Furnace for fluidised bed oxidation of products such as sludge has open-topped vessel inside closed cover to create ascending and descending flows of fumes

摘要

The furnace (1), comprising a vessel (2) forming a confinement chamber (3) for a fluidised bed (4) made from a mixture of products to be treated and inert materials, a circuit (10) that delivers fluid under pressure to the base of the chamber, a delivery system for the products to be treated and a heater (11), has the vessel made open-topped and located inside a closed cover (15) with a gap. The gap forms a post-combustion chamber that has an outlet (22) for smoke and fumes at its lower end, creating an ascending trajectory for the smoke and fume flow inside the vessel and a descending trajectory outside it of the same cross-sectional area. Both vessel and cover are made from refactory metal, with thermal insulation round the cover and the double base of the vessel.