JPS6356384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the internal environment of a tank during tank construction, and in particular, after assembling an outer tank, an inner tank for substantially accommodating liquid stored therein is assembled with a double shell. The present invention relates to a method for improving the internal environment of a tank, by which the inner tank assembly work can be carried out comfortably by sprinkling water on the outer tank and cooling the internal atmosphere when constructing the tank.

Generally, as a tank for storing low-temperature liquefied gas such as LNG or LPG, there is a cylindrical double-shell tank that is equipped with an outer tank and an inner tank that essentially stores liquid inside the tank. Spiral construction methods, helical construction methods, jack up construction methods, roof air rising construction methods, etc. are known.

In each of these construction methods, an outer tank constituting the outer shell of the tank is first assembled, and then an inner tank that substantially accommodates the stored liquid is assembled within the outer tank.

For example, in the roof air raising construction method, the first step is to assemble the side wall of the outer tank, which constitutes the outer shell of the tank, into a cylindrical shape on a foundation provided on the ground. The second step is to assemble the roofs of the outer tank and inner tank at the bottom of the outer tank.
Once the assembly is complete, a blower is used to blow pressurized air from below the roofs, the connected roofs are floated upward along the inner wall of the outer tank, and the roofs are welded and fixed to the upper ends of the side walls. It's getting old.

After the assembly of the outer tank is completed in this way, the third step is to carry the materials for assembling the inner tank into the outer tank through the material entrance provided on the lower side wall of the outer tank, and then the side wall of the inner tank is assembled. It was getting worse.

By the way, in this type of construction method, when assembling the inner tank, etc. is performed inside the assembled outer tank, the outer tank is almost sealed and the air circulation in the internal atmosphere is poor, so the atmosphere can reach high temperatures (60°C), especially in the summer.
℃) became humid, resulting in a poor working environment and a significant drop in efficiency during assembly work, etc. For this reason, attempts have been made to bring in cooling equipment such as coolers to cool the atmosphere inside the outer tank and improve the working environment, but as the tank has become larger and the internal volume has increased, sufficient effects have not been achieved. I couldn't do it.

It is also possible to improve the air circulation inside the outer tank by enlarging the material entrance for assembling the inner tank, but in that case, the sealing performance when air raging the roof of the outer tank may be affected. The situation has gotten worse and they have not been hired.

The present invention has been devised to address the above-mentioned problems and effectively solve them.

An object of the present invention is to provide a method that can improve the working environment when constructing a double shell tank.

In order to achieve the above object, the present invention provides a method for constructing a double shell tank by assembling an outer tank and then assembling an inner tank for substantially storing liquid therein. A water sprinkling means is provided above the roof, and the water sprayed from the water sprinkling means is made to flow down along the outer wall of the tank, thereby cooling the atmosphere inside the outer tank.

The method of the present invention will be further explained in detail below based on specific examples shown in the accompanying drawings.

First, as a first step, as shown in Fig. 1, the side wall 3 of the outer tank 2, which will become the outer shell of the tank, is assembled and welded on the foundation 1 buried above ground, and in parallel with this, the bottom 4 of the outer tank 2 is At , the roof 5 of the outer tank 2 and the roof 19 of the inner tank are assembled. Once the assembly with the side wall 3 and the roof 5, 19 is completed, the blower 6 installed at the bottom 4 of the outer tank 2 blows pressurized air from the bottom 4 of the outer tank 2 to the inside. Then, the roofs 5 and 19 are floated upward along the inner wall 7 of the outer tank 2 with the roofs 5 and 19 connected,
Only the roof 5 of the outer tank 2 is welded and fixed to the upper end 8 of the side wall 3. Once the outer tank 2 has been assembled by the roof air raising method as shown in FIG. 2, the next step is to proceed to the second step.

In this second step, water sprinkling means 9 is provided on the roof 5 of the outer tank 2 for cooling the atmosphere inside the outer tank. Specifically, as shown in FIGS. 3 and 4, this watering means 9 includes an annular watering pipe 12 provided on the outer part 10 of the roof 5 so as to surround the central part 11 of the roof 5, and It mainly consists of a water supply pump 13 provided at the lower part of the tank 2 and for supplying water to the water sprinkler pipe 12.

