Continuous membrane emulsification by using a membrane system with controlled pore distance

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• 作者：V. Schadler and E.J. Windhab
• 关键词：Controlled pore distance ; Membrane emulsification ; Rotating membrane ; Taylor vortex
• 刊名：Desalination
• 出版年：2006
• 出版时间：1 March 2006
• 年：2006
• 卷：189
• 期：1-3
• 页码：130-135
• 全文大小：1245 K

文摘

Conventional emulsification processes are usually coupled with a high energy input and high shear rates. Not only in pharmaceutical industry but also in food industry, temperature and shear can mutate or destroy sensitive product components. Therefore membrane emulsification processes can be used. The droplets are formed at pores and pressed into the continuous phase. For small ratios of pore distance to pore size, droplet coalescence on the membrane surface can occur. Membranes are usually used static up to now and the detaching force is limited with the overflow velocity of the continuous phase. A method to resolve this limitation is designed and described as follows. To avoid coalescence on the membrane surface a controlled pore distance membrane was developed combined with a special treatment of the surface. A measuring cell provides insight into the phenomena on the membrane surface. The drop detachment is monitored by two cameras from the top and the side view. In order to decouple the detaching force from the overflow of the continuous phase, the membrane is fixed on a cylinder and can be rotated in a variable gap. Up to now the influence of the rotational speed, the gap size and the volume ratio of the two phases were tested for W/O emulsions. The higher the rotational speed the smaller are the droplets and the narrower is the size distribution. The phase ratio does not influence the results, which is an advantage compared to a static membrane set-up. The gap width has a significant influence on the emulsification process and is coupled with formation of Taylor vortices.