Single-port optical access for spectroscopic measurements in industrial flue gas ducts

Abstract.

An in situ optical access to industrial-scale flue-gas ducts under high pressure has been designed and realised. The system is used here for the determination, by excimer-laser-induced fragmentation fluorescence (ELIF), of alkali species released from the combustion of coal in a pressurised circulating fluidised bed (PCFB) combustor. However, it could be applied to the detection of other species in a variety of industrial plants. The essential feature of the design is the access for the light source and collection of signal via the same, single window. The set-up is compact, robust and durable, having been tested under realistic flue-gas conditions for periods of up to two weeks in the PCFB pilot plant. The main features of the access are described and examples of data collected are presented to demonstrate its capabilities.