JPH04285398A - Construction method of double-shell low temperature storage tank - Google Patents

Abstract

PURPOSE:To improve the workability in carrying-in of side plates and assembling and welding thereof and enhance the efficiency and the economy of construction cost at the time of constructing both the inner tank side plate and outer tank side plate of a double-shell low temperature storage tank in parallel to each other by means of a helical construction method. CONSTITUTION:An inner tank helical opening part 9 for assembling an inner tank helical inserting plate 8 is formed within the opening angle of an outer helical opening part 19 for assembling an outer tank helical inserting plate 18, and the inner tank helical opening part 9 is formed in a position lower than the outer tank helical opening part 19. The inner tank helical inserting plate 8 is carried through the outer tank helical opening part 19 and built up in the inner helical opening part 9, and the outer tank helical inserting plate 18 is built up in the outer tank helical opening part 19.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is useful for constructing both the inner and outer tank side plates of a double-shell cryogenic storage tank for storing low-temperature liquids such as liquefied petroleum gas and liquefied natural gas in parallel using the helical construction method. This invention relates to a method for constructing a double-shell cryogenic storage tank that is easy to construct and can be constructed efficiently.

0002

[Prior Art] Conventional examples of applying the double helical construction method to the construction of double-shell low-temperature storage tanks include, for example, an invention in which both the inner and outer tanks of a double-shell storage tank are simultaneously assembled using a spiral construction method similar to the helical construction method. This method is disclosed in Japanese Patent Publication No. 52-18405 entitled "Method for Construction of Low Temperature Liquefied Gas Storage Tank".

[0003] The invention of this Japanese Patent Publication No. 18405/1983 is as follows:
A notch is provided in a part of the cold insulation foundation, and this notch is used as a supply passage for the inner tank side wall plate.A small hoist crane for supplying the inner tank side wall plate is installed inside the inner tank around this notch, and also outside. A small crane is placed outside the tank to supply the outer tank side wall plates, and workbenches for assembly and welding work are placed inside the inner tank, outside the outer tank, and between the inner and outer tanks to assemble on the bottom plate. This is a method of constructing a cylindrical double tank low-temperature liquefied gas storage tank in which the side walls of the inner and outer tanks are simultaneously assembled using a spiral method using a jig.

0004

[Problems to be Solved by the Invention] In the conventional construction method described above, in which the side walls of both the inner tank and the outer tank are assembled simultaneously by the spiral construction method, the assembly and welding work of the side walls of both the inner and outer tanks are performed at a fixed position in a low place. These construction methods can be carried out independently and in parallel, and even in the case of rain, work on the inner tank can proceed without being affected by the rain, which is effective in shortening the construction period. Since the supply path for transporting the inner tank side wall plates and the space for assembling the inner tank side wall plates are provided in different locations, the route from supplying the side wall plates to assembling them is longer, making it difficult to carry materials and equipment horizontally. This not only makes it impossible to carry out a series of work in the same place continuously, which reduces work efficiency and increases construction costs. Repairs, construction of the bottom cold insulation layer, and installation of piping nozzles at the bottom of the inner tank side wall plates are time consuming, and in addition, the inner and outer tank side wall plates located above the cutout in the cold insulation foundation part are bent, and the bottom cold insulation effect after completion. There was a risk that it would cause problems. In addition, many hanging tools and frames are required, such as a small hoist crane for supplying the inner tank side wall plates, a small crane for supplying the outer tank side wall plates, and a workbench for welding work, making the construction equipment large-scale and complicated. Ta.

[0005]

[Means for Solving the Problems] This invention has been made to solve the above-mentioned problems, and the upper side plates of both the inner tank and the outer tank are arranged in parallel in the upper end circumferential direction of each lower side plate. Rotate spirally on a plurality of rollers provided in the lower side plate to create an opening that meshes with the upper part of the lower side plate in a stepped manner, insert the side plate insertion plate into the opening, and rotate to create the opening in this way. When constructing the double helical construction method, in which the intermediate plate of the side plate is constructed by repeatedly inserting the side plate and inserting the side plate in sequence, the inner tank is located at a lower position than the outer tank helical opening formed at the top of the lower side plate of the outer tank. The inner tank helical opening formed at the top of the lower side plate of the is formed within the opening angle of the outer tank helical opening, and the inner tank helical insertion plate is carried in through the outer tank helical opening and assembled at the inner tank helical opening. This is a method of constructing a double-shell low temperature storage tank in which an outer tank helical insertion plate is inserted into an outer tank helical opening and assembled.

