Control of titanium dioxide kilns

This paper reports an application of LQG theory to the control of three TiO2 kilns. Previously derived results on steady state modeling are used to obtain a set of linear partial differential equations to describe the process. A low-order model is derived by matching the input-output frequency responses. LQG theory is used to determine the sampling period and to justify the selection of actuating and measured variables. A minimum-variance control law is finally obtained and applied to three kilns. This control proves to be more effective than existing control, while requiring much less memory.