Cement rotary kilns are used extensively in cement production industry.They consist basically of a large metal tube,gear ring of rotary kiln,kiln tyre and support roller. Both co-current and counter-current configurations are used. Below is a schematic of a typical dryer used to dry polymer powders:

Often final product quality and profitablilty is heavily dependent on the drying operation. On one hand, if the dryer is run too cool, residual liquid may be left in the product and ultimately effect the polymer"s performance when it is extruded. On the other hand, running the kiln too hot may cause the polymer to burn or melt prematurely, changing the polymer's properties and again effecting its performance when it is molded. Finally, lest we forget we are ultimately trying to make money, suppose our customer allows a certain amount or moisture in your product. Why spend the extra energy over-drying your product?

Cement rotary kiln are also used extensively in the paper industry to convert lime "mud" into powdered lime. Typically the air flow for this application is counter current and there are two manipulated variables and two measured outputs:

For this case study problem we will be modeling, simulating, and finally controlling a lime kiln. You will be given a "black box" in Simulink format which you are to regard as the actual plant. You will perform step tests to develop a model, then using that model, develop controllers to run the process. Since this is a reasonable system, you will also be asked to suggest the controller "pairing" that is best for this system. Finally, you will present and discuss your results.