GB218343A - Improvements in annular furnaces or kilns - Google Patents

Abstract

218,343. Woodall, Duckham, & Jones (1920), Ltd., and Duckham, Sir A. M. Feb. 2, 1923. Tunnel furnaces and kilns. - Relates to annular tunnel furnaces or kilns and comprises methods of stacking the goods and flue arrangements by which a more even distribution of the heating gases is obtained. The kiln shown has an open loading and unloading section b, a drying and burning section extending between the inlet door a<1> and the combustion gas inlet h, and a cooling section extending to the outlet door a<2>. Producer gas is supplied through the flues h and burns with air which has been preheated in flues i<1> in the walls and roof of the drying and burning sections, and the products are exhausted to the chimney k' through inner and outer dampercontrolled ports k, and through distributed damper-controlled ports l in the lower part of the heating-chamber leading to side flues l<1> in the walls. The cooling of the goods is effected by air passed through flues o in the walls and roof of the cooling-sections, and the air thus heated is passed either to a drying-floor or into the drying section of the kiln. The. roof of the tunnel is inclined downwards slightly in the direction of travel of the goods, and a seal at the roof is made by sand contained in trough shaped bricks placed at the rear end of each stack. The sidewalls of the heating-section of the tunnel may be formed with projections to deflect the heating- gases on to the: goods. Charging.-To promote even distribution of the gases the goods are stacked with interspaces, which, at the forward end of each stack, increase in size from top to bottom, and from the sides to the middle: alternatively definite circumferential flues may be formed in the stack near the travelling platform.