Condition monitoring of exhaust system blowers using infrared thermography

Electrical and mechanical machines are integral parts of engineering plants. Machine failures can occur due to many reasons. Thermal energy produced during the operation of all machines can be in the form of friction losses within machines, energy losses within machines, as a characteristic of the process media, or any combination thereof. Infrared thermography (IRT) is an ideal Non-Destructive Testing (NDT) technique to investigate abnormal temperature distribution on machine surfaces, because it provides thermal images of a machine or component remotely. In this paper, we discuss an important application of thermal imaging for condition monitoring of blower bearings, shaft and the motors in ventilation systems used in nuclear plant areas. Sources of abnormal temperatures are detected at the bearings and shaft at the impeller end of the blower of an exhaust system. Also, abnormal temperature distribution is detected in one of the belts of the pulley drive system due to over-tightening. IRT was effectively utilised to pinpoint the sources of excessive heat in the blower and to carry out necessary corrections. We demonstrate the usefulness of IRT to detect the sources of abnormal temperatures in various components of the blower at an early stage of impending malfunction failure that could prevent major breakdowns.