Early Agglomeration Recognition System (EARS)

In fluidised-bed combustion and gasification of biomass and waste, agglomeration of bed/ash particles is a major problem area. This paper deals with a new method for monitoring and controlling fluidised-bed hydrodynamics, which enables the recognition of agglomeration in an early stage and provides control measures to prevent further agglomeration and defluidisation. The method, named Early Agglomeration Recognition System (EARS), is based on recognising significant differences between reference time-series of pressure fluctuations and successive time-series measured during prolonged plant operation. The early recognition provides a time interval for taking dedicated actions to counteract the agglomeration. EARS thus can be a tool helping plant operators in preventing agglomeration induced plant shutdowns and minimising bed material make-up and residue production. Results are presented of small-scale experiments showing the effectiveness and selectivity of the early agglomeration recognition. Subsequently, the development of control strategies is discussed.