JP7077277B2 - Cryogenic liquefied gas pumping device - Google Patents

Description

The present invention relates to a cryogenic gas pumping device that pumps the cryogenic gas from a storage tank that stores a cryogenic gas such as liquid helium.

At universities, etc., low-temperature liquefied gas such as liquid helium used for research is stored in dedicated equipment. The cryogenic liquefied gas is stored in a large storage tank (for example, about 5000 L), and the cryogenic liquefied gas is pumped from the storage tank into a small container for transfer (for example, about 100 L) and transferred to a laboratory or the like.

A pump is installed in the storage tank of the low-temperature liquefied gas, and when pumping out, the low-temperature liquefied gas in the storage tank is pumped up by driving this pump, and the pumped low-temperature liquefied gas is connected to the pump. It is pumped into a small container through a pump pipe.

As an example of a pump installed in a liquid, Patent Document 1 discloses a "submersible pump device". However, the technique of Patent Document 1 is intended to be used in a general liquid such as water, and is not applicable to a storage tank for a special liquid such as a cryogenic liquefied gas.

Here, a conventional pumping device in a storage tank for low-temperature liquefied gas will be described with reference to FIG.
In the conventional cryogenic gas pumping device 29, as shown in FIG. 5, the liquefied gas pump 33 is attached to one end of the metal pumping pipe 31 installed at the opening of the storage tank 3 on the inner side of the storage tank 3 in a state of being suspended. ing. At this time, the pumping pipe 31 is directly connected to the discharge port 33a of the liquefied gas pump 33, and the low-temperature liquefied gas pumped by the liquefied gas pump 33 is discharged from the other end of the pumping pipe 31 on the outer side of the storage tank 3. ..

The tip of the storage tank 3 on the outside of the pumping pipe 31 is inserted into the insertion port of a small container (not shown) to pump out the low temperature liquefied gas. It is possible to swing (see Fig. 2). Therefore, the liquefied gas pump 33 attached to the pumping pipe 31 also rotates with the movement of the pumping pipe 31 shown by the white arrow in FIG.

Japanese Unexamined Patent Publication No. 2009-79489

However, the pumping pipe 31 used for the low-temperature liquefied gas is not high in strength because it is formed thin due to the property that the invasion heat must be reduced as much as possible.
The liquefied gas pump having high liquid feeding performance is relatively large, and further, the vibration of the liquefied gas pump may cause distortion in the thin pumping pipe 31. Therefore, in the conventional method of suspending the liquefied gas pump 33 directly to the pumping pipe 31, only the small and lightweight liquefied gas pump 33 that the pumping pipe 31 can withstand can be applied.

Further, since the conventional method is to directly connect the pump pipe 31 to the discharge port 33a of the liquefied gas pump 33 and suspend it, the liquefied gas pump 33 having the discharge port 33a in the center of the upper part as shown in FIG. It is suitable and difficult to apply to those with a discharge port at a position other than the center of the upper part (side, side, etc.).

The present invention has been made to solve such a problem, and is applicable to a relatively large liquefied gas pump having high performance without being limited by the durability of the pump pipe, and further, the discharge port of the liquefied gas pump. It is an object of the present invention to provide a low temperature liquefied gas pumping device that does not limit the position of.

(1) The low-temperature liquefied gas pumping device according to the present invention is installed at the opening of a storage tank for storing low-temperature liquefied gas, and is for pumping out the low-temperature liquefied gas stored in the storage tank. , A lid member installed in the opening, a pump pipe pierced through the lid member and attached so as to be swingable, and a support member attached to a surface of the lid member corresponding to the inner side of the storage tank. A liquefied gas pump attached to the support member for pumping out the low-temperature liquefied gas and a flexible tube for connecting the discharge port of the liquefied gas pump and the pumping pipe are provided, and the flexible tube and the pumping pipe are connected to each other. It is characterized in that the portion is provided at a position deviated from the axis of the swing of the pumping pipe.

