JP2691726B2 - Double shell low temperature tank equipped with breather and breather used for the tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a double shell low temperature tank provided with a breather near a connecting edge between an outer tank side and a roof, and a breather used for the tank. Regarding

(Prior Art) In the double shell low temperature tank in the conventional example, the pressure fluctuation between the inner tank and the outer tank caused by the expansion and contraction of the inner tank due to the temperature change accompanying the putting in and out of the low temperature liquid stored in the inner tank. In order to absorb and maintain a constant pressure, it is usual to provide a breather, for example, as shown in Japanese Examined Patent Publication (Kokoku) No. 38-26542.

In the double shell low temperature tank in the conventional example, the breather is provided with an independent breather tank (21) separate from the double shell low temperature tank as shown in FIG. ), A pressure regulating mechanism with a diaphragm balloon (24) is formed, and a pipe is installed between the separate breather tank (21) and the double shell low temperature tank inner tank (23) and outer tank (22). Road (2
It was connected in 5).

(Problems to be Solved by the Invention) In the double-shell low-temperature tank in the conventional example, a breathing tank is separately provided outside and thus requires a vast land area, which is extremely higher than the stored low-temperature liquid amount. Since it requires equipment costs, there are problems in effective use of land and equipment and simplification of the breather.

In addition, there is a problem that a long pipe connecting the double shell low temperature tank and the breathing tank is required, and the repair and inspection of the pipeline must always be performed.

A breathing device in which an annular elastic bag is provided along the outer periphery of the low temperature tank and the bag has a breathing tank function is also considered, but there are inherent problems such as durability and economy. .

In order to solve the above problems, the present invention aims to provide a double shell low temperature tank provided with a breather near the connecting edge between the outer tank side and the roof of the double shell low temperature tank. It is formed into a sealed box shape with good airtightness and excellent durability, and the inside of this sealed box body is divided into lower parts by a partition film of a ring-shaped strip plate with a simple structure and excellent durability. Formed by
It is intended to provide a new breather.

(Means for Solving the Problem) A double-shell cryogenic tank provided with a breather of the present invention has an outer tank provided with a breather on the outer periphery of the upper portion, and a space for separation is provided between the outer tank and the outer tank. In a double-shell low-temperature tank consisting of an internal tank formed inside, a box-shaped sealed body formed by using a flat plate material into a ring-shaped sealed box having a rectangular cross section, and the inside of the box-shaped sealed body As it is divided into a compartment and a lower compartment,
A partition film of a ring-shaped band plate made of a rubber material whose slack is vertically movable and airtightly fixed at its periphery, an air vent pipe connected to the upper compartment, and a communication connecting the lower compartment and the space. The tube is provided to form a breather.

Further, the breather used in the double shell type cryogenic tank of the present invention is such that a purge pipe for introducing an inert gas is connected to the lower compartment of the breather.

(Function) Since the breather is formed into a box-shaped sealed body of a ring-shaped sealed box with a rectangular cross section using a flat plate material, the flat plate material such as a steel plate is processed and assembled by means such as welding and joining, and the rigidity is high. It is possible to form a box-shaped sealed body having excellent durability and airtightness.

In addition, the partition membrane that divides this box-shaped sealed body into upper and lower compartments is made of a ring-shaped strip made of rubber material, so it has a complicated structure such as a curved shape or a bag shape, and a special structure. It does not need to be formed on a rubber body with a unique shape or a large surface area, and has a simple flat membrane shape, a small flat area, a small stretchable area, a narrow deterioration range, etc. can do.

Also, since this partition film is provided inside the box-shaped sealed body,
It is protected from the ultraviolet rays of sunlight, the atmosphere and humidity, and has less aging and improved durability.

In addition, since the upper compartment communicates with the atmosphere through the air vent pipe, even if the cover plate is opened during use, there is no hindrance to pressure fluctuations. It is possible to perform an airtight test of the peripheral fixing portion and maintenance such as inspection and repair of the weight fixing portion. In this case, since the partition membrane has a planar membrane shape and the peripheral edge fixing portion is also in the horizontal direction of the peripheral wall, the above work can be easily performed only from the upper portion in the same direction.

Furthermore, the breather used in the double-shell cryogenic tank of the present invention was formed by connecting a purge pipe for introducing an inert gas to the lower compartment of the breather, so that it was connected to the lower compartment. The purge pipe can be used to exhaust air in the lower compartment and the inner / outer tank space, and to supply an inert gas into the lower compartment and the inner / outer tank space.

The double-shell cryogenic tank according to the present invention does not require a separate breathing tank, and can be effectively used by diverting the site area for that.

In addition, since long pipes are not required, repairs and inspections are easy.

(Example) An example will be described with reference to the drawings.

FIG. 1 is a cross-sectional explanatory view of an embodiment in which a breather (11) is provided on the shoulder portion of a double shell type low temperature tank equipped with an oil barrier (18).

In FIG. 1, the inner tank (13) is a flat-bottomed cylindrical closed tank made of steel plate, and an outer tank (12) made of steel plate is provided at a distance from the inner tank (13).

The inner tank (13) is just above the bottom cold insulation layer (17) of the outer tank (12).
Is in a mounted state.

