Proceedings of the Second International Energy 2030 Conference,
November 4-5, 2008, Abu Dhabi, UAE

Electrohydrodynamic (EHD)-Enhanced Separation of Fine Liquid Droplets from Gas Flows - Application to Refrigeration and Petro-chemical Processes

M. Al Shehhi
University of Maryland, USA

S. Dessiatoun
University of Maryland, USA

A. Shooshtari
University of Maryland, USA

M. Ohadi
The Petroleum Institute, UAE

A. Goharzadeh
The Petroleum Institute, UAE

Abstract
Development of effective techniques for separation of fine liquid droplets from moving gaseous mediums has grown significantly in recent years. Separation processes have applications in many industrial systems, particularly in the refrigeration, process, petrochemical, and cryogenics industries. In this work, the performance of an EHD wire-cylinder separator has been evaluated in separating oil droplets of micron and submicron size from an air flow. Also, a numerical model has been built to simulate the EHD effect on the particles. The wire and cylinder diameters are 0.08 and 20 mm, respectively, and their length is 150 mm. The effect of some parameters, such as emitter polarity, applied voltage, flow velocity and temperature, is addressed. The results of this study show that negative charging increases the average efficiency about 35% higher than the positive polarity. Also, the temperature has a positive effect on the separation efficiency. The average efficiency increases by about 15% when the temperature increases from 300 to 330 K. Moreover, decreasing flow velocity from 5.0 to 1.0 m/s enhances the average efficiency about 24%. The pressure drops analysis shows that EHD effect on the pressure drops for the case at hand is only 3.1 Pascal under an applied voltage of 9 kV. The numerical model shows that particles smaller than 0.25 µm are largely charged by diffusion charging, whereas particles bigger than 0.5 µm are mostly charged by field charging.