JP3723840B2 - Liquid helium pressure transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In various studies such as superconductivity studies, the present invention applies liquid helium for the purpose of cooling and transporting various objects and pressurizing and transferring liquid helium used to create a low-temperature atmosphere from a tank to its facility. The present invention relates to a pressure transfer device.
[0002]
[Prior art]
Liquid helium is used in large quantities day and night for research using the characteristic changes in electrical, magnetic or optical properties of various materials at cryogenic temperatures, nuclear magnetic resonance experiments, storage of biomaterials, etc. Liquid helium is used in various research facilities and is expected to be used more widely in the future. The liquid helium used at this time is a helium liquefier installed in a large-scale helium transfer device when a large amount of liquid helium is used, such as a university or a large-scale laboratory with many research facilities. In some cases, a batch management system is used to supply research facilities.
[0003]
However, in laboratories where it is not necessary to install such a large helium liquefier and its transfer device, a tank or cylinder filled with liquid helium is installed in the vicinity of a research facility that uses liquid helium, The liquid helium is used by appropriately replenishing or replacing the cylinder.
[0004]
[Problems to be solved by the invention]
When transferring high-pressure liquid helium filled in such tanks or cylinders to the use location of the research facility, strict regulations on the use of large cylinders must be cleared for high-pressure gas safety measures when using high-pressure cylinders. However, many measures are required, such as the use of expensive equipment and the placement of safety managers.
[0005]
When transferring a large amount of liquid helium as described above, conventionally, a liquid helium container has been pressurized by a 47 L helium gas cylinder and transferred at that pressure. Even if a small cylinder such as 10L is used when such a large cylinder is not required, the 10L cylinder and the 47L cylinder are almost the same price, so it is not practical from a cost standpoint to replace this. The use of large cylinders becomes efficient.
[0006]
On the other hand, when the organizational reform of the national university will be carried out and the regulation as a normal business office will be carried out in the future, when conducting research using a large cylinder as before, this regulation must be cleared. It is expected to become a big problem nationwide. Such a thing is not limited to the above-mentioned organizational reform of the national university, but it is highly likely that the same organizational reform will be carried out in the same organization in the future.
[0007]
As a conventional method that does not use a cylinder as described above, a rubber balloon-like pressurizing device connected to a liquid helium container is used. The pressurizing device was also repeatedly pressurized by waiting for the pressurizing device to swell naturally and then pressing it again when it returned to its original shape. However, this method is extremely inefficient and hinders smooth research.
[0008]
In contrast, for example, as shown in Japanese Utility Model Publication No. 5-12261, a pressurizing device using an electric pump has already been commercialized. As shown in FIG. 2, when supplying liquid helium 22 in a storage container 21 to a low-temperature experimental facility such as a cryostat 24 via a transfer tube 23, this apparatus uses a pump 30 of a pressurizing device 26 to connect a pressure transmission pipe 27. Thus, pressure vibration is applied to the gas layer 25 of the storage container 21, the liquid helium vibrates, a part of it evaporates, and the pressure inside the container increases to supply liquid helium to the cryostat 24. In this apparatus, the pressure in the pressure transmission pipe 27 is detected by the pressure detector 32, and when the pressure becomes a predetermined pressure or lower, the electromagnetic valve 29 is opened to operate the pump 30.
[0009]
Although the apparatus as described above can automatically transfer liquid helium, the pressure transmission pipe 27 is used as a metal pipe in order to cause in-machine vibration in the tank by the pressure change caused by the operation of a large electric pump. In addition, a dedicated connecting device for connecting such a specific pressure transmission pipe 27 to the storage container 21 side is required, and furthermore, a dedicated connection instrument for connecting the pressure transmission pipe 27 to the storage container 21 is required. In addition to the need for expensive members such as the need for jigs, there was a problem in terms of versatility. Moreover, since it is necessary to pressurize the inside of the container to a predetermined pressure directly and in a short time by the operating pressure of the pump, a large pump is required and it must be expensive.
[0010]
Therefore, according to the present invention, when transferring liquid helium in a container to a predetermined location, a small and inexpensive pump can be obtained by using a versatile and inexpensive apparatus without attaching a special expensive apparatus on the liquid helium container side. It is an object of the present invention to provide a liquid helium transfer device which can automatically transfer liquid helium when used.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention intermittently applies pressure to a container for storing liquid helium, a conduit for transferring the liquid helium in the container to a desired location, and an air layer portion in the container. In a liquid helium pressure transfer device equipped with a pressurization device that evaporates liquid helium by vibration and raises the pressure in the container, an electromagnetic valve and a pressure valve are added in order from the container side to the pressure line communicating with the gas layer in the container. A pressure tank, a pump for continuously supplying helium gas between the container and the solenoid valve in the pressurization line to the pressurization tank, and a controller for intermittently opening and closing the solenoid valve. The liquid helium pressure transfer device is characterized.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. In this apparatus, when the liquid helium in the container 4 is transferred from the storage container 4 to the low temperature experimental facility 1 through the pipe line 3 such as a transfer tube, the vaporized helium gas in the gas layer 8 existing at the upper part of the container 4 Is pressurized by the pressurizing device 10, and the liquid helium transfer device 15 is configured to transfer the liquid helium in the container 4 to the low temperature experimental facility 1 with the pressure.
