|
Microfiltration (commonly abbreviated to MF) is a type of physical filtration process where a contaminated fluid is passed through a special pore-sized membrane to separate microorganisms and suspended particles from process liquid. It is commonly used in conjunction with various other separation processes such as ultrafiltration and reverse osmosis to provide a product stream which is free of undesired contaminants. ==General Principles== Microfiltration usually serves as a pre-treatment for other separation processes such as ultrafiltration, and a post-treatment for granular media filtration. The typical particle size used for microfiltration ranges from about 0.1 to 10 µm.〔Baker, R 2012, ''Microfiltration, in Membrane Technology and Applications'', 3rd edn, John Wiley & Sons Ltd, California. p. 303〕 In terms of approximate molecular weight these membranes can separate macromolecules of molecular weights generally less than 100,000 g/mol.〔Microfiltration/Ultrafiltration, 2008, Hyflux Membranes, accessed 27 September 2013. The suspended liquid is passed though at a relatively high velocity of around 1–3 m/s and at low to moderate pressures (around 100-400 kPa) parallel or tangential to the semi-permeable membrane in a sheet or tubular form.〔Perry, RH & Green, DW, 2007. ''Perry's Chemical Engineers' Handbook'', 8th Edn. McGraw-Hill Professional, New York. p. 2072〕 A pump is commonly fitted onto the processing equipment to allow the liquid to pass through the membrane filter. There are also two pump configurations, either pressure driven or vacuum. A differential or regular pressure gauge is commonly attached to measure the pressure drop between the outlet and inlet streams. See Figure 1 for a general setup.〔Baker, R 2000, ''Microfiltration, in Membrane Technology and Applications'', John Wiley & Sons Ltd, California. p. 279.〕 The most abundant use of microfiltration membranes are in the water, beverage and bio-processing industries (see below). The exit process stream after treatment using a micro-filter has a recovery rate which generally ranges to about 90-98 %.〔Kenna,E & Zander, A 2000, ''Current Management of Membrane Plant Concentrate'', American Waterworks Association, Denver. p.14〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Microfiltration」の詳細全文を読む スポンサード リンク
|