摘要 |
<p>Fine-grained material such as raw cement meal is preheated in a multi-stage cyclone preheater, precalcined in a precalcination zone, sintered in a rotary kiln, and cooled in a cooler. Exhaust gases from the kiln are delivered to the precalcining zone and then to the preheater. Tertiary air from the cooler is divided into two streams one of which is mixed with kiln exhaust gases between the kiln and the precalciner and the other of which is delivered directly to the precalciner. The quantity of tertiary air flowing through each branch is regulated to maintain the temperature of the kiln exhaust gases at a selected value.</p> |