Optimization of drum rotation speed of decanter centrifuge for dewatering with different sludge properties

Abstract

Lightweight and stable treatment of sludge is urgently needed because of its dual characteristics of pollution and resources. The decanter centrifuge plays a crucial role in sludge treatment as highly efficient solid–liquid separation equipment. This paper extensively discusses the impacts of the sludge solid density, sludge concentration, and drum rotation speed on the separation performance of a decanter centrifuge through numerical simulation. Based on univariate analysis results, a supervised learning algorithm is employed to quantify the coupling effect of the sludge properties and drum speed on the separation efficiency by comparing the prediction accuracies of three different surrogate models. The optimum drum rotation speed for the decanter centrifuge to achieve the desired separation efficiency was determined for different sludge properties. At high speeds (>2500 r·min⁻¹), the drum rotation speed had the greatest effect on the separation efficiency, whereas at lower speeds (<2500 r·min⁻¹), the sludge solid density became the predominant factor affecting separation efficiency. When the speed is >3000 r·min⁻¹, the separation efficiency begins to decline. This study offers a fresh perspective for investigating flow characteristics and regulating separation efficiency in decanter centrifuges used for sludge dewatering.