CFD study of binary mixture mixing/segregation of supercritical carbon dioxide fluidized bed

Abstract

Mixing of binary mixture with small-sized particles component (SC) and large-sized particles component (LC) is simulated using unequal granular temperature-based kinetic theory (UGT-KT) in supercritical carbon dioxide fluid (S-CO2) fluidized bed. Synergy angle is applied to identify the tendency of mixing/segregation of SC and LC binary mixture according to the axial distribution of component volume fractions along bed height of S-CO2 fluidized bed. Three different regions, including segregation (SE) near the bed bottom, transition (TR) near the bed top and dense (DE) between the SE and TR regions along bed height, are discriminated. Large synergy angle reveals the tendency for the SC and LC particles to segregate. Small synergy angles occur with fluidizing velocity and temperature. Defluidization occurred at certain pressure ratio p/pcr of 1.22–1.62, leading to a large synergy angle in S-CO2 fluidized bed.