Redox catalysis of NO.sub.x in internal combustion engines
AssigneeFord Motor Company
InventorsVemulapalli D. N. Rao, Harry A. Cikanek
Life of this patent
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Abstract
The invention discloses internal combustion engines, particularly compression ignition engines such as diesel engines, having reduced nitrogen oxide emissions with concurrent reductions in particulate emissions. The invention provides a catalyst impregnated prechamber insert which operates in the fuel rich environments of internal combustion engines to reduce nitrous oxides.
Claims16
An internal combustion engine having reduced nitrogen oxide emissions, comprising:
- a piston and cylinder assembly, said piston and cylinder assembly having walls defining an enclosed variable displacement chamber which has a maximum volume when the piston is at bottom dead center and a minimum volume when the piston is at top dead center;
- means for admitting air into the chamber;
- a compact pot formed in a wall of the variable displacement chamber, and having a surface which partially defines a boundary of the chamber;
- means for injecting fuel into the pot when the piston is near top dead center to cause ignition and combustion of the resulting air and fuel mixture;
- a plurality of whisker-like protuberances extending outwardly from the surface of the compact pot;
- and
- an effective amount of a catalyst applied to the surface of the pot and to the whisker-like protuberances for reducing nitrogen oxides formed in the combustion gases produced by the combustion.
A diesel engine which generates combustion gases having reduced nitrogen oxides, comprising:
- a piston and cylinder assembly, said piston and cylinder assembly defining an enclosed variable displacement chamber which has a maximum volume when the piston is at bottom dead center and a minimum volume when the piston is at top dead center;
- means for admitting air into the chamber;
- a silicon nitride prechamber formed in a wall of the variable displacement chamber and having a surface which partially defines a boundary of the chamber and having a plurality of whisker-like protuberances extending outwardly from the prechamber surface;
- means for injecting fuel into the prechamber when the piston is near top dead center to cause autoignition and combustion of the resulting air and fuel mixture;
- an effective amount of a redox catalyst applied to the surface of the prechamber and the protuberances extending therefrom for reducing nitrogen oxides formed in the combustion gases produced by the combustion.
A diesel engine prechamber insert sized to fit within a prechamber pocket formed in a cylinder head and cooperating with a cylinder main chamber, comprising:
- a plurality of sections cooperating to form an external surface sized to fit within the cylinder head pocket and an interior surface defining an enclosed cavity and a honeycombed throat extending from the cavity to the cylinder main chamber;
- a plurality of whisker-like protuberances extending outwardly from the interior surface of the cavity and the honeycombed throat;
- and
- a catalyst applied to the interior surfaces of the cavity and the throat for reducing nitrogen oxides.
Dependencies are inferred from the claim text.