Process for the delivery of a cryogenically separated gas mixture component at a variable rate

摘要

Oxygen is delivered at a variable flow rate from a distillation system (124, 150) in which there is essentially constant flow rates within the columns (124, 150). Liquid oxygen (180) is withdrawn at a substantially constant rate from the distillation column system and at lest during periods of less than average oxygen delivery rates at least a portion of the withdrawn liquid oxygen is directed to a liquid oxygen storage vessel (182). Liquid oxygen (184) is withdrawn (184) from the liquid oxygen storage vessel at a variable rate and vaporized in a main heat exchanger (112) against an incoming variable flow rate of air (130) which is condensed to form a liquid air stream (132) and then sent to the distillation column system. A liquid mixture is withdrawn from the distillation column system at a location above the bottom of a column (124) where a liquid air stream (136) is fed to the distillation column system, and at least a portion of the liquid mixture is directed to a liquid mixture storage vessel (142) during periods of higher than average oxygen delivery rate. The invention also is generally applicable to cryogenic gas separations.