[0006]

[Function] In the method for constructing a double-shell cryogenic storage tank according to the present invention, the inner tank helical opening is formed within the opening angle of the outer tank helical opening, and the inner tank helical opening is made closer to the outer tank helical opening. The outer tank helical opening can be used as the entrance for the inner tank helical insertion plate, and the inner tank helical insertion plate can be assembled at the inner tank helical opening located at the shortest distance from the entrance. The helical insertion plates of both tanks are loaded through the common outer tank helical opening. Furthermore, the helical opening on the inner tank side is made lower than the helical opening on the outer tank side, and the inner tank helical insertion plate is smoothly fed into the inner tank helical opening from diagonally above the outer tank helical opening. In addition, so that a series of assembly lines can be carried out without carrying equipment sideways or duplicating tools, etc., the helical insertion plate is carried in by sharing the helical opening of the outer tank, and the helical insertion plate is assembled, welded, inspected, etc. Work is carried out near the helical openings of the inner and outer tanks located within a common opening angle. Furthermore, the piping nozzle attached to the lower helical plate of the inner and outer tanks, which has rollers at the upper end, and the bottom cold insulation layer between the inner and outer tanks, are removed during the assembly work of the lower helical plate of the inner and outer tanks, or when constructing the side helical intermediate plate. construction in parallel.

[0007]

[Example] An example will be described with reference to the drawings. FIG. 1 is a perspective explanatory view showing the helical construction method for the inner and outer tanks of a double-shell low-temperature storage tank according to the present invention, with a part of the outer tank removed. 1 is an inner tank for storing low temperature liquid, 2 is an outer tank that covers the outside of the inner tank 1 for cold storage, and the double shell of this inner and outer tank forms a low temperature storage tank. The inner tank 1 and the outer tank 2 have an inner tank helical roller 6 and an outer tank helical roller 16 arranged at the spirally inclined upper ends of the inner tank helical lower plate 7 and the outer tank helical lower plate 17, respectively. Inner tank roof 3 and inner tank helical upper plate 4, outer tank roof 13 and outer tank helical upper plate 14 are interlocked in a stepped manner on rollers 6 and 16.
After these are assembled, the inner tank helical intermediate plate 5 and the outer tank helical intermediate plate 15 are constructed by pushing up the inner and outer tanks parallel to each other in a spiral shape using the helical construction method described later. Inner tank helical lower plate 7 and outer tank helical lower plate 1
7 has an upper edge formed in a spiral shape with a height that does not hinder the installation of side nozzles for piping and construction of a bottom cold insulation layer (not shown) between the inner and outer tanks, etc. The points connecting the highest end point are the step portions 7a and 17a.
becomes.

The inner tank helical opening 9 and the outer tank helical opening 19 including the step portions 7a and 17a formed at the upper part of the inner tank helical lower plate 7 and the outer tank helical lower plate 17 are shown in FIGS. 3, the opening angle of the inner tank helical opening 9 is made to match the opening angle (a) of the outer tank helical opening 19, or the opening angle of the inner tank helical opening 9 is made to match the opening angle of the outer tank helical opening 19. Opening angle (a)
be positioned and formed so as to be included in it. In addition, the height of the lower end of the inner tank helical opening 9 is as shown in FIGS. 4 to 7.
The outer tank helical opening 19 is formed with a height difference slightly lower than the lower end height. Insert the inner tank helical insertion plate 8 and the outer tank helical insertion plate 18 into the corresponding openings of the inner tank helical opening 9 and the outer tank helical opening 19, and assemble them to the helical upper plates 4 and 14, respectively, Weld and assemble. Note that the inner tank helical insertion plate 8 is conveyed from diagonally upward through the outer tank helical opening 19 using the inclined upper surfaces of the outer mount 11 and the inner mount 10 to a predetermined position in the inner tank helical opening 9.

[0009] The procedure for constructing the inner tank 1 using the helical construction method is as follows:
After assembling the bottom plates of the inner and outer tanks, an inner tank helical lower plate 7 having a spirally inclined upper edge is assembled on the inner tank bottom plate 12, and a plurality of inner tank helical rollers 6 are placed along the circumference of the upper edge. The inner tank helical upper plate 4 is mounted on the inner tank helical roller 6 so that the upper plate 4 of the inner tank helical can be rotated spirally and pushed up. Build roof 3. After that, the entire upper part of the inner tank helical upper plate 4 is rotated spirally on the inner tank helical roller 6 and pushed up, and the inner tank helical insertion plate 8 is inserted into the inner tank helical opening 9 created in the stepped portion 7a. After that, the entire upper part is spirally rotated and pushed up again from the inner tank helical upper stage plate 4 to again create an inner tank helical opening 9 in the stepped part 7a, and this opening 9 has an insertion plate 8. is reinserted. In this way, the inner tank helical intermediate plate 5 is constructed to a predetermined height by sequentially repeating the formation of the inner tank helical opening 9 by spiral rotation of the entire upper part and the insertion and assembly of the inner tank helical insertion plate 8, and then The inner tank 1 is constructed by removing the helical roller 6 and joining the inner tank upper part and the inner tank helical lower plate 7.

