Common rail slurry fuel injector system

A combined double valve slurry fuel injector for injecting slurry fuels, containing supplementary atomizing gas dissolved into the continuous phase of the slurry, into the combustion chamber of a diesel engine;

• and comprising
• a source of high pressure hydraulic fluid, and a receiver of low pressure hydraulic fluid;
• a source of high pressure slurry fuel comprising fuel particles suspended in a continuous liquid phase;
• wherein each said double fuel valves fuel injector comprises a fuel injector body with a fuel injection nozzle, a fuel injection valve for admitting fuel flow to said fuel injection nozzle when open, and for stopping fuel flow to said fuel injection nozzle when closed, a fuel shut off valve for admitting fuel flow to said fuel injection valve when open, and for stopping fuel flow to said fuel injection valve when closed;
• said fuel injection valve comprising a fixed valve seat on the fuel injection body, a moveable valve seat on a fuel injection valve head, said fuel injection valve head being secured to one end of a moveable fuel injection valve shaft, said fuel injection valve being closed whenever said fixed valve seat and said moveable valve seat are forced together by said fuel injection valve shaft, and being open whenever said fixed valve seat and said moveable valve seat are pulled apart by said fuel injection valve shaft;
• said fuel shut off valve comprising a moveable valve seat on the fuel injector valve head, and another moveable valve seat on a fuel shut off valve shaft, said fuel shut off valve shaft being sealably operable within said fuel injector body, and said fuel injection valve shaft being sealably operable within said fuel shut off valve shaft;
• wherein the two separate moveable valve seats on the fuel injection valve head have a common outer radius;
• and the outer radius of the fuel shut off valve shaft is greater than the common outer radius of the two separate moveable valve seats on the fuel injection valve head, in order to create a fuel flow path past the common outer radius of the two valve seats on the fuel injection valve head;
• wherein an intershaft fuel flow passage exists between the lower portion of the fuel shut off valve shaft and the lower portion of the fuel injection valve shaft and the head thereof;
• said fuel injector body further comprising a slurry fuel connector and a fuel flow passage from said connector to a fuel manifold surrounding a portion of said fuel shut off valve shaft;
• wherein said fuel shut off valve shaft comprises one or more fuel passages between said intershaft fuel flow passage and said fuel manifold and said fuel manifold is sufficiently wide in the direction of motion of said fuel shut off valve shaft, that a fuel flow connection always exists between said fuel manifold and said intershaft fuel flow passage via said one or more fuel passages;
• whereby a fuel flow path is created so that:
• whenever both the fuel injector valve and the fuel shut off valve are open between their seats, fuel can flow from said slurry fuel connector, into said intershaft fuel flow passage, via said fuel manifold, and from said intershaft fuel flow passage into said fuel injection nozzle and the engine combustion chamber, via said open fuel shut off valve, followed by said open fuel injection valve;
• and further so that whenever the fuel shut off valve is closed between its two moveable seats, fuel cannot flow from said slurry fuel connector via said fuel flow path, into said fuel injection nozzle and the engine combustion chamber;
• each double valve slurry fuel injector further comprising, piston, cylinder, and spring slurry fuel injection valve driver means for opening and closing said fuel injection valve, via said slurry fuel injection valve shaft, wherein said driver piston is secured to said fuel injector valve shaft, and said driver spring acts on the vented closing side of said driver piston to close said fuel injection valve, and high pressure hydraulic fluid, from said source of high pressure hydraulic fluid, can act on the opposite, opening side of said driver piston to open said fuel injection valve, said high pressure hydraulic fluid being admitted into the opening side of said driver piston, from said source of high pressure hydraulic fluid, via a fuel injection valve pressure and vent valve, with pressure and vent connections and an operator, so that when said fuel injection valve pressure and vent valve is open to the pressure connection, high pressure hydraulic fluid can flow onto the opening side of said driver piston to open said fuel injection valve, and when said fuel injection valve pressure and vent valve is open to the vent connection, hydraulic fluid can be forced out of the pressure side of said driver piston by said spring, to close said fuel injection valve, and to return said hydraulic fluid to said receiver of low pressure hydraulic fluid;
• each double valve slurry fuel injector further comprising piston, cylinder, and spring slurry fuel shut off valve driver means for opening and closing said fuel shut off valve, via said slurry fuel shut off valve shaft, wherein said driver piston is secured to said slurry fuel shut off valve shaft, and said driver spring acts on the vented closing side of said driver piston to close said fuel shut off valve, and high pressure hydraulic fluid, from said source of hydraulic fluid, can act on the opposite opening side of said driver piston to open said fuel shut off valve, said high pressure hydraulic fluid being admitted into the opening side of said driver piston, from said source of high pressure hydraulic fluid, via a slurry fuel shut off valve, pressure and vent valve, with pressure and vent connections and an operator, so that, when said fuel shut off valve pressure and vent valve is open to the pressure connection, high pressure hydraulic fluid can flow onto the opening side of said driver piston to open said fuel shut off valve, and when said fuel shut off valve pressure and vent valve is open to the vent connection, hydraulic fluid can be forced out of the pressure side of said driver piston, by said spring, to close said fuel shut off valve;
• wherein the net opening force created by said piston, cylinder, and spring driver of said slurry fuel injection valve, is greater than the net closing force created by said piston, cylinder, and spring driver of said slurry fuel shut off valve;
• wherein the operator of said fuel injection valve driver pressure and vent valve is one chosen from the group of pressure and vent valve operators consisting of:
• mechanical cam and return spring operators;
• solenoid opener and separate solenoid closer operators;
• solenoid opener and spring closer operators;
• piezoelectric opener and closer operators;
• wherein the operator of said fuel shut off valve driver pressure and vent valve is one chosen from the group of pressure and vent valve operators consisting of:
• mechanical cam and return spring operators;
• solenoid opener and separate solenoid closer operators;
• solenoid opener and spring closer operators;
• piezoelectric opener and closer operators.