Phenomenological Study on Fine Particle Misplacement Behavior in Hydrocyclone

Abstract

In spite of widespread applications of hydrocyclone, imprecise particle separation is an inherent limitation associated with it and led to a significant effect on the grinding operation. Such inefficiency is primarily attributable to the misplacement of significant amount of fine particles in the coarser product stream and commonly known as “bypass” in literature. Concerted research efforts are still continuing at various directions to rationalize the occurrence of such phenomenon in a quantifiable manner. This study reveals a fundamental basis towards the genesis and occurrence of bypass in hydrocyclone based on the hydrodynamic of particulate suspension within the turbulent field. Through a series of experiments, we generated carefully controlled experimental data in a 50.8 mm hydrocyclone to analyse the physical response of different parameters (design and operating) on the bypass. Proceeding with the experimental observations we disclose that fines recovery is not equal to that of water split in the underflow. Following this lead, we concluded that the bypass is principally driven by the hydrodynamic condition and the turbulent dispersion of the suspended particle in the prevailing centrifugal force field. Detailed calculations are presented on the basis of solid–fluid two-phase turbulent model to describe the above phenomenological incident. Although our analysis presented here confined to the small diameter hydrocyclone, we are optimistic that the acquired knowledge will be rationale towards the perception of a physical meaning to bypass even for larger classifying cyclones.