Factors Affecdngthe Performance of a Codisposal Atmospheric Fluidized-bed Combustor

The history of fluidized bed technology dates back 60 years. Gasification of pulverized coal in the Winkler process during the 1920's marked the beginning of fluidized bed application. Consider­ ,able work done during World War II by U.S. oil companies to improve the catalytic cracking of kerosene led to the development of the Fluid Catalytic Cracking process. Fluidized bed technology later expanded into areas outside the petroleum industry. Roasting of sulfide ore, drying and sizing of fine dolomite particles, and calcination of limestone were among the many successful employments of the fluidized bed for industrial processes. The use of the Fluidized Bed Combustor (FBC) for municipal sludge incineration began in the 1960's with tremendous initial difficulties. One of the earliest successes was an experimental co-disposal pilot plant burning wet processed refuse with sludge in Franklin, Ohio, in the 1970's. The most significant advancement in FBC for sludge incineration is represented by the codispos­ al facility in Duluth, MinnesOta. The facility, owned and operated by the Western I ake Superi­ or Sanitary District, utilizes refuse-derived fuel to co dispose sewage sludge without auxiliary fuel. Recent research in fluidized bed technology has investigated the combustion of coal in conjunction with flue gas desulfurization. New concepts also include multi-stage FBC systems. OPERATION OF A CODISPOSAL