Hyper- and ultrafiltration

By use of selective membranes, water can be removed by filtration from the juice in order to effect its concentration. Depending upon the molecular size of the compounds and the cut-off value of the membrane used, there is likely to be some loss of flavour components. These may be recovered from the permeate by distillation and returned to the juice concentrate. Concentration by these methods is less effective in terms of folding than other methods but can provide advantages in specific cases for example, capital costs associated with hyperfiltration are around 10-30% less than for evaporative systems with aroma recovery equipment. 

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The cross-flow filtration method is applied mainly to hyper- and ultrafiltration as well as to some microfiltration.8 In cross-flow filtration the slurry solution or suspension fed to the filter flows parallel to the filter medium or membrane. The filtration product (permeate or filtrate) leaves the filtration module at right angles to the filter medium (the membrane). The traditional perpendicular flow filtration (where the flow of the suspension is directed at right angles to the filter medium and the permeate leaves the filter medium in the same direction) entails filter cake buildup, whereas cross-flow filtration is intended to prevent such filter... 

A.F. Turbak (Ed.), Synthetic Membranes Vol. I, Desalination Vol. 2, Hyper and Ultrafiltration Uses, ACS Symposium Series 153 and 154, American Chemical Society, Washington, DC, 1981. 

The large number of papers necessitated publishing the symposium in two volumes. Volume I describes the desalination and salt-rejecting hyperfiltration membranes. Volume II covers hyper- and ultrafiltration membrane utilization in the following areas food, medicine, pulp, paper, and textile industries, oily waste stream purification, and in the separation of gases, polymers, organic solutes, and biopolymers. 

Gel Limited or Osmotic Pressure Limited" , Chap. 22 in Synthetic Membranes, Voi. II, Hyper and Ultrafiltration Uses, A.F. Turbak, editor, ACS Symposium Series 154 (1981) pp. 373-409. 

TAYLOR, G.L 1969. Motion of axisymmetric bodies in viscous fluids. In Problems of Hydrodynamics and Continuum Mechanics, pp. 718—724. Philadelphia SIAM. TRETTIN, D.R. 8c DOSHl, M.R. 1981. Pressure-independent ultrafiltration—Is it gel limited or osmotic pressure limited In Synthetic Membranes-, vol. II Hyper- and Ultrafiltration Uses (ed. A.F. Turbak), pp. 373-409. ACS Symp. Series 154. Washington Am. Chem. Soc. 

Membrane separations Reverse osmosis Hyper- and ultrafiltration... 

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