JPS5940100A - Liquid discharging device for tank having secondary liquid storing function - Google Patents

Abstract

PURPOSE:To permit to suck the leakage of liquid from the lower part of a space between inner and outer tanks by a submerged pump through a strainer. CONSTITUTION:A pump pot 15 for housing the submerged pump is provided temporarily in a pit 14 formed in a foundation 2 below the space 12 between the inner and outer tanks. The space 12 and the pump pot 15 are connected by a liquid discharging pipeline 18 interposed with the strainer 16 and a solenoid main valve 17. When a crack is produced in the side plate 10 of the inner tank and reserved liquid 13 leaks into the space 12, a detector 19 is operated, the solenoid valve 17 is opened immediately through a control unit 20, the submerged pump is operated and the stored liquid 13, leaking into the space 12, may be retrieved.

Description

DETAILED DESCRIPTION OF THE INVENTION The disclosed technology belongs to the field of technology for dealing with unexpected storage Kjj and leakage of double-shelled tanks that store low-temperature liquefied gas such as LNG.

Therefore, the present invention provides a method for storing leaked liquid from the inner tank in the space between the inner tank for storing low-temperature liquefied gas such as LNG and the outer tank having a secondary liquid storage function or a liquid barrier. The invention relates to a drainage device for collecting liquid, and in particular, a pit is provided in the lower foundation for the space, a temporary polar truck is provided in the pit to accommodate a submerged pump for collecting the drained liquid, and the pot and the lower part of the space are connected. This invention relates to a draining device for a tank in which a draining surface and a draining surface having a replaceable strainer are connected therebetween.

As is well known, double-shell tank structures are often used for storage tanks for low-temperature liquefied gases such as LNG, but as the tank capacity increases with increasing demand, various problems have arisen. If a crack develops in the inner tank and the stored liquid spills out to a dike, there will be a delay in collecting the spilled liquid, and the evaporated gas will flow downwind due to lice, etc. It has the drawback of causing disaster over a wide area, requiring a large amount of extinguishing agent and spraying agent, and having the disadvantage that the recovered liquid is contaminated with dirt and dust, which requires a purification process before reuse.

However, it is also possible to quickly transfer the water to the 11L tank using the internal tank dispensing pump.
When troubles such as cracks in the inner tank vC occur, the nuclear dispensing pump often does not function completely, resulting in unpredictable problems.

In addition, it would be inconvenient to install a drainage pump or the like in place of this and install drainage transfer piping between the tank and other tanks, as the equipment mechanism would be complicated and costly, and management would be cumbersome. .

The purpose of this invention is to solve the problem of recovering the leaked liquid from the low-change double grain tank, which is present in the above-mentioned prior art, as a technical problem to be solved, and to provide a temporary equipment that requires high costs for this process. It can be permanently installed if necessary, and when it is permanently installed, it can be recovered with the same accuracy as the inner tank storage accuracy, providing an excellent secondary storage function that can benefit the field of use of low-l crystal double-shell tanks in the energy industry. The purpose of the present invention is to provide a draining device for a tank having the following characteristics.

The structure of the present invention for the above-mentioned purpose is to prevent the low-mass liquefied gas stored in the inner tank from leaking due to the failure of the inner tank and causing damage to the inner tank and the outer tank (4. If charcoal does not form and is stored secondary in the space, or if there is a risk of vomiting, store Zabmerge and Bimp in the pump pot temporarily installed in the pit at the bottom of the cough space. Then, a drainage pipe is installed between the tank and the transfer tank, and the leaked liquid is sucked from the bottom of the space to the submerge pump via the strainer and transferred to the chemical tank without being contaminated. The main point is that if a pump can be used, it is used in conjunction with the pump, and the liquid is drained immediately, and technical measures have been taken to eliminate the need for the installation and management costs of a drainage device during normal operation. It is something.

Next, embodiments of the present invention will be described below with reference to the drawings.

In the example shown in Fig. 1.2 V, l is a low-temperature double-shell tank with a secondary liquid storage function, and is installed on the foundation 2 via frost protection city piles 3.3... (An outer tank side plate 5 made of the same material is formed on the outer tank bottom plate 4 of the prestressed conch liver pod, and a dome roof 6 is integrally mounted on the top of the outer tank side plate 4.
Forming the outer shape of the bamboo dome Kotone tank, the side plates 5 and the dome roof 6. A urethane cold insulating material 7 is attached to the inner surface.

