Particle collection from aqueous suspensions by solid and hollow single fibers

Membrane separation

Chang, Daniel Pan Yih ; Friedlander, Sheldon K. (advisor)

University:California Institute of Technology

Department:Engineering and Applied Science

关键词: Membrane separation;   

Others  :  https://thesis.library.caltech.edu/6043/1/Chang_dpy_1973.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

An investigation of particle capture by single solid and hollow fibers was conducted. The experimental system consisted of a small water tunnel with a test section in which single fibers were inserted. The deposition rate of particles under conditions of controlled flow and chemical composition was measured with an optical microscope. Particles studied included human erythrocytes and latex spheres ranging in size from 2.0 µm polyvinyltoluene latex to 25.7 µm styrenedivinylbenzene copolymer latex. The fibers were composed of glass, fluoroethylene-propylene (teflon - FEP), and cellulose acetate. Surface chemistry was found to play a major role in the attachment of micron-size particles to the collector. However, electrical double layer theory could not predict the onset of rapid particle attachment quantitatively. Significant viscous interaction of particles approaching the collector surface was inferred from the data, confirming recent theory. A novel application of hollow fibers with permeable membrane walls was developed. The membrane permeability permits modification of the fiber suspension interface by means of chemical addition and flow alteration.The destabilizing chemicals form a thin concentration boundary layer around the fiber surface, reducing the total amount of chemical needed. Slight suction at the fiber surface reduces the hydrodynamic resistance acting on the particles as they approach the surface. An increase in the collection efficiency can occur when these methods are applied.