(2) Further, in the case described in (1) above, when the pumping pipe is rotated by the maximum angle of swing, the bending radius of the flexible tube is equal to or larger than the minimum bending radius specified for the flexible tube. The flexible tube is attached to the flexible tube.

(3) Further, in the one described in (1) or (2) above, the pumping pipe is a extending portion extending toward the bottom of the storage tank with the lid member attached to the storage tank. The flexible tube has a horizontal portion extending in the horizontal direction from the extending portion, and the flexible tube is attached via the horizontal portion.

In the present invention, by attaching the liquefied gas pump to the support member, a high-performance liquefied gas pump can be applied without being limited by the durability of the pump pipe. Further, by connecting the discharge port of the liquefied gas pump and the pump pipe via the flexible tube, the movement of the swing of the pump pipe is not hindered regardless of the position of the discharge port of the liquefied gas pump.

It is a figure explaining the low temperature liquefied gas pumping apparatus which concerns on Embodiment 1. FIG. It is a figure explaining the swing of the pumping pipe of the low temperature liquefied gas pumping device which concerns on Embodiments 1 and 2. It is a figure explaining the cryogenic liquefied gas pumping apparatus which concerns on Embodiment 2, FIG. 3 (a) is a plan view view of the structure inside a storage tank, and FIG. 3 (b) is a front view view. (Part 1) It is a figure explaining the cryogenic liquefied gas pumping apparatus which concerns on Embodiment 2, FIG. 4 (a) is a plan view view of the structure inside a storage tank, and FIG. 4 (b) is a front view view. (Part 2) It is a figure explaining the conventional cryogenic liquefied gas pumping apparatus.

[Embodiment 1]
As shown in FIG. 1, the low-temperature liquefied gas pumping device 1 according to the present embodiment can swing through the lid member 5 installed at the opening of the storage tank 3 for storing the low-temperature liquefied gas and the lid member 5. A pump pipe 7 attached to the lid member 5, a support member 9 attached to a surface corresponding to the inner side of the storage tank 3 in the lid member 5, and a liquefied gas pump 11 attached to the support member 9 for pumping low-temperature liquefied gas. The liquefied gas pump 11 is provided with a discharge port connecting pipe member 13 attached to the discharge port 11a for connecting the flexible tube, and a flexible tube 15 for connecting the pumping pipe 7 and the discharge port connecting pipe member 13.
The configuration of the low-temperature liquefied gas pumping device 1 will be specifically described below.

<Cover member>
The lid member 5 is installed at the opening of the storage tank 3 in a state of penetrating the pumping pipe 7. The pump pipe 7 is rotatably fixed to the lid member 5 by the Wilson seal 17 that transmits the rotational movement while maintaining the airtightness of the storage tank 3 which is a vacuum heat insulating storage tank.

<Pushing pipe>
The pump pipe 7 is a vacuum insulation pipe having a triple structure used when transferring the cryogenic liquefied gas in the storage tank 3 to a small container for transportation. One end of the pumping pipe 7 is arranged inside the storage tank 3 and the other end is arranged outside the storage tank 3, and the outer end of the storage tank 3 is inserted into the insertion port of the small container to pump out the low temperature liquefied gas.
Further, as shown in FIG. 2, the pumping pipe 7 can swing around the portion fixed to the Wilson seal 17. The range indicated by the arrow in the figure is the range in which the pumping pipe 7 can swing.

At the inner end of the storage tank 3 in the pumping pipe 7 of the present embodiment, there is an extension portion 7a extending toward the bottom of the storage tank 3 and a horizontal portion 7b extending horizontally from the extension portion 7a. It has a hanging portion 7c extending from the horizontal portion 7b toward the bottom of the storage tank 3.
Along with the swinging motion of the pumping pipe 7, the horizontal portion 7b and the hanging portion 7c rotate around the extending portion 7a on the swing axis (swinging shaft 19) (white arrow in FIG. 1). reference).

