JP4332932B2 - Low temperature tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a low-temperature tank having a double-shell structure comprising an inner tank for storing liquefied gas and the like and an outer tank surrounding the inner tank. The present invention relates to a low temperature tank that can tolerate heat shrinkage.
[0002]
[Prior art]
The low temperature tank for storing liquefied gas has a double shell structure consisting of an inner tank and an outer tank. The inner tank causes thermal contraction because it is in direct contact with low-temperature liquefied gas. Therefore, in order to fix the inner tank to the tank foundation, an anchor strap that allows thermal contraction in the radial direction of the inner tank and prevents the side plate from being lifted by the internal pressure of the inner tank has been used. On the other hand, anchor bolts were used to fix the outer tank to the tank foundation.
[0003]
In the low temperature tank with the above configuration, if the liquefied gas leaks from the inner tank, the outer tank may be rapidly cooled and damaged by low temperature embrittlement. There was a breakwater.
[0004]
However, the low-temperature tank as described above has a problem that the area occupied by the liquid barrier is large, and in recent years, a low-temperature tank having a new structure in which the outer tank is also used as the liquid barrier has been developed.
[0005]
As shown in FIG. 8, this low temperature tank is provided with a cold insulating material 59 such as pearlite concrete on an outer tank bottom plate 53 of an outer tank 52 provided on a tank foundation 51, and an inner tank 54 provided thereon. ing.
[0006]
The outer tank side plate 55 is provided with an anchor strap 56 whose lower end is fixed in the tank foundation 51. The inner tank side plate 57 is provided with an anchor strap 58 whose lower end penetrates the outer tank bottom plate 53 and is fixed in the tank foundation 51.
[0007]
As described above, both the outer tub 52 and the inner tub 54 are fixed by the anchor straps 56 and 58, respectively, so that both the outer tub 52 and the inner tub 54 are allowed to thermally shrink in the radial direction, and the side plate is lifted. Is a structure to prevent
[0008]
Accordingly, even if liquefied gas leaks from the inner tank 54, the outer tank 52 is not damaged, and can serve as a liquid barrier.
[0009]
[Problems to be solved by the invention]
However, since the anchor strap 58 is provided through the outer tank bottom plate 53 in the above-described low temperature tank, when the liquefied gas leaks from the inner tank 54, the outer tank bottom plate 53 undergoes thermal contraction and penetrates. Since the hole 61 moves radially inward and causes relative displacement with the hole 62 of the tank foundation 51, there is a problem that the anchor strap 58 is broken or the through hole 61 is deformed or broken.
[0010]
Therefore, the present invention has been devised to solve the above-described problem, and an object of the present invention is to provide a low-temperature tank that can prevent the anchor strap and the outer tank bottom plate from being broken during the thermal contraction of the outer tank. .
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a ring body that surrounds an inner tank bottom plate in a circumferential direction on an outer tank bottom plate in a double-shell structure low-temperature tank comprising an inner tank and an outer tank surrounding the inner tank. The ring body and the inner tank side plate are connected by an anchor strap, and a locking member for locking the ring body from above is provided on the inner peripheral surface of the outer tank side plate.
[0012]
According to the above configuration, the anchor strap is connected to the ring body provided on the outer tank bottom plate and locked to the locking member provided on the outer tank side plate, so that the anchor strap can penetrate the outer tank bottom plate. Even if the outer tub undergoes heat shrinkage, the anchor strap does not break. Moreover, even if stress in the lifting direction by the inner tank side plate is applied to the ring body via the anchor strap, the ring body is restricted from moving upward by the locking member, so that the inner tank side plate can be prevented from lifting. . Further, since the outer tank bottom plate does not have a conventional through-hole, it can be prevented from being deformed or broken.
[0013]
And it is preferable that the ring body is formed by integrally connecting a plurality of box bodies.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0015]
FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a cryogenic tank according to the present invention, FIG. 2 is a plan view showing a ring body, FIG. 3 is a front view showing an anchor strap attached state, and FIG. FIG. 5 is a side view showing the anchor strap attached state, FIG. 6 is a sectional view showing the anchor strap lower end attached state, and FIG. 7 is a sectional view showing the entire cryogenic tank. It is.
[0016]
First, the overall configuration of the low temperature tank will be described with reference to FIG.
