An experimental study on drying of food materials in a fluidized bed dryer

A batch type fluidized bed dryer is designed and constructed in order to investigate experimentally the effects of particle mass, drying air temperature and drying air velocity on drying performance of new harvested corn and pistachio in this study. A series of experiments is carried out in the covered range of 100g≤ mp ≤300g, 7 %≤MC(d.b.)≤186% , 7%≤MC(w.b.)≤65%, 0.08≤MR≤1, 50°C≤T≤75°C, 6.87 m/s≤Um≤10.86 m/s, 47632≤Re≤75296, 43Pa≤DPbed≤277Pa, 60Pa≤DPplate≤300Pa. The velocity, pressure, temperature and moisture measurements are performed. The acquisition and processing of the measured pressure data are carried out by means of the devised program PressureMeasurement.vi in LabView 2009-SP1® environment. An original model is proposed in order to utilize the thermodynamic analyses of drying process inside a batch type fluidized bed dryer. The effect of drying air velocity at constant drying air temperature, the effect of drying air temperature at constant drying air velocity and the effect of particle mass on drying performance such as drying time and drying rate are researched. It is concluded that increase in particle mass causes in increase in drying time. On the other hand, increase in drying air velocity and drying air temperature cause in decrease of drying time.