Improvements in or relating to methods of and means for supplying inert gases to the fuel tanks of aircraft

796,349. Forcing liquids by gaseous pressure. BRITISH OXYGEN CO., Ltd. July 5, 1956 [July 7, 1955], No. 19714/55. Classes 8(2) and 102(2). Inert liquefied gas, e.g., nitrogen is forced from an insulated container 10, Fig. 1, through an outlet 13 by pressure in the gas space of the container generated by a conventional pressurebuild-up circuit comprising an evaporating coil 15 in a valved bleed-branch of the outlet 13, a combined vent and pressure build-up valve 21 and a duct 19 leading to the gas space of the container, and the major part of the liquid nitrogen is forced through a vaporizing coil 26 heated by ambient air, e.g., in an aircraft cabin and the resulting nitrogen gas is bubbled through petrol in a tank 29 to effect cooling and discharge thereof. In a modification heating of the vaporizing coil 26 is effected by a muffle, the fuel supply to which is controlled by a valve responsive to the pressure difference between that in the gas space of the petrol tank and the atmosphere. In a further modification liquefied gas leaving the container 10, Fig. 3, is proportioned by a thermostatically controlled valve 45 into a first portion which passes through the vaporizing coil 26 into a mixing chamber 47 where it is mixed with the second portion in a duct 46 ; the resulting nitrogen gas then passing to the tank 29.