GB531818A - Improvements relating to the treatment of materials with gases - Google Patents

Abstract

531,818. Treating materials with gases. JORGENSEN, M. VOGEL-. April 5, 1939, No. 10659. [Class 51 (ii)] [Also in Group XXX] In a process for treating material with gas by drawing the gas transversely through a layer of the material on a gas permeable support, the support is inclined at an angle slightly less than the angle of repose of the material which is caused to slide as a whole down it, maintaining its initial uniform thickness, by reciprocating external action parallel to the support, the layer moving only on downward strokes. The process may be utilized to preheat cement raw materials or ores, or to cool cement clinker, or effect some chemical change such as the artificial ageing of cement by carbon dioxide. In Fig. 1, lime for a rotary kiln 1 is shown being conveyed down a grate 42 formed of inclined T-shaped bars alternately fixed and reciprocably supported on resilient bars 31, the lime being preheated by combustion gases from the kiln led through a firebrick lined chamber 5 to a sealed chamber 20 above the grate and drawn down through the material by a fan connected to an outlet 12 in a sealed chamber 21. A water-cooled rotary drum 15 forming a movable end wall at the bottom of a fixed curved extension 39 of the grate controls the feed of material which moves only if the drum rotates. Material falling through the grate is collected by hoppers 22, 23 and deposited on a feed conveyer 17. A partition 41 in the inlet hopper 14 permits a layer of some protective material for the grate to be used. The grate may be stepped transversely or lengthwise.