A cooling layer (14) and a space (15) are formed over the entire area of the gap between the inner tank (13) and the outer tank (12).

In other words, the inner surface of the outer tank (12) is formed by providing a cold insulating layer (14) laminated with a heat insulating material, and between the cold insulating layer (14) and the outer surface of the inner tank (13). Form in space (15).

The corridor (16) is composed of a floor plate formed into a ring-shaped flat plate and a handrail framed by standing vertically upward from the outer peripheral edge of the floor plate.
The inner peripheral edge of the ring-shaped flat plate is fixed to the outer tank (12) near the upper edge thereof.

The oil proof (18) is formed by providing a site area commensurate with the amount of stored low temperature liquid.

The breather (11) is formed at the connecting edge between the side of the outer tub (12) and the roof, so-called tank shoulder. Form it just inside the corridor (16).

FIG. 2 shows an embodiment in which a breather is provided on the shoulder of a double-shell cryogenic tank provided with a liquid-proof basin made of prestressed concrete.

In FIG. 2, the inner tank (13) is the same as in the first embodiment, and is a flat bottom cylindrical steel plate closed tank.

The liquid-proof basin (19) serving as an outer tank is formed of prestressed concrete in the shape of a flat-bottomed cylindrical container, and the height of the container side is formed to be substantially the same as the side height of the inner tank (13). Liquid proof (19)
A seal metal (20) made of a steel plate is provided on the entire inner peripheral surface of the side, and the upper edge of the seal metal (20) and the roof part made of the steel plate are connected to each other to form a hermetic seal. A bottom cold insulation layer (17) is formed on the inner bottom surface of the liquid-proof basin (19), and a seal metal (20) is formed.
A heat insulation layer (14) formed by laminating heat insulating materials is formed on the inner wall surface of the roof. Further, a space (15) is provided in the entire area including the roof portion between the cold insulation layer (14) and the inner tank (13).

The corridor (16) is formed by using the upper end surface of the liquid-proof basin (19) as it is and setting a handrail on the outer peripheral edge.

The breather (11) is formed on the upper end surface of the liquid-proof basin (19) so as to be placed thereon, and the communication pipe (9) is provided so as to communicate with the space (15), and the purge pipe (8) and the air vent are removed. The pipe (10) is provided so as to project to the outside.

As shown in FIG. 3, the breather (11) has a curved inner peripheral wall (1) formed with the same curvature as the outer peripheral wall of the outer tank.
A bottom wall (4) formed into a fan-shaped flat plate having the same width over the circumferential direction, and a cover plate (5) having the same shape as the bottom wall (4),
The inner peripheral wall (1) is formed by connecting the outer peripheral edges of the bottom wall (4) and the cover plate (5).
With the outer peripheral wall (2) having the same shape as the above, a box-shaped sealed body of a ring-shaped sealed box having a rectangular section is formed using a flat plate material. The side edge of the inner peripheral wall (1) of this box-shaped sealed body is fixed to the outer tank (12). In this case, the inner peripheral wall (1) may be formed by using a part of the side plate of the outer tank.

The inside of the breather (11) of the box-shaped sealed body is slightly above the middle, and is divided into an upper compartment and a lower compartment by a partition film (6) of a ring-shaped strip made of a rubber-based material. The membrane (6) is movable up and down, that is, a large slack is provided so that the central portion can move up and down, the periphery is hermetically fixed, and a bar-shaped rod is integrally formed on the upper or lower center of the partition membrane (6) as a weight. Fix the weight (7).

An air vent pipe (10) is connected to the divided upper compartment to open it to the atmosphere, and a purge pipe (8) for introducing an inert gas is connected to the divided lower compartment. A communication pipe (9) that connects the inner and outer tank spaces is connected.

The purge pipe (8) is projected outside the outer peripheral wall (2),
The communication pipe (9) penetrates the cold insulation layer (14) and communicates with the space (15).

The space (15) is purged with an inert nitrogen gas (8)
Through and eliminate internal air. The pressure in the space (15) is maintained at a set pressure indicated by the sum of the atmospheric pressure and the pressure due to the weight of the partition membrane (6) moving vertically and the weight (7).

The ring-shaped box-shaped sealed body having a rectangular cross section is provided with side walls (3) which vertically extend at predetermined intervals in the inner circumferential direction, and the side walls (3) have a plurality of predetermined circumferential lengths. It may be formed into a box-shaped sealed body. The breather (11) formed of a plurality of box-shaped sealing bodies pre-forms a box-shaped sealing body unit curved in an arc shape, and connects the plurality of sealing body units to the outer tank (12) near the upper edge thereof. It may be fixed and formed.

As described above, in the case of the breathing device formed by connecting and fixing a plurality of box-shaped sealed body units, since the plurality of box-shaped sealed body units are individually independent, the tank and the breathing device are in use. Even if there is, the pipe connection of the box-shaped sealed unit to be maintained is disconnected from the tank and other box-shaped sealed units, and the tank and other box-shaped sealed units are not affected and are independently It is possible to continue the repair and replacement individually. Therefore, it is possible to provide a breathing apparatus that can perform maintenance efficiently and economically without stopping the use of the tank and the breathing apparatus.

