Granular solids flow properties

Fig. 5.6. Flow and compression properties of feed solids for theoretical roll press design [15]. (a) Shear cell to measure internal friction of granular solid, (b) Cell to measure angle of friction between roll face and granular solid, (c) Pressure-density relationship of feed material.

Properties Off-wh. free-flowing granular solid faint, aromatic odor readily sol. in variety of org. soivs. incl. alcohols, ketones, ethyl acetate, and cosoivs. also sol. in aq. alkali m.w. 65,000 acid no. 190 Storage Unlimited shelf life in dry location Sea-Nine 211 [Rohm Haas]... 

The onset of powder motion in a hopper is due to stress failure in powders. Hence, the study of a hopper flow is closely related to the understanding of stress distribution in a hopper. The cross-sectional averaged stress distribution of solids in a cylindrical column was first studied by Janssen (1895). Walker (1966) and Walters (1973) extended Janssen s analysis to conical hoppers. The local distributions of static stresses of powders can only be obtained by solving the equations of equilibrium. From stress analyses and suitable failure criteria, the rupture locations in granular materials can be predicted. As a result, the flowability of granular materials in a hopper depends on the internal stress distributions determined by the geometry of the hopper and the material properties of the solids. 

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