Patent GB-630267-A (GB)
Title: Improvements in air conditioning systems for aircraft and like cabins
IPC: B64D13/06
Filed: 1947-01-08
Abstract: 630,267. Ventilating aircraft. GARRETT CORPORATION. Jan. 8, 1947, No. 637 Convention date, April 6, 1946. [Class 137] [Also in Groups XXVI and XXXV]  The cabin 10 of an aircraft has air supplied at 12 and exhausted at 14, the exhausted air being compressed at 30, passed through a heat-exchanger 55, supplied with combustion products at 33 and used to drive a turbine 32 which drives the compressor 30. The air then passes through a conduit 45 to be augmented with combustion products at 49 and used in the turbine 46 which drives the initial compressor 16 for the replenishing air. The turbine 46 is by-passed by a conduit 52 controlled by a valve 53 which, with the burner valve 50, determines the output of the turbine 46. The exhaust and by-passed air passes through the heat-exchanger 55 and conduit 51 to valves 57, 58, 59 which determine the flow of air to a de-icer through the pipe 61, to the atmosphere through the pipe 63, or through a pipe 62 to a heat exchanger 25 in the replenishment air supply conduit 22. The compressor 16 passes air through a cooler 20 to a conduit 18 which is connected at 130 to the conduit 14 whereby exhaust air may be supplemented by new air. The new air passes through a compressor 19 driven by the turbine 32, and then passes through a cooler 23 to a turbine 24 in which it is further cooled. The turbine 24 is coupled by bevels to the main turbine shaft 35. The new air then passes through the exchanger 25 in which it is heated and into the inlet conduit 22, 12. An orificed baffle 80 is placed in the conduit 22, the pressure difference on the two sides of the baffle being dependent upon the amount of flow through the orifice. The chambers 83 and 84 are connected to the conduit on opposite sides of the baffle and are separated by a diaphragm 86 which is pulled by a spring 87. This pull is balanced by the pull of an evacuated bellows 88 coupled to the diaphragm by a rod 89 which carries fingers 90, 91 arranged to press one or the other of contacts 92, 93 against the central contact 94 to control a reversible motor 67 geared to the control valve of the burner 33. The pressure in the cabin is controlled automatically by a unit 100 comprising a chamber 103 connected to the cabin atmosphere through a hole 126, a diaphragm 102 being responsive to differences between the pressure in the chamber 103 and in the cabin. The diaphragm is connected by levers 106, 108, 110 and rods 107, 109 with the valves 53, 50. The pressure in the chamber 103 is maintained constant by valves 115, 116 which bleed excess pressure from the chamber into the atmosphere pipes 122, 123 and are under the control of bellows bulbs 117, 118. The valves 115, 116 are carried on levers 120 or are mounted directly on the bellows, and are urged towards closed position by springs 121. The bellows 118 is connected at 124 to atmosphere, so that the valve 116 is actuated in relation to the difference of atmospheric and chamber pressures, whereas the bellows 117 is sealed, so that the  valve 115 is actuated in relation to the absolute pressure in the chamber. If the cabin pressure varies for the controlled chamber pressure, the diaphragm 102 moves accordingly to effect correcting movements of the valves 53, 50. A second air inlet, for rammed air, is provided, the conduit 131 being controlled by a check valve 132. Excess power from the turbine 32 is used in the generator 40.