[0017]
As illustrated, the low temperature tank 1 is constructed on a tank foundation 2 made of reinforced concrete. A disk-shaped outer tank bottom plate 3 is laid on the tank foundation 2, and an outer tank side plate 4 and an outer tank roof plate 5 are provided on the upper portion thereof to constitute an outer tank 6. The outer tank bottom plate 3 and the outer tank side plate 4 are each formed using a low temperature material having a low embrittlement transition temperature, and the outer tank roof plate 56 is formed using a normal temperature material that is a normal iron plate. Has been.
[0018]
On the outer tank bottom plate 3, a cold insulating material 7 such as pearlite concrete is provided in a columnar shape. A disc-shaped inner tank bottom plate 8 is laid on the cold insulating material 7, and an inner tank side plate 9 and an inner tank roof plate 10 are provided on the upper portion thereof to constitute an inner tank 11. Each part of the inner tank 11 is formed using a low temperature material having a low embrittlement transition temperature.
[0019]
That is, the outer tub 6 is formed so as to surround the inner tub 11.
[0020]
By the way, as shown in FIG. 1, the present invention provides a ring body 12 on the outer tank bottom plate 3 and connects the ring body 12 and the inner tank side plate 9 with an anchor strap 14. A locking member 15 for locking the ring body 12 from above is provided on the peripheral surface.
[0021]
As shown in FIG. 2, the ring body 12 integrally connects a plurality of box bodies 16 so as to surround the inner tank bottom plate 3 and the cold insulating material 7 in the circumferential direction. The box body 16 is formed by assembling a linear frame 17 made of a low-temperature material into a quadrangular prism shape, and a brace material 18 is provided in a truss shape on each surface and reinforced. Further, the box body 16 has a frame 17a radially inward when viewed in the plane direction, and has a trapezoidal shape.
[0022]
That is, the frames 17b constituting the oblique sides on both sides in the circumferential direction are arranged so as to be slightly inclined by being arranged so as to be aligned with the frames 17b of the adjacent box bodies 16. As a result, a polygonal ring body 12 having a suitable curvature in the entire box 16 is formed around the inner tank bottom plate 8.
[0023]
The adjacent box bodies 16 are fixed by welding.
[0024]
As shown in FIG. 1, a flexible plate-like anchor strap 14 is stretched between the inner tank side plate 9 and the ring body 12. The anchor straps 14 are provided on the outer peripheral surface of the inner tank side plate 9 at a pitch of about 1 m along the circumferential direction.
[0025]
The anchor strap 14 has a lower end fixed to the radially inner frame 17 a of the ring body 12 by welding or pin joining, and an upper end fixed to the inner tank side plate 9.
[0026]
The fixing structure of the anchor strap 14 to the inner tank side plate 9 is as shown in FIGS.
[0027]
As shown in the drawing, a plate 21 is attached to the upper end portion of the strap 19 constituting the anchor strap 14, and protrudes in the thickness direction.
[0028]
On the other hand, a locking plate 22 is attached to the inner tank side plate 9 to lock the strap 19 by locking the protruding plate 21. Two abutment plates 23 for attaching the locking plates 22 are attached to the inner tank side plate 9, and brackets 24 for spanning and attaching the locking plates 22 are fixed to the abutment plates 23, respectively. .
[0029]
The locking plate 22 is provided away from the inner tank side plate 9 by the thickness of the plate 21. Further, the locking plate 22 is inclined so as to gradually move away from the inner tank side plate 9 as it goes down along the anchor strap 14 to be attached.
[0030]
In addition, when adding the strap 19, the backing plate 25 is applied and butt welding is performed.
[0031]
An anchor strap 14 is stretched over the outer tank side plate 4 and the tank foundation 2 on the outer peripheral side thereof. As shown in FIG. 6, the lower end of the anchor strap 14 is fixed to the bottom of an anchor strap box 26 embedded in the tank foundation 2 by welding.
[0032]
The locking member 15 is made of L-shaped steel and is curved along the inner peripheral surface of the outer tank side plate 4. The locking member 15 is appropriately divided into lengths and fixed to the inner peripheral surface of the outer tank side plate 4 by welding.
