Pressurized air seal for combustion chamber

Abstract

Combustion apparatus ( ) includes a combustion chamber ( ), a cover ( ) covering an end wall ( ) of the combustion chamber and defining a buffer space ( ) therebetween, and a blower ( ) external to the cover and supplying air to the buffer space and pressurizing the buffer space to a higher pressure than the combustion chamber such that leakage at penetrations ( ) and/or interface ( ) flows from the buffer space into the combustion chamber, rather than the reverse, eliminating the need for leak-tight seals, and instead permitting leakage in a desired direction. In one embodiment, a first conduit ( ) supplies air along a path ( ) from the blower to the mixer and burner assembly without passing through the buffer space, and a second conduit ( ) independently supplies air from the blower to the buffer space. A pressure dropping orifice ( ) is provided between the blower and the mixer and burner assembly. A gas inlet port ( ) is external to the cover ( ) and downstream of the pressure dropping orifice ( ). The buffer space ( ) communicates with the blower ( ) along an air flow path ( ) upstream of the pressure dropping orifice ( ). In another embodiment, air flows through the buffer space ( ) to the mixer and burner assembly. The buffer space ( ) is thin and flat, and the cover ( ) covers only one end wall ( ) of the combustion chamber, not the other end wall nor the sidewall, such that the latter are accessible without removing the cover.