Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Designing thickeners by matching hindered settling and gelled suspension zones in the presence of aggregate densification
AU - Zhang, Yi
AU - Grassia, Paul
AU - Martin, Alastair
AU - Usher, Shane P.
AU - Scales, Peter J.
PY - 2015/9/29
Y1 - 2015/9/29
N2 - A model is presented for design of a thickener for solid-liquid separation where the flocs or aggregates within the solid-liquid suspension undergo an aggregate densification process due to the action of rakes. This aggregate densification facilitates suspension dewatering. The novel feature of the model is that it manages to couple together a hindered settling zone (higher up in the thickener, where the flocs are separated from one another, and the suspension cannot bear weight) and a gelled suspension zone (lower down in the thickener, where the flocs are packed together, and the suspension is able to bear weight). The model determines solids fraction profiles throughout the hindered settling zone and the gelled suspension zone, and also gives zone heights and residence times. Parametric investigations using the model are carried out for different suspension fluxes (which influence the solids fluxes and underflow solids fractions attained), and also for different specified amounts of and rates of aggregate densification.
AB - A model is presented for design of a thickener for solid-liquid separation where the flocs or aggregates within the solid-liquid suspension undergo an aggregate densification process due to the action of rakes. This aggregate densification facilitates suspension dewatering. The novel feature of the model is that it manages to couple together a hindered settling zone (higher up in the thickener, where the flocs are separated from one another, and the suspension cannot bear weight) and a gelled suspension zone (lower down in the thickener, where the flocs are packed together, and the suspension is able to bear weight). The model determines solids fraction profiles throughout the hindered settling zone and the gelled suspension zone, and also gives zone heights and residence times. Parametric investigations using the model are carried out for different suspension fluxes (which influence the solids fluxes and underflow solids fractions attained), and also for different specified amounts of and rates of aggregate densification.
KW - Gels
KW - Mathematical modelling
KW - Rheology
KW - Suspension
KW - Compressive yield stress
KW - Hindered settling function
KW - COMPRESSIVE YIELD-STRESS
KW - FLOCCULATED SUSPENSIONS
KW - RESOURCE INDUSTRIES
KW - SEDIMENTATION
KW - CONSOLIDATION
KW - PERFORMANCE
KW - SLUDGE
U2 - 10.1016/j.ces.2015.05.016
DO - 10.1016/j.ces.2015.05.016
M3 - Journal article
VL - 134
SP - 297
EP - 307
JO - Chemical Engineering Science
JF - Chemical Engineering Science
SN - 0009-2509
ER -