[0010] Like the inner tank 1, the outer tank 2 is also assembled by the helical construction method. That is, after assembling the outer tank helical lower plate 17 having a spiral upper edge on the outer tank bottom plate 20, the outer tank helical roller 16, the outer tank helical upper plate 14 pushed up in a spiral shape, and the outer tank roof 13 in this order, The entire upper part of the tank helical upper plate 14 is rotated spirally on the outer tank helical roller 16 and pushed up, and the outer tank helical insertion plate 18 is inserted and assembled into the outer tank helical opening 19 created in the stepped portion 17a, and the opening is completed. By sequentially repeating the formation of the section 19 and the insertion and assembly of the insertion plate 18, the outer tank helical intermediate plate 15 is built to a predetermined height, the outer tank helical roller 16 is removed, and the outer tank upper part and the outer tank lower board 17 are joined. Thus, the outer tank 2 is constructed.

The construction procedure of an embodiment in which the inner tank helical intermediate plate 5 and the outer tank helical intermediate plate 15 are assembled in parallel will be explained according to the process order of FIGS. 4, 5, 6, and 7. . In common to each figure, 20 is an outer tank bottom plate, and 12 is an inner tank bottom plate on the inner tank cooling foundation. The inner tank helical opening 9 is formed within the opening angle of the outer tank helical opening 19, and the vertical positional relationship is such that the inner tank helical opening 9 is provided at a slightly lower position than the outer tank helical opening 19. In addition, an inner pedestal 10 is installed between the inner tank helical lower plate 7 and the outer tank helical lower plate 17, and an outer pedestal 11 is installed outside the outer tank helical lower plate 17, so that the upper surface matches the slope between the openings. are provided at an angle so that the inner tank helical insertion plate 8 and the outer tank helical insertion plate 18 can be easily carried in through the outer tank helical opening 19. Note that the inner tank roof 3 and the outer tank roof 13 are not shown.

FIG. 4 shows a part of the state in which the inner tank helical insertion plate 8 is carried in through the outer tank helical opening 19 using the outer mount 11 and the inner mount 10, which are provided with inclined upper surfaces. It is a side cross-sectional explanatory view with a part removed. The carried inner tank helical insertion plate 8 is inserted obliquely from above so as to drop onto the inner tank helical roller 6 of the inner tank helical opening 9, and is then assembled and welded to the inner tank helical upper plate 4.

FIG. 5 is an explanatory side cross-sectional view with a portion cut away showing a state in which the outer tank helical insertion plate 18 is being transported using the outer frame 11 following the step of FIG. 4. The outer tank helical insertion plate 18 is inserted obliquely from above onto the outer tank helical roller 16 of the outer tank helical opening 19, raised, and assembled to the outer tank helical upper plate 14 and welded.

FIG. 6 is an explanatory side cross-sectional view with a portion cut away showing a state in which the inner tank helical insertion plate 8 and the outer tank helical insertion plate 18 are assembled by the steps shown in FIGS. 4 and 5. In this state, the upper parts of the inner tank 1 and the outer tank 2 on the inner tank helical roller 6 and the outer tank helical roller 16 are pushed up spirally by rotating them in the arrow directions shown in FIG. new openings 9
and 19.

FIG. 7 is an explanatory side cross-sectional view with a portion cut out showing a state in which new openings, an inner tank helical opening 9 and an outer tank helical opening 19 have been formed following the process shown in FIG. 6. be. After this process, the inner tank helical insertion plate 8 and the outer tank helical insertion plate 18 are carried in, assembled, welded, and inspected in order according to the steps shown in FIGS. 4 to 6 again, and the inner tank helical intermediate plate 5 and the outer tank helical The tank helical intermediate plates 15 are constructed while being pushed up in a spiral manner. Although not shown in the drawings, a work frame is provided inside the inner tank 1. In addition, the inner frame 10 and the outer frame 11 shown in FIGS. 4 to 7
Although the upper surface is inclined in consideration of convenience in carrying in materials, the upper surface may be formed substantially horizontally in consideration of ease of assembly and welding work.

