DE2654971

In the calcination of petroleum coke or the like in a rotary kiln, utilizing controlled air supply intermediate the ends of the kiln to burn removed volatiles and thereby generate all or nearly all of the heat required, highly effective control procedure includes establishing and repeatedly re-establishing target values for temperatures of exit gas and discharging product respectively at opposite ends of the kiln, such target temperatures representing conditions of desired position of the calcining zone and desired physical character of the calcined product which is achieved by proper maximum temperature in said zone. The procedure further includes adjusting one or more of the variables of combustion air supply, RPM of the kiln, and green coke feed rate so as to keep the end temperatures at target value. Preferably, only two variables are controlled in order to follow the updated target values, and the procedure also includes adjustment of one or both of such selected variables in order to compensate, when necessary, for changes in the other variable. Efficiency, economy, and unusual facility and reliability of control are achieved.