GAS TURBINE ENGINE FUEL DRAIN SYSTEM AND COOPERATING VALVE AND PUMP MEANS

• US 3,774,394 A
• Filed: 08/09/1971
• Issued: 11/27/1973
• Est. Priority Date: 08/09/1971
• Status: Expired due to Term

• Current Assignee: Melvin E. Criffield
• Original Assignee: Melvin E. Criffield
• Inventors: Criffield, Melvin E.
• Primary Examiner(s): Hart, Douglas
• Assistant Examiner(s): Olsen, Warren
• Application Number:
  US05/170,131
• Time in Patent Office: 841 Days
• Field of Search: 60/39.9R
• US Class Current: 60/39.091
• CPC Class Codes: F02C 7/232 Fuel valves control of fuel supply by means of fuel metering valves F02C9/263; Draining valves or systems valves in general F16K
• CPC Class Codes: F05D 2260/601 using an ejector or a jet pump
• CPC Class Codes: F05D 2260/602 Drainage

Abstract

A fuel drain system for an aircraft gas turbine engine includes an eductor pump and valve means therefor to direct both fuel pressurized by the engine during engine spin-down and fuel drained from the fuel supply system upon engine shutoff to the eductor so as to recycle the latter to a point in the fuel supply system which is upstream of the fuel supply system shutoff valve.

Claims

1. For use with a gas turbine engine, in combination, fuel supply means including means for injecting fuel into a combustion section of said engine, pump means for delivery of pressurized fuel to said fuel injecting means, and shutoff valve means for interrupting fuel flow to said fuel injecting means to effect engine shutoff;

drain valve means for draining fuel from the portion of said fuel supply means disposed downstream of said shutoff valve means upon closure of said shutoff valve means;

eductor pump means for pumping said drained fuel to a point in said fuel supply system disposed upstream of said shutoff valve means; and

pump valve means responsive to said shutoff valve means for directing fuel pressurized by said pump means during engine spindown to said eductor pump means, as motive fluid therefor, and for preventing such flow during engine operation, whereby said drained fuel is automatically recycled to the fuel system after each engine shutdown without charge to the pump means during engine operation.

2. The structure of claim 1 further characterized in that said pump means includes serially connected low and high pressure pumps, with said pump valve means operative to direct the output of said high pressure pump to said eductor pump means.

3. The structure of claim 1 further characterized in that said pump valve means is responsive to the pressure in said fuel supply system downstream of said shutoff valve means and includes check valve means for preventing reverse flow from said eductor pump toward said drain valve means.

4. The structure of claim 3 further characterized by and including a container for receiving drained fuel from said drain valve means, said eductor pump means including a suction side which is operatively connected to said container through said check valve means.

5. Apparatus for use with a gas turbine engine of the type having a fuel supply system including means for injecting fuel into the combustion section of said engine, pump means for delivery of preSsurized fuel to said fuel injector means, shutoff valve means for closing fuel flow to said fuel injector means to effect engine shutoff and drain valve means for draining fuel from the portion of said fuel supply system disposed downstream of said shutoff valve means, said apparatus comprising:

a housing including a first inlet for receiving pressurized fuel from said pump means, a second inlet for receiving drained fuel from said drain valve means, and an outlet for connection with said fuel supply system upstream of the outlet of said pump means;

eductor pump means for receiving high and low pressure fuel and for utilzing the energy of said high pressure fuel to pump said low pressure fuel to said outlet; and

pump valve means for delivery of pressurized fuel from said first inlet to said eductor pump means in response to a signal indicative of closure of said shutoff valve means, where said drained fuel is automatically recycled to said fuel supply system during engine spindown.

6. The apparatus of claim 5 further characterized by and including check valve means disposed between said second inlet and said eductor pump means for preventing fuel flow directioned from said eductor pump to said second inlet.

7. The apparatus of claim 6 further characterized in that said signal is the fuel pressure downstream of said shutoff valve means.