JPH0413502Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a storage tank for low-temperature fluids, etc., especially on the side walls of the inner and outer shells (tanks) of a double-shell tank installed on the ground.
This invention relates to a heat insulating structure provided between the two manholes in a low-temperature storage tank each equipped with a manhole that allows people to enter and exit.

[Prior art and its problems]

In a low-temperature storage tank that uses a metal double shell and has a manhole in the side wall of the inner and outer shells that allows entry and exit for inspection, the side walls of the inner and outer tanks (shells) forming the double shell are It is conventionally known to provide a heat insulating structure to the intermediate portion.

The most commonly used technology for the above-mentioned thermal insulation structure is to attach a fibrous insulation material such as glass wool to the middle part of the inner and outer tanks (shells) that make up the double shell, especially to the wall surface of the shell on the inner tank side. The idea was to fill the outside of the manhole with a powder insulation material such as perlite powder, but when creating a heat insulation structure for the manhole part, the only method that has been implemented is to simply attach a fibrous insulation material such as glass wool. Ta.

However, in the case of an insulating structure using only glass wool as in the conventional technology mentioned above, the insulating effect is difficult to achieve due to the large convection in the low temperature range, and as a result, frost etc. adhere to the outer surface of the tank. It was pointed out that it had some drawbacks.

[Purpose of invention]

The present invention attempts to address the above-mentioned problems, and is designed to accurately insulate the manhole portion formed in a double-shell tank, especially the intermediate portion between the inner tank manhole and the outer tank manhole. The purpose is to provide an insulating structure for low-temperature tanks.

In addition, another object of the present invention is the flow of cryogenic fluid (filling and taking out cryogenic fluid from a tank).
If the powder insulation material filled in the middle part of the two manholes formed in the inner and outer shells settles due to the repeated expansion and contraction of the tank due to the tank, and a gap is created at the upper end, It is an object of the present invention to provide a heat insulating structure for a low-temperature tank that can be automatically filled with a powder heat insulating material.

[Means for solving problems]

The present invention comprises an inner tank 1 and an outer tank 2 made of metal shells, and has lids for opening and closing on the side walls of the inner tank 1 and outer tank 2, and also for inspection. In a low-temperature storage tank formed with manholes 3 and 4 that allow entry and exit, the peripheral wall 41 of the manhole 4 formed in the outer tank 2 extends from the outer tank 2 toward the side wall of the inner tank 1, and The tip of the manhole 4 is configured so that the tip thereof is located slightly in front of the side wall 11 of the inner tank 1, and the peripheral wall 4 of the manhole 4
1 and the side wall of the outer tank 2, a manhole 4 is connected to the filler inflow guide cylinder 9 equipped with an opening/closing valve in the middle, and is further formed in the side wall of the outer tank 2.
A molded heat insulating material 6 for closure made of hard foamed synthetic resin or the like is integrally attached to the inside of the lid 42 provided on the opening surface of the tank, thereby configuring the heat insulating structure of the low temperature tank.

〔Example〕

An example of implementing the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a low-temperature tank according to the present invention, FIG. 2 is an enlarged cross-sectional view of a main part, and FIG. 3 is a cross-sectional view of a portion indicated by line aa in FIG. 2.

The low-temperature tank generally indicated by A is composed of an inner tank 1 and an outer tank 2 made of metal shells, and the side walls 11 and 2 of the inner tank 1 and the outer tank 2 are
Manholes 3 and 4 for entry and exit for inspection, etc. are integrally formed at appropriate positions on the wall 1, respectively.

In addition, the manholes 3 and 4 described above are connected to the side walls 11 of the inner tank 1 and outer tank 2 that constitute the respective shells.
Alternatively, it can be formed by directly drilling an opening in the wall surface of 21, but in order to make access convenient, a cylindrical body tilted laterally is attached to each of the side walls 11 and 21. It is preferable that the cover plates 32 and 42 for opening and closing operations are attached to the neck portions 31 and 41 of the cylindrical body so as to be openable and closable.

Reference numeral 5 denotes a heat insulating material made of a fibrous heat insulating material such as glass wool, which is installed so as to cover the outer circumferential surface of the side wall 11 constituting the inner tank 1 from the front surface to the neck portion 31 at the tip of the manhole 3.
It is attached to the inside of a manhole cover plate 42 formed in the outer tank 2.

Reference numeral 6 denotes a closing molded heat insulating material attached to the manhole 4 of the outer tank 2 so as to close the opening surface thereof, and is fixedly attached at a position in contact with the heat insulating material 5 attached to the inside of the cover plate 42.

The molded insulation material 6 for closure described above is formed using a hard foamed synthetic resin such as polyurethane foam, and the peripheral edge of the molded insulation material 6 for closure is formed to a size that matches the inner peripheral surface of the manhole 4. An adhesive is applied to the manhole 4, and the coated surface is brought into contact with the inner circumferential surface of the manhole 4 to be adhesively fixed.

In addition, the upper end of the above-mentioned molded insulation material 6 for closure,
That is, in order not to obstruct the inflow of the powder filler, the part of the powder filler adjacent to the inflow control valve 7 may be cut out a little, or
Alternatively, in order to facilitate the inflow, it is desirable that the upper end be rounded off at an angle that is greater than the angle of repose of the pearlite powder.

However, it is not essential for the present invention to configure the molded insulation material 6 for occlusion as described above. If the molded insulation material 6 for occlusion is provided at a slightly inner position than the position exemplified in FIG.
can also be shaped so as to close the entire opening surface of the manhole 4.

