Specific gravity mbbers

Global consumption of thermoplastic mbbers of all types is estimated at about 600,000 t/yr (51). Of this, 42% was estimated to be consumed in the United States, 39% in Western Europe, and 19% in Japan. At present, the woddwide market is estimated to be divided as follows styrenic block copolymers, 48% hard polymer/elastomer combinations, 26% thermoplastic polyurethanes, 12% thermoplastic polyesters, 4% and others, 9%. The three largest end uses were transportation, 23% footwear, 18% and adhesives, coatings, etc, 16%. The ranges of the hardness values, prices, and specific gravities of commercially available materials are given in Table 4. 

Coarse coal is to be pumped in a mbber lined 18 in pipe steel with an inner diameter of 17 in. A screen analysis of the coal indicates that it has a distrihution of 20% passing 200 mi crons. The velocity of pumping is 4.5 tn/s and the total weight concentration is 52%. The specific gravity of the coal is 1.35. Determine the hydraulic gradient due to wall friction in the horizontal pipeline. Assume a water dynamic viscosity of 1.2 cP, but correct for viscosity due to solids using Einstein s equation. Assume a drag coefficient of 0.75 for the coarse coal. 

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