Extractive Continuous Emission Monitoring at San Juan Generating Station

Continuous emission monitors at San Juan have had very high availability and reliability over the past two years. Three extractive systems are in service on two 350 MW units and one 515 MW unit. Another 515 MW unit is scheduled for startup in 1982. All units are coal-fired with electrostatic precipitators and Wellman-Lord desulfurization systems, and all units will have the same extractive emission monitor systems utilizing microprocessors for control and data acquisition.

This paper discusses the design of and operating experience with the extractive systems and microprocessors, including their problems, advantages, and disadvantages. It will also outline system costs and describe certification experience for two units.

Secondly, this paper describes five years of history on operating and maintaining two early in-situ analyzer systems, a temporary system, and the present extractive systems. Finally, the development of dedicated daily maintenance will be summarized as a major reason for successful emission monitor systems.