JPS6361459B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method of constructing a double shell tank.

Conventionally, in the construction of double-shell cryogenic tanks for storing low-temperature liquids, only the inner tank was made of low-temperature material (for example, JISG3126 carbon steel plate for low-temperature pressure vessels, JISG3127 nickel steel plate for low-temperature pressure vessels), and the outer tank was made of general-purpose material. It was made of steel, and pressure tests were conducted only on the inner tank. However, if low temperature liquid leaks from the inner tank due to unexpected forces such as an earthquake,
There is a risk that the damage will spread because the outer tank cannot withstand low temperatures and liquid pressure.In order to deal with this problem, in recent years both the inner tank and the outer tank have been made of low-temperature materials, so that in the unlikely event that the low-temperature liquid in the inner tank leaks, The outer tank can withstand liquid pressure even when
There is an increasing demand for a structure that prevents low-temperature liquid from leaking outside.

Conventionally, the construction of such a double-shelled tank has been carried out using the procedures shown in FIGS. 1A to 1E. That is, first, as shown in A, the outer tank a was made of low-temperature material, and then a pressure test was conducted by filling water b in the outer tank a, as shown in B, and then the water was drained as shown in C. After that, as shown in D, an inner tank c was made of low-temperature material inside the outer tank a, and then, as shown in E, water b was filled in the inner tank c and a pressure test was conducted.
water is being drained.

However, in the above-mentioned conventional method, the production of the inner tank c cannot be started at all until the pressure test of the outer tank a is completed, resulting in poor work efficiency. The number of man-hours and
This has the problem of increasing the construction period, and also requires a large amount of water to first perform a pressure test on the outer tank and then on the inner tank.

The present invention was made in view of these circumstances, and by airtightly connecting the bottom of the outer tank and the outer periphery of the bottom of the inner tank with a waterproof plate, the outer tank and the inner tank can be constructed simultaneously using low-temperature materials. The purpose is to improve work efficiency and shorten construction time by making pressure tests possible.

Embodiments of the present invention will be described below with reference to the drawings.

When constructing a double-shell tank using low-temperature materials, the second
As shown in FIGS. 5 to 5, an outer tank material 1 and an inner tank 2 are constructed in parallel. By constructing the outer tank 1 and the inner tank 2 at the same time in this way, related work can be carried out together, making it possible to perform the work efficiently. In the figure, 3 indicates an outer tank bottom plate, 4 indicates an outer tank side plate, 5 indicates an inner tank bottom plate, 6 indicates an inner tank side plate, 7 indicates an inner tank stand structure, and 8 indicates a bottom cold insulating material.

Furthermore, the outer tank 1 and the inner tank 2 constructed as described above are connected airtight at the bottom. Figures 2 to 5 show examples, and Figures 2 and 3 show examples.
The figure shows the case where waterproof plates 9 and 10 made of general steel are used, and Figure 2 shows the case where the outer circumference of the inner tank bottom plate 5 and the outer tank bottom plate 3 are airtightly connected by the waterproof plate 9 by welding 13. In FIG. 3, the outer circumferential portion of the inner tank bottom plate 5 and the outer tank side plate 4 are connected by a waterproof plate 10. In this case, the waterproof plates 9 and 10 are removed after the pressure test is completed. Figures 4 and 5 show the case where waterproof plates 11 and 12 made of low-temperature material are provided, and in this case, they can be used as they are even after the pressure test is completed, and for this reason, they have a shape that can absorb deformation due to temperature changes. There is.

In a double shell tank configured in this way,
As shown in FIGS. 6 and 7, each of the water supply pipes 15 and 16 branched from the water supply pump 14 is connected to a valve 17,
It is separately connected to the outer tank 1 and the inner tank 2 via 18.
In the figure, 19 indicates the tank roof, and 20 indicates water.

When constructing a double shell tank, please refer to the above figure 2 ~
As shown in Fig. 5, the outer tank 1 and the inner tank 2 are assembled in parallel, and the outer tank 1 and the inner tank 2 are further airtightly connected at the bottom position by a waterproof plate 9 or 10, 11, 12. . Thereafter, as shown in FIG.
By closing and driving the water supply pump 14,
A pressure test of the inner tank 2 is performed by supplying water 20 to the inner tank 2 via the water supply pipe 16 and valve 18, and then as shown in FIG. 7, the valve 18 is closed and the valve 17 is opened to supply water 20.
The pressure resistance test of the outer tank 1 is performed by supplying the inside of the outer tank 1.

After the pressure test is completed, all the water 20 in the inner and outer tanks 1 and 2 is removed. Thereafter, as shown in FIGS. 2 and 3, if the waterproof plate is made of general steel, it is removed, and then work such as filling a cold insulating material between the outer tank side plate 4 and the inner tank side plate 6 is performed.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and various changes may be made to the airtight connection method using the waterproof plate, the water supply method, etc. without departing from the gist of the present invention.

According to the method for constructing a double shell tank of the present invention described above, the following excellent effects can be achieved.

(i) The outer and inner tanks were constructed using low-temperature materials in parallel, and the pressure resistance tests of the inner and outer tanks were conducted at the same time, greatly improving work efficiency and significantly shortening the construction period. can.

(ii) The amount of water used for pressure tests can be significantly reduced.

(iii) When carrying out pressure tests of the inner and outer tanks simultaneously at the same time,
Since the space between the bottom of the inner tank and the bottom of the outer tank is sealed by a waterproof plate, water does not enter the lower surface of the inner tank, and moisture can be prevented from entering the bottom cold insulation material.

(iv) Tank construction costs can be reduced.

[Brief explanation of drawings]

Figures 1A, B, C, D, and E are explanatory diagrams showing the conventional method of constructing a double-shell tank using low-temperature materials, and Figures 2 to 5 illustrate the construction method and waterproofing of the present invention. FIGS. 6 and 7 are explanatory diagrams showing an example of the structure of a plate, and FIGS. 6 and 7 are explanatory diagrams showing an example of a pressure resistance test. 1 is the outer tank, 2 is the inner tank, 8 is the bottom cold insulation material, 9, 1
0, 11 and 12 are waterproof plates, 13 is a welding, 14 is a water supply pump, 15 and 16 are water supply pipes, and 17 and 18 are valves.

Claims (1)

[Claims] 1. After constructing an outer tank and an inner tank in parallel using low-temperature materials and airtightly connecting the bottom of the outer tank and the outer periphery of the bottom of the inner tank with a waterproof plate, water is supplied to the inside of the inner tank. A method for constructing a double-shell tank, characterized by carrying out a hydraulic pressure test of the inner tank, and then supplying water to the inside of the outer tank to perform a hydraulic pressure test of the outer tank.