GB889284A - Gas turbine engine fuel system - Google Patents

Abstract

889,284. Gas turbine plant. ROLLS-ROYCE Ltd. June 28, 1960 [July 3, 1959], No. 23034/59. Addition to 877,811. Class 110 (3). [Also in Group XXIX] Fuel for delivery to main and pilot burner manifolds 71, 70 of a gas turbine engine enters a housing 10 through an inlet 68 and is delivered by an engine-driven centrifugal impeller 14 through a passage 16 to a chamber 15 and thence through an orifice 55 controlled by a valve member 43 to ports 58, 59 leading through a shut-off and dump valve 62 to the burner manifolds. The ports 58, 59, or the port 59 only, are controlled by a tubular valve member 44 slidably mounted on the valve member 43 and subject at its opposite ends to the pressures downstream of the orifice 55 and in a chamber 29 so that any inequality between these pressures is corrected by an adjustment of the throttling of the ports 58, 59. The chamber 29 is fed and exhausted through orifices 33, 34 which are simultaneously but oppositely adjusted by a valve member 17 movable against an adjustable loading spring 27 by the impeller pressure in the chamber 15. The pressure in the chamber 29 is thus related to engine speed. A stirrup piece 19 coacts with adjustable acceleration and deceleration stops 21, 22. The orifice 55 is adjusted by a capsule assembly 47 subject externally to a pressure derived from the compressor delivery pressure of the engine, the latter pressure being fed through an orifice 52 and discharging to atmosphere through an orifice 52a. One element 48 of the capsule assembly is evacuated and the other element 49 subject internally to the compressor inlet pressure. To reduce static friction the valve members 17, 43, 44 are rotated by gearing 31, 32, 40, 41, 42, 45. A starting and flight idling stop (not shown) coacts with the gear 45, and a further stop (not shown) may limit movement of the capsule 47 to limit maximum thrust. When the valve 62 is moved to the shut-off position it causes fuel in the passages 60, 61 to be recirculated to the impeller inlet through a passage 67 and the manifolds 70, 71 to be connected to a dump line 74.