| 초록 |
A modified three-phase model is proposed for batch drying of fine powders in an inert medium fluidized bed. The overall heat and mass tranfer coefficients between the interstitial gas and solid phases have been determined by the proposed surface stripping model in which Biot number is a governing parameter. The effects of gas velocity, inlet gas temperature and mass ratio of starch to inert particles on the drying characteristics of starch in a 0.083 m-ID ( 0.80 m-high medium fluidized bed have been determined. Based on the proposed model, the internal resistance of mass transfer at the powder equals to the external resistance. The model predicts well the bed temperature, humidity of outlet gas, moisture content of solid particles, heat and mass transfers in an inert medium fluidized bed
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