Powder Characterization by Bed Collapsing

Powder Characterization by Bed Collapsing (Relevant references include Tung, 1981 Tung and Kwauk, 1982 Tung et a ., 1989.) 

Broadly speaking, for G/S systems, three modes of particle-fluid contacting may be recognized to take place simultaneously, as shown in Fig. 2 bubbles containing sparsely disseminated particles, emulsion of densely suspended 

an intermediate stage of hindered sedimentation with constant velocity of the dense emulsion of mobile particles, and 

a final decelerating stage of solids consolidation for the incompletely suspended particles. 

the random, spatial distribution of the three modes of particle-fluid contacting is transformed into the ordered, temporal sequence of the three stages of the sedigraph. The bed collapsing method has been used, too, for other objectives in studies on fluidization (Rietema, 1967 Morooka et at., 1973). 

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