Process and installation for the separation of a gaseous mixture by cryogenic distillation

摘要

Process and installation for the production of variable flow rates of at least one pure component by fractionation of a mixture in a distillation apparatus (15), containing structured packing (17) and dimensioned to handle a nominal flow rate of the mixture at nominal pressure. To obtain higher production than the nominal production, there is increased proportionately to the ratio of the productions, the flow rate of the mixture distilled in the apparatus (15). Also increased is the operating pressure of the apparatus so as to increase the flooding limit of the apparatus under similar proportions. Preferably, the mixture is air. There is a compressor (3) for the mixture to be fractionated designed for nominal capacity and, upstream of the latter, a blower (1). Alternatively, there can be a compressor (3) for the mixture to be fractionated designed for maximum capacity. There is a heat exchange line (9) in which is effected an indirect heat exchange between the mixture to be fractionated which is cooled therein and at least one product of the apparatus (15) which is reheated therein, the heat exchange line being designed for operation at nominal production, and in which the ratio between the number of passages allotted to the mixture to be fractionated and the number of passages allotted to at least one product of the apparatus is variable according to the production regime that prevails.