Abstract: A device for supplying cooling air under pressure, e.g. for cooling the electric apparatus in an aeroplane at rest on the ground, comprising an internal combustion motor, such as a diesel motor, an air compressor having its suction line connected to the atmosphere, the pressure side of this air compressor supplying air under pressure; and a cooling circuit for cooling this air under pressure, said cooling circuit including a compressor, a condenser and a cooler. A cooler with air-cooling is operative between the air compressor and the said cooler in the cooling circuit, while actuating means, which reacts to the temperature of the atmosphere switches the compressor in the cooling circuit on and off when the temperature of the atmosphere rises or falls to a predetermined value.

Abstract: In a heat exchanger, a thin tube plate is reinforced by means of a heavy support plate spaced therefrom. The tubes are fixed to the tube plate and pass through enlarged openings in the support plate but are anchored to the support plate by anchoring devices which allow the liquid to be heated to pass from the chamber provided between the two plates through the annular passages between the tubes and the enlarged openings of the support plate.