circles of hangers on the ceiling, with 96 vertical hangers and 96 diagonal hangers distributed in the outermost circle, corresponding to a distribution radius of 41.80m. The distance between two adjacent vertical hangers is d = 2πr / 96 = (2 × 3.14 × 41.4) / 96 ≈ 2.71m, and they are connected in the middle by diagonal hangers. The length of the vertical hanger is 4.50m, and the material is 304 stainless steel. The design allowable stress value is 155.13MPa and the yield strength is 205MPa (according to the standard API Std 620-2002 Design and Construction of Large Welded Low-pressure Storage Tanks, selected from Table Q-3).

[0092] The total mass of the ceiling and its accessories is distributed on the hangers, of which the mass of the outermost hangers is 9000kg. The connection points of each hanger are fixed, with point O as the base point. a is the force on the vertical hanger, F b is the force on the oblique boom, θ is the angle between the vertical boom and the oblique boom, θ = 31°, such as Fig.12 shown.

[0093] Assume that both the vertical and diagonal hangers are rigid rods and perform a force analysis on them. The gravity generated by the ceiling and its accessories is evenly distributed to the three rods. Assume that the average force on each rod in the vertical direction is equal and is F. It is known that the angle between the vertical hanger and the diagonal hanger is θ = 31°, from which the tension F on the diagonal tie rod can be obtained. b =F / cosθ=1.17F, vertical suspension rod F a =F, F b >F a , the force borne by the oblique hanger is greater than the force borne by the vertical hanger.

[0094] (2) Actual measurement of the suspension rod force

[0095] In order to obtain accurate hanger stress data, the strain gauge method was used to measure the actual stress of the hanger of a 220,000 m3 LNG storage tank in a certain project.

[0096] a. Basic principles of testing

[0097] The resistance strain gauge is a sensitive device that converts the strain change on the test piece into an electrical signal. The strain gauge is usually tightly bonded to the mechanical strain matrix through a special adhesive. When the matrix is ​​stressed and the stress changes, the resistance strain gauge also deforms, causing the resistance of the strain gauge to change, thereby changing the voltage applied to the resistor. The resistance change of this strain gauge when subjected to force is usually small. Generally, this strain gauge is composed of a strain bridge, which is amplified by a subsequent instrument amplifier and then transmitted to the processing circuit (usually A / D conversion and CPU) for display. This is called the resistance strain test method. After measuring the strain, the stress tester can directly read the force of each suspension rod.

[0098] b. Test preparation

[0099] In this project, the cross-sectional area of ​​a single suspension rod is small and is subjected to uniform unidirectional tension. In order to reduce the impact of electromagnetic interference and changes in isolation resistance on the readings, a strain gauge with a soft phenolic material as the substrate, foil type, 3mm×2mm wire grid size, 120 ohm and temperature self-compensation is selected. The model is BF120-3AA(11)-D-P150. The strain gauge reading device is the PCD-400A stress tester produced by KYOWA. The working principle is that the numerical change data of the strain gauge is transmitted to the stress tester, and the stress value of the tested suspension rod is calculated internally and output to the computer screen. In order to minimize the physical interference of the strain gauge, the installation position is selected at 1 / 3 and 2 / 3 of the length of the suspension rod, such as Figure 3 During the test, if the difference between the two strain gauge values ​​is small, the average value of the two measuring points is taken as the stress value of the hanger; if the difference between the two strain gauge values ​​is too large, there is a problem such as a defect, damage, or improper installation of the strain gauge at a certain location, and it is necessary to check and replace it before continuing the test.

[0100] c. Test the installation

[0101] When installing the strain gauge, the area on the boom where the strain gauge is to be pasted needs to be cleaned and checked for flatness. Secondly, the area is ground to remove surface oil or scratches to improve the adhesion of the strain gauge. Finally, apply appropriate glue on the back of the strain gauge and paste it in the correct position on the boom, compacting it to make it evenly pasted. Be careful not to touch the surface of the strain gauge to prevent damage to the strain gauge and cause inaccurate readings.

[0102] d. Test results

[0103] The measured stress values ​​of each suspender rod are plotted in Table 1. It is found from the table that the force borne by the oblique suspender rod in the measured values ​​is about 1.9 times that of the vertical suspender rod.

