Jacking and roof-changing construction method for vault storage tank buoyancy tank

Abstract

The invention provides a vault storage tank buoyancy tank jacking top changing construction method, and relates to the technical field of storage tank top changing construction, and the vault storage tank buoyancy tank jacking top changing construction method comprises the steps of placing a buoyancy tank in a storage tank, installing a tank top plate on the buoyancy tank, injecting water into the storage tank, enabling the tank top plate to rise to the top of the storage tank through buoyancy of the buoyancy tank, firmly connecting the tank top plate with the storage tank, and draining water. And after drainage, a hole is formed in the bottom of the storage tank, the buoyancy tank is removed through the hole, and the storage tank is sealed. The construction method can improve work efficiency, reduce cost and shorten construction period.

Description

Technical Field

[0001] The invention relates to the technical field of tank roof replacement construction, in particular to a method for lifting and replacing the roof of a pontoon tank. Background Art

[0002] At present, the replacement of the tank top plate of the arched oil storage tank requires the cooperation of a crane. Since the oil storage tank area is equipped with a firewall, the height of the oil storage tank above 5,000 cubic meters is generally between 20m and 24m. Therefore, a large-tonnage crane of more than 150 tons must be used during the installation to meet safety requirements. In addition, the installation is carried out piece by piece, and the adjustment and positioning are difficult, resulting in a great waste of crane hours and increased safety risks. Summary of the invention

[0003] In view of the above-mentioned prior art, the present invention proposes a construction method for lifting and replacing the roof of a pontoon of a dome-shaped storage tank.

[0004] The present invention provides a method for lifting and replacing the roof of a pontoon tank, comprising: placing a pontoon inside the tank, installing a tank top plate on the pontoon, injecting water into the tank so that the tank top plate rises to the top of the tank through the buoyancy of the pontoon, firmly connecting the tank top plate to the tank, draining water, opening a hole at the bottom of the tank after draining water, removing the pontoon through the hole, and sealing the tank.

[0005] Preferably, the method specifically comprises the following steps: S1. Making a pontoon: The pontoon is made of steel plates into a closed rectangular parallelepiped, and ear plates are provided at both ends of the pontoon, and the ear plates are used to connect the pontoons to each other; S2. Calculate buoyancy: determine the number of pontoons according to the weight of the tank top plate, and connect the pontoons with connecting steel pipes; S3, installing columns and tire frames: welding a number of columns on the upper side of each pontoon, and installing three to five tire frames on the upper ends of the columns; S4, installing the tank top plate: dragging and installing the tank top plate on the buoyancy box; S5. Water injection: Pour water into the storage tank, and the tank top plate will float into place in 2-4 days. When the tank top plate is in place, the edge of the tank top plate should be 95-105mm higher than the tank wall; S6. Install the edge angle steel: weld the edge angle steel in sections to the inner side of the tank wall, drain the water, and make the tank top plate slowly drop and fall on the edge angle steel, and stop draining the water; S7, fixing the tank top plate: connecting and fixing the tank top plate to the edge angle steel; S8, drainage: drain the water in the storage tank, open a hole at the bottom of the tank wall, enter the tank body, remove the buoyancy box and transport it out of the tank body, clean and seal the tank body; S9. Install tank top accessories.

[0006] Preferably, in S1, a partition is arranged at a certain interval inside the pontoon, the size of the pontoon is 1500*1500*4000-1500*1500*6000mm, the size of the ear plate is 10×200×300mm, and the exposed length of the ear plate when welded to the pontoon is not less than 150㎜.

[0007] Preferably, in S3, the columns are made of D108×8 steel pipes, the welding height is not less than 6 mm, and the tire frame is made of No. 12 channel steel.

[0008] Preferably, in S3, when installing the tire frame, it is rolled into a predetermined radius by a plate rolling machine, and then corrected by heating and cold working to ensure that the upper edge is flush. The joints of the tire frame are beveled, fully welded and polished, and connected to the columns by connecting steel plates. The connecting steel plates are first welded to the tire frame, and then welded to the columns after eliminating welding deformation.

[0009] Preferably, in S4, when laying the planks, the overlap width is not less than 30 mm, and the maximum gap between the two planks at the overlap is not greater than 1 mm.

[0010] Preferably, in S4, during welding, the bottom weld of the tank top plate is first welded intermittently, with a spacing of 200 mm, and a welding distance of 150-200 mm, and then the front corner weld of the tank top plate is fully welded, and the distance between the edge of the tank top plate and the tank wall is greater than 40 mm.

[0011] Preferably, in S6, the hemming angle steel is an unequal angle steel of 90*125*8 mm.

[0012] Preferably, in S8, the specifications of the hole are 1800*3000-1800*4000mm.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention provides a method for jacking up and replacing the roof of a dome storage tank by means of a pontoon, which changes the conventional tank roof replacement construction method and adopts a pontoon jacking process. The manufactured tank roof is slowly floated up by the buoyancy of water until it reaches the designed elevation, and then welding is performed to complete the installation of the tank roof.

