Effects of the inlet duct length on the performance of a dense medium cyclone: An experimental and numerical study

The effects of the inlet duct length on the performance of the dense medium cyclones were investigated in this study. The pressure drops and separation efficiencies of the dense medium cyclones with different inlet duct lengths were measured in a cold test rig. A numerical simulation using the four-way coupling method was also conducted to es-timate the flow field inside the dense medium cyclone. The experimental results show that a longer inlet duct length results in a lower static pressure drop. The overall se-paration efficiency first increases and then keeps almost unchanged as the inlet duct becomes longer. The simulated results show that the energy loss decreases as the inlet duct length increases. The changing trends of the static and total pressure drops with the inlet duct length are similar. According to the simulated flow fields, lengthening the inlet gas reduces tangential velocity near the vortex finder and therefore reduces the gas swirling loss. The inlet duct length affects the separation performance mainly by affecting the swirling particle roof. A longer inlet duct leads to fewer particles moving in the swirling particle roof in the dense medium cyclone, which accounts for a better separation efficiency. It was also found that the conventional one-way coupling method fails to qualitatively analyze the effects of inlet duct length on the separation performance of the dense medium cyclone.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the effects of inlet duct length on the performance of dense medium cyclones. Experimental measurements and numerical simulations show that a longer inlet duct length can reduce static pressure drop and improve separation efficiency. The simulations also reveal that increasing the inlet duct length helps decrease gas swirling loss and enhance separation performance.