| abstract |
The invention relates to an apparatus for separating air by cryogenic distillation comprising a compressor (100), an exchange line (4), a system of columns (1), an electric motor (M) for driving the compressor, a duct for extracting a liquid from the system of columns, a pump (6) for applying pressure to the extracted liquid, means enabling heat exchange between the air compressed by the compressor and the liquid (16) pressurized by the pump, and means for lowering the output pressure of the pump depending on the frequency of the electricity powering the electric motor. |