[0013]
When the electromagnetic valve 6 provided in the pressurization pipe line 11 is released, the pressurization device 10 causes the pressure from the pressurization tank 7 in which pressurized liquid helium gas is stored as described later to pass through the pressurization pipe line 11. And reaches the gas layer 8 of the container 4. At this time, pressure vibration is applied to the gas layer 8 in the container 4, and the liquid helium vibrates to partially evaporate, and the pressure inside the container increases to supply liquid helium to the low temperature experimental facility 1. Can be done.
[0014]
On the other hand, the pressurization line 11 is provided with a pump 5 such as a diaphragm pump that is operated by an electric device 12, and its operation is controlled by a control unit 13, and helium gas in the pressurization line 11 is continuously supplied into the pressurization tank 7. To be able to supply. This control device 13 includes a timer circuit, and for example, releases the electromagnetic valve 6 for 1 to several seconds per minute. An on-off valve 14 is provided between the pump 5 and the pressurizing tank 7 so that the pressure in the pressurizing tank 7 does not leak through the check valve of the pump when the pressurizing device 10 is stopped. . The on-off valve 14 may be a manual type or an electromagnetic valve.
[0015]
In the operation of the liquid helium transfer device 15 of the illustrated embodiment having the above-described configuration, when the device is turned on, the normally closed electromagnetic valve 6 is temporarily opened when the device is turned on. The pressure of the helium gas stored in the gas reaches the gas layer 8 of the liquid helium container 4. The electromagnetic valve 6 closes immediately, but opens intermittently at regular intervals of about 1 minute. In addition, the pump 5 starts to move simultaneously with the power-on of the apparatus. Under the influence of the first helium gas fed in, liquid helium evaporates and the pressure in the container 4 becomes atmospheric pressure or higher. While the solenoid valve 6 is closed, a part of the evaporated helium gas is sucked by the pump 5 and stored in the tank 7. During this time, the pressure in the container 4 is maintained at atmospheric pressure or higher. Helium is continuously sent to the experimental facility 1 through a conduit 3 such as a transfer tube.
[0016]
During this time, the pump 5 performs V · Δp work on the helium gas (V is the tank internal volume, Δp is the change in pressure), and the internal energy of the helium gas increases by the same amount according to the first law of thermodynamics. Thereafter, when a predetermined time such as 1 minute elapses, the solenoid valve 6 is opened, the helium gas having high internal energy stored in the tank 7 is sent again into the container 4, and the pressure in the container 4 rises. According to the experiment, a 250 L liquid helium container could be pressurized to around 0.1 atm with only a small diaphragm pump in which the pressure of the tank with an internal volume of 10 L becomes atmospheric pressure + 1 atm in about 1 minute. This is the ability to transfer 40 L of liquid helium in about 30 minutes.
[0017]
According to the present invention, unlike the conventional one shown in FIG. 2, there is no need to provide a pump for supplying a predetermined high-pressure gas in a short time in order to pressurize the inside of the container directly by the operation of the pump. Since the pressurizing tank 7 may be maintained at a predetermined pressure by being operated, it can be operated only by using an extremely small pump such as an air pump for supplying air to a small aquarium for ornamental fish. Therefore, the entire apparatus can be made inexpensive and downsized, and the apparatus can be operated with a small amount of electric power. In addition, there is no need to install a special device on the liquid helium container side, and this device can be used simply by connecting a rubber tube or the like that is normally used to the connection port where a conventional cylinder or manual pressurizing balloon has been connected. Can be used.
[0018]
In the above embodiment, an example in which the pump for supplying helium gas to the pressurizing tank 7 is a diaphragm pump is shown. However, various pumps can be used, and the pressurization capacity of the pump is Since it may be low, an inexpensive and small pump that could not be used for transferring liquid helium in the past can be selected.
[0019]
【The invention's effect】
Since the present invention is configured as described above, it requires a large-sized pump capable of obtaining a predetermined high pressure in a short time, a strong and expensive pressure transmission pipe, a special connection device for the tank, etc. as in the conventional apparatus. In addition, since a very inexpensive and small pump can be used and a pressure transmission pipe such as a general-purpose rubber pipe and a connector for the tank can be used, an inexpensive and small liquid helium pressure transfer device can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall system of an embodiment of a liquid helium transfer apparatus according to the present invention.
FIG. 2 is an overall system configuration diagram of a conventional liquid helium transfer device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Experiment apparatus of liquid helium transfer destination 2 Liquid helium 3 Pipe line 4 Liquid helium container 5 Pump 6 Electromagnetic valve 7 Tank 8 Gas layer part 10 Pressurization apparatus 11 Pressurization pipe line 12 Electric apparatus 13 Control apparatus 14 On-off valve

Claims (1)

A container for storing liquid helium;
A conduit for transferring liquid helium in the container to a desired location;
In a liquid helium pressurizing and transferring device including a pressurizing device that intermittently applies pressure to the gas layer portion in the container and vaporizes liquid helium by air column vibration to increase the pressure in the container.
A solenoid valve and a pressurization tank are installed in order from the container side on the pressurization line communicating with the gas layer part in the container,
A pump for continuously supplying helium gas between the container and the solenoid valve in the pressure line to a pressure tank;
A liquid helium pressurizing and transferring apparatus, comprising: a control device that intermittently opens and closes the electromagnetic valve.

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