JPS5952267B2 - Construction method of double shell cryogenic storage tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for a double-shell cryogenic storage tank.

In general, a double-shell cryogenic storage tank is a cylindrical flat-bottomed dome roof type, and consists of an inner tank made of low-temperature steel and an outer tank made of ordinary steel. The space has a cold-insulating wall structure filled with cold-insulating material such as perlite.

In this construction method, first the inner and outer tank side panels are assembled, then the inner and outer roofs are assembled together inside the inner tank, and then the inner tank side panels and the inner tank roof are made airtight and compressed air is sent to the lower part of the inner tank roof. There is a construction method in which the inner and outer tank roofs are floated to a predetermined position and then assembled by mounting the roofs on the upper ends of the side panels.

However, each construction method has its advantages and disadvantages, especially problems such as drying of the perlite concrete for cooling the bottom, moisture prevention of the perlite material filled between the inner and outer tanks, and construction time, as well as the amount of use of hoisting equipment such as tower cranes and tow trucks, scaffolding, etc. There are problems with this, and the reality is that no construction method has yet been discovered that can do this.

By the way, for the construction of single-layer large cylindrical tanks for storing crude oil and the like, the helical construction method is known as a method of assembling the tank at a low location while working in a fixed location.

To briefly explain this construction method, as illustrated in FIG.
4 are assembled in an interlocking state, and an appropriate number of rollers 5 are arranged at regular intervals between the engaging edges 3 and 4 of the lower peripheral wall 1 and upper peripheral wall 2. By rotating the upper circumferential wall 2 in the direction of the arrow using the roller 5 as a guide, an arc-shaped gap 6 is formed between the upper circumferential wall 2 and the lower circumferential wall 1 in a diagonal manner. The circumferential wall member 7 (hereinafter referred to as the intermediate side plate) is applied and added by welding it to the upper circumferential wall, and then the rotation of the upper circumferential wall 2 and the addition of the intermediate side plate 7 are repeated alternately, and the final , remove roller 5 and
This is a construction method in which the upper and lower peripheral walls 1 and 2 are joined to form an integral cylindrical tank.

□ Therefore, with this helical construction method, the intermediate side plate can be assembled and welded at a low location and at a fixed position, making it easier to control work safety and welding quality.

Therefore, the present invention utilizes the advantages of this helical construction method,
When constructing a double-shell cryogenic storage tank, this helical construction method was used to assemble the outer tank, and the general brick machining method was used to assemble the inner tank, using an improved construction method to solve the various problems mentioned above. be.

The construction method of the present invention will be specifically explained below.

First, after the foundation 11 is completed, if a heating device, etc. is required, embed the necessary equipment in the foundation, and
Arrange 3 and weld.

Thereafter, the lowermost side plate 14 of the outer tank is erected on the bottom plate 13.

(Fig. 2-1) As shown in Fig. 1, this side plate 14 is a side plate having an inclination unique to the helical construction method along with the uppermost side plate to be described later. This creates a difference in height of 1 minute.

After this side plate 14 is erected, a pearlite concrete ring 15 which is a cold insulating material is placed along the inner circumference of the innermost part of the outer tank.
An annular sketch plate 17 is attached thereon to receive the side plate of the inner tank 16.

(Fig. 2-2) After completely welding the inner tank sketch plate 17, the side plate materials, roof plate materials, and roof plate materials for assembling the inner tank are taken into the tank, and after the materials are brought in, the inner tank roof 18 is attached to the inner tank roof. Assemble on the assembly stand 19.

(Fig. 2-3) On the other hand, as shown in Fig. 2-4, in the outer tank 12, an appropriate number of rollers 5 are arranged at regular intervals around the entire circumference of the spiral mouth edge of the lowermost side plate 14 of the upright outer tank. Set up

Furthermore, as shown in FIGS. 2-5, the spiral mouth edges of the outer tank uppermost side plate 21 with the outer tank roof 20 directly attached to the lowermost side plate 14 are engaged and set.

In other words, the upper part of the outer tank with the roof integrated is the lowermost part of the outer tank 21.
It is mounted on a rack so that it can rotate.

Next, a suspension support device 22 such as a tongue buckle is suspended from the lower surface of the outer tank roof 20, one of which is attached to the upper surface of the inner tank roof 18 assembled in the front=q inner tank, and the outer tank roof 18.
20 are connected together and the inner tank roof 18 is suspended from the outer tank roof 20.

A hoist running rail 24 is provided along the entire circumference of the lower surface of the inner tank roof 18, and a small trolley hoist 23 for supplying inner tank side plates is attached to this rail.

(Figure 2-5 and Figure 2-5A) Since the inner and outer tank roofs 18.20 were suspended, the inside of the storage tank
- As shown in Figure 5, the tank is covered with an integrated roof inside and outside, which acts as an umbrella and prevents rain from falling into the storage tank.

At this point, the cold-insulating pearlite concrete 25 at the bottom of the inner tank is cast for the first time, and the inner tank bottom plates 26 are arranged and laid on top of this.

(Fig. 2-6) In parallel with this operation, as shown in Fig. 2-7, the turning roller 5 is driven as a guide to assemble the intermediate side plate 27 of the outer tank 12.

