Mathematical modeling of continuous cross-flow diffusion-controlled dryers

摘要: A mathematical model has been developed for continuous cross-flow dryers operating in diffusion-controlled regime. In the model, a dryer is treated as series of gas-solid contact stages, each purged by stream drying gas while wet solids are passing through. By analyzing interactions stage, boundary conditions intra-particle diffusion were established and equations obtained. The correlates amount moisture removed to number process variables (diffusivity, partition coefficient, particle size, residence time, total loading, humidity purge rate) allows effects these on be studied. For fine powders, effect reduced mass transfer efficiency due agglomeration channeling taken into account factoring an parameter Fourier number. Model predictions product concentration based laboratory-measured diffusivity, factor found closely match data from commercial HDPE powder dryer.