Free-surface slurry flow

For a free-surface slurry flow in an open conduit inclined to the horizontal, the transport of the suspended load is similar to that of a closed conduit. However, for the case of free-surface flow, there is no pressure differential across the length of the conduit, and direct application of Equation 27 is not meaningful. For sediment transport in open-channel flow, Yalin [57] and Novak and Nalhuri [58] showed that the Froude number is an important parameter that describes sediment transport, and is given as... 

Wilson, K. C. 1980. Analysis of slurry flows with a free surface. Paper C4 read at Hydrotransport 7, Sendai, Japan. Cranfield, UK BHRA Group, pp 123-132. 

In the other mode, the flow of suspension is parallel to the medium, and some of the liquid flows through the medium by virtue of there being a pressure difference across it. The remainder of the slurry flows on and out of the filter. Very little of the suspended solid remains on the medium, and the intention is that the flow of liquid across the surface of the medium should indeed keep it scoured free of any deposit. This is called cross-flow filtration (sometimes tangential-flow), and while it can give extremely clear filtrates (in this context usually called permeates), it is only a thickener as far as the slurry is concerned. 

The catalyst used throughout this study was prepared by impregnation. To a slurry of silica (M5 Cab-O-Sil, Surface Area 200 m2g 1) in water sufficient copper nitrate solution was added to give a loading of 8.6 % w/w Cu. The resulting suspension was dried at 353 K until a free flowing powder was obtained. 

In abrasive wear by hard particles we often find either two-body abrasive wear or three-body abrasive wear, as shown in Figure 5.3. Two-body wear is caused by hard protuberances on the counterface, while in three-body wear hard particles are free to roll and slide between two sliding surfaces. Wear rates due to three-body abrasion are generally lower than those due to two-body abrasion. Various mechanisms of material removal in these two cases differ only in relative importance. Slurry erosion belongs to the abrasive wear category. Erosion is caused by hard particles sticking to the surface entrained in a flowing liquid. 

White or slightly cream-colored, free-flowing powder. I pproxitnate analysis CaO 19%, SiOa 67%. HaO 6 to 8%. 12,10. Bulk density IS to 16 Ib/cu ft. Absorbs I to 2.5 moits weight of liquids and still remains a free-flowing (order. Total absorption power for water about 600%, for iotral oil about 500%. Available surface area 95 to 175 uVg Ultimate particle size 0.02 to 0.07 pH of aq slurry 90 to 10.0. Practically insol in water. Forms a siliceous gel nth mineral acids. 

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