Quality of dried product depends on the temperature and velocity at each position in the dryer. Simultaneous\r\nmicroscopic and macroscopic simulation on Computational Fluid Dynamic (CFD) is a general problem of fixed bed dryer\r\nconsisting of water transportation in porous media and dynamic flow of hot air in the dryer. Simplifying the dryer by\r\nassuming the packed bed as porous volume, viscous and inertial resistances (1/ and C2) are necessary for calculating the\r\npressure drop and velocity change in the bulk. Comparing the P/L of the standard packing with experimental results, the\r\nporosity and resistance parameters can be estimated. Simulation of unmodified, adding false floor and invest mesh, and\r\ninsulating the dryer wall are used for validation with previous results. Adding the round holed sieve as false floor and invert\r\nmesh can produce better profile but cannot obtain uniform distribution. Air velocity distribution shows similar but the\r\ncalculating temperature is higher than that from the experiment. By analysis of thermal efficiency of dryer without insulator,\r\nthe heat loss rates with flue gas and heat flux at wall are in the range 14%-17% and 5.5%-7.3%. Integrating with single fruit\r\nor thin layer drying kinetic in the future, the CFD simulation can be used for optimal design of fixed bed dryer.
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