Abstract: A dual-fuel injector is provided which allows precisely controlled injection of liquid and slurry fuels into an engine or the like, which prevents separation of solid material from the liquid carrier in the slurry fuel, and which prevents abrasion of selected surfaces of the injector by the solid material. The preferred injector includes a housing and an electronically actuated liquid and slurry fuel assemblies. In operation, pressurized liquid fuel supplied to the injector is used to amplify the injection pressure of the respective fuels for discharge through respective nozzles. The slurry fuel is continously circulated through the injector to prevent separation of the solid material from the liquid carrier and liquid fuel is used to purge selected surfaces of the injector to prevent the abrasion thereof by the solid material in the slurry fuel.

Abstract: An electronically controlled, microprocessor equipped fuel injection system for new manufacture or retrofit of existing diesel engines has a tubular injector provided with a fuel pressure amplification chamber next adjacent and communicating directly with an injector nozzle at one end of the tube; the nozzle has atomizing orifices for spraying the pressure amplified fuel into the engine cylinder. A fuel flow controlling solenoid is provided at the opposite end of the tube and all component parts in the tube between the nozzle and a spring loaded solenoid armature are disposed along a common axis extending longitudinally of the tube. Such parts include a fuel pressure amplification plunger, a hydraulic pumping piston for actuating the plunger, a spool valve shiftable toward and away from the armature and a needle valve normally closing the orifices.