GB553062A - Means for treating and feeding material - Google Patents

Abstract

553,062. Drying and heating materials. KENNEDY, J. E. Sept. 23, 1941, No. 12317. [Class 78 (i)] [Also in Group XII] Apparatus for utilising furnace gases for drying and preheating material to be passed through the furnace, e.g. limestone or coal, comprises a bin B leading to a casing C the bottom of which leads to a hopper 10 fitted with a shoot 12 which conducts the material to a rotary or other furnace 3. A suction fan F draws the gases from the furnace into a housing 4 whence they proceed by way of a conduit 24 to openings 22 in the lower part of the casing C. Leading from the openings 22 into the casing C are inclined inverted V-shaped channels 31 which diminish in cross-sectional area toward their upper ends. Located above these channels in laterally staggered relation, are two rows 32, 33 of inverted V-channels which increase in area toward their upper ends and lead to outlets 28<SP>1</SP>, 28. The outlet 28<SP>1</SP> communicates with a duct 27 from the outlet 28 to take the gases by way of a separator S to the fan F and thence to a stack 6. The housing 4 is connected directly with the base of the stack 6 by a passage 5 controlled by a manually operated damper 7. Between the outlet 28<SP>1</SP> and the duct 27 is a pivoted valve 34 controlled automatically through thermo-electric means by the temperature of the gases leaving the fan F. The damper 7 and valve 34 thus provide means for adjusting the degree of drying and heating imparted to the material in its passage down through the casing C. The downward fall of the material is effected and controlled by a grid 18 of horizontal bars which is reciprocated by power means over a grating formed of parallel elongated platforms 14 separated by narrow gaps, the bars serving to push the material first one way and then the other into the gaps. Located over the medial lines of the platforms 14 and over the gaps is a series of stationary triangular baffles 15 which direct the material on to the edges of the platforms 14, and between which and the platforms the grid 18 moves. The reciprocation is effected by an eccentric adjustable to vary the stroke. The shoot 12 may have a hollow wall through which a cooling fluid, such as air, is sucked by the fan F. The separator S consists of a cylindrical chamber into which the duct 27 leads tangentially, the gases passing spirally downward and then rising through a tube 41 to the fan F. Matter deposited from the gases collects in a lower cone and can be abstracted by way of a valve.