| 摘要 |
A fuel flow dividing ecology valve (35, 59) selectively conveys fuel from a fuel source (31) to at least a secondary gas turbine engine intake manifold (25) during engine operation and withdraws fuel therefrom upon cessation of engine operation. The valve includes a flow dividing valve portion (41) having an inlet (65) coupled to the fuel source and an outlet (67) coupled to the secondary manifold. The flow dividing valve portion transitions from a fuel flow blocking condition to a condition in which fuel may flow from the source to the manifold solely in response to the fuel pressure differential between the inlet and the outlet. The valve also includes an ecology valve portion (43) controlled solely by the fuel pressure differential between the dividing valve portion inlet and outlet for withdrawing fuel from the secondary engine intake manifold when the engine is de-energized thereby purging the manifold of fuel, and returning withdrawn fuel to the manifold during subsequent engine operation. In one form, fuel is conveyed from the fuel source exclusively to the secondary gas turbine engine intake manifold during engine operation and withdrawn exclusively therefrom upon cessation of engine operation. In another form, fuel from the fuel source is conveyed to both a primary (23) and a secondary (25) intake manifold during engine operation, and withdrawn from both manifolds upon cessation of engine operation. In either form, the ecology valve portion is controlled solely by the fuel pressure differential between the fuel source and the flow restricting inlet and includes a housing with a piston disposed therein for movement between first and second extreme positions. The piston defines, in conjunction with the housing, a variable volume chamber for withdrawing fuel from the engine intake manifolds when the engine is de-energized and the piston moves from the first extreme position toward the second extreme position thereby purging the manifolds of fuel.
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