More attention is being paid to the hydrodynamics and applications of micro fluidized beds in recent years.Considering the application of micro fluidized bed to gas-solids reaction analysis

the gas back-mixing characteristics in two beds of 10 mm and 21 mm inner diameter was studied by using the gas impulse tracer approach.The influences of bed diameter

static particle bed height

bed particle size and superficial gas velocity on the extent of gas back-mixing were investigated.It was shown that the extent of gas back-mixing increased with increasing inner bed diameter

static particle bed height and superficial gas velocity

but decreased with increasing bed particle size.The tested two micro fluidized beds that had a shallow layer of coarse particles in size of about 270 mm had both low extent of gas back-mixing and the estimated Peclet numbers for them were above 27

showing that the gas flow in these beds was very close to plug flow.This

as a consequence

verified that using micro fluidized bed for gas-solids reaction analysis could minimize the effect of gas back-mixing on reaction testing so as to get the near-intrinsic reaction kinetics.