Hollow fiber membrane inner diameters

A DEA group was appended onto a polyethylene porous hollow-fiber membrane with a density of 2.2 mmol per gram of the resultant DEA-EA fiber. The inner and outer diameters of the hollow fiber were 2.4 and 4.4 mm, respectively. The liquid permeability, i.e., the permeation rate per unit of inside surface area, of the DEAEA fiber for the buffer was maintained at 50% of that of the original hollow fiber. Volume swelling of the porous hollow fiber accompanied by graft polymerization prevented the graft chains from filling the pores. 

The BS Amultilayer-adsorbed porous hollow-fiber membrane was mounted ona single hollow-fiber module, as showninFigure 13. The module size was 5 mm in inner diameter and 40 mm in effective length. The module was incorporated into a liquid chromatography system. A... 

FIGURE 32.8 Effect of structural parameters of hollow-fiber membrane used in the experiments. (From Pei, L. et al., J. Rare Earths, 27, 447, 2009.) (a) Effect of thickness of membrane, (b) Effect of inner diameter of fiber, (c) Effect of membrane porosity. 

Figure 3.8b is an electron micrograph of a typical hollow fiber membrane. The fiber is 300 pm in diameter and the walls are 50 pm thick. The outer wall is highly porous and the inner walls are dense and sparsely porous. The space in the wall between the inner and the outer surfaces is filled with intricate cellular stmctures, 10 x 40 pm cells with perforated walls. The pores are 0.5-5 pm in size. 

Inner Diameter Outer Diameter Number of Lumina Diameter Length Area per Unit Volume (cm" ) Hollow Fiber Membrane Material Source/ Supplier... 

When the membrane tube is reduced in diameter to a certain level, that is, ID < 1 mm, it becomes a hollow fiber and the fiber lumen may take on the effect of a microchannel on the fluid flow. The catalyst can be coated on the inner surface of the hollow fiber or impregnated inside the porous wall, while the separation is achieved by the porous hollow fiber itself or by the membrane formed on the outer surface of the hollow fiber, as shown in Figure 8.5. Such catalytic hollow fiber membranes can easily be fabricated into MMRs, called hollow fiber membrane microreactors (HFMMRs). 

The hollow-fiber membrane bioreactor took the simple cylindrical geometry housing [dimension 13 mm inner diameter (ID) x 22 mm outer diameter (OD) x 40 mm L see Fig. 14.2]. Cellulose acetate hollow-fiber membranes [200 p,m ID, wall thickness of 14 p,m and molecular weight cutoff (MWCO) of 10 kDa] derived from hemodialysers used to construct the HFMBs. The hollow-fiber membranes were fixed in the bioreactor by using molded silicon rubber. The effective length of the fiber in the reactor was 30 mm with approximately 200 fibers in each bioreactor. The distance between adjacent fibers was approximately 400 p-m, of the order of the distance between natural blood capillaries in human bone. The volume external to the hollow fibers in each HFMB was approximately 3.5 mL, and this volume was available for the collagen gel together with the microcarriers with adherent cells. 

Hollow Fiber with Sorbent Walls. A cellulose sorbent and dialy2ing membrane hoUow fiber was reported in 1977 by Enka Glan2stoff AG (41). This hoUow fiber, with an inside diameter of about 300 p.m, has a double-layer waU. The inner waU consists of Cuprophan ceUulose and is very thin, approximately 8 p.m. The outer waU, which is ca 40-p.m thick, consists mainly of sorbent substance bonded by ceUulose. The advantage of such a fiber is that it combines the principles of hemodialysis with those of hemoperfusion. Two such fibers have been made one with activated carbon in the fiber waU, and one with aluminum oxide, which is a phosphate binder (also see Dialysis). 

Aromatic polyamide (aramid) membranes are a copolymer of 1-3 diaminobenzene with 1-3 and 1-4 benzenedicarboxylic acid chlorides. They are usually made into fine hollow fibers, 93 [Lm outer diameter by 43 [Lm inner diameter. Some flat sheet is made for spirals. These membranes are widely used for seawater desalination and to some extent for other process applications. The hollow fibers are capable of veiy high-pressure operation and have considerably greater hydrolytic resistance than does CA. Their packing density in hoUow-fiber form makes them veiy susceptible to colloidal fouling (a permeator 8 inches in diameter contains 3 M fibers), and they have essentially no resistance to chlorine. 

The polyethersulfone capillary ultrafiltration membranes (Daicel Chemical Industries, Ltd., inner diameter 0.8 mm, outer diameter 1.3 mm, length 40 cm, molecular weight cutoff 150 000, water permeability 3 x 10 m m s kPa at 298 K) were used. The length and area of membrane consisting of seven hollow fibers are 40 cm and 70 cm. ... 

Membrane contactors can be made out of flat sheet membranes, which have some commercial applications. However, the most common commercial membrane contactors are made from small-diameter microporous hollow-fiber (or capillary) membranes with fine pores that run from the inner surface to the outer surface of the hollow-fiber wall. The contactor resembles a tube-in-shell configuration with inlet-outlet ports for the shell side and tube side. These kinds of membranes are typically made of hydrophobic materials such as polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), poly(tetrafluoroethylene-co-perfluorovinylether) (PEA), or polyvinylidene fluoride (PVDE). The membrane in a contactor acts as a passive barrier and as a means of bringing two immiscible fluid phases, such as gas and liquid or an aqueous liquid and an organic liquid, into contact with each other... 

Internal pressure hollow fiber ultrafiltration membrane was used in the experiment. The membrane material is modified PVC with effective membrane area of 40 m, the inner diameter and outer diameter of the hollow fiber is 1.0 mm and 1.5 mm, respectively, and the average membrane pore size is 0.01 xm, the molecular weight cutoff (MWCO) is 100 Ku. 

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