[0014] 2. The present invention adopts the inverted installation method to change the high-altitude operation to the bottom operation, which reduces the labor intensity and improves the safety factor. In addition, the frequent crane lifting is changed to hydraulic floating, which is stable and reliable during construction, avoiding the erection and dismantling of the full-hall scaffolding, which can improve work efficiency, reduce costs and shorten construction period.

[0015] 3. During the installation process, the present invention uses the buoyancy of water as power to lift the tank top, saving a large number of crane shifts, reducing the pollution of crane exhaust to the environment, and is beneficial to environmental protection.

[0016] 4. Compared with the traditional process, the use of floating box jacking can shorten the construction period by 10 days and reduce the cost by 100,000 to 150,000 yuan for each replacement of a tank top. The invention has safe construction and good stability. After the floating box is used, it is coated with anti-rust paint for protection and can be used more than 20 times. The amortization cost of each use is very small, which avoids the erection of full-house scaffolding, avoids high-altitude operations, reduces the labor intensity of workers, and saves labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the buoyancy box in an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of the connection between buoyancy tanks in an embodiment of the present invention.

[0019] Figure 3 It is an installation plan view of the tire frame in an embodiment of the present invention.

[0020] Figure 4 It is an installation elevation view of the tire frame in an embodiment of the present invention.

[0021] Figure 5 Schematic diagram of the structure of the tank top plate in an embodiment of the present invention.

[0022] In the figure: 1. pontoon; 2. partition; 3. ear plate; 4. connecting steel pipe; 5. column; 6. tire frame; 7. connecting steel plate; 8. tank top plate. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific diagrams.

[0024] Example: Figure 1-5 As shown, a construction method for lifting and replacing the roof of a pontoon tank of a dome roof storage tank comprises the following steps: S1. Making a pontoon: The pontoon 1 is made of a 6mm thick steel plate as a closed rectangular parallelepiped, and the size of the pontoon 1 is 1500*1500*4000mm. A partition 2 is arranged every 1m inside the pontoon 1 to increase the rigidity of the pontoon 1. Ear plates 3 are welded at both ends of the pontoon 1, and the size of the ear plates 3 is 10×200×300mm. The exposed length of the ear plates 3 when welded to the pontoon 1 is 150mm, and has a corresponding angle for connecting the pontoons 1 to each other.

[0025] S2. Calculate buoyancy: Take the replacement of the roof of a 3,000 cubic meter oil tank as an example. Make a 1.5m×1.5m×4m pontoon. The buoyancy of pontoon 1 is 9t, its deadweight is 1.7t, and its net buoyancy is 7.3t. The rated buoyancy is 5t. The weight of the tank roof varies according to the size of the tank, ranging from 15 to 40t. The number of pontoons is determined based on the weight of the tank roof. The tank roof of a 3,000 cubic meter oil tank weighs about 30t. Six pontoons 1 can be used. The pontoons 1 are connected by D108*6 connecting steel pipes 4. Now take the replacement of the 3,000 cubic meter tank as an example for the subsequent steps.

[0026] S3. Install columns and tire frames: weld six columns 5 in three rows inside, middle and outside on the upper side of each pontoon 1. The columns 5 are made of D108×8 steel pipes with a welding height of 6 mm. Prefabricated tire frames 6 are installed on the upper ends of the columns 5. The tire frames 6 are made of No. 12 channel steel. Three circles of tire frames 6 are set according to the radius of the tank top. When installing the tire frames 6, they are rolled into a predetermined radius by a plate rolling machine, and then corrected by heating and cold working to ensure that the upper mouth is flush. The joints of the tire frames 6 are beveled, fully welded and polished, and connected to the columns 5 with 8 mm thick connecting steel plates 7. The connecting steel plates 7 are first welded to the tire frames 6, and then welded to the columns 5 after eliminating welding deformation. The tire frames 6 are installed with a level, and their elevation deviation is strictly controlled, and they are firmly welded to the columns 5.

[0027] S4. Install the tank top plate: The grid lines and number of grid blocks of the tank top plate 8 must be constructed strictly according to the requirements of the drawings. A winch is used in conjunction with a hand winch to drag the prefabricated tank top plate 8 into place and then weld it. Before installing the tank top plate 8, the installation grid lines are set on the inner ring tire frame and the outer ring tire frame according to the number of tank top plates 8 to avoid error accumulation, uneven distribution of the top plate, and even inability to close. When laying the plates, the overlap width is 30mm, and the maximum gap between the two plates at the overlap is 1mm. After assembly is completed and spot welding is firm, welding can be carried out. When welding, the bottom weld of the tank top plate 8 is intermittently welded first, with a spacing of 200mm and a welding of 160mm, and then the front corner weld of the tank top plate 8 is fully welded to reduce welding deformation; the distance between the edge of the tank top plate and the tank wall is 45mm.

[0028] S5. Water filling: During the water filling process, a group of two people are in the tank, taking turns on duty for 24 hours, equipped with a walkie-talkie to communicate with the outside. The water filling speed should not be too fast, and the tank top plate 8 will be floated into place in 3 days. The on-duty personnel in the tank should patrol around the tank top plate 8 and deal with abnormal situations in time. When the tank top plate 8 is in place, the edge of the tank top plate 8 should be 100mm higher than the tank wall.

