Patent ID: 6619025
Filing Date: 2003-09-16
Classification: F02C,F05D,Y02T

Abstract:
A fuel system for use in an aircraft engine, the fuel system comprising:a fuel pump adapted to pressurize fuel from a fuel supply; a plurality of nozzles arranged in a combustion chamber; a fuel metering unit adapted to control the flow of fuel from the fuel pump to the fuel nozzles; a fuel manifold adapted to communicate the flow of fuel to the fuel nozzles; an ecology valve having a piston chamber, a piston slidable in the piston chamber dividing piston chamber into a sump chamber and an actuation chamber, the piston sliding between shut-off and run positions, the piston sliding toward the shut-off position upon engine shut-off and suctioning sufficient fuel from the fuel manifold into the sump chamber to prevent coking of the nozzles, pressurization of the actuation chamber driving the piston toward the run position returning fuel contained in sump chamber to the fuel manifold; and a drain passageway having an open state and fluidically connecting the actuation chamber to sump chamber when the piston is sliding toward the shut-off position allowing fuel contained in the actuation chamber to drain to the sump chamber.