Is there any difference in fuel or waste derived fuel use in your two kiln?Source of Asulphur may be difference in fuel used.It is  also practically observed that all other parameters being same, the bigger size kiln is more ssceptable to coating hazard.

Another important aspects which calls for an indepth study is the recirculation of fines within the preheater tower.A very high fine dust load, due to recirculation,offers excessive surface area for volatile condensation and make material stream bulkier.This leads to clogging of the cyclone cone and material chute.

Dear cement lover , can you write me please kiln intlet temperature in both systems (old, new), raw meal chemical analysis, and calcination of the old systems.

Please write your kilns' dimentions  and pressure drop after preheater tower too.

David Babayan (Armenia)