Investigation of the role of viscosity on electrocoalescence of water droplets in oil

被引:52
作者
Chiesa, M. [1 ]
Ingebrigtsen, S.
Melheim, J. A.
Hemmingsen, P. V.
Hansen, E. B.
Hestad, O.
机构
[1] SINTEF Energy Res, NO-7465 Trondheim, Norway
[2] NTNU, NO-7491 Trondheim, Norway
[3] Ugelstad Lab, NO-7491 Trondheim, Norway
关键词
water-in-oil emulsion; sedimentation stability; flocculation; viscosity; coalescence; dipole-dipole forces; film-thinning force; drag force; buoyancy force;
D O I
10.1016/j.seppur.2005.12.003
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
The sedimentation velocity of water droplets in oil increases proportionally to the square of the droplets diameter. It is therefore beneficial for the separation of water from oil to increase the droplet size by enhancing the coalescence process. Electric fields are used for this purpose in order to separate stable water-in-oil emulsion. Field-induced charges on the water droplets will cause adjacent droplets to align with the field, attract each other and ultimately coalesce. The efficiency of electrically induced coalescence is strongly dependent on the oil characteristics. In the present study experiments are performed to observe the behavior of a droplet falling onto a stationary one at different oil viscosity. The droplet is exposed to an electric field of different magnitude parallel to the direction of the droplet motion. Experimental observations are compared with numerical prediction of the droplet kinematics, and the contribution of the forces acting on the droplets and their dependency on viscosity is discussed in detail. (C) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:267 / 277
页数:11
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