we are experiencing frequent blockages at the c2.our plant is a four stage precalciner kiln rated at 115t/h.normal operating conditions are

cyclone1-temp - 400degrees c, pressure - 550mmaq

cyclone2-temp - 655degrees c, pressure - 365mmaq

cyclone4 material temp - 810-815 degrees c

cyclone4 calcination level - 85% av.

fuel used - heavy fuel oil

sulphurdioxide level at the kiln inlet analyser - 600ppm

rawmeal quality - lsf - 0.94-0.96%,Fe2O3 -2.18%av.,Al2O3 -3.25%av,Mgo -3.25%av,

Cyclone2 - So3 -1.25%av,ASR -1.25%av.

Fellow gentlemen help me understand why this cyclone is blocking so frequently and how to prevent reccurence.

Thanks in advance,

Austin kiio.