Flow Field and Thermal Behaviour of Bagasse in a Furnace with Tangential Over Fire Air System

Abstract

Furnaces with tangential over fire air system are vortex-combustion units and are widely used in modern steam generation units of industrial plants. In these furnaces, the fuel particles are accelerated by the distributor air jets to enter the furnace chamber. As soon as they enter the furnace, they are further subjected to undergrate air and tangential over fire air, which helps in rapid mixing of the fuel with air. The present study provides computational and experimental investigations made on an industrial biomass-fired furnace with spreader stoker suspension burning. The influence of tangential over fire air system on temperature distribution and the flow model of the turbulent reacting flows across the tangential plane are well predicted. Also, the thermal behaviour of the fuel which influences the combustion is investigated. The predicted temperature distribution along the tangential plane is in good agreement with the temperature measured at tangential plane level. The model prediction gives higher heat flux and gas concentration on walls than at the center.