METHOD OF AIR SEPARATION BY LOW-PRESSURE DISTILLATION AND RELATED DEVICE Russian patent published in 2009 - IPC F25J3/04 

FIELD: motors and pumps.

SUBSTANCE: air pressure is increased to the high level exceeding the medium pressure level. Then air is cleaned. Part of the clean air flow (11) is cooled in a heat-exchanger (9) and separated into two fractions (13, 15). Each of the fractions is expanded in the turbine expander (17, 19). Pressure at the inlet of two turbine expanders is at least in five bars more than the medium pressure. In addition, pressure at the outlet of at least one turbine expander is equal to the medium pressure. Part of the air subject to expansion in one of the turbine expander, is directed to the medium pressure column (100) of double-column or triple-column air separator. After that air is supplied to the low-temperature compressor (23), which is mechanically connected with one (19) of turbine expanders. The said air is pre-cooled in the main heat-exchanger and pumped at the temperature higher than that at the outlet. So the compressed fluid is again directed to the heat-exchanger where one part of the fluid is condensed. While pressurised fluid (25) discharged from one of the columns (200) is subject to (pseudo)evaporation in heat exchangers under evaporation temperature, the turbine expander (17) not linked with low-temperature booster compressor is connected to the booster compressor (5), which is followed by the cooler.

EFFECT: possible use of process charts based on low-temperature booster compressor without energy dissipation system, which is built into turbine expander shaft for any air separating plants.

8 cl, 2 dwg