JPS6149468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tank shell constructed within a ship's hull or an external structure such as an above-ground or underground structure, specifically, a tank shell constructed within a ship's hull or an external structure such as an above-ground or underground structure. A heat shield is installed around the outer periphery of the tank shell provided in the external structure to accommodate liquefied petroleum gas or low-temperature liquefied gas in a temperature range close to that temperature, such as liquefied butane gas at -33.4℃ or liquefied ammonia gas at -33.4℃. Concerning how to construct walls.

Conventionally, a heat-insulating wall was built around the outer circumference of the tank shell by foaming urethane or other foaming materials on-site, but when using this method, it is necessary to take measures against harmful gases generated due to on-site foaming. Therefore, the construction efficiency and economic efficiency are poor, and since the heat insulation wall is constructed over a wide area by foaming on site, the foaming ratio at each part of the heat insulation wall must be set uniformly over the entire range of the heat insulation wall. Therefore, it is difficult to stabilize the quality of the heat insulation wall, and in addition, a large working space is required around the tank shell for the foam formwork equipment. In particular, in the case of an in-hull tank, it is necessary to secure such a large working space between the tank shell and the ship's hull, which has the disadvantage of leading to a reduction in the size of the tank shell.

Furthermore, when constructing a thermal barrier using on-site foaming as described above, the foamed urethane etc. that make up the thermal barrier adhere to the outer surface of the tank shell, so it is difficult to construct a thermal barrier according to the tank type specified by IMCO (Intergovernmental Maritime Consultative Organization). , independent type A and type B (hereinafter referred to as IMCO
Types A and B) require relatively low pressure resistance, making it difficult to apply them as a heat insulation means to economically constructed in-hull tanks.

In other words, in order to construct a heat shield wall around the outer circumference of the tank shell of IMCO Type A and B, it is necessary for safety reasons because the pressure resistance of the tank shell itself is relatively low, and cracks may occur in the tank shell and gas may leak. If this happens, it is required to be able to detect this quickly and reliably.
In addition, although it is required by intergovernmental agreements, when a heat shield is tightly attached to the outer surface of the tank shell, as in the above-mentioned in-situ foaming heat shield, gas leakage from the tank shell is generally prevented by installing a wall at the bottom of the tank. It was not possible to guide the gas to the leak detection part located in the tank without dissipation, and the detection of gas leaks from the tank shell was uncertain.

Furthermore, in the conventional method described above, it is conceivable to add a means to form a passage such as a groove to guide leaked gas to the leak detection part on the wall surface portion of the heat insulation wall facing the outer periphery of the tank shell. If this is the case, not only will construction efficiency and economic efficiency further deteriorate, but it will also be impossible to arrange passages, etc. all around the outer circumference of the tank shell in order to ensure the desired heat insulation. If a gas leak occurs in the shell part, the leaked gas can be guided to the detection part, but if a gas leak occurs in the tank shell part that is separated from the passage, the leaked gas cannot be guided to the detection part. As a result, the safety standards required when constructing a heat barrier around the outer circumference of IMCO type A and B tank shells cannot be met.

In view of the points detailed above, the present invention not only excels in workability and economy and requires less work space, but also reduces leakage gas from the tank shell.
In a state where there is little risk of evacuation to the outside world,
The purpose is to efficiently construct a heat insulating wall that can reliably lead to the bottom of the tank.

The characteristic structure of the tank heat insulation wall construction method according to the present invention for achieving the above object is that a plurality of molded heat insulating materials are applied to the outer surface of the tank shell, and
The edges of adjacent molded insulation materials are juxtaposed in close contact with each other, and each molded insulation material is attached to the tank shell using a plurality of fastening fixtures scattered at multiple locations on the outer surface of the tank shell. It is fixed, and the outside of the joint of the adjacent molded insulation material is sealed with adhesive tape to construct the heat insulation wall.
This configuration provides the following effects.