[0033]
The radially inner end of the locking member 15 extends to the inside of the radially outer frame 17 c of the box body 16. The locking member 15 is not limited to L-shaped steel. For example, a square pipe or H-shaped steel may be used as long as it has a predetermined strength or more.
[0034]
Next, the operation of the low temperature tank 1 according to the present invention will be described.
[0035]
When liquefied gas is stored in the inner tank 11, the inner tank 11 slightly heat shrinks radially inward. At this time, since the inner tub 11 is fixed by the anchor strap 14, the movement in the radial direction can be allowed.
[0036]
The internal pressure of the liquefied gas in the inner tank 11 is increased by the vaporization of the liquefied gas, and a stress in the lifting direction is applied to the ring body 12 from the inner tank side plate 4 via the anchor strap 14. It can be countered by the rigidity of the.
[0037]
Further, in the case of an earthquake or the like, even if a pulling force larger than the above stress is applied to the low temperature tank 1, the ring body 12 is locked from above by the locking member 15, so that the ring body 12 moves upward. Is prevented, and the floating of the inner tank side plate 9 can be prevented. After the pulling force is transmitted to the locking member 15, the pulling force is transmitted to the tank foundation 2 through the outer tank side plate 4 and the anchor strap 14 of the outer tank 6, and counters here. Similarly, the pulling force applied to the outer tank side plate 4 is transmitted to the tank foundation 2 via the anchor strap 14 of the outer tank 6 and counters here.
[0038]
Moreover, according to the said structure, since the anchor strap 14 attached to the inner tank side plate 4 was fixed to the ring body 12 provided on the outer tank bottom board 3, it became unnecessary to fix to the tank foundation 2, and conventionally Thus, it is not necessary to make a through hole in the outer tank bottom plate 3.
[0039]
Therefore, even if the liquefied gas leaks from the inner tank 11 and the outer tank 6 undergoes thermal contraction, the anchor strap 14 is not affected by the relative displacement between the outer tank bottom plate 3 and the tank foundation 2. It will not break. Further, since the outer tank bottom plate 3 does not have a conventionally formed through hole, the heat shrinkage stress is not locally applied, and deformation / breakage of the outer tank bottom plate 3 can be prevented.
[0040]
Even if the outer tub 6 undergoes thermal shrinkage, the ring body 12 is formed of a low-temperature material, so that the same heat shrinkage as that of the outer tub 6 occurs, and the outer tub 6 and the ring body 12 collide. There is nothing.
[0041]
By forming the ring body 12 by integrally connecting the plurality of box bodies 16, it is possible to improve transportation and assembly efficiency when the ring body 12 is formed. In addition, since a curved member is not used for the box 16, manufacturing costs and labor can be omitted.
[0042]
Furthermore, since the locking member 15 is also divided, it is possible to improve transportation and assembly efficiency.
[0043]
In addition, in the said embodiment, although the ring body 12 is comprised with the box 16, if it has intensity | strength more than predetermined, it will not be restricted to this.
[0044]
【The invention's effect】
In short, according to the present invention, the excellent effect of preventing breakage of the anchor strap and the outer tank bottom plate during the thermal contraction of the outer tank is exhibited.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing a first embodiment of a cryogenic tank according to the present invention.
2 is a plan view showing the rigid member of FIG. 1. FIG.
FIG. 3 is a front view showing an anchor strap attached state.
FIG. 4 is a plan view showing an anchor strap attached state.
FIG. 5 is a side view showing an attached state of the anchor strap.
FIG. 6 is a cross-sectional view showing an attached state of the lower end of the anchor strap.
FIG. 7 is a cross-sectional view showing the entire low-temperature tank.
FIG. 8 is a cross-sectional view showing a main part of a conventional cryogenic tank.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Low temperature tank 3 Outer tank bottom plate 6 Outer tank 9 Inner tank side plate 11 Inner tank 12 Ring body 14 Anchor strap 15 Locking member 16 Box

Claims (2)

In a low-temperature tank having a double shell structure comprising an inner tank and an outer tank surrounding the inner tank, a ring body is provided on the outer tank bottom plate to surround the inner tank bottom plate in the circumferential direction, and the ring body and the inner tank side plate And a locking member for locking the ring body from above on the inner peripheral surface of the outer tank side plate. The low temperature tank according to claim 1, wherein the ring body is formed by integrally connecting a plurality of boxes.

Images