HEAT TRANSFER COEFFICIENT IN STATIONARY HEATING-PLANE TYPE OF INDIRECT-HEAT AGITATED DRYER

The heat transfer coefficient between the heating wall and the granular bed in the stationary heating-plane type of indirect-heat agitated dryer was measured. Taking account of the effect of the clearance between heating wall and agitating blade, an improved heat transfer model was proposed. This model can also describe the dependence of the heat transfer coefficient on the circumferential velocity of the agitator, the thermal properties of the granular material, the particle size and so on. Furthermore, it was confirmed that this model was usable when the particles were non-spherical or when scale-up of the dryer was considered.