AIR SEPARATION METHOD IN CRYOGENIC DISTILLATION APPARATUS HAVING AT LEAST ONE COLUMN AND CRYOGENIC DISTILLATION APPARATUS

摘要

PURPOSE: To make strict purity requirements unnecessary by storing refrigeration in the form of nitrogen rich liquid by removing refrigeration from a distillation apparatus as supply material air pressure increases and adding refrigeration from the stored nitrogen rich liquid to the distillation apparatus. ;CONSTITUTION: Refrigeration in the form of nitrogen liquid is removed from a distillation column 24 via a pipeline 44 in order to respond to increase in a demand of a gaseous oxygen product by a pipeline 48 and is stored in a holdup tank 60. As a result, purity of a product is prevented from being lowered. Accompanying the demand of the gaseous oxygen product decrease, the liquid in the distillation column 24 is evaporated into gas and temperature in the distillation column 24 decrease, and for compensating this, flow rate entering an LP column 42 of liquid nitrogen flowing from the holdup tank 60 into the distillation apparatus 24 is increased by means of a valve 54. With this method, an additional reflux can maintain purity of low pressure nitrogen product in a pipeline 46 within specifications.;COPYRIGHT: (C)1993,JPO