Centrifugal fluidized combustion of coal. Final report

Abstract

A laboratory test unit was built; and batch experiments on bed startup, minimum fluidization, and pressure drop were performed using room temperature air at atmospheric pressure. Particular attention was given to the effects of grid pressure drop, grid taper angle, mass of bed material, speed of rotation, and particle size and density on fluidization. The batch experiments demonstrated that, over the range of conditions studied, it is possible to start up a centrifugal fluidized bed (CFB) from rest, that the system fluidizes in a predictable fashion, and that the minimum fluidization velocities and bed pressure drops are in good agreement with the theoretical models developed for the CFB. Test sections based on two different techniques for operating a CFB with continuous feed and removal were designed and fabricated. The experimental data indicate that with these techniques, it is possible to feed and remove solids continuously and achieve a stable bed thickness in a rotating fluidized bed. Experiments performed on particle elutriation show that the air flow rate at which particle loss is initiated is a strong function of the angular velocity of the bed and the bed thickness. At higher flow rates, the rate of particle loss depends on airmore » flow rate, angular velocity and bed thickness.« less