Carrots mass transfer coefficients

Fig. 8.9 Identified mass transfer coefficients for carrot drying with (75 W, 21.7 kHz) and without ultrasound applications at different mass load densities. From Carcel etal. (2011a).

The drying of a cylindrical sample in a fluidized-bed dryer containing inert particles was studied by Honarvar and Mowla (2012). For this purpose, a pilot-scale fluidized-bed dryer was constructed in which two different heat sources -hot air and IR radiation - were applied, and pieces of carrot were chosen as test samples. The heat-transfer coefficient for cylindrical objects in a fluidized bed was also measured. The heat absorption coefficient for carrot was studied this can be computed by dividing the heat absorbed by the carrot by the heat absorbed by an aqueous solution of black ink. Subsequently, a mathematical model was proposed based on mass and heat transfer phenomena within the drying sample, and the results obtained in this way were in favorable agreement with the experimental data. 

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