Self-pressurizing device for liquid helium dewar and pressurizing method

Abstract

The invention discloses a self-pressurizing device for liquid helium dewar and a pressurizing method, and aims at solving the technical problems that according to a liquid helium dewar pressurizing manner in the prior art, helium waste is likely to be caused, and the pressurizing operation cost is high. The self-pressurizing device comprises the dewar for storing low-temperature liquefied gas. Thedewar communicates with an external heat exchange piston through a first pipeline. The first pipeline is provided with a pressurizing valve. The heat exchange piston comprises a heat exchange cavityand a piston rod capable of sliding in the heat exchange cavity in a reciprocating manner. The first pipeline comprises an outer pipe and an inner pipe. Gas flow in the outer pipe and the inner pipe is independent. The heat exchange cavity comprises a first side wall and a second side wall. The first side wall is provided with an air inlet valve. The second side wall is provided with an exhaust valve. The air inlet valve is connected with the end, away from the dewar, of the outer pipe through a second pipeline. The exhaust valve is connected with the end, away from the dewar, of the inner pipe through a third pipeline, and the other end of the inner pipe is connected with a heat exchange air bag arranged in the dewar.

Description

technical field [0001] The invention relates to the technical field of liquid helium pressurization, in particular to a self-pressurization device and a pressurization method for a liquid helium Dewar. Background technique [0002] In the process of carrying out scientific research in the low temperature field, it is an indispensable link to transport liquid helium to experimental instruments. At present, the commonly used delivery method is to insert the infusion tube at room temperature (300K) into the Dewar (4.2K) , the liquid helium vaporizes when heated, the pressure in the Dewar bottle rises, and the liquid helium is squeezed out from the infusion tube, thereby completing the delivery of the liquid helium. The liquid level keeps dropping, the infusion tube and the liquid helium gradually reach thermal equilibrium, and the pressure in the Dewar drops accordingly. When the pressure in the Dewar drops to a certain threshold, the liquid helium in the Dewar cannot continue ...

AI Technical Summary

Problems solved by technology

[0009] The present invention provides a self-pressurizing device and a pressurizing method for liquid helium Dewar in order to overcome the technical problems that the liquid helium Dewar pressurization method easily causes helium waste and the cost of the pressurization operation is relatively high in the prior art , the device can realize the continuous pressurization of liquid helium dewar, and the pressurization operation is convenient and efficient

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