How best can we improve kiln feed to clinker ratio of our kiln? We operate a DOPOL model 3 stage suspension pre heater kiln and the clinker conversion factor has been consistently high approximately 1.75. Does it have anything to do with the collection efficiency of our cyclones? Someone suggested optimising the dip tubes in our cyclones can help us, is that correct? Somebody help us with some ideas please.

Dear Bashar,

Certainly improving the collection efficiency of the cyclones in the preheater will improve the kiln feed to clinker ratio. With kiln feed of typical lime saturation and calcium carbonate content the kiln feed to clinker factor would be expected to be around 1.54 due to loss of CO2 from the CaCO3. That factor is increased by the dust losses from the preheater to the raw mill and dust filters. If your factor is 1.75 then you must have high dust losses from the preheater so improving collection efficiency will reduce the factor. However, it will also increase the pressure drop across the preheater. Does your induced draft fan have sufficient spare capacity to operate with a higher pressure drop across the preheater?

Dr Michael Clark

Dear Bashar, Dr Clark very correctly explained you, how can you reduce dust emission from kiln system. I can only confirm that, and tell you from my own experience (from our plant operation), that dip tube increasing reduces dust emission and temerature of exhaust gases from kiln system as well. But you must calculate how this can influence on your ID fan efficiency. 

Dr of Engineering David Babayan