A high purity nitrogen gas generator is provided which can be rapidly returned to a stable state when boil-off gas is generated in a liquid nitrogen storage tank 10.;The high purity nitrogen gas generator includes a liquid nitrogen storage tank 10, a rectification column 7, a liquid nitrogen introduction pipe P15 for supplying liquid nitrogen from the liquid nitrogen storage tank to the rectification column, an inverted U-type pipe P13 whose upper end is positioned at a height in the vicinity of the top portion of said liquid nitrogen storage tank connected to the bottom portion of said liquid nitrogen storage tank 10, said liquid nitrogen storage tank 10 and said liquid nitrogen introduction pipe P15 being connected with each other by way of said inverted U-type pipe, the upper end of the inverted U-type pipe and the top portion of said liquid nitrogen storage tank are connected with each other by means of a pipe P17 and a control valve V3 provided on the way of said pipe P17.
展开▼
