Patent ID: 6499313
Filing Date: 2002-12-31
Classification: F25J

Abstract:
A process for generating high-purity nitrogen by low-temperature fractionation of air in a rectification system for nitrogen/oxygen separation, which has at least a first rectifier column (4), said process comprising:a. introducing compressed air into the first rectifier column (4), b. removing cycle nitrogen (24) in gas form from an upper region of the first rectifier column (4), and c. compressing the removed cycle nitrogen in a cycle compressor (30), d. liquefying a first part (35) of the compressed cycle nitrogen, e. introducing a nitrogen fraction (52) of the cycle nitrogen into a high-purity nitrogen column (39) which has a top condenser (54), f. removing high-purity nitrogen (56) from an upper region of the high-purity nitrogen column (39), g. cooling the top condenser (54) of the high-purity nitrogen column (39) at least partially by liquefied cycle nitrogen (40)(67), and h. removing oxygen from the rectification system.