JPS5836959Y2 - Anchor strap for cryogenic liquid tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an anchor strap for fixing the inner tank of a metal double shell type cryogenic liquid tank to a concrete slab of the foundation.

Among the currently used cryogenic liquid tanks for LNG, LPG, etc., the metal double shell type has an inner tank 1, an outer tank 2, and a space between the inner and outer tanks, as shown in the cross-sectional view of Figure 1. Insulation material 3,
The bottom insulation material 4 and the like are placed on the concrete slab 5, the upper end of the anchor strap 7 is welded to the patch plate 6 welded to the outer periphery of the side plate 1α of the inner tank 1, and the lower end is engaged with the concrete slab 5. As a result, the inner tank 1 is held and fixed to the concrete slab 5, and due to this structure, (1) the inner tank 1 swells due to the internal pressure generated when a part of the liquid content evaporates, and the center of the bottom plate The anchor strap prevents the surrounding area from being pushed up due to the inability to move downwards, which prevents abnormal stress from occurring at the joint between the bottom plate and the side plate. .

(2) In the event of an earthquake, the anchor strap acts as a member to prevent overturning against the overturning moment caused by the horizontal force acting on the inner tank 1.

The anchor strap 7 of the conventional structure is as shown in the side view of FIG. 2, which is an enlarged view of the inside of the circle in FIG. 1, and the front view of FIG. It is welded to the backing plate 6.

The inner tank 1 is heated by the side plate 1α due to temperature changes caused by cool-down, warm-up, and the addition and removal of liquid during use.
moves in the radial direction.

For example, in a 60,000 Kl class LNG tank, the side plate 1α moves about 50 mm in the radial direction due to cooldown, so the welded peripheral edge of the upper end of the anchor strap 7 welded to the outer periphery of the side plate 1α In addition to the above-mentioned tensile stress for restraint, there is stress concentration in the vicinity, such as bending stress, and the repeated stress that causes the bending direction to change. Due to the material's tendency to be brittle at low temperatures due to its close contact with the inner tank 1 that houses it, cracks are likely to occur, and in the worst case, there is a concern that the same portion may progress to breakage.

In the present invention, in order to prevent the above-mentioned drawbacks, a hole whose upper side is a horizontal line is provided at the upper end of the anchor strap, and the hole engages with a hook fixed to the outer periphery of the side plate of the inner tank. The horizontal part of the upper side is brought into contact with the bottom of the recess of the hook so that the angle of the anchor strap is free with respect to the side plate, thereby preventing bending stress from occurring at the upper end of the anchor strap and preventing damage to the same part. Eliminating concerns about I-
Ta.

The details of the invention will be explained below by way of example and with reference to the drawings.

4 and 5 are a side view and a front view, respectively, of the anchor strap 7 according to the present invention in a state in which it is attached.

A hole 8 is provided at the upper end of the anchor strap 7, and the upper side 8α is a horizontal line. The upper side 8 is engaged with the bottom surface 9a of the recess of the hook 9.
The anchor strap 7 has a structure in which the horizontal portion of α contacts freely in rotation, and the angle of the anchor strap 7 with respect to the side plate 1α is free.

When locking the inner tank 1 with the anchor strap 7 of the present invention, the inner tank 1 swells due to internal pressure caused by vaporization of a part of the liquid contained in the inner tank, as well as temperature rise due to cool-down, warm-up, putting in and out of liquid, etc. Even if the side plate 1α of the inner tank 1 moves in the radial direction due to the change, no bending stress is added to the vicinity of the upper end of the anchor strap 7, which prevents cracks caused by abnormal stress seen in the periphery of the same in the prior art. There is no fear of occurrence or damage, and it is safe.

In this way, we were able to change the complicated stress concentration to a simple structure with only tensile stress without any special expense, and eliminate the root cause of failure accidents.

The structure of the present invention can also be applied to locations where the lower end of the anchor strap is fastened to a concrete slab.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional cryogenic liquid tank, Figure 2 is an enlarged side view of the circle in Figure 1, Figure 3 is a cross-sectional view taken along the arrows in Figure 2 - ■, and Figure 4 is the present invention. In the side view of the anchor strap, the view inside the upper left circle is a sectional view of the upper end thereof, and FIG. 1...Inner tank, 1α...Side plate of inner tank, 2
...Outer tank, 3...Insulation material, 4...
...Bottom insulation material, 5...Concrete slab,
6... Back plate, 7... Anchor strap, 8... Hole, 8α... Upper side of hole,
9...Hook, 9α...Bottom of hook recess.

Claims (1)

[Scope of utility model registration request] In the anchor strap of a double-shell type cryogenic liquid tank, a hole of approximately U fixed to the outer periphery of the side plate of the inner tank is attached to the horizontal part of the upper side of the hole provided at the upper end of the anchor strap.
An anchor strap for a low-temperature liquid tank, characterized in that a recessed portion of a hook having a letter-shaped recess is engaged.