Considering the pressing needs of developing micro fluidized bed reaction analyzer (MFBRA) suitable for analyzing chemical vapor deposition reaction

this study conducted a preliminary research on the hydrodynamics of internally circulating micro fluidized bed.It investigated the influences of central jetting tube height

in-bed draft tube diameter and initial particle bed height on the start-up gas velocity of internal particle circulation and the gas bypass into the annulus.The results showed that raising the height of jetting tube increases the start-up gas velocity for particle internal circulation.There is an existed optimal draft tube diameter (20 mm) that minimizes such a start-up gas velocity.The start-up gas velocity becomes lower with the increase of initial particle bed height.The gas bypass into the annulus was evaluated according to the mass-spectrum intensities of the tracer gas.For the tested experimental conditions

the bypass of gas from draft tube to annulus was ignorable in the bottom section but discernable at the top of the annulus.