Separation Performance of a Novel Liquid–Liquid Dynamic Hydrocyclone

Abstract

To investigate the separation performance of a novel liquid–liquid dynamic hydrocyclone (LLDH), a series of experiments and numerical simulations were conducted. Algebraic slip mixture model was used to simulate the multiphase flow in the LLDH, in which the turbulence was modeled using Reynolds stress model and the rotation of the walls was modeled by multiple reference frame model. The numerical results showed a good agreement with the observations and measurements in experiments. The results showed that the increase of rotation speed would strengthen the swirling intensity in LLDH and thereby separation efficiency was raised. However, increase of flow rate would decrease the residence time of oil droplets, causing reduction in efficiency. By comparison, flow split ratio had slight influence on the flow field, and the efficiency rose a little as flow split ratio increased. The efficiency of the LLDH could remain high when the nondimensional rotation rate was large enough.

Numerical and Experimental Biomass Separation from Fermentation Process by Minihydrocyclones

“…Initially, Reynolds stress was used for modeling water as the continuous phase. The RSM model was reported as an acceptable model with a reasonable computing time and cost 31, 32. After continuous phase development, the air core was modeled by the volume‐of‐ fluid (VOF) model.…”

New, efficient and low-cost technology to separate oil from bilge water

“…There are several studies describing complex methods for bilge water treatment, which are intended for the use in vessels above 400 GT: hydrocyclones [9][10][11], ultrafiltration (UF) method [12][13], wet air oxidation [14][15], electrocoagulation [16][17], UF/photocatalytic oxidation [13,18], biotechnology [19][20], and UF/membrane distillation [21][22]. These water separators (OWS) correspond to the regulations in Annex I of the 1973 International Convention for the Prevention of Pollutions from Ships, which was modified by the Protocol of 1978, and which is today known as MARPOL [23].…”

The dynamic behaviour of a large‐scale 250‐mm hydrocyclone: A CFD study

“…The multiphase models used in the hydrocyclone CFD studies are divided into Eulerian and Lagrangian approaches. More advanced full and simplified Eulerian–Eulerian (EE) multiphase models have been also extended for cyclone performance predictions . The single particle based Lagrangian considerations is less relevant for the concentrations of particle fractions at given points and times in the hydroclone.…”

“…It was already proved that the usage of k‐ε model limited due to isotropic turbulence assumption, that is, equality of Reynolds stresses in all directions . This has led some of the researchers to use the differential Reynolds stress turbulence model to model the turbulence in hydrocyclones. However, some recent studies have shown that the large eddy simulation (LES) technique has given better flow field predictions over Reynolds averaged turbulence models in hydrocyclones with computationally practical grids.…”