US Patent 7410526 System for the preparation of air

The present invention relates to a system for the preparation of air in an aircraft comprising a compressor charged with air on the inlet side, comprising a supply air heat exchanger which is downstream of the compressor, is charged with air compressed in the compressor on the pressurized air side on the inlet side and which is in communication on the pressurized air side on the outlet side with a system or unit which is to be supplied with pressurized air, and comprising a turbine which is charged on the inlet side with pressurized air from a pressurized air supply separate from the air supply of the compressor and is in communication on the outlet side with the low pressure side inlet of the supply air heat exchanger and which is in communication with the compressor such that the compressor can be driven by means of the turbine.