A Magnetic Sensor to Measure Wear in Centrifugal Pumps

Structural wear on impeller blades of industrial centrifugal pumps leads to reduced pump efficiency and occasional plant downtime. An online sensor that can measure the pump wear allows for maintaining the efficiency through a predictive maintenance schedule. A magnetic sensor is designed to measure the structural wear on impeller blades. This sensor can be installed on existing pumps and does not require any pump modifications. Using a magnetic circuit with the pump and its components, wear is estimated by measuring the gap between the impeller and the pump housing. As the impeller wears, the gap between the impeller and the pump housing increases causing the reluctance of the magnetic circuit to increase which in turn reduces the inductance of the coil driving the magnetic circuit. This online magnetic sensor includes an electronic circuit and has an unamplified sensitivity of 0.60 V/mm.