Title: DRYING BEHAVIOR OF FRESH GREEN BEANS IN AN INERT MEDIUM FLUIDIZED BED
Abstract:ABSTRACT The effects of the presence of inert particles as heat carrier on the rate of drying in a fluidized bed dryer are studied. A pilot-scaled fluidized bed dryer with inert particles was set up t...ABSTRACT The effects of the presence of inert particles as heat carrier on the rate of drying in a fluidized bed dryer are studied. A pilot-scaled fluidized bed dryer with inert particles was set up to investigate the drying behavior of green beans. Glass beads, hollow steel balls and polyethylene particles were used as inert materials. Several length-to-diameter ratios of fresh green beans were considered and the effects of inert material type, inert material diameter, air velocity and temperature on the rate of drying were studied. It was found that the presence of inert particles enhanced the rate of drying and improved the fluidization quality of cylindrical green beans. The experimental drying curves for long samples were adjusted to the diffusional model of Fick's law for infinite cylinder without considering shrinkage to measure moisture diffusivity. Estimated moisture diffusivities in the presence of inert materials are greater than those without the presence of inerts. PRACTICAL APPLICATIONS Addition of some inert particles to the drying materials in fluidized bed dryers can improve fluidization behavior of drying materials and increase the drying rate of drying materials and thermal efficiency of the dryer.Read More