초록 ▼

The invention discloses method and apparatus for achieving higher O2 delivery pressure coupled with high product recovery in cryogenic air distillation plants, without additional power consumption. Products include high purity oxygen plus coproduct argon, or medium purity oxygen plus optional coprod

The invention discloses method and apparatus for achieving higher O2 delivery pressure coupled with high product recovery in cryogenic air distillation plants, without additional power consumption. Products include high purity oxygen plus coproduct argon, or medium purity oxygen plus optional coproduct nitrogen. Compander driven compressor (5) boosts the pressure of a minor fraction of air which totally condenses to evaporate LOX in evaporator (6), and liquid air is split into 2 intermediate refluxes.

대표청구항 ▼

A dual pressure cryogenic distillation process for producing gaseous oxygen from a supply of compressed and cleaned air comprising: a. cooling a major fraction of said compressed and cleaned air: b. rectifying said major fraction in a high pressure rectifier to liquid nitrogen overhead product and k

A dual pressure cryogenic distillation process for producing gaseous oxygen from a supply of compressed and cleaned air comprising: a. cooling a major fraction of said compressed and cleaned air: b. rectifying said major fraction in a high pressure rectifier to liquid nitrogen overhead product and kettle liquid bottom product; c. distilling the kettle liquid in a low pressure column to liquid oxygen bottom product and gaseous nitrogen overhead product; d. working expanding a compensating vapor comprised of at least 77% N2 thereby producing refrigeration; e. further compressing the remaining minor fraction comprising no more than about 30% of said compressed, cleaned warm air in a compressor powered by said expansion work; f. pressurizing said liquid oxygen to at least about 0.2 ATA above LP column bottom pressure; g. cooling the minor air fraction to near its dewpoint; h. condensing substantially all the minor air fraction by exchanging latent heat with said pressurized liquid oxygen; i. withdrawing evaporated oxygen as product; j. dividing the condensed air into two streams, each comprising at least 15% of said minor fraction; k. injecting one of said streams into an intermediate height of the HP rectifier and injecting the second stream into an intermediate height of the LP column; and l. separately reboiling said LP column bottoms by exchanging latent heat with at least one of: (i) HP rectifier overhead vapor and (ii) partially condensing major fraction of said supply air.