A Preliminary Control System on a Barium Sulphide Rotary Kiln Process

Rotary kiln processes are strongly coupled multivariable nonlinear systems with large lag. A barium sulphide rotary kiln process is still under manual control because of the lack of analysis instrument, so that the burning status cannot be maintained stable and the product quality is hard to be kept consistent. To deal with this problem, this paper proposes a preliminary control strategy based on the exiting instruments, as fundamental parts of a desired hierarchical automation system. To overcome the immeasurability of the calcinating status of the kiln´s output, a secondary objective for control was selected through careful observation on the field. A PID controller was then used to keep the Hot-end temperature stable, while the feeding rate was controlled based on a regressive model generated by a segmented least square method. A fluctuation in the temperature series caused by the rolling of raw meal in the kiln was analyzed and a moving average filter was used for denoising. The automatic system has been implemented by an IPC+PLC structure and the performance has been proved effective.