Continuous sedimentation of a suspension with a nonconvex flux law

✍ Scribed by C.A. Petty

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 779 KB
• Volume: 30
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(75)85022-6

✦ Synopsis

The continuous thickening of a solid-liquid suspension by gravity sedimentation is analyzed as an initial-boundary value problem of a nonlinear conservation equation. The concept of a limiting flux, commonly employed in steady state design, emerges as an intrinsic nonlinear phenomenon induced by nonuniform initial conditions and the instability of a certain class of discontinuous solutions. A limiting fhrx does not obtain for some uniform initial states; instead, the solids concentration follows a hysterisis path as the applied flux increases and then decreases. The model also shows that shock discontinuities caused by the interaction of rarefaction and plane waves dominate the transient resuonse of a thickening column uerturbed from its steady state by simultaneously decreasing the applied flux and undefiow rate.