Afterburner for internal combustion engine

Claim 1

An afterburner for burning unburned exhaust gases remaining in the exhaust from an internal combustion engine comprising: an outer cylindrical sleeve having first and second end walls, an inner cylindrical sleeve mounted within said outer sleeve and including a neck extending from said inner sleeve through one end of said inner sleeve, means for coupling said neck to an exhaust coupling of an engine to receive exhaust gases therefrom, a mixing chamber having bell-shaped inner and outer walls defining an annular chamber therebetween and a top opening coupled to an end of said neck within said inner sleeve and remote from said coupling means, said mixing chamber including a plurality of openings in said inner wall at an end remote from said neck and spaced around the periphery thereof, said mixing chamber further including a central opening for allowing mixed gases and air to exit therefrom, a tube having one end coupled through said outer wall of said mixing chamber and communicant with said annular chamber, and a remote end extending from said afterburner adapted to couple said tube to a source of compressed air to provide a pressurized stream of air from said plurality of openings in said mixing chamber thereby mixing sufficient air with exhaust gases to cause self-ignition of the mixture within said inner sleeve, a plurality of grids mounted within said inner sleeve in spaced relationship between said mixing chamber and an end of said sleeve remote from said neck and heated in response to the presence of the ignited air-gas mixture to a temperature sufficient to sustain combustion in said inner sleeve between said grids to burn remaining unburned gases, an exhaust pipe coupled to an end of said inner sleeve remote from said neck to provide an exhaust passage for exhaust gases from said engine, an air intake pipe having one end coupled through said outer sleeve and communicant with the space between said inner and outer sleeves and having a remote end adapted to be coupled to an air blower for providing a stream of cooling air between said inner and outer sleeves, a plurality of cooling fins positioned along an outer surface of said inner sleeve and spaced around the periphery thereof for transferring heat from said inner sleeve to said stream of cooling air, and air outlet means in said second end wall of said outer sleeve for providing an outlet for said cooling air.