<Support member>
The support member 9 is attached to a surface of the lid member 5 corresponding to the inner side of the storage tank 3 and fixedly supports the liquefied gas pump 11. The material of the support member 9 is preferably a material having a low thermal conductivity such as G-10 (a kind of epoxy resin-based glass reinforced plastic) or GFRP (glass fiber reinforced plastic).

By fixing the liquefied gas pump 11 to the support member 9, it is not necessary to suspend the liquefied gas pump 11 from the pump pipe 7 as in the conventional example. Therefore, since there is no limitation due to the durability of the pump pipe 7, it is possible to apply the liquefied gas pump 11 having higher performance than the conventional one and having a relatively large size.
Further, since the load of the liquefied gas pump 11 is not applied to the pumping pipe 7, the load in the swinging operation of the pumping pipe 7 is reduced.
Further, in the conventional example, as shown in FIG. 5, a load is applied to the discharge port 33a of the liquefied gas pump 33, which is a part having a mechanically low strength, due to its own weight. There is no load.

<Liquefied gas pump>
The liquefied gas pump 11 is an immersion type liquefied gas pump (for example, a liquid helium pump), and a centrifugal force is generated by the rotation of the rotary blade, and the low temperature liquefied gas is pumped by the centrifugal force. The pumped low-temperature liquefied gas is discharged from the discharge port 11a of the liquefied gas pump 11.
A feedthrough 21 which is a mechanism for supplying power to a device inside the vacuum is installed in the lid member 5, and power is supplied to the liquefied gas pump 11 by a lead wire 23 via the feedthrough 21.

<Discharge port connection pipe member>
The discharge port connection pipe member 13 is for connecting the flexible tube 15 described later to the discharge port 11a of the liquefied gas pump 11. It has an extension 13a that is connected to the discharge port 11a and extends toward the upper part of the storage tank 3, and a horizontal portion 13b that extends horizontally from the extension 13a and has an end connected to the flexible tube 15. ..

As shown in FIG. 1, the liquefied gas pump 11 in the present embodiment is provided with a discharge port 11a at the lower part of the side surface for discharging low-temperature liquefied gas toward the upper part of the storage tank 3. As will be described in detail later, if the flexible tube 15 is directly connected to the discharge port 11a at such a position, when the pumping pipe 7 swings, stress in the twisting direction is applied to the flexible tube 15 to reduce the durability. There is a risk that it will end up. In order to avoid such a decrease in durability, in the present embodiment, the flexible tube 15 and the discharge port 11a are connected via the discharge port connection pipe member 13.

However, when the discharge port 11a of the liquefied gas pump 11 is located at a position where the swing of the pumping pipe 7 does not cause the flexible tube 15 to be twisted, the flexible tube 15 is directly connected without going through the discharge port connecting pipe member 13. May be connected to the discharge port 11a.

<Flexible tube>
The flexible tube 15 is a flexible metal tube, one end of which is connected to the pumping pipe 7 and the other end of which is connected to the discharge port connecting pipe member 13.
Although the liquefied gas pump 11 in the present embodiment is fixed to the support member 9, since it is connected to the pumping pipe 7 via the flexible tube 15, the swinging operation of the pumping pipe 7 is not hindered.

Further, since the position of the discharge port 11a of the liquefied gas pump 11 is not limited when connecting to the pumping pipe 7, it is easy to install even when the liquefied gas pump 11 is replaced.
Further, heat shrinkage may occur in the pump pipe 7 and the support member 9 due to contact with the low temperature liquefied gas, and such shrinkage can be absorbed by the flexibility of the flexible tube 15, so that the load on the pipe can be suppressed. ..

