Hot- to cold-side precipitator conversion project at George Neal Station Unit 4, Sioux City, Iowa

The Iowa Public Service (IPS) George Neal Unit 4 is a 650 MW gross (600 MW net) electric generating station that began commercial operation July 1, 1979. The unit burns low-sulfur, Powder River Basin coal. Neal Unit 4 was originally equipped with four hot-side precipitators for particulate control. The precipitators are weighted wire design. Neal Unit 4 has had a history of operating problems with the hot-side precipitators and the utility sought a long-term solution. A feasibility study determined that a cold-side conversion was the most feasible means of achieving long-term performance. In march of 1988, construction crews began a $12.8 million project which converted the precipitator from a hot-side to a cold-side precipitator. Of the total project costs, $2.8 million was planned for precipitator upgrade work, regardless of the conversion, and does not include the economic evaluation for the conversion. This paper summarizes the scope of work performed, presents features of the project, and discusses the overall operating impacts of the hot-side to cold-side conversion.