FIELD: machine building.
SUBSTANCE: invention relates to low-temperature air separation. Air is compressed in main air compressor (2). First partial flow (8, 11, 14) of compressed air (7) is cooled in the main heat exchanger (13) and expands in the first air turbine (15). First part of the expanded first flow (16) is introduced into the system of distillation columns. Second partial flow (12, 27, 29, 30) of air compressed in compressor (2) is compressed in additional compressor (9), cooled in heat exchanger (13), compressed in second additional compressor (28), cooled in heat exchanger (13) and then expanded (31) and introduced (32) into system of distillation columns. Third partial flow (436, 37) of supplied air (7) compressed in compressor (2) is cooled in the main heat exchanger (13) and expands in the second air turbine (38). First part (339) of the expanded third partial flow is introduced (340) into the system of distillation columns. First flow of product (69; 75) in liquid form is extracted from the system of distillation columns, compressed (71; 76), evaporated, heated in the main heat exchanger (13) and extracted as the first compressed gaseous product. Third partial flow (37) expands in the second air turbine (38). First part (339) of expanded third partial flow is cooled in heat exchanger (13), liquefied and then expanded (341) and introduced into system of distillation columns.
EFFECT: technical result is higher energy efficiency.
8 cl, 3 dwg
