Rotary kiln for cement clinkering - has bucket chain to ensure mixing with minimum suspension of dust in furnace gas

摘要

The caloridic exchange between solid material and gas in a rotary kiln for prepn. of cement, is improved by a process including the following steps. (1) a sloping heap of solid material is formed, the slope falling away in the forward direction of rotation during the ascending part of the motion; (2) a certain quantity of material is removed from the region of this slope and carried in the forward direction of motion in the surfaces; (3) this quantity of material is held captive for at least part of the upward motion of the furnace beyond the sloping heap and for part of the descent; (4) the captive material is then released close to the furnace wall during the descending part, from the monomer when the vertical trajecting of the material falling is far enough from centre of the kiln; (5) a second sloping heap of material is then formed in the descending part of the kiln. As well as the improvement in heat exchange, the system avoids putting dust particles into suspension in the gas near the centre of the kiln.