Critically Loaded Thickener

Figure 3.15 shows flux plots for a critically loaded thickener. The line of slope F/A represents the relationship between feed concentration and feed flux for a volumetric feed rate, F. The material balance equations [Equations (3.43) and (3.44)] determine that this line intersects the curve for the total flux in the downflow section when the total flux in the upflow section is zero. Under critical loading conditions the feed concentration is just equal to the critical value giving rise to a feed flux equal to the total continuous flux that the downflow section can deliver at that concentration. Thus the combined effect of bulk flow and settling in the downflow section provides a flux equal to that of the feed. Under these conditions, since all particles fed to the thickener can be dealt with by the downflow section, the upflow flux is zero. The material balance then dictates that the concentration in the downflow section, Cb, is equal to Cp and the underflow concentration, Cp is FCp/L. The material balance may be performed graphically and is shown in Figure 3.15. From the feed flux line, the feed flux at a feed concentration, Cp is Ups = FCf/A. At this flux the concentration in the downflow section is Cb = Cp. The downflow flux is exactly equal to the feed flux and so the flux in the upflow section is zero. In the underflow, where there is no sedimentation, the underflow flux, LCl/A, is equal to the downflow flux. At this flux the underflow concentration, Cl is determined from the underflow line.

Analytical A proc is described for the quant titrimetric analysis of TeNMe in nitric acid (Ref 35)s and a spectrophotometric method is described in Ref 41 for the detn of small amts of TeNMe in air and w Critical Diameter. The crit diam for deton propagation of TeNMe thickened with poly-(methyl acrylate) and loaded with up to 75% inert solids was detd and found to decrease with increasing solids loading. It was postulated that the solids acted as reaction foci ahead of the deton front (Ref 45)... 

Fatigue behavior is the most critical for anchor groups having anchors installed through holes in a steel plate or other fixture, since there is significant potential for unequal shear load distribution. Where fatigue due to shear is determined to be important, it is advisable to eliminate movement in the connection via welded thickened washers or supplemental grouting of the annular gap. 

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