Replacement of a wound rotor motor with an adjustable speed drive for a 1400 kW kiln exhaust gas fan

The use of adjustable speed drives for process fan applications in the cement industry is already well established. However, a variety of solutions are possible due to different requirements and influences in a particular application. The paper describes the project concerning a conversion of a fan drive from fixed speed to variable speed. The different variants, which have been investigated, are stated and the final solution is shown in detail. Furthermore, all relevant concerns for the final decision making such as costs, reliability and efficiency were analyzed. The energy savings and process advantages by means of applying an adjustable speed drive are pointed out and a ROI calculation justifies the expenditures.