[0104] Table 1 Stress distribution of the suspender rod

[0105]

[0106] (3) Results analysis

[0107] It can be seen from Table 1 that when using Fig.13 (a) In the original hanger scheme, both the vertical hanger and the diagonal hanger are cylindrical stainless steel with a diameter of 16 mm. The stress of the vertical circular hanger in the original hanger scheme is about 143.37 MPa, and the stress of the diagonal circular hanger is about 270.89 MPa. The stress on the diagonal circular hanger is greater than that on the vertical circular hanger, which not only exceeds the allowable stress of 304 stainless steel, but also exceeds its yield strength. The diagonal hanger does not meet the strength requirements and has a high risk of fracture.

[0108] In order to prevent the oblique hanger from failure, a new hanger solution is adopted in which the specifications of the oblique hanger are replaced with flat steel with a cross section of 50mm×8mm, such as Fig.13 As shown in (b), at this time, the stress of the vertical circular hanger rod is about 147.76MPa, and the stress of the oblique flat steel hanger rod is 137.15MPa, which is lower than the allowable stress of 304 stainless steel 155.13MPa. Both the vertical hanger rod and the oblique hanger rod meet the strength requirements.

[0109] By measuring the stress of each hanger rod, it was found that the stress of the oblique hanger rod was greater than that of the straight rod, and the original hanger rod design did not meet the strength requirements; in actual engineering applications, many oblique hangers have been damaged, which also indirectly proves that it is consistent with the test results. Applying the new hanger rod scheme of this patent, the outermost circle of the ceiling is changed to a combination of circular hangers and flat steel, that is, vertical flat steel with a cross section of 50mm×8mm is used, so that the stress of the vertical hanger rod and the oblique hanger rod is uniform, which improves the stress state of the oblique hanger rod, avoids damage to the oblique hanger rod, and is also conducive to the installation of ceiling cold insulation materials.

[0110] The preferred embodiments of the present invention are described above, however, the above description is not intended to be limiting. A person skilled in the art may make many changes or modifications to the present invention without departing from the spirit and scope of the present invention. The changes or modifications should be included within the scope of the appended claims.

Claims

1. A tank assembled ceiling, characterized in that: The invention comprises a support beam (6) located on the top of the storage tank, a ceiling hanger (4) fixing the support beam to the vault of the storage tank, a corrugated plate (9) laid on the support beam, and a sealing device for sealing the ceiling and the inner wall of the storage tank. The support beams include a plurality of ceiling annular beams (14) distributed sequentially from the central part of the upper part of the storage tank to the outer periphery and a plurality of ceiling longitudinal beams (19) distributed radially. The ceiling annular beams (14) and the ceiling longitudinal beams (19) are located at the upper part of the storage tank and the lower part of the vault and are arranged horizontally. The sealing device is used to seal the natural gas in the inner tank, and comprises a ceiling edge plate (12), a sealing ring plate (18), a sealing wall plate (16), and an elastic blanket (11). The ceiling edge plate (12) is fixed to the upper part of the outermost ring ceiling beam, and its shape is a ring around the inner wall of the storage tank. The sealing ring plate (18) is fixed to the upper part of the ceiling edge plate (12), and it is also a ring plate, partially overlapping with the ceiling edge plate (12). The end of the sealing ring plate (18) away from the ceiling edge plate is fixed to the inner side wall of the sealing wall plate (16). The sealing wall plate (16) is a cylindrical shape that is open up and down around the inner tank wall (1). An inner tank reinforcement ring (3) is fixed to the upper part of the inner tank wall (1), and the lower end of the sealing wall plate (16) is connected to or in contact with the inner tank reinforcement ring (3). An annular gap is formed between the sealing wall plate (16) and the inner tank wall (1), and an elastic blanket (11) is filled in the annular gap.