[0029] S6. Install the hemming angle steel: The hemming angle steel is an unequal angle steel of 90*125*8mm. The prefabricated hemming angle steel is welded in sections to the inner side of the tank wall. The upper and lower welds are fully welded, and the weld height is 6mm. Drain the water and let the tank top plate slowly drop. After it falls on the hemming angle steel, stop draining the water. Check whether the tank top plate 8 and the hemming angle steel are in the same circle, and whether the gap is less than 3mm. Otherwise, trim it.

[0030] S7. Fix the tank top plate: perform perimeter welding on the tank top plate 8 located on the edge angle steel. First, spot weld the tank top plate 8 with a spacing of 200 mm, a welding length of 50 mm, and a weld height of 3 mm. Then perform perimeter welding on the tank top plate. During welding, use segmented back welding to reduce deformation. The weld height is 6 mm.

[0031] S8. Drainage: After the water is drained, a hole of 1800*3000mm is opened at the bottom of the tank wall to enter the tank body. After disassembling the pontoon 1 and cutting off the upper column 5 of the pontoon, the pontoon etc. is transported out of the tank body by a winch and rollers, and then cleaned, sealed and welded.

[0032] S9. Install tank top accessories: After installing tank top accessories such as level gauges, air vents, manholes, etc., conduct tightness tests, strength tests and stability tests on the tank top in accordance with relevant national standards.

[0033] The above are only implementation modes of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention's specification and drawings, directly or indirectly used in other related technical fields, are also within the patent protection scope of the present invention.

Claims

1. A construction method for lifting and replacing the roof of a pontoon tank, characterized in that: include: A buoyancy box is placed inside the storage tank, and a tank top plate is installed on the buoyancy box. Water is poured into the storage tank so that the tank top plate rises to the top of the storage tank through the buoyancy of the buoyancy box. After the tank top plate is firmly connected to the storage tank, the water is drained. After the water is drained, a hole is opened at the bottom of the storage tank, and the buoyancy box is removed through the hole to seal the storage tank.

2. The method for lifting and replacing the roof of a pontoon tank according to claim 1, characterized in that: The specific steps include: S1. Making a pontoon: The pontoon is made of steel plates into a closed rectangular parallelepiped, and ear plates are provided at both ends of the pontoon, and the ear plates are used to connect the pontoons to each other; S2. Calculate buoyancy: determine the number of pontoons according to the weight of the tank top plate, and connect the pontoons with connecting steel pipes; S3, installing columns and tire frames: welding a number of columns on the upper side of each pontoon, and installing three to five tire frames on the upper ends of the columns; S4, installing the tank top plate: dragging and installing the tank top plate on the buoyancy box; S5. Water injection: Pour water into the storage tank, and the tank top plate will float into place in 2-4 days. When the tank top plate is in place, the edge of the tank top plate should be 95-105mm higher than the tank wall; S6. Install the edge angle steel: weld the edge angle steel in sections to the inner side of the tank wall, drain the water, and make the tank top plate slowly drop and fall on the edge angle steel, and stop draining the water; S7, fixing the tank top plate: connecting and fixing the tank top plate to the edge angle steel; S8, drainage: drain the water in the storage tank, open a hole at the bottom of the tank wall, enter the tank body, remove the buoyancy box and transport it out of the tank body, clean and seal the tank body; S9. Install tank top accessories.

3. The method for lifting and replacing the roof of a pontoon tank according to claim 2, characterized in that: In S1, a partition is arranged at a certain interval inside the pontoon, the size of the pontoon is 1500*1500*4000-1500*1500*6000mm, the size of the ear plate is 10×200×300mm, and the exposed length of the ear plate when welded to the pontoon is not less than 150㎜.

4. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S3, the columns are made of D108×8 steel pipes, the welding height is not less than 6 mm, and the tire frame is made of No. 12 channel steel.

5. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S3, when installing the tire frame, it is rolled into a predetermined radius by a plate rolling machine, and then corrected by heating and cold working to ensure that the upper edge is flush. The joints of the tire frame are beveled, fully welded and polished, and connected to the columns by connecting steel plates. The connecting steel plates are first welded to the tire frame, and then welded to the columns after eliminating welding deformation.

6. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S4, when laying the boards, the overlap width shall not be less than 30 mm, and the maximum gap between the two boards at the overlap shall not be greater than 1 mm.

7. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S4, the bottom weld of the tank top plate is welded intermittently first, with a spacing of 200mm and a welding distance of 150-200mm, and then the front corner weld of the tank top plate is fully welded, and the distance between the edge of the tank top plate and the tank wall is greater than 40mm.

8. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S6, the edge angle steel is an unequal angle steel of 90*125*8mm.

9. The method for lifting and replacing the roof of a pontoon tank according to claim 2 or 3, characterized in that: In S8, the specifications of the opening are 1800*3000-1800*4000mm.

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