Dear Rizwan ,
This is common in cement industries,Particularly in Preheater Fans due to high sulphur content and various other Process parameters.
But in case of Raw mill Bag house it is the question of effectiveness of the fabric filters, first course of action would be through checking of the filter bags.second would be asking your process people to measure the dust loading and flow measurements to know whether any change happened.
if both are ruled out , then if coating is the real issue , then you may go for Auto balancers which will reduce the frequency of stoppages.
Hope this helps ! Thank you !