Fuel divider and ecology system for a gas turbine engine

A fuel control system for supplying metered quantities of fuel from a fuel supply, through a fuel pump, a metering valve and a pressurizing valve to a plurality of engine fuel manifolds including an atomizer nozzle manifold, an upper air blast nozzle manifold and a lower air blast nozzle manifold, an improved fuel flow dividing arrangement intermediate the pressurizing valve and the engine fuel manifolds for appropriately distributing fuel flow among the plurality of engine fuel manifolds comprising:

• a concatenated pair of two-way splitter valves comprising a first splitter valve distributing the fuel flow between the atomizer nozzle manifold and the remaining air blast manifolds, and a second splitter valve distributing the down stream fuel flow from the first splitter valve between the upper and lower nozzle manifolds.

An ecology valve for withdrawing fuel from a plurality of discrete engine fuel manifolds during cessation of engine operation and for returning fuel to at least one of the engine fuel manifolds to be burned during engine operation comprising:

• a valve housing including at least two ports adapted to be coupled to corresponding ones of the engine fuel manifolds, and a control port adapted to be connected to a corresponding control port of a fuel pressurizing valve;
• and
• a movable piston supported within the valve housing for reciprocable motion along an axis, the piston dividing the valve housing into a variable volume control chamber coupled to the control port and a variable volume fuel reservoir, piston motion opening and closing selectively at least two ports, the piston having one extreme position in which a first of the two ports is open to couple the fuel reservoir to a first engine fuel manifold while the remaining one of said at least two ports is closed isolating the reservoir from the remaining engine fuel manifold, and a second extreme position in which a second of said two ports is open to couple the fuel reservoir to a second engine fuel manifold while the first of said two ports is closed isolating the reservoir from the first engine fuel manifold.

An ecology valve for withdrawing fuel from a plurality of discrete engine fuel manifolds during cessation of engine operation and for returning fuel to at least one of the engine fuel manifolds to be burned during engine operation comprising:

• a valve housing including a plurality of ecology ports adapted to be coupled to-corresponding ones of the engine fuel manifolds, and a control port adapted to be connected to a corresponding control port of a fuel pressurizing valve;
• and
• a movable piston supported within the valve housing for reciprocable motion along an axis, the piston dividing the valve housing into a variable volume control chamber coupled to the control port and a variable volume fuel reservoir uncoupled selectively from the ecology ports by the piston, the piston having one extreme position in which the piston closes at least a first ecology port and a second extreme position in which the piston closes at least a second ecology port.

A fuel control system for supplying metered quantities of fuel to a plurality of engine fuel manifolds which include an atomizer nozzle manifold, a lower air blast nozzle manifold and an upper air blast nozzle manifold, the improvement comprising:

• a fuel flow restricting valve which comprises a valve member, means for exerting a load upon the valve member, and a pin member, the fuel flow restricting valve communicating with both fuel pressure being supplied to the atomizer nozzle manifold and fuel pressure being supplied to the lower air blast nozzle manifold, whereby the fuel flow restricting valve reduces fuel flow to the air blast nozzles of the lower air blast nozzle manifold in order to compensate for greater fuel flow to the atomizer nozzle manifold during engine start-up conditions, and the combined fuel flow of the atomizer nozzle manifold and lower air blast nozzle manifold substantially equals that of the upper air blast nozzle manifold during both engine start-up and running conditions.

A fuel control system including a pressurizing valve and for supplying metered quantities of fuel to a plurality of engine fuel manifolds which comprise an atomizer nozzle manifold, a lower air blast nozzle manifold and an upper air blast nozzle manifold, the improvement comprising:

• fuel flow dividing means intermediate the pressurizing valve and the engine fuel manifolds for appropriately distributing fuel flow among the plurality of engine fuel manifolds, the dividing means including first passage means for fuel flow directly to the atomizer nozzle manifold during engine start-up, second passage means for receiving fuel flow directed also to the lower air blast nozzle manifold during engine run conditions and restricting the received amount of fuel that flows to the atomizer nozzle manifold, whereby the fuel flow dividing means responds sequentially to increased fuel pressure to effect via the first passage means distribution of fuel to the atomizer nozzle manifold during engine start-up and then for engine run conditions, via the second passage means permitting increased fuel flow for the upper and lower air blast nozzle manfolds while effecting a lesser rate of fuel flow to the atomizer nozzle manifold, such that fuel flow to the nozzles of the manifolds is substantially equal during engine run conditions.