JPS6027345B2 - Tank bottom plate welding assembly method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a method of welding the bottom plate of a large storage tank from both sides to stand it up, and is particularly suitable for the bottom plate of the inner shell of a double-shell low-temperature tank.

The conventional method is to first perform various operations such as arranging, welding, and inspecting the bottom plate on a pedestal or support, and after completing the assembly of the bottom plate, the bottom plate is lifted from the roof frame or side plate with a single wire, and then placed on the pedestal. or remove support;
The second method is to assemble the bottom plate using the same method as the first method, attach a sealing material to the outer periphery of the bottom plate, lift it up by air raising, and use a mount or support. The third step is to dig a groove in the foundation in advance, install a supporting support or pedestal in this groove, and arrange the bottom plate on top of this pedestal. After welding, inspection, etc. are completed and the bottom plate assembly is completed, the supporting support or pedestal on the premises is removed and the groove is filled.Fourth, a certain amount of time has passed after the bottom plate assembly is completed on the pedestal or support. Then, there are methods that support the bottom plate with something that melts (for example, ice) and then remove the pedestal or support.

In these conventional cases, the first method has the disadvantage that the roof frame and side panels must be made stronger than necessary, and additional welded parts such as hanging pieces must be attached, while the second method requires There is a disadvantage in that it is dangerous because the worker must remove the workbench during the pressure operation in step 3.
The disadvantage of the second method is that it is not easy to backfill the trench, which is time-consuming and uneconomical.Also, with the fourth method, it is difficult to secure the melted material.For example, when ice is used, it is difficult to treat the water generated by melting. It also has the disadvantage of being impractical. The present invention aims to provide a method for welding and assembling a tank bottom plate that eliminates the drawbacks of the conventional method.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained by way of embodiments, with reference to the drawings.

In FIG. 1, a plurality of supports whose heights can be adjusted are erected and arranged at appropriate intervals on the cold insulation layer 1 of the tank foundation in accordance with the arrangement of the tank bottom plates. In this embodiment, a pipe support 4 consisting of an outer pipe 2 and an inner pipe 3 is used.
The inner tube 3 is slidably inserted into the outer tube 2, and the height can be adjusted and fixed using screws or screws. The level of each of these pipe supports 4 is adjusted uniformly, and as shown in FIG. 2, the support beam 6 is passed between adjacent pipe supports 4 and connected with bolts and nuts, etc.
A workbench 7 is formed. In FIG. 3, the base materials of the tank bottom plate 8 are arranged on the workbench 7. A plan view at this time is shown in FIG. In FIG. 7, the annular plate 5 has been laid in advance to form a workbench 7 on the entire surface corresponding to the entire tank bottom plate, the base plate base material is arranged on it, and the weld joint 10 of the entire bottom plate 8 is welded. After the inspection is completed, jacks 9 are installed in multiple rows along the chords that are substantially parallel to each other on one end side of the bottom plate 8 in FIG. 4, lift the bottom plate 8 to a position slightly higher than the workbench 7, and in this state, remove the pipe supports, 4 and support beams 6 from around the positions of the x and ○ marks in Fig. 7. After removing all of the workbench 7, jack down the jack 9 located at the position marked with an "X" near one end of the bottom plate 8, put the jack 9 in an unloaded state as shown in Figure 6, and remove it. Starting from one end, lower the layer 1 onto the cold insulation layer 1, move the removed jacks 9 from the jacks near the other end of the bottom plate 8 to the layers marked with △ along the chord closer to the edge of the pond, and install them in the same way as above. Then jack up each jack 9 to raise the bottom plate 8 to a position slightly higher than the workbench 7. In this state, after removing the workbench 7 around the △ mark in Fig. 7, move the bottom plate closer to one end. The jack 9 at the position marked with a circle is jacked down along the chord, and the bottom plate 8 around this area is lowered onto the cold insulation layer 1. Next, move the jack at the position marked ○ to the position marked ■ along the chord near the other end of the bottom plate, lift the bottom plate 8 in the same way as above, remove the workbench 7 around the jack, and use the jack-down operation to create a cold insulation layer. By repeating the lowering of the bottom plate 8 upward and the removal movement of the jack 8, the bottom plate 8 is sequentially lowered onto the protective layer toward the other end of the bottom plate 8.
You can lower the whole thing. According to the present invention, first, no special equipment is required, the work is easy and construction costs are low, second, the work is safe, and third, the bottom plate does not need to be hung from the roof or side panels, so the roof There is no need to give the side plates more strength than necessary.Fourthly, the entire workbench can be easily leveled by adjusting the level of the pipe support.Fifthly, the jacks can be moved in sequence and used repeatedly. Sixth, the base plate base material is arranged on the entire surface of the workbench, and after all the welding and inspection work for the entire bottom plate is completed, the bottom plate is lowered, so the entire bottom plate can be welded on both sides, resulting in high quality. Effects such as ensuring guarantees are recognized.

[Brief explanation of the drawing]

All of them are for explaining the embodiments of the present invention, and FIGS.
The figure shows a partially enlarged side view, and FIG. 7 shows a plan view. 1... Cold insulation layer, 2... Outer tube, 3...
・Inner pipe, 4... Pipe support, 5... Annular plate, 6... Support beam, 7... Workbench, 8... Bottom plate, 9. ...Jack, 1
0...Welded joint part. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. On the tank foundation or its cold insulation layer, a plurality of height-adjustable supports are erected at appropriate intervals to match the arrangement of the bottom plate base material, the levels of the supports are adjusted uniformly, and the support beams are are passed between adjacent supports and joined together to form a workbench, the base plate base material is arranged on the entire surface of the workbench, and after all the welding and inspection work of the entire bottom plate is completed, one end side of the bottom plate is Jacks were arranged in multiple rows along the almost parallel chords of the bottom plate, and the one end of the bottom plate was pushed up and supported by the jacks, and the workbench in this area was dismantled and removed, and then the one end of the bottom plate was pushed up and supported by the jacks. Remove the jacks located in the row near the side by lowering them, lower the bottom plate in this area, and move these jacks to positions further along the strings closer to the other end than the jacks near the other end of the bottom plate. The workbench in this part is dismantled and removed while the bottom plate of this part is pushed up and supported by jacks, and then the jack near one end is lowered, the jack is moved to the other end, the bottom plate is pushed up and supported, and the workbench is dismantled. A method for welding and assembling a tank bottom plate, characterized by repeating the above steps and lowering the bottom plate sequentially from one end side to the other end onto the foundation or its cold insulation layer.