The flexible tube 15, which is a piping product, is provided with installation conditions such as a minimum bending radius, and installation and use under these conditions are required. Continued use outside the proper range may result in loss of flexibility or damage, which may reduce durability.
In particular, when connecting to a moving pipe such as the pump pipe 7 in the present embodiment, it must be installed so that the installation condition is satisfied in any state within the movable range.

Further, the flexible tube 15 is a member that cannot absorb the twist. Therefore, it is necessary to install the pumping pipe 7 so that the rotation due to the swing of the pumping pipe 7 does not give a twist to the flexible tube 15.
In this respect, since the pumping pipe 7 in the present embodiment includes the horizontal portion 7b, the connecting portion 25 with the flexible tube 15 is provided at a position laterally displaced from the swing shaft 19 of the pumping pipe 7. It is devised so that the flexible tube 15 is not stressed in the twisting direction due to the swing of the pumping pipe 7.
Specifically, since the extension portion 7a, the horizontal portion 7b, and the hanging portion 7c of the pumping pipe 7 have a crank shape, the horizontal portion 7b and the hanging portion 7c are integrated with the extending portion 7a as an axis when swinging. Since the connection portion 25 between the hanging portion 7c and the flexible tube 15 moves so as to draw an arc around the swing shaft 19, no twist is applied to the flexible tube 15.

On the other hand, if the other end of the flexible tube 15 is directly connected to the discharge port 11a of the liquefied gas pump 11 fixed to the support member 9, stress in the twisting direction may occur to some extent when swinging.
In this respect, in the present embodiment, the flexible tube 15 can be connected in the horizontal direction via the discharge port connecting pipe member 13, and stress in the twisting direction is less likely to be applied even when the pumping pipe 7 swings.

As described above, since the connecting portion 25 of the pumping pipe 7 and the flexible tube 15 moves in an arc in accordance with the swing of the pumping pipe 7, the distance from the discharge port connecting pipe member 13 is the longest. It is preferable to have an appropriate length so that a tensile load is not applied to the flexible tube 15 even when the flexible tube 15 is used.

As described above, in the present embodiment, by attaching the liquefied gas pump 11 to the support member 9, the high-performance liquefied gas pump 11 can be applied without being limited by the durability of the pump pipe 7. By connecting the discharge port 11a of the liquefied gas pump 11 and the pumping pipe 7 via the flexible tube 15, the swinging movement of the pumping pipe 7 is not hindered regardless of the position of the discharge port 11a. ..

[Embodiment 2]
In the first embodiment, an example in which the connecting portion 25 of the pumping pipe 7 and the flexible tube 15 is provided at a position horizontally displaced from the swing axis 19 of the pumping pipe 7 has been described, but the flexible tube in the vicinity of the connecting portion 25 has been described. Since 15 is parallel to the swing axis 19, stress in the twisting direction is likely to occur in the flexible tube 15 when the horizontal displacement distance is short.
It is necessary to lengthen the horizontal portion 7b of the pumping pipe 7 in order to lengthen the distance to be shifted in the horizontal direction, but the longer the horizontal portion 7b, the lower the operability when swinging the pumping pipe 7. There is a fear.

Therefore, in the present embodiment, as shown in FIG. 3, as a method in which stress in the twisting direction is not applied to the flexible tube 15 even if the horizontal portion 7b of the pumping pipe 7 is shortened, the pumping pipe 7 and the flexible tube 15 are used. Changed to connect horizontally.
FIG. 3 is a diagram showing the state of the pumping pipe 7 and the flexible tube 15 when the pumping pipe 7 is at the position of the solid line in FIG. 2. Since the configuration of the storage tank 3 and the outside of the storage tank 3 is the same as that of the first embodiment, only the configuration inside the storage tank 3 will be illustrated and described in the present embodiment. FIG. 3A shows a plan view, and FIG. 3B shows a front view. Further, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The pumping pipe 7 of the cryogenic gas pumping device 27 in the present embodiment has an extending portion 7a extending toward the bottom of the storage tank 3 and a horizontal portion 7b extending horizontally from the extending portion 7a. The flexible tube 15 is directly connected to the horizontal portion 7b because the hanging portion 7c described in the first embodiment is not provided.
Further, the point that the liquefied gas pump 11 is fixed to the support member 9 attached to the lid member 5 and the discharge port connecting pipe member 13 is attached to the discharge port 11a of the liquefied gas pump 11 is the same as that of the first embodiment.