The outer tank bottom plate 4-l-2 is provided with a bottom cooler 8 made of foamed concrete, and on top of that is provided an inner tank bottom plate 9 made of aluminum alloy, and from the annular base there is a cylindrical inner tank. A plate 10 is integrally provided, and a dome roof 11 is provided at the lower end of the plate 10.

Therefore, the above-mentioned side cold insulation vJ7 and inner 41) ill plate 1
0, a space 12 having a secondary liquid storage function is formed.

Note that 13 is LNG as a stored low-temperature liquefied gas.

Reference numeral 14 denotes a pinto, which is formed at the bottom of the space 12 of the foundation 2, and has a pump bot 15 (not shown) for housing the Zabmerge pump fixed in a temporary state, and is exchangeable between it and the space 12. A possible well-known strainer 16 and a drainage pipe 18 interposing a valve 17 as a main valve are connected to each other.

19id: It is a well-known leakage liquid detector, and includes a warning device that does not indicate 1, and a suppressor head 2 that operates a dispensing pump as appropriate.
0 through a cable 21.

Further, the control device 20 is connected to the terminals 24 of the two solenoid valves 17 and pump valves 15 via cables 22 and 23.

Incidentally, the cables 22 and 23 may be permanently installed together with the drain pipe 25 extending 7 inches to another tank when the submerged pump is installed.

In the above-mentioned configuration, in a steady state, the LNG stored in the inner tank 9 and 10 is normally discharged and operated.

When a crack unexpectedly occurs in the inner tank side plate 1OV and the stored liquid 13 leaks into the 42 space 12, the detector 19 is activated.
If a sluggish signal is issued via the control device 20 and a dispensing pump (not shown) is activated, it is activated to transfer all of the stored liquid to another tank.

Then, at least one submerge pump (not shown) stored in a plurality of tanks 1. Connect crabs.

Therefore, the solenoid valve 17 is immediately opened via the control device 20, and the submerged pump is operated to collect the stored liquid 13 for leakage into the air i(I) 12.

This collected liquid contains almost no dirt, dust, etc., and is transferred to a chemical tank without the need for purification.

Therefore, except for one extreme case, multiple tongues,
In contrast to 1., one or two submerged pots are required, and temporary pump bots 15, straights 16, and electricity I
The culms of the R-valve 17-rise temporary forest and recitation sound are not expensive, and the lining costs such as management costs are low.

・In the embodiment shown in Fig. 3, a liquid barrier 26 is provided outside 1UII of the outer tank 6', a gap 12' is formed between the outer tank 5', and a gap 12' is formed in the lower part of the space 12'. - Same as the record 1411 case 1
This is a mode in which temporary equipment for children has been set up.

It goes without saying that the embodiments of this invention are not limited to the above-mentioned embodiments VC, and if filled, it is possible to employ 4 Φ's of bears such as the lease pen de no do detsu kita no ku and the 4 Φs. .

As mentioned above, according to the present invention, the liquid device is provisionally installed in the secondary liquid storage space of the low-temperature double-shell tank, which makes it more efficient than the permanent equipment. However, there is not only no initial cost, but also lining costs such as management, maintenance and inspection. Since only a few units are required, there is a shared enclosure and the overall cost is low, which is an excellent effect.

Therefore, by installing a bit in the lower foundation of the secondary liquid storage space and connecting it to the drainage pipe with a sight valve to the pump bot for the submerged pump, these equipments can be easily manufactured. It has the advantage of being inexpensive, taking up little space, and requiring low maintenance and management costs.

In addition, even if the stored liquid leaks unexpectedly, the secondary stored liquid is recovered in the original secondary storage space, so there is no contamination of the tank and there are fewer disasters in the surrounding area. In addition, the submerged pump and drainage piping can be easily and quickly connected to other tanks before problems become serious.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, and FIG.
A schematic sectional view of the embodiment, FIG. 2 is an enlarged sectional view of temporary equipment,
FIG. 3 is a partial sectional view of another embodiment. 13...Low temperature liquefied gas, 9.10.11-...Inner tank, 5.26 Secondary liquid storage tank, 12.1 Shi'...Empty 1
..., 15.16.17.18・jll liquid storage, 2...
Basics, 14. Focus. 15...bot, 16...stray, 1
8. Piping, 17. Original seal 481

Claims (1)

[Claims] In the leakage liquid drainage device installed in the space between the low-temperature liquefied gas storage inner tank and the secondary liquid storage tank, a pit is provided in the foundation at the bottom of the space, and a temporary structure for the Zabmerge pump is installed in the pit. A secondary liquid storage function characterized in that a pot is provided, and a drainage pipe connected to the pot via a stone has a main valve and is open-connected to the lower part of the space. Tank drainage device with.