In other words, in addition to laying multiple molded insulation materials on the outside of the tank shell, which can be mass-produced in factories that are advantageous for quality control and measures against harmful gases generated during foaming,
After joint treatment of the adjacent molded insulation material,
This is a so-called panel construction method in which a heat-insulating wall is constructed around the outer circumference of the tank shell, and the tank is intended for low-temperature liquefied gases such as liquefied petroleum gas (liquefied petroleum gas) at -50°C or higher, and liquefied natural gas at -160°C. Focusing on the fact that there is no requirement that the joints of adjacent insulation materials must be treated with on-site foaming of urethane, etc. for heat insulation purposes, as in the case of cryogenic liquefied gases such as gases, the above-mentioned Since the joint treatment is performed by gluing tape to the outside of the joint, it is easy to work, economical, and requires only a small working space. Moreover, the advantage of the panel construction method is that unless the molded insulation material is fully bonded to the outside surface of the tank shell using adhesive, even if the molded insulation material is in contact with the outside surface of the tank shell, the molded insulation material and tank Focusing on the fact that a path is inevitably formed between the tank shell and the tank shell's outer surface through which gas can permeate and flow down, molded heat insulating material is applied to multiple locations on the tank shell's outer circumferential surface. It is fixed to the outer surface of the tank shell at multiple points using multiple tightening fixtures scattered throughout the entire molded insulation. By constructing the material from vinyl chloride foam, which has low moisture absorption, or by covering the back side of the molded heat insulating material with a vinyl chloride foam film, aluminum plate, elastomer, polymer film, etc., the desired reduction in heat insulation performance can be prevented. It is possible to form a high-quality heat-insulating wall that prevents gas leaking from the tank shell from entering the heat-insulating material while suppressing it as much as possible or ensuring the desired heat-insulating performance. There is no need to embed liquid or gas detection passages, etc., and the leakage gas from the tank shell can be detected by simply fixing the molded insulation material to the outer surface of the tank shell and treating the joints with tape. Regardless of the location of the leak, it is possible to form a passageway that quickly and reliably leads the leaked gas to the bottom of the tank with little risk of dissipation to the outside world. It is easy to detect leaked gas quickly and reliably at the leak detection unit, which is a leak detector, and as a result,
Even for IMCO type A and B tank shells, which can be constructed economically, a heat insulating wall can be efficiently installed around the outer periphery while meeting safety standards against gas leakage.
Moreover, it has become possible to construct it economically.

Hereinafter, embodiments of the method of the present invention will be described based on the drawings.

Mainly, a plurality of molded insulation materials 3 made of PVC foam are installed so that a heat insulation wall 2 is constructed around the outer periphery of the tank shell 1 of IMCO types A and B for storing liquefied petroleum gas at around -50℃. Molded insulation materials 3, 3 that are in contact with and adjacent to the outer surface of the tank shell 1
. . . are juxtaposed so that their edges are in close contact with each other, and each of the molded heat insulating materials 3 . Fix it to the tank shell 1 using a tool and attach the adjacent molded insulation materials 3, 3.
...The outside of the joint is sealed by adhesion using a low-elasticity adhesive such as tape 4 (aluminum glass cloth, etc.), and the heat insulating wall 2 is constructed.

Among the molded heat insulating materials 3..., the rectangular plate-shaped flat molded heat insulating material 3A... disposed on the flat portion of the tank shell 1 has an upper layer portion protruding outward from a lower layer portion on two sides of the rectangle. It has a multi-layered structure, with the lower layer protruding outward from the upper layer on the other two sides.
When these flat molded heat insulating materials 3A are arranged side by side along the outer surface of the tank shell 1, one side of the flat molded heat insulating materials 3A of the adjacent flat molded heat insulating materials 3A, 3A is placed on the outside. The upper layer portion that is formed to protrude toward the other flat molded heat insulating material 3
It is used in combination so as to overlap the lower layer portion formed on one side of A in a state of protruding outward.
Further, the corner molded heat insulating material 3B arranged at the corner portion of the tank shell 1 is the flat molded heat insulating material 3.
The lower layer portion is made to protrude more than the upper layer portion on two sides adjacent to A... and one side adjacent to another corner molded heat insulating material 3B, and the upper layer portion is made to protrude more than the lower layer portion on the remaining side. It is structured to allow

And the adjacent flat molded heat insulating materials 3A, 3
As mentioned above, the means for bringing the edge portions of A... into close contact with each other is as follows:
Means for vertically stacking the protruding upper layer portion of one flat molded heat insulating material 3A and the protruding lower layer portion of the other flat molded heat insulating material 3A, that is, adjacent flat molded heat insulating materials 3A. ,3A...
This is a means of overlapping the edge portions of the heat insulating wall 2 in the thickness direction without changing the wall thickness, and the same means is used when the edge portions of the adjacent corner molded heat insulating materials 3B, 3B... are brought into close contact with each other. It is.