In addition, the above-mentioned molded insulation material 6 for closure is not used as a single plate, but is made by piecing together two disk-shaped plates cut into two vertically, as illustrated in FIG. 3, or two pieces cut into two pieces horizontally. If a piece is used as a two-piece joint, inspection work can be easily carried out by drilling a hole in one piece of the two-piece piece and cutting it out.

Reference numeral 8 denotes a powder filler filled between the fibrous heat insulating material 5 and the outer tank 2, and uses pearlite powder having relatively small particles.

9 is a guide cylinder for naturally filling the manhole 4 of the outer tank 2 with the powder and granular filler 8 filled in the outer tank 2 when the powder and granular filler 8 in the manhole 4 is insufficient; One end is connected to the side wall 21 of the outer tank 2, and the other end is connected to an inflow regulating valve 7 for powdery filler formed at the upper end of the manhole 4 of the outer tank 2.

The above-mentioned inflow control valve 7 is normally kept fully open, so that when the granular filler 8 in the manhole 4 is insufficient, the granular filler 8 can be automatically flow-filled.

The shape of the guide tube 9 is preferably an inverted conical shape with a downward taper so that the powdery filler 8 can easily flow down. It is preferable to set it to about 2 inches.

Peripheral wall 43 of manhole 4 formed in outer tank 2
A fibrous heat insulating material 51 is attached to the inner upper surface of the housing.

This is to prevent the deterioration of the heat insulating effect due to the fact that when the manhole 4 is filled with powdery filler 8, pearlite particles are difficult to fill up to the top of the peripheral wall 41 due to their angle of repose. It is something.

The fibrous heat insulating material 51 is preferably made of compressed glass wool fibers, and it is desirable that the fibrous heat insulating material 51 should be installed so as to cover about the upper half of the inside of the manhole 4.

[Effect of idea]

The effects of the present invention configured as described above are as follows.

(1) A heat insulating structure is formed in the middle between the inner tank 1 and the outer tank 2 that constitute the double shell tank, and a fibrous heat insulating material 5 is attached to the side wall surface of the inner tank 1.
Since the surface side of this heat insulating material 5 (the side of the outer tank 2) is filled with a granular filler 8 made of perlite powder, a double heat insulating material is provided between the inner tanks 1 and 2. It has the characteristic of being completely filled and exhibiting an effective heat insulating effect.

(2) Since it has a two-layer structure in which the surface of the fibrous heat insulating material 5 made of glass wool is filled with powdery filler 8, convection in low temperature ranges is reduced, preventing frost from adhering to the outer surface of the tank. is absolute.

(3) Since the guide tube 9 equipped with the inflow control valve 7 is provided between the side wall 21 of the outer tank 2 and the manhole 4, the inner tank 1 can be prevented from shrinking due to tank operation (inflow or outflow of low-temperature fluid). Manhole 4
Sedimentation of the powdery filler 8 inside the manhole 4 occurs, or due to natural settling of the powdery filler 8, etc.
When a void is created inside the manhole 4 and the pressure decreases, the powdery filler 8 filled inside the side wall 21 located above the manhole 4 moves into the guide tube 9 and inside the manhole 4 where the pressure has decreased. Since it is automatically guided and filled through the inflow control valve 7, it is now possible to stably maintain the heat insulation effect of the portion of the manhole 4 where the drop in heat insulation effect is most feared.

Further, an inflow control valve 7 is provided at the lower end of the guide tube 9.
Since this is provided, when an inspection is performed, by closing this inflow control valve 7, the flow of the powdery filler 8 is completely stopped, which has the advantage that internal inspection work can be carried out with peace of mind.

(4) At the opening of the manhole 4 formed in the outer tank 2,
Since the molded heat insulating material 6 is installed to close this opening surface, even if the lid 42 is opened, the manhole 4
It was possible to prevent the powdery filler 8 inside from overflowing and ensure the safety of subsequent work.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional side view of a cryogenic tank showing the mounting position of the manhole, Fig. 2 is an enlarged sectional view of the main part, and Fig. 3 is a of Fig. 2. It is a sectional view along the -a line. A...Low temperature tank, 1...Inner tank, 2...Outer tank,
11, 21... Side wall, 3, 4... Manhole, 3
1, 41...Neck part, 32, 42...Lid, 43
... Peripheral wall, 5 ... Heat insulating material, 6 ... Molded heat insulating material for closure, 7 ... Inflow control valve, 8 ... Powder-like filler, 9 ... Inflow guide cylinder.

Claims (1)

[Scope of utility model registration request] The inner tank 1 and the outer tank 2 are constructed of metal shell bodies, and the side walls 11 and 21 of the inner tank 1 and the outer tank 2 described above are
A peripheral wall 41 of a manhole 4 formed in a side wall 21 of an outer tank 2 in a low-temperature storage tank having a lid for opening and closing and manholes 3 and 4 formed therein for inspection. extends from the outer tank 2 toward the side wall of the inner tank 1, and the peripheral wall 4
The tip of the manhole 4 is located slightly in front of the side wall 11 of the inner tank 1, and
A manhole 4 formed in the side wall 21 of the outer tank 2 is connected with a filler inflow guide cylinder 9 equipped with an opening/closing valve in the middle part so as to extend between the peripheral wall 41 of the outer tank 2 and the side wall 21 of the outer tank 2. The insulation structure of the low-temperature tank is formed by integrally mounting a molded insulation material 6 for closure made of hard foam synthetic resin or the like on the inside of a lid 42 applied to the opening surface.