Then, the inner and outer tank roofs 18, 20 become higher accordingly.

Therefore, the intermediate side plate 21 of the outer tank 12 is raised using the helical construction method until the height range is within a height range where the side plate assembly work of the inner tank 16 can be performed.

In this state, the side plates forming the inner tank peripheral wall are assembled one by one from the bottom using the so-called bricklaying method.

In this case, the side plate for the inner tank is the trolley hoist 23.
The intermediate side plate 27 of the outer tank 12 is used for lifting and assembling work such as welding in the circumferential direction and height direction.
This is done using scaffolds 28 for assembling the inner tank provided at several locations on the inner surface.

Incidentally, in parallel with the assembly turning of the outer tank 12 by the helical method, the inner tank assembly scaffold 28 rises while turning around the peripheral wall of the inner tank, as shown in FIGS. 2-7. Functions as a scaffold.

Therefore, in parallel with the assembly of the outer tank peripheral wall, this scaffold 28
If you use this, you can assemble the inner tank peripheral wall.

In this way, the side plates of the inner and outer tanks 16 and 12 are added and assembled to a predetermined height by parallel work using the helical construction method and the brick masonry method, and finally, the inner tank roof is integrated with the outer roof 20. 18 suspension support turnbuckles 2
2 is removed and welded to the inner tank uppermost side plate 29 to connect it.

Assemble the double-shelled inner and outer tanks 16, 12 using the above steps,
Thereafter, the side plate turning roller 5 is removed, and the circumferential joint 30 of the outer tank upper peripheral wall 14 and lower peripheral wall 24 is finally welded to assemble the entire tank into an integral double shell cylindrical tank structure.

After that, the outer tank 12 is made airtight and the gap between the collapsed roots 31 is filled with perlite, and the construction is completed.

(Figures 2-8) Therefore, the construction method of the present invention makes full use of the features of the helical method and is well arranged with the brick masonry method, and can exhibit the following effects.

゛Firstly, the side panels of the inner and outer tanks can be assembled independently and in parallel, so the construction of the inner tank itself, the casting of the cold insulation material at the bottom of the inner tank, and the installation of the inner tank bottom plate can be completed completely on the inner and outer tanks. Since the work is done under a roof, the moisture-proofing of the cold insulation material is not sufficient, so the cold insulation material can be cured efficiently.

Additionally, the welding process, which is considered the most important part of the construction of the inner tank, can be carried out without being affected by wind or rain, even in rainy weather, which greatly contributes to shortening the construction period.

Second, when assembling the inner tank side panels, the side panels can be supplied in sufficient time using a transporter such as a small trolley hoist, and the scaffolds used for installation are placed at several locations on the inner wall of the outer tank side panels using the helical construction method. The installed movable swing scaffolding can be used,
The construction cost is extremely low and the workability is safe.

Thirdly, since the movable scaffold is used to assemble the inner tank side plates, there is no need to temporarily attach jigs, scaffolding, etc. to the inner tank wall, which requires strict strength in double-shell cryogenic storage tanks. There is no need to worry about damage to the tank.

Therefore, the present invention greatly contributes to shortening the construction period, reducing construction costs, and improving welding quality, and the effects brought about by this inventive method are very large.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the helical construction method, and Figs. 2-1 to 2-8 are explanatory diagrams of the assembly procedure of the method of the present invention, and Fig. 2-5A is an explanatory diagram of the helical construction method.
The figure is an enlarged view of part A in Figures 2-5. ) 1... Lowermost peripheral wall portion, 2... Uppermost peripheral wall portion, 3... Spiral mouth edge, 4... Spiral mouth edge, 5... ...Roller, 6 ...Archive gap, 7 ... Side plate intermediate plate, 11 ... Foundation, 12 ... Outer tank, 13 ... ...outer tank bottom plate,
14... Lowermost outer tank side plate, 15... Perlite concrete ring, 16... Inner tank, 17... Sketch plate, 18...・・・
・Inner tank roof, 19 Inner tank roof assembly jig, 20
......Outer tank roof, 21...Top of outer tank side plate, 22...Suspension support device, 23...
Trolley hoist, 24... Rail for hoist running, 25...; Perlite concrete for cold insulation at the back of the inner tank, 26... Inner tank bottom plate, 27...
...Outer tank side plate intermediate plate, 28...Inner tank assembly scaffolding, 29...Inner tank topmost side plate, 30...
Circumferential joint, 31... side/roof gap.

Claims (1)

[Claims] 1. When constructing a double-shell low-temperature storage tank, the outer tank is constructed using the helical construction method, and the inner tank is constructed using the brick construction method. In particular, when constructing the inner tank using the brick construction method, the inner tank roof is suspended from the roof of the outer tank in advance. A feeding device for the inner tank side plate is installed to connect the lower part of the inner tank roof and move in the circumferential direction of the lower surface of the inner tank roof, and a scaffold for assembling the inner tank side plate is also erected at a suitable place inside the outer tank side plate. A construction method for a double-shell low-temperature storage tank, characterized in that by using a lifting supply device for side plates and scaffolding for assembly, the bricklaying method for the inner tank is simultaneously carried out in parallel with the assembly work using the helical construction method for the outer tank.