The means for bringing the adjacent flat molded heat insulating material 3A and corner molded heat insulating material 3B into close contact is to
The end surfaces of the lower layer portions of B are brought into contact with each other, and a third heat insulating material 3C
This is a means for overlapping them so that their upper surfaces are flush with the upper surfaces of the flat molded heat insulating material 3A and the corner molded heat insulating material 3B.

The means for fixing the flat molded heat insulating material 3A to the tank shell 1 are stand bolts 5 scattered at multiple locations on the outer surface of the tank shell 1 and fixed to the outer surface by welding or the like, and stand bolts 5 made of plywood. Watsushia 6,
The fixing means is a tightening fixture using corrosion-resistant metal washers 7 and nuts 8, and the fixing means for fixing the corner molded heat insulating material 3B to the tank shell 1 are scattered at multiple locations on the outer surface of the tank shell 1. With a tightening fixture that tightens and fixes the edge part of the flat insulation material 3A together with the edge part of the flat molded heat insulating material 3A using a stud bolt 5, a corrosion-resistant metal washer 7, and a nut 8, which are fixed to the outer surface of the stud bolt 5 by welding or the like. It is a means. In the figure, 9 and 10 are a heat insulating material and a moisture-proof seal that close the stepped mounting hole 3a formed in the flat molded heat insulating material 3A, and 9' is a mounting hole 3a formed in the third heat insulating material 3C. This is a tape 4 that is adhered to the joint between the third heat insulating material 3C and the flat shaped heat insulating material 3A, and the joint between the third heat insulating material 3C and the corner shaped heat insulating material 3B. , 4 to prevent it from coming off.

Further, 11 is a partial secondary barrier, 12 is a leak hole formed in the bottom part of the heat insulation wall 2, and 13 and 14 are a suction detection element and a detector for detecting gas from the leak hole 12. It is.

As shown in FIG. 4, the molded heat insulating material 3 has a structure in which a splashing barrier B is formed on the back side of the heat insulating material body 3A' from aluminum, vinyl chloride foam, elastomer, polymer film, etc. It's okay if it's something.

[Brief explanation of the drawing]

The drawings show an embodiment of the tank heat insulation wall construction method according to the present invention, and FIG. 1 is a perspective view of the main part, FIG. 2 is an enlarged sectional view of the main part, FIG. 3 is a sectional view of the main part, and FIG. The figure is an enlarged vertical cross-sectional view of main parts showing another embodiment. 1... Tank shell, 2... Heat insulation wall, 3... Molded insulation material, 4... Tape.

Claims (1)

[Claims] 1. A method of constructing a heat-insulating wall 2 around the outer periphery of a tank shell 1 that is constructed within an external structure and accommodates liquefied petroleum gas or low-temperature liquefied gas in a temperature range close to it. A plurality of molded heat insulating materials 3...
are brought into contact with the outer surface of the tank shell 1, and the adjacent molded insulation materials 3, 3...are placed side by side in a state in which the edge portions are in close contact with each other, and each molded insulation material 3... is placed on the tank shell 1, respectively. is fixed to the tank shell 1 using a plurality of tightening fixtures scattered at multiple locations on the outer surface of the tank shell 1, and the outside of the joints of adjacent molded insulation materials 3, 3... is sealed by adhering tape 4. A method for constructing a tank heat-insulating wall, comprising: constructing a heat-insulating wall 2. 2. The means for bringing the edge portions of the adjacent molded heat insulating materials 3, 3... into close contact with each other is a means for overlapping the end portions of the adjacent molded heat insulating materials 3, 3 in the thickness direction within the wall thickness of the molded heat insulating materials. A tank heat insulation wall construction method according to claim 1.