Model-based leakage detection in a pulverized coal injection vessel

A method for detecting and isolating incipient leakages in the valves of a pulverized coal injection vessel for a blast furnace process is presented. Nonlinear physical gray-box models of the plant are developed. Values of the unknown parameters are estimated by identification. Observers are constructed for these models and the residuals are used in a generalized likelihood ratio test. The method is successfully tested with real leakages intentionally introduced in the plant.