Experimental and computational analysis of the feed accelerator for a decanter centrifuge

Abstract

Industrial decanter centrifuges are used in a wide range of industries to separate mixtures of solids and liquids. One of the main elements of these devices is the feed accelerator, which accelerates the incoming mixture to the high rotational speed required for separation. A well-designed feed accelerator can increase product throughput, solids recovery, and liquid clarity, while a poorly designed accelerator can increase wear and reduce the overall efficiency of the machine. This article presents experimental and computational quantification of the performance of six feed accelerator designs that are currently used in decanter centrifuges. The experimental method allowed for the measurement of accelerator and pool speed efficiencies, and high-speed photography of the flow in the annular space between the accelerator and the rotating pool. The computational model allowed for prediction of the flow path in the annular space and the torque imparted on the fluid by the accelerator. A parametric study was conducted using the aforementioned computational model for drum and disk accelerators. It was found that several of the accelerator design parameters were critical to the overall performance, reinforcing the need for an optimised design. It was found that increasing the surface area of the port faces of the drum accelerator and increasing the discharge angle and discharge radius for the disk accelerator improved the performance of the accelerators.