Back to results
US 5,345,773 AGranted
Method and apparatus for the production of ultra-high purity nitrogen
AssigneeTeisan Kabushiki Kaisha
InventorsTakashi Nagamura, Takao Yamamoto
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeTeisan Kabushiki Kaisha
InventorsTakashi Nagamura, Takao Yamamoto
Estimating the term…
A method and apparatus for separating air by low temperature liquefaction and fractionation wherein feed air is compressed and cooled and supplied to the high pressure stage of a two-stage fractionation column from the bottom of the high pressure stage of which liquid is expanded and introduced at an intermediate level of the low pressure stage and a gaseous nitrogen product is removed from the top of the high pressure stage of the column, and wherein an oxygen product is removed from the bottom of the low pressure stage and a gaseous nitrogen product is removed from the top of the low pressure stage. Both stages contain solid material providing solid surfaces on which mass transfer takes place to effect fractionation over a substantial vertical distance. The improvement comprises removing a liquid from the high pressure stage intermediate the height of the solid material therein. The removed liquid is subcooled and expanded to produce a gas and a liquid, and the last-named liquid is withdrawn as ultra-high purity nitrogen.
In a method for separating air by low temperature liquefaction and fractionation wherein feed air is compressed and cooled and supplied to a high pressure stage of a two-stage fractionation column from the bottom of the high pressure stage of which liquid is expanded and introduced at an intermediate level of a low pressure stage of the column and a gaseous nitrogen product is removed from the top of the high pressure stage, and wherein an oxygen product is removed from the bottom of the low pressure stage and a gaseous nitrogen product is removed from the top of the low pressure stage, both of said stages containing solid material providing solid surfaces on which mass transfer takes place to effect fractionation over a substantial vertical height in each said stage;
Apparatus for separating air by low temperature liquefaction and fractionation wherein feed air is compressed and cooled and supplied to a high pressure stage of a two-stage fractionation column from the bottom of the high pressure stage of which liquid is expanded and introduced at an intermediate level of a low pressure stage of the column and a gaseous nitrogen product is removed from the top of the high pressure stage, and wherein an oxygen product is removed from the bottom of the low pressure stage and a gaseous nitrogen product is removed from the top of the low pressure stage, both of said stages containing solid material providing solid surfaces on which mass transfer takes place to effect fractionation over a substantial vertical height;
Dependencies are inferred from the claim text.