Fluid Bed Waste Heat Boiler Operating Experience in Dirty Gas Streams

Abstract

The first industrial fluid bed waste heat boiler in the U. S. is operating on an aluminium melting furnace at the ALCOA Massena Integrated Aluminum Works in upstate New York. Waste heat from an aluminum melting furnace is captured for general plant use for the first time in this plant. It is accomplished with advanced fluid bed heat recovery that typically can save energy equivalent to 40% of the furnace firing rate. Previous attempts to recovery energy conventionally on this type of furnace were unsuccessful due to fouling. The resolution of this fouling problem by using an automatically self-cleaning Fluidfire fluid bed unit is discussed. The paper further discusses how this project incorporates unique technology which increases the inlet gas temperature capability by 57% and reduces casing size by 40% over fluid bed heat recovery in Japan and Europe. Also that the Fluidfire unit is operating well and has demonstrated the characteristics required. The paper explains how experience in the difficult environment of an aluminum melter flue is indicative of the fluid bed system's capability to withstand most other difficult industrial operating conditions.