[0016]

[Effects of the Invention] The present invention has the following effects. The inner tank helical opening formed on the upper part of the lower side plate of the inner tank is located within the opening angle of the outer tank helical opening formed on the upper part of the lower side plate of the outer tank, and the inner tank helical opening is further positioned within the opening angle of the outer tank helical opening formed on the upper part of the lower side plate of the outer tank. Since it is formed at a lower position than the helical opening, the insertion plates for both the inner and outer tanks can be carried in using the common outer tank helical opening, and the inner helical insertion plate can be inserted into the inner tank located at the shortest distance from the loading port. It can be assembled at the tank helical opening, and the route for supplying and assembling the inner tank helical insertion plate is shortened, making the construction work very easy and shortening the working time. In addition, since the helical opening on the inner tank side is lower than the helical opening on the outer tank side, the inner tank helical insertion plate can be carried in smoothly from diagonally above the outer tank helical opening. Improves the workability of transporting helical insertion plates. In addition, since the inner and outer helical intermediate plates are constructed on rollers installed on the lower helical plates of the inner and outer vessels, the installation work of piping nozzles to the lower helical plates of the inner and outer vessels is independent of this intermediate plate construction work. It is also possible to construct a bottom cold insulation layer between the inner and outer tanks, further improving workability and cooling function after completion.

[0017] The intermediate plates of the inner and outer tank side plates can be carried in and assembled and welded at the helical openings of the inner and outer tanks located within a common opening angle. You can do a series of parallel tasks with
Assembly work can be done without sideways holding of equipment or duplication of tools, improving work efficiency and reducing construction costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective explanatory view with a part of the outer tank removed, showing the state of construction of a double-shell cryogenic storage tank using the helical construction method for inner and outer tanks according to the present invention.

FIG. 2 is an explanatory plan cross-sectional view showing the positional relationship between the opening angles of the inner and outer tank openings of the double-shell low-temperature storage tank according to the present invention.

FIG. 3 is an explanatory plan cross-sectional view showing the positional relationship between the opening angles of the inner and outer tank openings of another embodiment of the double-shell low-temperature storage tank according to the present invention.

FIG. 4 is an explanatory side cross-sectional view with a portion cut away showing a state in which the inner tank helical insertion plate is carried in from the outer tank helical opening of the double-shell low temperature storage tank according to the present invention.

FIG. 5 is an explanatory side cross-sectional view with a part cut out showing a state in which the outer tank helical insertion plate is being transported following FIG. 4 of the double-shell low-temperature storage tank according to the present invention.

FIG. 6 is an explanatory side cross-sectional view with a part cut out, showing the double-shell low-temperature storage tank according to the present invention, with insert plates for the inner tank and outer tank constructed by the steps shown in FIGS. 4 and 5. be.

FIG. 7 is an explanatory side cross-sectional view with a part cut out, showing a state in which new openings of the inner and outer tanks are formed following FIG. 6 of the double-shell low-temperature storage tank according to the present invention.

[Explanation of symbols]

1 Inner tank 2 Outer tank 3 Inner tank roof 4 Inner tank helical upper plate 5 Inner tank helical intermediate plate 6 Inner tank helical roller 7 Inner tank helical lower plate 8 Inner tank helical insertion plate 9 Inner tank helical opening 13 Outer tank roof 14 Outer tank helical upper plate 15 Outer tank helical intermediate plate 16 Outer tank helical roller 17 Outer tank helical lower plate 18 Outer tank helical insertion plate 19 Outer tank helical opening

Claims (1)

[Claims] The upper side plates of both the inner tank and the outer tank are rotated in a spiral manner on a plurality of rollers provided in the circumferential direction of the upper end of the lower side plate of each side plate in parallel, and an opening that meshes with the upper part of the lower side plate in a stepped manner In the double helical construction method, a side plate insertion plate is inserted into the opening, and the side plate intermediate plate is constructed by repeatedly repeating the rotation to create the opening and the insertion of the side plate insertion plate in order to build the side plate intermediate plate. The inner tank helical opening formed at the upper part of the lower side plate of the inner tank is formed within the opening angle of the outer tank helical opening formed at the upper part of the lower side plate of the outer tank, and the inner tank helical opening is It is formed at a lower position than the tank helical opening, and the inner tank helical insertion plate is carried in through the outer tank helical opening and assembled at the inner tank helical opening, and the outer tank helical insertion plate is assembled at the outer tank helical opening. A method for constructing a double-shell cryogenic storage tank.