Selecting the right preheater fan and drive

The preheater fan is a key piece of equipment in any cement plant. In many cases, this fan limits clinker production by limiting the gas flow through the preheater. It consumes about 10 percent of the total power used at the plant. Large gas flows, high gas temperatures and static pressure, and the potential for material abrasion and buildup on the impeller makes the design of a fan for this application complex. Selecting the optimum fan and drive requires careful consideration of each application and of all design options available. Preheater fans proposed by vendors in recent projects vary significantly. For example, some vendor's proposed single width, single inlet type fans, while others proposed double width, double inlet type fans. Some vendors proposed radial blade fans while others proposed backward curved or airfoil fans. The degree of wear protection also differed significantly. This paper discusses various topics that are important when selecting a fan and drive for this application. Topics discussed are: the process requirements and conditions, the options available for fans and drives, the advantages and disadvantages of fans and drives available, and the impacts of each fan and drive on capital and operating costs.