| 摘要 |
PROBLEM TO BE SOLVED: To provide a nitrogen generating method capable of substantially reducing power consumption, amount of cold and equipment costs by substantially reducing amount of material air. SOLUTION: The compressed air introduced into a high-pressure tower 11 is cryogenically separated so that liquid air 13 is stored at a bottom portion, nitrogen is taken out from an upper portion in a gas state, the liquid air 13 at the bottom portion of the high-pressure tower 11 is introduced to a low-pressure tower 12, the liquid air 13 introduced into the low-pressure tower 12 is cryogenically separated so that oxygen-enriched liquid air 22 is stored at the bottom portion, nitrogen is taken out from the upper portion as a product gas in a gas state, nitrogen taken out from the upper portion of the high-pressure tower 11 is introduced into a condenser 16 to be liquefied, a part of the liquid nitrogen is refluxed to the high-pressure tower 11, the residual is supplied to the upper portion of the low-pressure tower 12, and the liquid nitrogen or liquid oxygen as cold is introduced into the low-pressure tower from the outside of a system. The liquid air 13 taken out by a taking-out pipe 20 is introduced from a part having the number of theoretical stages within a range of 1-10 stages from a tower bottom portion side in a rectifying portion 12a of the low-pressure tower 12. COPYRIGHT: (C)2007,JPO&INPIT
|