2. The assembled ceiling of the storage tank according to claim 1 is characterized in that: The ceiling ring beam (14) includes 4-10 ring beams distributed from the inside to the outside, and further 5-8 ring beams, such as 6 ring beams. The spacing between adjacent ring beams is preferably basically equal. A plurality of ceiling longitudinal beams (19) (for example, 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) extend from the entire periphery of the inner ring beam to the inner side of the outermost ring beam. A plurality of ceiling longitudinal beams (19) (for example, 4-8 longitudinal beams, preferably 6 longitudinal beams, and evenly spaced) also extend from the second-to-last ring beam of the inside to the inner side of the outermost ring beam. Preferably, the plurality of ceiling longitudinal beams extending from the second-to-last ring beam of the inside are respectively located between two adjacent longitudinal beams extending from the innermost ring beam, preferably in the middle of two adjacent longitudinal beams. The ceiling longitudinal beams and the ceiling ring beams are in the same horizontal plane. The ceiling longitudinal beams (19) are disconnected at the ceiling ring beam (14) and welded to the ceiling ring beam.

3. The assembled ceiling of the storage tank according to claim 1 or 2, characterized in that: In the outermost circle of hangers 401, the oblique hanger connecting the two adjacent circular hangers (402) is made of stainless steel flat steel, that is, the flat steel hanger (403). The oblique hanger is used to connect the upper end of one of the two adjacent round bars with the lower end of the other; preferably, the width of the stainless steel flat steel is 50±5mm and the thickness is 8±2mm, preferably 50*8mm.

4. The assembled ceiling for a storage tank according to any one of claims 1 to 3, characterized in that: The inner tank reinforcement ring (3) comprises a cylindrical wall and an annular plate with one end fixedly connected to the outer wall of the cylindrical wall and the other end fixedly connected to the inner tank wall.

5. The assembled ceiling for a storage tank according to any one of claims 1 to 4, characterized in that: The width of the corrugated plate (9) is 1200±100 mm, preferably 1200±50 mm, preferably 1200±10 mm, for example 1206 mm, the wave height is 84±5 mm, preferably 84±2 mm, for example 84 mm, the wave distance is 134±20 mm, preferably 134±10 mm, for example 134 mm, and the plate thickness is 1.4±0.2 mm, preferably 1.4±0.1 mm, for example 1.4 mm; and / or The length of the corrugated plate (9) is 8-13 m, preferably 10-13 m or 12-13 m, preferably 13 m.

6. The assembled ceiling for a storage tank according to any one of claims 1 to 5, characterized in that: The corrugated plate is provided with a transverse lap joint (901) and a longitudinal lap joint (902). The longitudinal lap joint is arranged at the long sides of the two corrugated plates and is used to connect the two adjacent corrugated plates. The transverse lap joint is arranged at the short sides of the two corrugated plates and is used to connect the two adjacent corrugated plates. The transverse lap joint is shaped like the edge of the corrugated plate, and the edges of the two corrugated plates are squeezed and overlapped together at about half a wavelength. The longitudinal lap joint overlaps 100 mm.

7. The assembled ceiling for a storage tank according to any one of claims 1 to 6, characterized in that: The ceiling edge plate (12) is annular, has an inner radius of 42250 mm, an outer radius of 42550 mm, a thickness of 10 mm, and is made of 304 stainless steel; and / or The closest distance between the ceiling edge plate (12) and the inner tank wall is 400-600mm, and further 425mm-450mm.

8. The assembled ceiling for a storage tank according to any one of claims 1 to 7, characterized in that: The lower part of the ceiling edge plate is welded to the support beam, and the upper part is connected to the sealing ring plate through a connecting bolt (17).

9. The assembled ceiling for a storage tank according to any one of claims 1 to 8, characterized in that: The sealing ring plate (18) is annular, has an inner radius of 42450 mm, an outer radius of 42575 mm, a thickness of 10 mm, and is made of 304 stainless steel; and / or The sealing wall plate (16) is cylindrical, with an inner radius of 42575 mm, a height of 350 mm, a thickness of 10 mm, and is made of 304 stainless steel.

10. The assembled ceiling for a storage tank according to any one of claims 1 to 9, characterized in that: A lifting ear (13) is fixed in the middle of the ceiling edge plate, and the lifting ear (13) is connected to the suspension rod through a bolt. A hole for the lifting ear to pass through is provided on the ceiling edge plate (12), and the lifting ear is welded to the support beam; and / or The longitudinal ring beams of the suspended ceiling are welded to form a frame, which is used to place a corrugated plate (9) on the upper part, and a glass fiber mat (10) is laid on the corrugated plate (9).

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