Abstract—The separation efficiency of a hydrocyclone has extensively been considered on the rigid particle assumption. A collection of experimental studies have demonstrated their discrepancies from the modeling and simulation results. These discrepancies caused by the actual particle elasticity have generally led to a larger amount of energy consumption in the separation process. In this paper, the influence of particle elasticity on the separation efficiency of a hydrocyclone system was investigated through the Finite Element (FE) simulations using crude oil droplets as the elastic particles. A Reitema’s design hydrocyclone with a diameter of 8 mm was employed to investigate the separation mechanism of the crude oil droplets from water. The cut-size diameter of the crude oil was m 10 in order to fit with the operating range of the adopted hydrocylone model. Typical parameters influencing the performance of hydrocyclone were varied with the feed pressure in the range of 0.3 - 0.6 MPa and feed concentration between 0.05 – 0.1 w%. In the simulation, the Finite Element scheme was applied to investigate the particle-flow interaction occurred in the crude oil system during the process. The interaction of a single oil droplet at the size of m 10 to the flow field was observed. The feed concentration fell in the dilute flow regime so the particle-particle interaction was ignored in the study. The results exhibited the higher power requirement for the separation of the elastic particulate system when compared with the rigid particulate system. Keywords—Hydrocyclone, separation efficiency, strain energy density, strain rate. I. INTRODUCTION RADITIONALLY, hydrocyclones have been widely used in mineral processing industry to separate solid particles from liquids by a force field induced by swirl flow of tangentially fed slurry mixture [1], [2]. The hydrocyclone applications can be categorized as suspension concentration, liquid clarification, thickening, classification, sorting of solid M. H. Narasingha is with the Department of Chemical Engineering, King Mongkut’s University of Technology North Bangkok,1518 Piboonsongkhram Rd., Bangsue, Bangkok 10800, Thailand (e-mail: mhc@kmutnb.ac.th, monpilai@gmail.com). K. Pana-Suppamassadu is with the Department of Chemical Engineering, King Mongkut’s University of Technology North Bangkok, 1518 Piboonsongkhram Rd., Bangsue, Bangkok 10800, Thailand (e- mail:karanp@kmutnb.ac.th). P. Narataruksa is with the Department of Chemical Engineering, King Mongkut’s University of Technology North Bangkok, 1518 Piboonsongkhram Rd., Bangsue, Bangkok 10800, Thailand (e-mail:phn@kmutnb.ac.th). by size and density, liquid-liquid separation, and liquid-gas separation. In the past, many researchers investigated the performing principles of hydrocyclones in order to improve their capacity. Even though, hydrocyclones have been originally designed to operate in solid-liquid separation, they are also used in conventional solid-solid [3], liquid-liquid [4] and gas-liquid separations [5]. In the last two decades, the use of hydrocyclones in solid- liquid separations involving biology materials has been widely investigated. They have been used in food industry for starch refining, and as multi-stage separator systems for soluble coffee production [6]. In addition, hydrocyclones have been employed to separate yeast cells in continuous yeast cell cultivation and in beer industry [7]; Reference [8] and [9] investigated several parameters, such as pressure and temperature, to find out how they would affect the performance of mini-hydrocyclones in the field of the recovery and concentration of yeast cells. Many industries have increasingly adopted mini- hydrocyclones (e.g., 10 mm diameter) in performing difficult phase separations. Furthermore, these hydrocyclones also have their potential for fine particle ( m 10 ) suspensions classification, especially in the sub-micron fraction collection. It is investigated that the important parameters affecting the performance in dewatering and classification of 10-mm hydrocyclones are the operating pressure and feed solids concentration [10]. The separation efficiency of these mini- hydrocyclones can be determined primarily by the cut-size, the bypass and the water recovery to underflow. Recently, the powerful computational fluid dynamics or CFD can provide an insight of fluid flow in hydrocyclones, together with the separation mechanism and performance [11] - [13]. Reference [14] conducted the computation study to investigate the separation of microorganisms and mammalian cells. In their study, the presence of a cylindrical air core caused by a low pressure central portion and occupying the whole length of hydrocyclone was observed. In general, two important stages can be distinguished in a separation process; namely, i) separation of particles from the main swirling flow and their migration to the boundary layer on the hydrocyclone wall, and ii) the removal of the separated particles from the wall into the apex and out of the Hydrocyclone. At the latter stage, most of particles will go through the outer vortex under the influence of centrifugal forces and this implies that the centrifugal forces must be greater than the drag forces; otherwise they tend to move inward in the radial direction. The separation performance of Effect of Crude Oil Particle Elasticity on the Separation Efficiency of a Hydrocyclone M. H. Narasingha, K. Pana-Suppamassadu, and P. Narataruksa T World Academy of Science, Engineering and Technology International Journal of Chemical and Molecular Engineering Vol:3, No:5, 2009 288 International Scholarly and Scientific Research & Innovation 3(5) 2009 scholar.waset.org/1307-6892/14827 International Science Index, Chemical and Molecular Engineering Vol:3, No:5, 2009 waset.org/Publication/14827