METHOD FOR REDUCING PRELIMINARY COOLING OPERATING TIME OF ARGON UNIT

摘要

PURPOSE: A method for reducing preliminary cooling operating time of argon unit is provided to reduce time required for producing argon gas in the pure liquid state by sucking in and compressing the atmospheric air so that crude argon gas is fractionated by boiling point difference and removing oxygen contained in the crude argon gas. CONSTITUTION: The method is characterized in that a boiler (600A) of a pure argon column (600) is precooled by the crude argon in the liquid state after preparing crude argon in the liquid state by heat exchanging crude argon gas (-184 deg.C) coming out of a lower column (200A) of a crude argon column (200) composing the argon unit (10) and liquid nitrogen (-197 deg.C) coming out of an upper column (100C) of an air separator (100) each other in a heat exchanger (800), wherein an argon compressor (400) is operated early by vaporizing the liquid crude argon so that the vaporized crude argon is supplied into the lower column (200A) of the crude argon column (200), thereby obtaining the proper concentration (2.8%) of oxygen contained in gas emitted from the lower column (200A) of the crude argon column (200) within six hours after storing almost refined crude argon in the liquid state disused from a lower column (600B) of the pure argon column (600) into a liquid crude argon recovery tank (700) until proper purity (purity when concentration of other gases except argon is 10 ppm or less) of the liquid argon is obtained.