The Leamington kiln baghouse project: why, how and the outstanding results

Ash Grove Cement\´s Leamington, UT plant was constructed by Martin Marietta Corporation, Cement and Aggregate Division, in 1980 and produced "first clinker" on November 15, 1981. Now long past its original equipment design life, the plant is still running strong. Continuous plant improvements and modernization to the kiln and preheater have increased production over the years. The production increases high lighted bottlenecks, including insufficient draft through the kiln and vertical raw mill. The original mill baghouse was too small to handle the expanded load. The original two-fan kiln/mill baghouse system experienced high pressure losses due to increased gas flow and a requirement to lower the baghouse inlet temperature. The baghouse ID fan was unable to maintain its desired performance limiting production. In addition, the physical condition of the original reverse air baghouse had deteriorated due to abrasion wear and corrosion. Replacement of the old baghouse was decided upon for the 2004 spring shut-down. Production requirements for the year allowed only 28 days to replace the entire reverse air baghouse, ID fan, stack, material handling, and controls system with a state-of-the-art low pressure pulse-jet filter and upgraded equipment. The normal two week shut-down was extended to four weeks to accommodate the baghouse replacement. The revamped system\´s performance exceeded all expectations. Power consumption decreased and clinker production increased significantly. Even with the two week extension to a typical outage, in 2004, the revamped baghouse system allowed the Leamington plant set a production record. This paper describes the project, including the existing baghouse system, the project objectives, the vendor selection, the construction project and the post-project operational results.