Abstract:
A jacket extends around the refractory wall of a gas-fired kiln and defines an air chamber within which air is heated by the heat from the wall prior to being delivered to gas-air mixers and used as combustion air. Ceramic burner blocks are fitted within the wall and are formed with specially designed fuel delivery passages which cause ignition of the fuel mixture to be delayed until the mixture is nearly within the work chamber of the kiln and which also, in one embodiment of the invention, direct the resultant flame around the wall of the kiln.