The water supply pump 13 and the sprinkler pipe 12 are connected by a supply pipe 14 for supplying water, and
The water sprinkling pipe 12 is provided with water nozzles 15 facing the roof 5 at appropriate intervals along its circumferential direction, and the water discharged from the water nozzles 15 hits the outer wall 16 of the outer tank 2. It is configured to flow down along the outer tank to cool the atmosphere inside the outer tank.
Once the installation of the water sprinkling means 9 has been completed in this way, the process moves to the third step.

In this third step, the side wall of the inner tank 17 for accommodating the liquid in the outer tank 2 is assembled.
Specifically, as shown in FIG. 5, water 18 is discharged from the water sprinkling nozzles 15 provided in the water sprinkling pipe 12 of the water sprinkling means 9 installed in the second step, and the discharged or sprinkled water 18 is poured into the outer tank 2. The water flows down along the entire outer wall 16 of the outer tank, thereby cooling the entire atmosphere inside the outer tank. In parallel with this, the inner tank 17 is sequentially assembled in this cooled atmosphere.
Therefore, the worker can perform the assembly work in a comfortable, air-conditioned environment, thereby improving his or her work efficiency.

Next, as the fourth step, as shown in Fig. 6, once the assembly of the outer tank 2 and the inner tank 17 has been completed, and all testing and inspection work in the inner tank 17 has been completed,
The water sprinkling means 9 is removed and the tank construction is completed.

In the above specific example, an annular water sprinkling pipe 12 is used as the water sprinkling means 9, but the shape is not limited to this and may be any shape as long as it can effectively cool the atmosphere inside the outer tank. Of course.

In addition, a groove is formed in the lower part of the outer tank 2 to collect water flowing down along the outer wall 16, and the water collected here is supplied again to the watering means 9 and circulated, and is used for cooling. It may also be possible to make a contribution.

Further, in the above specific example, the water sprinkling means 9 was installed before assembling the inner tank 17 and removed after completion, but instead, a water sprinkling means provided for tank fire protection may be used. . That is, once the assembly of the outer tank is completed, a water sprinkling means (usually installed after the tank construction is completed) is installed for fire prevention and safety of this tank, and then the atmosphere inside the outer tank is cooled while sprinkling water from this means. Alternatively, the inner tank may be assembled. In this case, there is no need to remove this watering means after the tank construction is completed.

Further, although the above specific example has been explained with respect to the roof air raising method, it is needless to say that the method is not limited to this method.

In summary, according to the method of the present invention, the following excellent effects can be achieved.

Since the atmosphere inside the outer tank is cooled when assembling the inner tank after the outer tank is assembled, the assembly work environment can be improved, and work efficiency can therefore be improved.

The method according to the invention can be easily adapted to conventional construction methods.

Water spray means for tank fire protection can be used, in which case there is no need to remove it after construction of the tank is completed.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the roof of the tank outer tank being assembled by the air raising method to explain the method of the present invention, and Fig. 2 shows the state in which the assembly of the tank outer tank is completed. A vertical sectional view, FIG. 3 is a partially cutaway view showing a state in which a water sprinkling means is provided on the roof of the outer tank, FIG. 4 is a plan view of the same, and FIG. 5 is a longitudinal sectional view showing a state in which the inner tank is assembled. , FIG. 6 is a longitudinal cross-sectional view showing the completed construction of the tank. In the figure, 1 is the foundation, 5 is the roof, 9 is the watering means,
16 is an outer wall, and 17 is an inner tank.

Claims (1)

[Claims] 1. After assembling the outer tank, when assembling an inner tank for substantially storing liquid in the outer tank and constructing a double-shell tank, after assembling the outer tank, above the roof of the outer tank. A method for improving the internal environment of a tank during tank construction, characterized in that a water sprinkling means is provided in the tank, and the water sprinkled from the water sprinkling means flows down along the outer wall of the outer tank to cool the atmosphere inside the outer tank. .