GB235325A - Improvements in and relating to the drying of peats and other material - Google Patents

Abstract

235,325. Donald, W. March 24, 1924. Small chambers; trucks, moving; special pressures, drying at.-Apparatus for drying peat &c. by first subjecting it to radiant heat in a boiler until the vapour pressure exceeds that of the atmosphere, then reducing the pressure while continuing to apply heat, and finally reducing the pressure to that of the atmosphere comprises a boiler a, Figs. 1 and 2, having steam-tight doors a<1>, a<2>, a pressure gauge b<1>, and an outlet valve b<2>. The boiler is heated by furnaces or gas burners e in a casing c which communicates with a flue g. The peat is supported in the boiler upon wheeled trucks. In a modification in which several boilers are employed, the boilers are arranged in parallel and with pipe connections by which steam may be passed from one boiler into another in which the pressure is lower. Figs. 10 and 11 show another arrangement comprising central dehydrating- boilers a and end boilers e<6>, the central boilers being provided with burners and flues. The boilers are separated by slide valves which may be opened to facilitate the passage of the trucks. Steam may be passed from the central to the end boilers through pipes s<1>, s<3> and to either of the central boilers through pipes s<2>. Further, steam may be passed from exterior sources into the dehydrating-boilers so as to accelerate the drying. The vapour escaping from the dehydrating-boilers is used for preheating wet materials either by radiated heat or conduction.