One end of the spirally arranged flexible tube 15 is horizontally connected to the horizontal portion 7b of the pumping pipe 7, and the other end is connected to the horizontal portion 13b of the discharge port connecting pipe member 13. Therefore, the flexible tube 15 is connected to the swing shaft 19 in a state close to a right angle in the vicinity of the connecting portion 25.

In the present embodiment as described above, since the stress due to the swing is not easily transmitted in the twisting direction of the flexible tube 15, even if the horizontal portion 7b is shortened, the same effect as that of the first embodiment can be obtained.

Further, in the present embodiment, since the flexible tube 15 is arranged in a spiral shape with a certain bending condition, this bending condition is set to the flexible tube 15 in any state within the swing movable range. It must be installed so that it is at least the minimum bending radius.
FIG. 4 shows the state of the flexible tube 15 when the bending radius is the smallest when the pumping pipe 7 swings. In FIG. 4A, the state before the swing of the pump pipe 7 and the flexible tube 15 (same as in FIG. 3) is shown by a broken line, and the state after the swing is shown by a solid line. The position of the pumping pipe 7 after swinging corresponds to the position of the broken line under the pumping pipe 7 shown by the solid line in FIG.

As shown in FIG. 4, when both ends of the flexible tube 15 are closest to each other in a plan view, the bending radius becomes the smallest. Therefore, in the present embodiment, the flexible tube 15 is attached so as to have a minimum bending radius specified for the flexible tube 15 or more even when the head is swung at the maximum angle in that direction.

1 Cryogenic liquefied gas pumping device (Embodiment 1)
3 Storage tank 5 Lid member 7 Pump-out pipe 7a Extension part 7b Horizontal part 7c Hanging 9 Support member 11 Liquefied gas pump 11a Discharge port 13 Discharge port connection pipe member 13a Extension part 13b Horizontal part 15 Flexible tube 17 Wilson seal 19 Swing shaft 21 Feedthrough 23 Lead wire 25 Connection part 27 Low temperature liquefied gas pumping device (Embodiment 2)
29 Cryogenic liquefied gas pumping device (conventional example)
31 Pumping pipe (conventional example)
33 Liquefied gas pump (conventional example)
33a Discharge port

Claims (3)

It is a cryogenic liquefied gas pumping device for pumping out the cryogenic liquefied gas stored in the storage tank by installing it at the opening of the storage tank for storing the cryogenic liquefied gas.
A lid member installed in the opening, a pump pipe pierced through the lid member and attached so as to be swingable, a support member attached to a surface of the lid member corresponding to the inner side of the storage tank, and the like. It is provided with a liquefied gas pump attached to a support member for pumping out the low temperature liquefied gas, and a flexible tube for connecting the discharge port of the liquefied gas pump and the pumping pipe.
A low-temperature liquefied gas pumping device characterized in that a connection portion between the flexible tube and the pumping pipe is provided at a position deviated from the axis of swing of the pumping pipe. The flexible tube is attached so that the bending radius of the flexible tube becomes equal to or larger than the minimum bending radius specified for the flexible tube when the pumping tube is rotated by the maximum angle of swing. The low temperature liquefied gas pumping device according to claim 1. The pumping pipe has an extension portion extending toward the bottom of the storage tank and a horizontal portion extending horizontally from the extension portion with the lid member attached to the storage tank, and the flexible tube. The low temperature liquefied gas pumping device according to claim 1 or 2, wherein is attached via the horizontal portion.

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