Cross-flow filtration techniqu

Buesseler KO, Bauer JE, Chen RF, Eglinton TI, Gustafsson O, Landing W, Mopper K, Moran SB, Santschi PH, Vernon Clark R, Wells ML (1996) An intercomparison of cross-flow filtration techniques used for sampling marine colloids overview and organic carbon results. Marine Chem 55 1-31 Buffle J, Perret D, Newman M (1992) The use of filtration and ultrafiltration for size fractionation of aquatic particles, colloids, and macromolecules. In Enviroiunental particles. Buffle J, van Leeuwen HP (eds) Lewis Publishers, Boca Raton FL, pl71-230... 

To continuously separate FT wax products from ultrafine iron catalyst particles in an SBCR employed for FTS, a modified cross-flow filtration technique can be developed using the cross-flow filter element placed in a down-comer slurry recirculation line of the SBCR. Counter to the traditional cross-flow filtration technique described earlier, this system would use a bulk slurry flow rate below the critical velocity, thereby forcing a filter cake of solids to form between the filter media and the bulk slurry flow, as depicted in Figure 15.2b. In this mode, multiple layers of catalyst particles that deposit upon the filter medium would act as a prefilter layer.10 Both the inertial and filter cake mechanisms can be effective however, the latter can be unstable if the filter cake depth is allowed to grow indefinitely. In the context of the SBCR operation, the filter cake could potentially occlude the slurry recirculation flow path if allowed to grow uncontrollably. 

Buesseler, K. O., Bauer, J. E., Chen, R. F., Eghnton, T. I., Gustafsson, O., Landing, W., Mopper, K., Moran, S. B., Santshi, P. H., VemonClark, R., and Wells, M. L. (1996). An intercomparison of cross-flow filtration techniques used for samphng marine coUoids Overview and organic carbon resrflts. Marine Chemistry 55(1—2), 1—31. 

Application of cross-flow filtration for the removal of FT wax products can be a useful technique to maintain a constant catalyst loading in an FTS reactor in continuous operation. Addition of 1-dodecanol (at a concentration of 6 wt%) was found to decrease the permeation rate of the cross-flow filter used for the separation of simulated FT wax and activated iron catalyst slurry. However, additional... 

Inulinase Candida kefyr Comparison of cross-flow filtration, RME, expanded-bed adsorption techniques for DSP [88]... 

Although this technique is not limited to the initial cell recovery stages of a downstream process, cross-flow filtration is commonly used for product recovery operations, particularly in lower volume processes where stringent hygiene requirements apply, as in the pharmaceutical and food industries. 

Cross-flow filtration (CFF) also known as tangential flow filtration is not of recent origin. It began with the development of reverse osmosis (RO) more than three decades ago. Industrial RO processes include desalting of sea water and brackish water, and recovery and purification of some fermentation products. The cross-flow membrane filtration technique was next applied to the concentration and fractionation of macromolecules commonly recognized as ultrafiltration (UF) in the late 1960 s. Major UF applications include electrocoat paint recovery, enzyme and protein recovery and pyrogen removal. 

Ultrafiltration and reverse osmosis have always used a fluid management technique known as "cross-flow filtration" to sweep away deposited particles from the membrane surface. "Cross-flow filtration" (CFF) is compared with "through-flow filtration" (TFF) (sometimes called "dead-ended filtration") in Figure 2.38. 

Cross-flow filtration can be used in the ultra and micro-filtration range. Operating pressures are normally very low, hence this type of filtration technique is ideal for applications in areas where consistent sampling can take place within especially turbid conditions. 

The possibihty of using conventional precoating techniques in cross-flow filtration in tubes has also been suggested . With respect to the filtration velocity, Krauss suggested that tubular filtration systems should obtain filtration velocities in excess of 4.72 x 10 m s to be economically viable. 

In order to desalinate seawater in a small-sized plarrt, it is envisaged to use a hollow-fiber modttle (Figure 14.10), the sketch of which has been formd in the Techniques de Tlngenietrr. Salt water flows inside drcular cylindrical hollow fibers of inner diameter 40 rm and outer diameter 80 jrm through which the permeate (salt free) is filtered by reverse osmosis as it passes from the inside to the outside of the fibers. In this cross-flow filtration device, a substarrtial fraction of the salt feed flow rate leaves without being filtered. 

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