JPS5947198B2 - Pump barrel support device for double shell cryogenic tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The disclosed technique belongs to a technique of supporting a pump barrel which is vertically installed in a double-shell cryogenic tank and has a pump in its lower part without applying any weight to the inner tank.

According to the present invention, in a storage tank for cryogenic liquefied gas such as LNG, the upper end is fixed to the inner tank of the double-shelled cryogenic tank, and a pump is provided at the lower part. It relates to a device for supporting a pump barrel, and in particular, the barrel is divided into an upper barrel fixed to an inner tank and a lower barrel fixed to a bottom plate, and both barrels are connected by an upper telescopic pipe, and the lower barrel is A pump is attached to the bottom of the pump, a lower telescopic pipe is provided on the lower side of the pump, the lower part of the lower telescopic pipe is rigidly connected to the upper barrel, the weight of the pump is supported by the bottom plate, and the upper and lower parts of the pump are This is a double-shell cryogenic tank pump that is connected by a communication pipe to balance the force exerted on the inner tank due to pump pressure between the upper and lower parts of the pump, and to distribute and support both dead load and live load on the inner tank roof and bottom plate. This relates to a barrel support device. Generally, as shown in FIG.
A heat insulating material 3 is interposed between the inner tank 2 and the inner tank 2 to form a double shell structure.
In a so-called double-shell cryogenic tank 5 that stores a low-temperature liquefied gas 4 such as LNG inside, a pump barrel 6 is vertically installed in the inner tank 2, and a supmerged pump 1 is installed at the lower end of the tank.
, the low-temperature liquefied gas 4 is sucked in and discharged to the outside through a pipe 8 connected to the upper end.

Conventionally, as a structure for supporting the pump barrel 6, the upper part of the barrel is fixed to the inner tank roof 9, and the upper end protruding above the inner tank roof 9 is connected to a retractable pipe into one port of the outer tank roof. They were connected via 11.

However, in the above conventional pump barrel support structure,
The weight of the barrel itself, the weight of the pump 1, and the weight of the liquid column inside the barrel are all supported by the inner tank roof 9, and this total weight may be about 25 tons per pump barrel. If 3 or 4 are installed, 100 tons
This has the disadvantage that the structural design of the inner tank roof 9 to support it is extremely complicated, and construction is difficult. Therefore, the pump barrel 6
Although it is possible to make the inner tank roof 9 a low-strength structure by fixing the lower end directly on the bottom plate 12, in this embodiment,
If the inner tank roof 9 behaves and moves up and down due to warming up and cooling down, there is a disadvantage that the welded parts may be damaged.

Also, in order to deal with this, a pump barrel 6 is installed on the bottom plate 12.
If the pump barrel 6 is fixed and a telescopic tube is inserted, the behavior of the inner tank can be absorbed. In this case, the pump pressure generated in the barrel causes the inner tank roof 9 to
There is an inconvenience that an upward reaction force acts on the roof 9, and the structure of the roof 9 must be strengthened to support this force.

The purpose of this invention is to solve the problem of the pump barrel support structure of a double-shell cryogenic tank based on the above-mentioned conventional technology, and to install a pump on a lower barrel fixed to a bottom plate, and to
By connecting the upper barrel attached to the inner tank and communicating the upper and lower parts of the pump, the above drawbacks and difficulties are eliminated, and the thermal behavior of the inner tank is improved. It is an object of the present invention to provide an excellent pump barrel support device for a double-shell low-temperature tank, which is capable of absorbing the force caused by pump pressure and is capable of distributing and supporting dead and live loads on the inner tank roof and bottom plate.

In accordance with the above object, the pump is fixed on the tank bottom plate to support part of the dead load of the barrel and the pump, and when the inner tank is thermally affected, the pump is fixed on the top and bottom of the barrel. The vertical effect of thermal behavior can be absorbed by the arranged expandable tube, and when the stored liquid is discharged by the pump, the pressure generated by the pump acts uniformly on the upper and lower parts of the pump, The gist of this system is to prevent force from acting on the connection between the pump barrel and the inner tank by canceling out the feeding force in the vertical direction of the barrel by the rigid support.

Next, an embodiment of the present invention will be described below based on FIG.

The same parts as those in the first embodiment are given the same reference numerals, and
This will be explained with reference to figures. FIG. 2 shows a pump barrel support device which is the gist of the present invention, and the pump barrel includes an upper barrel 13 whose upper part is fixed to the inner tank roof 9,
It is divided into a lower barrel 15 fixed on the bottom plate 12 by support legs 14.

The lower barrel 15 is equipped with a well-known submerged pump 16.
is installed inside the submerged pump 16, and a suction port 17 is opened at the bottom of the submerged pump 16, and the lower part of the suction port 17 and the upper part of the submerged pump 16 are communicated through a communication pipe 18. .

The upper part of the lower barrel 15 is connected to the lower end of the upper barrel 13 via a bellows-type upper telescopic tube 19. A bellows-type lower telescopic tube 20 is connected to a portion of the lower barrel 15 below the suction port 17, and the lower end of the lower barrel 15 is closed by a plate 21.

A plate 22 having the same shape as the plate 21 is fixed to a portion of the upper barrel 13 above the upper telescopic tube 19, and the mutually opposing plates 21 and 22 are connected by a tie rod 23. ing.

