JPS5810638B2 - Teion Exhaust Tank - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tank for storing low-temperature liquefied gas.
In particular, it concerns double-shelled tanks of the suspended ceiling type.

Recent experience in the United States shows that more than half of the low-temperature liquefied gas storage tanks constructed are of the suspended ceiling type, which has the following advantages:

■ Reducing the weight of the roof reduces costs.

■ There is no need to control the pressure of the cold insulation layer or the differential pressure between the cold insulation layer and the inner shell.

■ There is no need for dry gas to be sealed in the cold insulation layer.

■ Increased paper space slows internal pressure fluctuations due to temperature and other causes.

However, since our country is an earthquake-prone country, surface fluctuations in the stored liquid become a major barrier, and for this reason, the above-mentioned suspended ceiling type has not been adopted in the past.

As shown in Fig. 1, a suspended ceiling type double shell tank consists of an inner shell 1 and an outer shell 2, with a suspended ceiling 6 above. The flammable stored cryogenic liquid overflows from the upper end and flows into the cold insulation layer 3,
The outer shell 2 made of general structural steel plate causes brittle fracture.

As a result, there is a major drawback in that the flammable stored gas leaks to the outside, creating an extremely dangerous situation.

This invention provides a double-shell tank for storing low-temperature liquefied gas, which eliminates the disadvantages of hot liquids caused by liquid surface waves caused by earthquakes, etc., with respect to suspended ceiling tanks that have the various advantages described above. , in a double shell tank having a suspended ceiling with a predetermined gap between the periphery and the inner surface of the inner shell, between the upper end of the inner shell and the inner surface of the ceiling of the outer shell, over the entire circumference of the inner shell, A partition wall is provided for partitioning an upper space inside the inner shell and an upper space continuous with the cold insulation layer between the inner shell and the outer shell, and the partition wall at the upper end of the inner shell is provided with a partition wall for separating liquid droplets of the liquefied gas. A ventilation member having a large enough contact surface area to block passage and having ventilation is provided in the form of a window to communicate the upper space inside the inner shell and the upper space of the cold insulation layer. It has characteristics.

The present invention will be described in detail below with reference to the drawings.

Embodiments of the present invention are shown in FIGS. 2 to 5. Figure 2 is an elevational sectional view of one example, Figures 3a and b are enlarged views of section A in Figure 2 and its right side view, Figure 4 is a perspective view of a microtubule bundle used in the vent, and Figure 5. shows an elevational sectional view of the main part of another example.

As shown in FIG. 2, a double shell tank according to an embodiment of the present invention includes an inner shell 1, an outer shell 2, an inner shell bottom plate 4, an outer shell bottom plate 5, a peripheral edge thereof, and the inner shell 1. A suspended ceiling 6 with a predetermined gap between it and the inner surface, an outer shell ceiling 7, and the entire circumference of the inner shell 1 provided between the upper end of the inner shell 1 and the inner surface of the outer shell ceiling 7. It is provided with a partition wall 9 for partitioning an upper space inside the inner shell 1 and an upper space continuous to the cold insulation layer 3 between the inner shell 1 and the outer shell 2. teeth,
A ventilation member 10 having a large enough contact surface area to block the passage of liquid droplets of liquefied gas and having good ventilation is arranged in a window shape between the upper space inside the inner shell 1 and the upper space of the cold insulation layer 3. It is set up so as to communicate with each other.

Since the inner shell 1 and the inner shell bottom plate 4 are in contact with the stored liquefied gas 14 on the inside thereof, low-temperature resistant materials are used.

Portions such as the outer shell 2 that are not in direct contact with the liquefied gas 14 may be made of general structural materials as in the past.

The cold insulation layer 3 is filled with, for example, a solid heat insulating material.

The suspended ceiling 6 is suspended from the outer shell ceiling 7 by suitable hanging devices.

The partition wall 9 may be provided in the form of a thin film and provided between the upper end of the inner shell 1 and the outer shell ceiling 7, as shown in FIGS. 2 and 3.

As shown in FIG. 3, the ventilation members 10 are provided, for example, in the form of windows at regular intervals on the partition wall 9 at the upper end of the inner shell 1, and several layers of mesh 11 made of metal or other material are stretched over the ventilation surface. .

Instead of the mesh 110, a tube bundle made up of a large number of small diameter tubes 12 of a predetermined length may be used as shown in FIG.

In this invention configured as described above, the liquefied gas 14
is stored in the inner shell 1 as shown in Figure 2, but the liquefied gas 1
The following expansion and contraction are repeated at the time of injection or discharge of step 4.

During injection, the temperature of the inner shell 1 decreases and the inner shell 1 contracts.

Conversely, when the liquefied gas is discharged, the temperature of the inner shell 1 rises and expands.

In this way, during use, the inner shell 1 expands and contracts repeatedly, but at this time, the imbalance in pressure between the inner shell 1 and the cold insulation layer 3 is caused by the pressure inside the inner shell 1 passing through the ventilation member 10 to the cold insulation layer. 3 or vice versa and is automatically adjusted.

During storage, the inner shell 1 is set at a height that can sufficiently tolerate displacement of the liquid level, but surface waves of the liquid level may become significantly large due to earthquakes and the like.

The liquid splashes generated at this time hit the partition wall 9 and the ventilation member 10, but since the ventilation member 10 has air permeability as described above and has a sufficiently large contact surface area, such as the mesh 11, which is stretched, the liquid droplets remain in a liquid state and reach the ventilation member 10. The liquefied gas 14 cannot pass through.

It is vaporized by the time it reaches the cold insulating layer 3, and the cold insulating layer 3 is kept completely isolated from the liquid.

As described above, the present invention provides a partition between the inner shell and the cold insulation layer, and a ventilation member that has a large enough contact surface area to block the passage of liquid droplets of liquefied gas and is breathable. Therefore, even if the inner shell expands or contracts or there are liquid surface waves, the pressure between the inner shell and the cold insulation layer remains almost the same at all times, and there is no possibility that liquid will enter the cold insulation layer. An industrially useful effect can be obtained in that the tank will not be destroyed due to brittleness or the like and dangerous flammable gas will not leak outside.

[Brief explanation of the drawing]

Fig. 1 is an elevational sectional view of a conventional suspended ceiling type double shell tank, Fig. 2 is an elevational sectional view of an example of a suspended ceiling type double shell tank of the present invention, and Figs. An enlarged view of part A in FIG. 2 and a right side view thereof, and FIG. 4 is a perspective view showing another example of the ventilation member. 1... Inner shell, 2... Outer shell, 3...
... Cold insulation layer, 6 ... Suspended ceiling, 7 ...
Outer shell ceiling, 9... partition wall, 10... ventilation member, 11... mesh, 12... microtubule bundle, 14... liquefaction gas.

Claims (1)

[Scope of Claims] 1. In a double-shell tank having a suspended ceiling with a predetermined gap between the periphery and the inner surface of the inner shell, the upper end of the inner shell;
A partition wall is provided between the inner surface of the outer shell ceiling and the entire circumference of the inner shell to partition an upper space inside the inner shell and an upper space continuous to the cold insulation layer between the inner shell and the outer shell. A ventilation member having a large enough contact surface area to block the passage of liquid droplets of the liquefied gas and having ventilation is provided on the partition wall at the upper end of the inner shell, and is connected to the upper space inside the interior in the form of a window. A double-shell tank for storing low-temperature liquefied gas, characterized in that the tank is provided so as to communicate with the upper space of the cold insulation layer.