| 摘要 |
An inerting system for an aircraft fuel tank 10 uses an air separation device to produce a supply of nitrogen-enriched air 12 to replenish the fuel tank on consumption of fuel and to maintain the pressure difference across the walls of the tank below design limits. The air separation device provides substantially the whole of the mass of the gas required and so there is substantially no inward venting. This provides a substantially homogenous nitrogen content in the air in the tank. In a preferred embodiment, the nitrogen-enriched air is supplied to the fuel tank 10 in a number of spaced apart locations 20 to reduce variations in concentration of nitrogen within the tank 10. The nitrogen-enriched air is supplied at a higher rate during descent, relative to the flow rate at cruise conditions. At lower flow rates the concentration of nitrogen is higher, while at higher flow rates the concentration of nitrogen is lower. Preferably, the air separation device comprises a hollow fibre membrane. |