A plurality of tie rods 23 are arranged so as to surround the lower barrel 15, and the stored liquid can flow in from the space between the tie rods 23. Further, the support leg 14 is connected to the lower barrel 15 through the tie rod 23.
installed on.

In the above configuration, the inner tank 2 behaves thermally due to warming up and cooling down when receiving and discharging low-temperature liquefied gas 4 such as LNG, and when the inner tank roof 9 moves up and down, it is fixed to the roof 9. The upper barrel 13 also moves up and down accordingly. Thus, the lower barrel 15 fixed to the bottom plate 12
and the upper barrel 13 are connected by the upper telescopic pipe 19 and also by the lower telescopic pipe 20 via the plate 22, tie rod 23, and plate 21, so that the vertical movement of the upper barrel 13 is prevented. This is absorbed by the bellows function of the telescopic tubes 19 and 20.

That is, when the upper barrel 13 descends, the lower telescopic tube 20
expands and the upper telescopic tube 19 contracts, and when rising, the upper telescopic tube 19 extends and the lower collapsible tube 20 contracts.

Therefore, no large stress is generated in any of the lower barrel 15, the upper barrel 13, and the inner tank roof 9, and the dead load is always distributed and supported by the roof 9 and the bottom plate 12.

Next, when the submerged pump 16 is operated, the low temperature liquefied gas 4 is sucked in through the suction port 17 and discharged through the upper barrel 6 and pipe 8.

When the low-temperature liquefied gas 4 is discharged, a pressure p is generated above the submerged pump 16. Since the submerged pump 16 is fixed on the bottom plate, this pressure p causes an upward force F to act on the upper barrel 13, which tends to act to lift the inner tank roof 9 upward. . However, the liquid in the upper and lower parts of the submerged pump 16 is communicated through the communication pipe 18! The same pressure p is also generated below the submerged pump 16.

This pressure p causes a force F' of the same magnitude as the above-mentioned upward force F to be applied downward to the plate 21. Therefore, the two forces F and F' are canceled out by the tie rod 23, and the F caused by the operation of the submerged pump 16 does not substantially act on the upper barrel 13, which eliminates the need to strengthen the inner tank roof 9. The live load is equally distributed and supported by the inner tank roof 9 and the bottom plate 12.

However, the embodiments of the present invention are not limited to those described above, and may be modified in various other ways. For example, instead of connecting the upper barrel 13 and the lower barrel 21 with the tie rod 23, the upper barrel 13 and the lower barrel 21 may be connected to each other. It is also possible to omit the lower barrel 21 by connecting it by the tube 18.

As described above, according to the present invention, a pump for a double-shell cryogenic tank is provided with the pump in a lower position, and the upper part is fixed to the inner tank to support the pump barrel which is vertically installed inside the cryogenic double-shell cryogenic tank. In the barrel support device, the upper barrel and the lower barrel are connected via two telescopic tubes on the upper and lower sides of the pump, so that even if the inner tank expands and contracts due to thermal behavior and the upper barrel moves in the vertical direction, This behavior is absorbed by the expandable tubes, and the dead load is always supported and distributed to the inner tank roof and bottom plate, which has an excellent effect.

In addition, by connecting the upper and lower parts of the pump with a communicating pipe, the pressure sent when the pump is driven acts on the upper and lower parts of the pump in a state that cancels each other out, so that the upper barrel and the inner tank roof 9 are pushed upward by the reaction force caused by the pump pressure. This has an excellent effect in that the live load is dispersed and supported on the inner tank roof and bottom plate without being pushed up by the tank.

Furthermore, since the pump, which has the largest proportion of the weight of the pump barrel, is fixed on the bottom plate, a large weight does not act on the inner tank roof.

Therefore, as mentioned above, the load is always distributed to the bottom plate, so there is no need to strengthen the structure of the barrel attachment part of the inner tank roof, which simplifies the strength design, eases construction, and reduces the amount of material used. It is light in weight and has the effect of reducing costs.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a double-shell cryogenic tank showing the prior art, and FIG. 2 is a longitudinal cross-sectional view of a pump barrel support device for a double-shell cryogenic tank according to an embodiment of the present invention. 7, 16...Pump, 9...Inner tank, 1
2... Tank bottom plate, 15... Lower barrel, 20... Lower telescopic tube, 13... Upper barrel, 19... Upper telescopic tube. tube, 21, 22,
23... Rigid support body, 17... Inflow port, 18... Communication pipe.

Claims (1)

[Claims] 1. In a pump barrel support device for a double-shell cryogenic tank that supports a pump barrel that is vertically installed in a tank with a pump installed at the bottom and whose upper part is fixed to the inner tank, the lower barrel fixed to the tank bottom plate is A pump is attached, and a lower telescopic pipe is connected to a portion of the lower barrel below the pump, and a portion of the lower barrel above the pump is connected to an upper barrel fixed to the inner tank via the upper telescopic pipe. a lower portion of the lower telescopic tube is closed and the lower portion and the upper barrel are connected by a rigid support;
Also, a pump barrel support device for a double shell low temperature tank, characterized in that an upper part and a lower part of the pump are connected by a communicating pipe.