Browse Prior Art Database

Liquid Nitrogen

IP.com Disclosure Number: IPCOM000087311D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Halperin, BI: AUTHOR

Abstract

In certain applications, liquid nitrogen is used as a refrigerant.

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This is the abbreviated version, containing approximately 89% of the total text.

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Liquid Nitrogen

In certain applications, liquid nitrogen is used as a refrigerant.

For example, in certain processes for the treatment of industrial wastes, a solvent containing air is passed over a refrigerant coil containing the cooled refrigerant. By lowering the air temperature, the solubility of the solvent in the air is greatly reduced and the solvent with its pollutants condenses on the coil. Water in the form of ice is also deposited on the coil, so that periodically a defrosting cycle is required to remove the ice.

With conventional type refrigerants, the refrigeration system is highly sensitive to contaminants or impurities in the refrigerant. Thus, it was necessary to employ a closed loop system to avoid contamination of the refrigerant. Consequently, defrosting was accomplished externally or otherwise a complex purging system and/or very special noncontaminating defrosting agent were required to insure that the defrosting agent was removed from the coil prior to the next refrigerant cycle. Alternatively, in an open loop system, the refrigerant in the coil is expelled into the atmosphere as it is being replaced by the defrosting agent at the commencement of the defrosting cycle. Since the refrigerant and/or the special defrosting agent used therewith generally contain harmful pollutants, conventional open loop systems were in general not desirable.

However, by using liquid nitrogen it is less susceptible to contamination from the defrosting agent. More...