Granular materials, flows

FIGURE 7.4 Air induction into a bin from flowing granular materials. 

Sudah, O., D, Coffin-Beach, and F. J. Muzzio. Quantitative characterization of mixing of free-flowing granular materials in tote(bin)-blenders. Powder Technol. (in press), 2001. 

Rotating cylindrical diyers are suited for free-flowing granular materials that require diying times of the order of 1 hr or less. Materials that tend to agglomerate because of wetness may be preconditioned by mixing with recycled dry product. 

Sodium Metasilicate occurs as a white, free-flowing, granular material. It is a hydrous (pentahydrate) or anhydrous silicate having a 1 1 molar ratio of Si02 to Na20. At 30°, the anhydrous Sodium Metasilicate is easily soluble in water (270 g/ L) as is its pentahydrate (610 g/L). The pH values of 1% solutions of anhydrous Sodium Metasilicate and of its pentahydrate are about 12.6 and 12.4, respectively. 

Tor example, Aldrich supply funnels which are designed to deliver free-flowing granular material to reactions under vacuum conditions This procedure removes the mineral oil. 

Similar applications of tumble/growth agglomeration are conceivable if powders or suspensions of metallic solids (obtained by precipitation or other ultrafme particle formation methods, for example in nanotechnology (Chapter 11)) must be converted into a dry, freely flowing granular material for further processing. 

Nedderman, R.M. Laohakal, C. (1980) The thickness of the shear zone of flowing granular materials. Powder Technol, 25, 91-100. 

It is known that multiple samples taken from a bulk (population) will give a distribution of measurements. For completely random mixture, such as a mixture of two free-flowing granular materials of equal size and density, the variance can be calculated theoretically as... 

When designing pneumatic conveying systems for light and free flowing granular materials, the unstable zone should be avoided. For such purpose, the accurate prediction of pressure drop caused by the long slugs in the unstable zone can provide some useftil information for the determination of the unstable zone boundaries. 

G. Metcalfe and M. Shattuck. Pattern formation during mixing and segregation of flowing granular materials. Physica A Statistical Mechanics and its Applications, 233(3-4) 709-717, 1996. 

M.F. Handley and M.G. Perry. Measurements of stresses in flowing granular materials. Rheologica Acta, 4(3) 225-235, 1965. 

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