Effect of PM size distribution on CEMS response in a coal CHP plant

Continuous emissions monitoring systems (CEMS) are used in power plants to monitor the level of emitted particulate matter from the stack. In order to evaluate which changes affect CEM calibration, it is important to understand the sources of possible changes in PM size distribution inside the stack.

The response of a PM CEM was compared with a non-continuous real-time PM instrument and the effect of changes in PM size distribution was evaluated in a large-scale coal CHP plant. A Dekati® High Temperature ELPI®+ was used to examine the PM size distribution changes. The advantages of this included its ability to measure PM size distribution in real-time, and directly from the high temperature source. This showed a similar trend for mass concentration, and the number size distribution shape was significantly different before and after a large baghouse cleaning spike.

Dekati Ltdinstruments are distributed by Scielutions Ltd (UK), which provides aerosol instruments and measurement services from leading manufacturers and will exhibit at AQE on stand 65.