Evaluation of wall slip effects on the flow characteristics of petroleum coke–water slurry flow along pipelines

Abstract

Flow characteristics of petroleum coke-water slurry (PCWS) were investigated in a slurry transportation facility. True rheological properties, drag reduction, and flow resistances of PCWS under the influence of wall slip were studied using the Tikhonov regularization method. Results show that the shear viscosity is insensitive to changes in the shear rate when the solid loading of PCWS is 59.8 wt%. However, the PCWS of 61.1 wt% exhibits typical dilatant fluid properties. As the shear rate increases, the PCWS of 63.4 wt% initially exhibits shear thinning, and then, the viscosity increases sharply when the shear rate exceeds 250 s À1 . In addition, the slurry also displays shear thinning at the shear rates exceeding 600 s À1 . Modified friction factor-generalized Reynolds number correlation is established to describe the resistance properties of a laminar flow of PCWS. When increasing the velocity, the drag reduction produced by the wall slip behavior reduces for the 59.8 wt% PCWS but increases for the 61.1 wt% PCWS. The drag reduction decreases at the outset followed by an increase for the 63.4 wt% PCWS. A decrease in the inner diameter of pipeline could enhance the effect of drag reduction of PCWS flowing in a pipeline.