초록 ▼

An APU compartment drain system is provided that ensures thorough draining of fluids from the compartment that may otherwise accumulate therein. Such drainage is achieved despite the presence of a predetermined range of negative pressure differentials across the compartment. In accordance with one e

An APU compartment drain system is provided that ensures thorough draining of fluids from the compartment that may otherwise accumulate therein. Such drainage is achieved despite the presence of a predetermined range of negative pressure differentials across the compartment. In accordance with one embodiment of the invention, a floor disposed along the tailcone lower skin is configured to collect any and all liquids that may leak or otherwise drop from the APU. A drain tube is in fluid communication at its upper end to the floor and at its lower end to a check valve selectively open and placed as closely as possible to the aircraft overboard drain port. Liquids collected by the floor are gravitationally directed into the drain tube upper end. The check valve is configured to be open to fluid drainage from the tube out of the drain port when the pressure head of fluid upstream of the check valve exceeds fluid pressure at the drain port due to aircraft or APU operating conditions. The check valve is configured to be closed to fluid drainage from the tube out of the drain port when the fluid pressure at the drain port due to aircraft or APU operating conditions exceeds the pressure head of fluid upstream of the check valve. Once the maximum negative pressure differential encountered by a particular aircraft is determined, the check valve is placed relative to the floor pan such that fluid completely filling only the tube will provide the maximum pressure head necessary to open the check valve and provide draining.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for draining fluid from an aircraft auxiliary power unit compartment to atmosphere comprising:a false floor, said false floor placed below the auxiliary power unit, said false floor configured to collect fluids released by the auxiliary power unit;a tube comp

[ What is claimed is:] [1.] An apparatus for draining fluid from an aircraft auxiliary power unit compartment to atmosphere comprising:a false floor, said false floor placed below the auxiliary power unit, said false floor configured to collect fluids released by the auxiliary power unit;a tube comprised of a material that is at least fire resistant, said tube having first and second ends, said first end in fluid communication with said false floor; anda check valve comprised of a material that is at least fire resistant having an inlet and an outlet, said inlet being attached to and in fluid communication with said tube second end, said outlet being in fluid communication with the atmosphere, said check valve being configured to close when fluid pressure at said outlet exceeds fluid pressure at said inlet, and to open when fluid pressure at said inlet at least equals fluid pressure at said outlet.