Einen Flammabriss verhinderndes Kraftstoffpumpensystem

摘要

A fuel pumping system for delivering fuel from an aircraft fuel supply tank (12) to an aircraft engine includes a fuel transfer circuit for conducting fuel from the supply tank to the engine, a fuel boost pump (16), and an accumulator device (20) positioned in the transfer circuit between the boost pump and the engine for accumulating fuel and vapor so as to provide a reserve supply of fuel to the engine while minimizing the amount of undissolved vapor delivered to the engine. The fuel boost pump is a self-priming modified centrifugal type pump, capable of pumping liquid, vapor and mixtures thereof. The system includes a return passage (40) communicating, at one end, to the accumulator and at an opposite end with the inlet (22) to the boost pump (e.g., in fuel transfer circuit upstream of the boost pump) for directing fuel and vapor from the accumulator into the transfer circuit so as to dissolve the vapor into the fuel in controlled quantity for delivery into the engine. A flow limiting device (49) positioned along the return passage limits the flow rate of fuel and vapor flowing from the accumulator. A check valve (46) positioned in the return passage prevents the release of vapor from the accumulator to the inlet of the boost pump when loss of pump "prime" becomes possible as a result of a significant drop in pump outlet pressure. Closing of the return passage permits the boost pump to reprime itself by applying full inlet suction to the fuel conduit from the supply tank, so as to continue supplying fuel to the engine. In general, this boost pump system will supply fuel to the inlet of a "main stage" pump which will, in turn, supply fuel to the aircraft engine.