Kiln seal retrofits for energy efficiency

Significant energy is wasted in air leakage associated with inlet and outlet kiln seals in cement plants. There are a variety of kiln seal technologies in place in the cement industry. The common problem with traditional seal technology is the degradation over time that produce gaps that allow “tramp air” into the main kiln air flow stream. This tramp air requires increased fan energy in the primary kiln ID fan, kiln/raw mill baghouse fans, and often in the raw mill up-draft and clinker cooler fans. In addition, since the tramp air enters the kiln system at ambient temperatures, this requires the use of significant additional fuel use to maintain process temperatures. Advanced kiln seal technology has been evaluated and successfully implemented at California cement plants to reduce leakage and produce both electricity and fuel savings. Projects to replace traditional leaf seals and hydraulic-piston plate seals with advanced kiln seal technologies have also qualified for significant energy incentives from electric utilities. By their simplicity, they also present the advantage of requiring much less maintenance over time. This paper will describe the energy savings (electricity and fuel) estimating methodology and provide a case study on measured and verified savings and incentives for a successful installation of advanced kiln seal technology at a California cement plant.