Abstract
In fluidized-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 fluidized-bed hydrodynamics, which enables the recognition of agglomeration in an early stage and provides control measures to prevent further agglomeration and defluidization. The method, called early agglomeration recognition system (EARS), is based on recognizing 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. Thus, EARS can be a tool to help plant operators prevent agglomeration-induced plant shutdowns and minimize bed material makeup 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.
