Filtration principles

C. Orr, Filtration, Principles andPractice, 2 vols., Marcel Dekker, Inc., New York, 1977. 

Filtration Principles and Practices, Second Edition, edited by Michael J. Matteson and Clyde Orr... 

Filtration Principles and Practices Second Edition, edited by Michael J. Matteson and Clyde Orr Corrosion Mechanisms, edited by Florian Mansfeld Catalysis and Surface Properties of Liquid Metals and Alloys, Yoshisada Ogino... 

Fig. 22.3 Back-pulse filtration principles (a) filling step ...

The success of this and the other operations derives from the correct application of back-pulse filtration principles, in particular the back-pulse step itself in which the filter cloths are cleaned and made ready for further filtration. The properties of the GORE-TEX membrane, composed of expanded polytetrafluoroethylene, give rise to the desirable results of these brine filtrations, in particular ... 

Matteson, M. S. and Orr, C. Filtration Principles and Practice, 2nd edn. (Marcel Dekker, New York, 1987). Purchas, D. B. Industrial Filtration of Liquids, 2nd edn. (Leonard Hill, London, 1971). 

Data from Amersham Biosciences Handbook, Gel filtration Principles and methods 18-1022-18. Edition A1... 

Amersham Biosciences (2002) Gel filtration principles and methods (www.chromatography.amershambiosiences.com)... 

Pharmacia Biotechnology, Gel Filtration Principles and Methods, 5th ed. (1991), Pharmacia Biotechnology, S-751 82 Uppsala, Sweden, or 800 Centennial Avenue, Piscataway, NJ 08854. An excellent guide on theory, practice, and applications of gel filtration. 

We can use the same filtration principle for the separation of small particles down to small size of the molecular level by using polymeric membranes. Depending upon the size range of the particles separated, membrane separation processes can be classified into three categories microfiltration, ultrafiltration, and reverse osmosis, the major differences of which are summarized in Table 10.2. 

Type of Reaction and Application. An increased emphasis on gas-solid reactions has been evident for about a decade. Three of the papers in this symposium treat gas-solid reactions, two (13,18) dealing with coal combustion and the other (11) with catalyst regeneration. Of the four papers which consider solid-catalysed gas-phase reactions, one (15) deals with a specific application (production of maleic anhydride), and one (12) treats an unspecified consecutive reaction of the type A B C the other two (14,16) are concerned with unspecified first order irreversible reactions. The final paper (17) considers a relatively recent application, fluidized bed aerosol filtration. Principles of fluid bed reactor modeling are directly applicable to such a case Aerosol particles disappear by adsorption on the collector (fluidized) particles much as a gaseous component disappears by reaction in the case of a solid-catalysed reaction. 

Schafer, A.I., Pane, A.G., and Waite, T.D., Nano filtration Principles and Applications, Elsevier Advanced Technology, Oxford, United Kingdom, 2005. 

Soo and Radke (11) confirmed that the transient permeability reduction observed by McAuliffe (9) mainly arises from the retention of drops in pores, which they termed as straining capture of the oil droplets. They also observed that droplets smaller than pore throats were captured in crevices or pockets and sometimes on the surface of the porous medium. They concluded, on the basis of their experiments in sand packs and visual glass micromodel observations, that stable OAV emulsions do not flow in the porous medium as a continuum viscous liquid, nor do they flow by squeezing through pore constrictions, but rather by the capture of the oil droplets with subsequent permeability reduction. They used deep-bed filtration principles (i2, 13) to model this phenomenon, which is discussed in detail later in this chapter. 

Soo and Radke (11) also studied the effect of average droplet size of emulsion on the flow behavior in porous media. The droplet size distribution of the emulsions that were prepared with surfactants and NaOH in a blender are shown in Figure 12. These droplet size distributions were found to be log-normal distributions. Others (9, 27) have also observed that the size of emulsion droplets was log-normally distributed. Soo and Radke (11) conducted experiments with emulsions having different average mean diameter in fine Ottawa water-wet sand packs. Their results of the reduced permeability, k/ko, and reduced effluent volume concentration as a function of the pore volume of oil (in the emulsion) injected are shown in Figure 13. All emulsions were of 0.5% quality, and the initial permeability, ko, was 1170 mD (millidarcies). The lines in the figure represent results of flow theory (12,13) based on deep-bed filtration principles. 

Filtration Model. A model based on deep-bed filtration principles was proposed by Soo and Radke (12), who suggested that the emulsion droplets are not only retarded, but they are also captured in the pore constrictions. These droplets are captured in the porous medium by two types of capture mechanisms straining and interception. These were discussed earlier and are shown schematically in Figure 22. Straining capture occurs when an emulsion droplet gets trapped in a pore constriction of size smaller than its own diameter. Emulsion droplets can also attach themselves onto the rock surface and pore walls due to van der Waals, electrical, gravitational, and hydrodynamic forces. This mode of capture is denoted as interception. Capture of emulsion droplets reduces the effective pore diameter, diverts flow to the larger pores, and thereby effectively reduces permeability. 

Filter types Filtration principles Advantages Drawbacks... 

Pich J. In Matteson MJ, Orr C, eds. Filtration Principles and Practices. New York Marcel Dekker, 1987. 

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