Development of a model for the prediction of hydrodynamics of a liquid–solid circulating fluidized beds: A full factorial design approach

Abstract

Hydrodynamics ofa liquid–solid circulating fluidized bed (LSCFB) system has a significant impact on the reactor design. In the present study, statistical design approach was adopted to model the hydrodynamic behavior of an LSCFB in terms of average solids holdup and solids circulation rate. Primary liquid velocity, auxiliary liquid velocity, solids inventory and liquid viscosity are the input variables, called factors, which affects the system. Average solids holdup and solids circulation rate are called responses of the system. A full factorial design approachwithfourfactorsandthreelevelsofthefactorswereconsidered.Variousmodelssuchaslinear,twofactor interaction, quadratic, and cubic models weretestedfor theadequacy.Withintherangeofexperimentsconducted,forbothresponses,thequadraticregressionmodelissuggested.Themodelshowsthatsomeoftheinteraction effects between the factors are dominant. The developed model was verified by using various statistical tests. Also, the model was validated using various experimental data sets chosen at different conditions. Results based on ‘R’ value, and deviations in parity plot were falling within agreement level. This suggests that the proposed model can be adopted for various processing applications in the LSCFB unit.