Experimental studies and thin layer modeling of pearl millet using continuous multistage fluidized bed dryer staged externally

The fluidized bed dryers are one of the prominent moisture removal dryers in industries. Various studies have been conducted by previous researchers to improve the product quality and efficiency of dryers with various modified designs. In the present study, experiments were carried out using multistage fluidized bed dryer staged externally, changing operating conditions such as wall temperatures (313–328 K), velocity of air (1.01–1.3 m/s), downcomer height (50–70 mm) and solid flow rate (5–10 kg/h). Drying characteristics of solids in dryers at various stages was reported and comparison was made with single and multiple stage fluidized bed dryer. Experimental data were validated with various models and reported model parameters of multistage fluidized bed dryer at various conditions and stage-wise were reported at minimum RMSE error. Moisture diffusivity and activation energies were estimated at various conditions and reported.