CALCULATION OF CARBON LOAD AND AXIAL PROFILES OF OXYGEN CONCENTRATION IN THE BED OF A FLUIDIZED COMBUSTOR

A model, based on the two phase theory of fluidization, is presented for calculating carbon load and spatial oxygen concentration in a fluidized bed combustor operated with multisized coal feeds. It accounts for both the cases of complete mixing and piston flow of gases in the particulate phase and uses the number of transfer units X between the bubble and the particulate phases as a parameter. Allowance is made for the different burning rates of volatiles and carbon, and temperature effects on the latter are reconsidered. Experimental data of previous authors are used to test the proposed model. Values of X required to fit these data are compared with those expected from the flow characteristics of the bubbling bed. © 1979, Taylor & Francis Group, LLC. All rights reserved.