U.S. Patent Specifications September 1958

In a combustion system for burning fluid fuel in a gaseous stream of combustion‐supporting medium, ducting immersed in the said stream and comprising first and second duct portions both extending gcnsrally in the direction of flow of said stream and enclosing between them an annular passage open at both ends, an annular ring portion extending radially from the downstream end of said second duct portion and away from said first duct portion so as to form a sudden enlargement of said annular passage, an annular fuel supply chamber comprising a wall of porous material adjoining that edge of said annular ring which is the more remote from said first duct portion and extending downstream from said edge, a third duct portion extending downstream from said annular fuel supply chamber, and a flame deflector spaced downstream from said fuel supply chamber and extending part way across said passage.