GB820732A - Apparatus for pre-heating and/or calcining dry powder - Google Patents

Abstract

820,732. Charging rotary kilns. BERZ, W. Nov. 24, 1955 [Nov. 26, 1954; May 9, 1955], No. 33741/55. Class 51 (2). Before entering a kiln h raw cement is heated by passage in counter-current to the exhaust gases of the kiln in chambers b, m, Fig. 1, which comprise base-plates d, dm, with valve-regulated openings e, em, for the counter-current passage of the gases and the cement and rotary agitators c, cm, above the plates. A suction fan n draws the gases through the chambers and fine particles trapped in the precipitator may be supplied through a screw conveyer k either directly to the kiln or to one of the chambers. Each opening e, em may comprise an annular passage a<SP>1</SP>, Fig. 2, having inclined partitions c<SP>1</SP> so that a whirl is given to gas passing therethrough. The Specification describes various base-plates. In one, the circular plate 1, Fig. 3, has annular sectional openings 2 and co-operates with a rotatably-mounted sliding disc valve 3 having openings 4 and an actuating linkage. In another, the base-plate 12, Fig. 6, is annular and a cone 14 projects therefrom. A modification of this plate comprises two concentric sets of annular openings with concentrically arranged cone formations projecting upwardly from the plate. The apparatus shown in Fig. 8 has superimposed chambers 31, 32, each having a base-plate with concentric sets of annular openings 34<SP>11</SP>, 34<SP>111</SP>. Each chamber comprises concentric compartments 35, 36. The depth of the cement layer above the baseplate 42, Fig. 9, is regulated by an overflow pipe 45.