Abstract: Tunnel kiln preheat and firing section arrangement. The firing section includes a plurality of excess air burners based along each side thereof and a plurality of exhaust ports disposed between adjacent burners. The hot combustion products from the burners plus entrained air are directed upward through damper controlled slots disposed adjacent the walls of the kiln firing section. The hot gases stream upward along the kiln wall, over along the kiln roof, downward and through the stacks of ware to be fired and then are drawn upward again with the stream of burner combustion products so as to form a powerful current of recirculating hot gases which provides a uniform firing temperature throughout the stacks of ware to be processed. The preheat section uses the hot gases exhausted from the firing section, such gases being introduced at the bottom, circulated upward, in the same manner and with the same effect as the gases in the firing section.