Abstract: A plate fin heat exchanger assembly (S) for a cryogenic air separation unit, comprising: a heat exchanger having at least two cryogenic liquid inlets (B,C) at least two cryogenic liquid outlets (B,C), at least one nitrogen-rich stream inlet (D) at a first end of the heat exchanger and at least one nitrogen-rich stream outlet at a second end of the heat exchanger, the heat exchanger configured to receive a flow of at least one nitrogen-rich stream (WN,LPGAN) of the air separation unit at the at least one nitrogen-rich stream inlet and separate flows of at least two cryogenic liquids (LOX,LIN,LR) at the at least two cryogenic liquid inlets; wherein the inlet of the first of the cryogenic liquids is closer to the first end than the outlet of the second of the cryogenic liquids.

Abstract: The object of the present invention is to provide a different solution for revamping existing producing apparatuses so as to increase the production of low pressure pure nitrogen while controlling as far as possible the capital and operation expenditures. The revamping solution comprises increasing the diameter and/or height of a pure nitrogen column to thereby improve the production capacity thereof; choosing to switch the conduits where the waste liquid nitrogen and pure liquid nitrogen are passed through in the subcooler according to the increment of the low pressure pure nitrogen production; adding an additional heat exchanger to conduct a heat exchange between a portion of the medium pressure air and the increased low pressure pure nitrogen; or simultaneously switching the main parts of the conduits which transfer the pure liquid nitrogen and waste liquid nitrogen from a first column of higher pressure to a second column of lower pressure while performing the above revamping.

Abstract: The object of the present invention is to provide a different solution for revamping existing producing apparatuses so as to increase the production of low pressure pure nitrogen while controlling as far as possible the capital and operation expenditures. The revamping solution comprises increasing the diameter and/or height of a pure nitrogen column to thereby improve the production capacity thereof; choosing to switch the conduits where the waste liquid nitrogen and pure liquid nitrogen are passed through in the subcooler according to the increment of the low pressure pure nitrogen production; adding an additional heat exchanger to conduct a heat exchange between a portion of the medium pressure air and the increased low pressure pure nitrogen; or simultaneously switching the main parts of the conduits which transfer the pure liquid nitrogen and waste liquid nitrogen from a first column of higher pressure to a second column of lower pressure while performing the above revamping.

Abstract: An apparatus and process for separating air by cryogenic distillation includes a heat exchanger, a column system having at least one cryogenic distillation column, a conduit for supplying the column system with cooled air from the heat exchanger, a storage tank, a conduit for removing a liquid from the column system and sending it to the storage tank, at least one pump, at least one conduit for sending pumped liquid from the outlet of the or each pump to the heat exchanger, at least one conduit connected to the outlet of the pump or at least one outlet of at least one pump and to a column of the column system, said conduit passing directly to the column without passing via the storage tank.

Abstract: An apparatus and process for separating air by cryogenic distillation includes a heat exchanger, a column system having at least one cryogenic distillation column, a conduit for supplying the column system with cooled air from the heat exchanger, a storage tank, a conduit for removing a liquid from the column system and sending it to the storage tank, at least one pump, at least one conduit for sending pumped liquid from the outlet of the or each pump to the heat exchanger, at least one conduit connected to the outlet of the pump or at least one outlet of at least one pump and to a column of the column system, said conduit passing directly to the column without passing via the storage tank.