SIMULATION OF FLUIDIZED BED DRYER

Abstract

This thesis describes the simulation of fluidized bed dryer. Basically it deals with the development of a mathematical model of fluidized bed dryer based on two phase theory of fluidization. Further the mathematical model has been validated with the data of "Lai & Yiming Chen" in the end the effect of operating parameters on the performance characteristics has been investigated. The operating parameters include particle inlet moisture content of the drying gas, temperature of the drying particle, diameter of the drying particle, density of the drying particle, residence time of the drying particle and superficial air velocity of the drying gas. A fluidized bed includes two phases one is the emulsion phase and the other is the bubble phase. Solid particles in the emulsion phase are lumped and in the bubble is assumed plug flow regime, whereas emulsion phase is considered to be in mixed flow regime. Bubble size is one of the most important parameter in the design and simulation of fluidized bed dryer. A correlation of bubble size in fluidized bed dryer is incorporated. The developed mathematical model has been solved by Matlab 7.0. numerical simulation based on the model was done and the model is tested against the data of "Lai and Yiming Chen and found in good agreement with the maximum deviation of 3%. The parametric effects on the output variables namely "the moisure content of the outlet solid and the temperature of the outlet solid" has been investigated on the performance of the dryer.