Revision of the AMB-Supported Coolant Pump after the Long-Term Operation in the Power Plant

with active magnetic bearings (AMBs). This AMB-supported pump was installed and tested in the inter-cooling circuit of a 500 MW block-unit in a lignite power station as a demonstration plant. The aim was to proof the suitability of magnetic bearings for using on turbo machines under operation conditions in a power station [1]. After the phase of commissioning the pump was used in a long term operation as the main operation pump [2]. The pump was subjected to a revision after an approx. three and a half year running time. Thereby the condition of the pump, especially of the bearing components was checked. The disassembling of the pump was covered by some difficulties, caused by corrosion of mechanical parts. In addition with detected damages on single components, countermeasures for prevention had to be derived. Furthermore design criterions, applicable materials and requirements e. g. for the shaft seals can be concluded. This report gives an insight into the increase of experience and knowledge collected during the revision of the AMB-supported coolant pump.