Model predictive control with non-uniformly spaced optimization horizon for multi-timescale processes

Studies on parameter estimation and model predictive control of paste thickeners

A study on model predictive control in paste thickeners with rake torque constraint

Depositional processes in Saldanha Bay and Langebaan Lagoon

Paper 1 – hydraulic transport of bulky materials

Settling velocities of coal particles falling by gravity in a mineral oil have been measured for particle sizes ranging from 80 to 2,000 microns, at slurry porosities of between 0.6 and 1.0. Velocities for the latter figure correspond to the terminal velocities of single particles.



The terminal velocities were found to be within 25% of the predicted values for spheres and could, for Reynolds numbers less than 0.2, be related to the particle size (d) by the equation V = Kd2,15.



The settling velocities of the slurries, which were all in the laminar region, are shown to be related to the slurry porosity (e) by the theoretical equation of Maude and Whitmore, namely V = V, where Vo is the terminal velocity. Values of n between 6.5 and 7.5 were found.



Les vitesses de sedimentation naturelle de particules de charbon, variant de 80 a 2000 microns, dans une huile minerale et a des porosites de la suspension variant de 0.6 a 1.0, ont ete mesurees. Les vitesses pour cette derniere valeur correspondent a la vitesse limite de particules en chute libre.



Les vitesses limites de sedimentation sont en deca de 25% des valeurs calculees pour des sphees et, pour des nombres de Reynolds inferieurs a 0.2, peuvent ětre assimilees a la dimension des particules (d) selon la relation V = Kd2,15.



Les vitesses de sedimentation des suspensions, toutes en regime laminaire, sont en relation avec la porosite de la suspension selon l'equation theorique de Maude et Whitmore, soit V = V0 V, ou Va, est vitesse limite. Les valeurs de n ont varie entre 6.5 et 7.5.

C. Moreland

Papers

Settling velocities of coal particles