GB165005A - Improved means for introducing gaseous fuel into the combustion chambers of continuous tunnel kilns - Google Patents

Abstract

165,005. Metcalfe, R. C. Oct. 6, 1920. Liquid and geous fuel furnaces and kilns.-Consists in improved means for introducing gaseous fuel and air into the combustion chambers of a tunnel kiln, and for decarbonizing each fuel nozzle with a stream of decarbonizing fluid, such as steam or air. The combustion chambers are constructed, in a known manner, with channelled tiles b, ba which facilitate the circulation, by convection, of the kiln atmosphere. A portion of a combustion chamber, shown in cross-section in Fig. 1 and in sectional elevation and sectional plan in Figs. 2 and 3 respectively, is arranged with a refractory 'block C in its floor, the block having a large central aperture C<1> which is large enough to permit of expansion due to temperature changes and small side apertures C<2> which register with the channels in the wall tiles. The gas nozzle comprises fireclay sections D, F and projects through the aperture C<1> of the block C, the nozzle receiving a regulable supply of gas from the duct A<2>. The section F directs the gas forwardly through the opening F<1>, and a decarbonizing stream of relatively cool air is supplied under pressure by the duct A<3> to the concave surface of the section F and prevents carbon from depositing on that surface. The combustion air is admitted from the kiln chamber through porte b<5> in the channelled tiles ba and is directed forwardly by a hood G, and adjustable channel-like dampers are arranged in the channelled tiles to regulate the quantity of air admitted. A number of nozzles are arranged along the combustion chambers. In a modification, the gas is admitted through a side wall by means of a steam or air jacketed forwardlydirected elbow pipe, decarbonizing air being supplied to the concave surface through holes in the inner jacket. In another modification, the gas is supplied through a side wall by an elbow pipe and the decarbonizing fluid is supplied by an internally-arranged pipe, and in both modifications the combustion air is supplied through a port in the end wall.