Gas generator for the preparation of highly pure nitrogen

摘要

PROBLEM TO BE SOLVED: To provide a highly pure nitrogen gas producing apparatus which can return to a stable condition quickly when a boil off gas is generated in a liquid nitrogen storage tank 10. ;SOLUTION: This apparatus is provided with a liquid nitrogen tank 10, a filler type fractionating column 7 using a liquid nitrogen as reflux liquid, a liquid nitrogen introduction pipe P15 to supply the liquid nitrogen to the filler type fractionating column from the liquid nitrogen tank and a heat exchanger 6 for cooling compressed air to be supplied to the filler type fractionating column. An inverted U-shaped piping P13 with the height of the upper end part thereof positioned at the height near the top part of the liquid nitrogen tank is connected to a bottom part of the liquid nitrogen tank 10 and the liquid nitrogen tank 10 is connected to a liquid nitrogen introduction piping P15 through the inverted U-shaped piping while the upper end part of the inverted U-shaped piping is connected to the top part of the liquid nitrogen tank by a piping P17. A control valve V3 is provided in the course thereof.;COPYRIGHT: (C)1997,JPO