Control of titanium dioxide kilns

This paper reports an application of LQG theory to the control of three TiO2kilns. 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.