The double-shell cryogenic tank according to the present invention does not require a separate breathing tank, and can be effectively used by diverting the site area for that. In addition, since long pipes are not required, repairs and inspections are easy.

In addition, the double-shell low-temperature tank equipped with prestressed concrete liquid-proof basin further eliminates the need for a vast site, and it is possible to solve today's problems that enable effective use of land.

(Problem of the invention) In the double-shell low-temperature tank provided with the breather of the present invention, the breather is formed into a box-shaped sealed body of a ring-shaped sealed box having a rectangular cross section using a flat plate material, so that a steel plate or the like is used. Since the flat plate material is processed and can be easily and easily assembled by means such as welding and joining, the breather of the box-shaped sealed body has high rigidity, durability, airtightness, and economy. Can be obtained.

In addition, the partition membrane that divides this box-shaped sealed body into upper and lower compartments is formed by a ring-shaped strip made of rubber material, so it has a complicated structure such as a curved shape or a special shape. , It is not necessary to form the whole into a shape with a large surface area such as a bag, it has a simple flat film shape and a small flat area,
Since the stretchable part is small and the range of deterioration is narrow, the breather can be provided with a partition film having excellent durability and economical efficiency.

Also, since this partition film is provided inside the box-shaped sealed body,
Since it has good shielding properties from the ultraviolet rays of sunlight, the atmosphere and humidity, it is a partition film with little aging of the rubber material, a long service life, and excellent economical efficiency.

In addition, since the upper compartment communicates with the atmosphere through the air vent pipe, even if the cover plate is opened during use, there is no hindrance to pressure fluctuations. The airtightness test of the peripheral fixed portion and the maintenance work such as inspection and repair of the weight fixed portion can be appropriately performed. Further, in this case, since the partition membrane has a planar membrane shape and the peripheral edge fixing portion is also in the horizontal direction of the peripheral wall, it is possible to perform the maintenance work only from the upper portion in the same direction without extending over the lower portion or the back surface. In addition, it can be performed efficiently.

Furthermore, the breather used in the double-shell cryogenic tank of the present invention was formed by connecting a purge pipe for introducing an inert gas to the lower compartment of the breather, so that it was connected to the lower compartment. The purge pipe can be used to exhaust air in the lower compartment and the inner / outer tank space, and to supply an inert gas into the lower compartment and the inner / outer tank space.

Therefore, before starting the storage of the low temperature liquid in the tank, it can be used for the operation of discharging the air in the tank inner / outer tank space and supplying the inert gas by using the purge pipe, that is, the gas purging operation in the space.

In addition, while the tank is in use, it is possible to replenish the space with an inert gas using a purge pipe and maintain the space at a predetermined inert gas pressure higher than atmospheric pressure, thus keeping the space and the space cool. The layer can prevent the cold insulation performance of the cold insulation layer from deteriorating due to freezing of water in the atmosphere, and even if the stored gas inside leaks into the space, there is no oxygen in the atmosphere. It is possible to provide a double-shell low-temperature tank that is more safe and has no fear of gas explosion due to leak gas.

[Brief description of the drawings]

1 is a cross-sectional explanatory view of a double-shell low-temperature tank equipped with a breather, FIG. 2 is a cross-sectional explanatory view of a double-shell low-temperature tank equipped with a liquid-proof basin equipped with a breather, and FIG. 3 is Explanatory drawing which made a part of breather the cross section, FIG. 4 is sectional explanatory drawing of the double shell low temperature tank which shows one of the prior art examples. 1 ... Inner peripheral wall, 2 ... Outer peripheral wall, 3 Side wall, 4 ... Bottom wall, 5 ... Cover plate, 6 ... Partition film, 7 ... Weight, 8 ... Purge pipe, 9 ... Communication pipe, 10 ... … Air vent pipe 11 …… Breathing device, 12 …… Outer tank 13 …… Inner tank, 14 …… Cooling layer 15 …… Space, 16 …… Walkway 17 …… Bottom cooling layer, 18 …… Oil barrier 19 …… Liquid barrier, 20 …… Seal metal 21 …… Breathing tank, 22 …… Outer tank 23 …… Inner tank, 24 …… Diaphragm balloon 25 …… Pipeline

Claims (2)

(57) [Claims] 1. A double-shell low-temperature tank comprising an outer tank having a breather on the outer periphery of the upper part thereof, and an inner tank formed inside with a space provided between the outer tank and the outer tank. A box-shaped sealed body formed in a ring-shaped sealed box shape having a rectangular cross-section using, and a slack that is vertically movable so that the inside of the box-shaped sealed body is divided into an upper compartment and a lower compartment. A partition film of a ring-shaped strip made of a rubber-based material that is horizontally fixed airtightly,
A double shell low temperature tank equipped with a breather, characterized in that an air vent pipe connected to the upper compartment and a communication pipe communicating the lower compartment with the space are provided to form a breather. 2. A breather for use in a double-shell cryogenic tank according to claim 1, wherein a purge pipe for introducing an inert gas is connected to a lower compartment of the breather.