Basic ideas for equipment design

In view of the fact that most materials needing to be dried are powdery or granular solids, the development of the circulative impinging stream dryer is aimed at this kind of material. 

For drying, the typical parallel heat and mass transfer process, the feature of impinging streams that significantly enhances transfer, should of course be fully utilized. 

The dryer shown in Fig. 6.12 can only be operated in batch, and this is its major disadvantage. However, lengthening the residence time by circulating the solid material employed is an effective measure. 

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