METHOD FOR LOW TEMPERATURE SEPARATION OF COMPRESSED MATERIALAIR FOR PRODUCING HIGH PRESSURED OXYGEN AND NITROGEN PRODUCT

摘要

PURPOSE: To produce elevated pressure oxygen and nitrogen products through low pressure distillation of air by cooling a portion of material air through indirect heat exchange with boosted nitrogen rich flow thereby condensing it partially and then withdrawing an oxygen flow and a vapor flow containing a specified quantity of nitrogen from a low pressure column. CONSTITUTION: Oxygen rich column bottom liquid from a high pressure column 5 in a pipe line 10 is fed from an intermediate part to a low pressure column 6 and that flow is distilled in the low pressure column 6 along with liquid air being fed to the top of the low pressure column 6 in a pipe line 162 and separated into a liquid oxygen column bottom liquid and nitrogen rich column top product containing at least 80% of nitrogen. A portion of the liquid oxygen column bottom liquid in the pipe line 20 is withdrawn from the bottom of the low pressure column 6 and separated into a liquid oxygen product and a gas oxygen product gasified through a heat exchanger 1. The nitrogen rich column top product is withdrawn from the top of the low pressure column 6 through a pipe line 30. According to the method, elevated pressure oxygen and nitrogen product can be produced through low pressure distillation of air.