METHOD OF WASHING AIRCRAFT FUEL SYSTEM, COMPLEX AND GAS SATURATION APPARATUS FOR REALIZATION OF THIS METHOD Russian patent published in 2006 - IPC B08B9/93 B05B7/04 B01F3/04 

FIELD: methods of cleaning aircraft fuel tanks and fuel lines; servicing light, medium and heavy aircraft.

SUBSTANCE: proposed method may be used for cleaning aircraft fuel tanks and fuel lines equipped with drain valves, tank venting and pressurization systems, refueling system before conducting acceptance flight tests. Method is used for cleaning the fuel tanks equipped with drain valves, venting system and pressurization system, refueling system. Proposed method consists in introducing nitrogen into fuel, delivery of nitrided fuel to fuel tanks, circulation of this fuel through tanks and draining it from tanks. Nitrided fuel is supplied to tanks through drain valves of tanks; after expansion of nitrided fuel in tanks due to pseudo-boiling, fuel is drained through aircraft refueling system; ratio of sectional areas of drain and delivery mains is maintained equal to or exceeding degree of expansion of nitrided fuel in tanks. Complex proposed for realization of this method includes fuel truck, nitrogen storage and supply unit, fuel and nitrogen dispensing unit mounted on mobile trolley and fuel drain and filtration unit which are connected with system to be washed by means of flexible hoses. Proposed complex is also provided with fuel and nitrogen dispensing manifold connected with fuel and nitrogen dispensing unit and additional fuel truck; dispensing manifold is fitted with cocks which are connected with outlet branch pipes of aircraft by means of flexible hoses; additional fuel truck is connected with aircraft refueling system by means of flexible hose for drainage, filtration and check of washing. Gas saturation apparatus for washing the aircraft fuel system has cylindrical hollow housing with filtering cartridge inside it; on one side this housing is provided with contraction with spiral volute having axial and spiral inlets for connection with compressed nitrogen and fuel supply lines; on other side, housing is provided with diffuser forming outlet for connection with nitrided fuel supply line. Filtering cartridge is made in form of thick-walled porous hollow cylinder made from sintered titanium or corundum powder; it has blind end face and open end is mounted in axial inlet of spiral volute; inner surface of cylindrical hollow housing is provided with regular vortex-forming projections formed by intersection of two helical grooves at equal pitches of rectangular section and opposite direction of rotation.

EFFECT: increased productivity of process; enhanced ecological safety; reduce danger of fire; reduced toxic emissions of expansion products of nitrided fuel.

8 cl, 2 dwg