Fuel transfer apparatus

摘要

A fuel supply system including a fuel tank, a feed conduit through which fuel is pumped from the fuel tank, and a return conduit through which excess fuel is returned to the fuel tank. The fuel tank has first and second sumps. The system comprises an ejector pump having a pressure chamber opening through a throat into the first sump. The pressure chamber is connected through a communication conduit to the second sump. The ejector pump includes a fuel nozzle having an inlet port connected to the return conduit and a discharge end opening into the pressure chamber for discharging a jet of fuel into the pressure chamber to create a negative pressure in the pressure chamber so as to suck fuel through the communication conduit from the second sump. In one aspect of the invention, a relief valve is provided which is responsive to a back pressure produced in the fuel nozzle for relieving the back pressure to the first sump when the back pressure exceeds a predetermined value. In another aspect of the invention, the fuel nozzle is designed to diffuse the fuel discharged therefrom over the cross-sectional area of the throat. In still another aspect of the invention, the throat has a length and an inner diameter to provide a length-to-diameter ratio ranging from 2 to 8.