| abstract |
An installation for separating air by cryogenic distillation comprises a compressor, a heat-exchange line, a system of columns, an electric motor for driving the compressor, a pipe for taking off a liquid from the system of columns, a pump for pressurising the liquid drawn off and means for affording an exchange of heat between the air compressed by the compressor and the liquid pressurised by the pump and means for reducing the output pressure of the pump according to the frequency of the electricity supplying the electric motor. |