A method and device for preparing solid argon by liquid nitrogen

Abstract

The invention belongs to the field of ultra-low temperature solid preparation, and in particular relates to a method and a device for preparing solid argon through liquid nitrogen. The method includes: placing step: placing the heat conduction container with liquid nitrogen in the argon-containing liquid; vacuumizing step: vacuumizing the liquid nitrogen until the temperature of the liquid nitrogen drops to less than or equal to subzero 196°C to become super-cooled liquid nitrogen; the super-cooled liquid nitrogen cools the argon-containing liquid to obtain solid argon. The device includes: an outer cylinder, an outer cover, an inner cylinder, and an inner cover; the outer cylinder and the outer cover form an argon-containing liquid chamber, and the inner cylinder and the inner cover form a Liquid nitrogen warehouse. The invention obtains ultra-cold liquid nitrogen by vacuumizing the liquid nitrogen, which can freeze the impure argon-containing liquid, promote the rapid growth of solid argon (argon ice), and improve the preparation efficiency. The invention is simple and easy to implement, has low cost, is convenient for industrialized production of solid argon, and is suitable for popularization and use.

Description

technical field [0001] The invention belongs to the field of ultra-low temperature solid preparation, and in particular relates to a method and a device for preparing solid argon through liquid nitrogen. Background technique [0002] At present, the most commonly used cryogenic cold source is liquid nitrogen. Liquid nitrogen is a hazardous chemical, which is inconvenient and expensive to transport, especially when it is transported in small quantities. When liquid nitrogen is used to transport biological samples at ultra-low temperature, a Dewar tank filled with liquid nitrogen adsorption materials can be used before it can be transported as general cargo. This kind of Dewar tank with adsorption material is also called dry liquid nitrogen tank. The liquid nitrogen adsorption process takes a long time, from cooling to adsorption up to 24 hours. At present, filling liquid nitrogen into the Dewar tank is a manual operation, and the service life and performance of the adsorpti...

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Problems solved by technology

[0005] In the prior art, there are two methods for cooling liquid argon: the first is by vacuuming: put the liquid argon into a closed container, and the container is connected to a vacuum pump; in this way, part of the liquid argon absorbs heat to vaporize, and the rest of the liquid argon is cooled , can generate solid argon; the disadvantage of this method is that the cost is high; in addition, when the liquid argon is crude argon containing oxygen and nitrogen, the evaporation rates of liquid argon, liquid nitrogen, and liquid oxygen are different, and the quality of engineering and solid argon ice components hard to control

The second is through heat exchange between liquid nitrogen and liquid argon: put a test tube containing liquid argon into a beaker containing liquid nitrogen, and the liquid argon in the test tube is cooled to obtain solid argon; the disadvantage of this method is the efficiency Low speed, slow speed, high requirements on the purity of liquid argon

If liquid argon contains liquid oxygen and liquid nitrogen, it is not easy to obtain solid argon simply by cooling the test tube because the melting point is lowered; in addition, the melting point of liquid argon containing nitrogen and oxygen will be lowered, and a lower temperature is required for freezing. In the laboratory, liquid helium and low-purity liquid argon are used for heat exchange, which is expensive and not suitable for industrial production of solid argon.

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