GB175674A - Method of and means for drying coal or other material in a granular or percolatable body or mass form - Google Patents

Abstract

175,674. Goskar, T. A. Oct. 1, 1920. Gravity, materials descending by; air and gascs, controlling circulation of.- Powdered coal and like granular material in a downwardly diverging porous column is dried by being subjected to the effects of induced currents of heating and cooling air or gases, the air or gases being a common supply to the whole of the column. As shown in Fig. 4, the apparatus comprises an air-tight casing A having concentric and perforated metal walls B<1>, B<2> between which the material is fed through the funnel B<4>, and inlet and outlet pipes D, E<1> respectively for the heated gases, the outlet pipe being connected to a fan. The dried material falls upon a rotary discharge plate G. Steam coils J may be arranged within the drying compartment. In a modification, the inlet pipe D, Fig. 3 is arranged centrally within the casing, the heated gases passing through the tubes H, into the space C and thence through the upper portion of the material to the outlet pipe E'. In another arrangement, 'the transverse walls B<3>, Fig. 5, are formed of metal slats which extend across the casing. A rotary discharge drum K or the like is provided. In a further modincatlon, a rectangular casing A, Fig. 7 is divided into compartments by transverse perforated walls B<6>, and the gases are passed through tubes H and the upper part of the material to the outlet pipe E'. In another arrangement, in which two drying compartments are arranged side by side, the hot gases are supplied to the tubes through a central pipe. Fig. 13 shows a further modified form of apparatus wherein the gases from a furnace M pass into a flue N and through openings T and compartments V<1>, V<2>, into the annular drying compartment B and thence to the outlet E<1>. The material at the bottom of the compartment B is cooled by atmospheric air which is drawn into the compartment V<4> through the openings P<1>. The compartments V<1>, V<2>, &c. communicate with one another through valves R which may be automatically controlled by means of pyrometers or the like. In another arrangement, the drying compartments B, Fig. 11 are disposed around a flue N which communicates with a furnace M the gases from which pass through the louvered walls of the drying compartments and the valve-controlled outlets E<2>, to the outlet pipes which is connected to the fan F. The material is fed into the compartments B by a rotary plate C and is discharged upon a rotary plate G, the material being swept off the plate G by scrapers G<2> secured to the casing. The lower part of the apparatus is cut off from the upper part by a plate N<2> and the material in the lower part of the drying compartment is cooled by atmospheric air which passes through the openings P<1>. The flue N communicates through openings P with the atmosphere.