The paper describes an IR thermographic inspection system used for detecting hidden defects in operating cylindrical
kilns widely used in cement production industry. The accent is done on the description of the identification algorithm
which is based on the proposed thermal model of kiln operation.
The earlier developed model of rotating kilns used in cement production is applied to the analysis of the efficiency of
external control actions, such as air blowing and water spraying, intended to optimize a refractory internal temperature. These actions might be used for detecting defects in a kiln thermal insulation.
The paper will describe the parameters of the IR systems used for inspecting the quality of thermal insulation in rotating kilns used in cement production. The systems are provided with a laser targeting device and a remote radio control device. They include: an 'Introcon-05' IR scanner, a laptop PC, an adapter of the communication line, a synchro-unit and a 'Thermoinspector' software. The latter one allows data filtering and thresholding in order to indicate defect zones. The built-in defect characterization algorithm enables estimates of a residual thickness of the thermal insulation layer. The systems are being used by several Russian producers of cement.