Download or read book A Fundamental Study of Aerosol Filtration by Fibrous Filters in the Transition Flow Regime written by Zhiqun Zhang and published by . This book was released on 1989 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fundamental Study of Aerosol Filtration by Fibrous Filters written by Hsu-Chi Yeh and published by . This book was released on 1972 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Filtration written by Dominique Thomas and published by Elsevier. This book was released on 2016-11-30 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filtration of aerosols is omnipresent in our daily lives, in areas as diverse as health, the protection of people and the environment, and air treatment inside buildings. However, the collection of particles within a filter media is not, contrary to popular belief, linked to a simple screen effect. The phenomena involved are much more complex and require the consideration of aerosol interactions, filter media and process conditions to select the best fiber filter for a given application. Aerosol Filtration, book for students, hygiene or process engineers, fibrous media manufacturers, designers, and filtration system suppliers or users addresses the filtration of aerosols in six chapters. These chapters cover physics and aerosol characterization, the fibrous media, and efficiency and filter clogging by solid or liquid aerosols, with special attention to the filtration of the nanoparticles. Analyses the behavior of fibrous media against solid and liquid aerosols Presents models of efficiency and pressure drop Introduces computing elements for estimating the lifetime of filters Provides guidance for designing filters and predicting their behavior over time
Download or read book Advances in Aerosol Gas Filtration written by Kvetoslav R. Spurny and published by CRC Press. This book was released on 1998-03-27 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols are generally associated with damaging effects to the ozone and human health, however, some aerosols enable productions of very clean, highly dispersed materials. Advances in Aerosol Filtration is dedicated to progress in aerosol science, presenting newly developed theories, filtration models, and novel applications of aerosol gas filtration. Topics include new filtration materials, filter testing methods, electrically enhanced filtration, mechanical and chemical filter resistivity, computational models, and much more. This book examines the history and development of aerosol filtration science and also considers research needs for the future.
Download or read book Study of Capture Fibre Wetting and Flow Processes in Wet Filtration and Liquid Aerosol Filtration written by Benjamin James Mullins and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis examines the particle capture, fibre wetting and droplet flow processes within wet filters collecting solid and liquid aerosols and within filters collecting only liquid aerosols. The processes involved in this type of filtration were examined through a series of experiments and models developed to describe the behaviour of fibre/liquid systems. -- This work can be summarized in 4 categories: (1) The bounce and immediate re-entrainment of liquid and solid monodisperse aerosols under a stable filtration regime (pre cake formation) by wet and dry fibrous filters. In this work it was found that the solid particles generally exhibited a lower fractional filtration efficiency than liquid particles (of the same size), although this difference decreased in the smaller size fractions. However, for the wet filtration regime (each fibre of the filter was coated by a film of water), no significant difference in filtration efficiency was detectable between solid and liquid aerosols. Either the bounce effect of the particles is inhibited by the liquid film, or the filtration conditions in the wet filter are so different that the aerosol properties are less significant with respect to capture. (2) A microscopic study of the effect of fibre orientation on the fibre wetting process and flow of liquid droplets along filter fibres when subjected to airflow and gravity forces was conducted. The flow of the liquid collected by the fibres was observed and measured using a specially developed micro-cell, detailed in the thesis. The experimental results were compared to a theoretical model developed to describe the flow of droplets on fibres. The theory and experimental results showed a good agreement. A sensitivity analysis of the model was performed which showed the droplet radius to be the most significant parameter. The model has the potential to improve filter self-cleaning and minimise water use. (3) An experimental study of the capture of solid and liquid (oil) aerosols on fibrous filters wetted with water. Variable quantities of liquid irrigation were used, and the possibility for subsequent fibre regeneration after clogging or drying was also studied. It was found that self-cleaning (removal of solid aerosols by water) occurred even under heavily dust-laden conditions, and post evaporation of water. With the collection of oil aerosols on fibres wetted with water, a predominance of the barrel shaped droplet on the fibre was observed, with oil droplets displacing water droplets (if the oil and fibre combination created a barrel shaped droplet), creating various compound droplets of oil and water not previously reported in literature. (4) An extensive experimental investigation of the wetting processes of fibre/liquid systems during air filtration (when drag and gravitational forces are acting) has shown many important features, including droplet extension, oscillatory motion, and detachment from fibres as airflow velocity increases. The droplet oscillation is believed to be induced by the onset of the transition from laminar to turbulent flow as droplet size increases. To model such oscillation it was necessary to create a new conceptual model to account for the forces both inducing and preventing such oscillation. The agreement between the model and experimental results is satisfactory for both the radial and transverse oscillations.
Download or read book A Fundamental Study of Filter Loading with Liquid Aerosols written by Gary S. Earnest and published by . This book was released on 2000 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Filtration written by R.C. Brown and published by Pergamon. This book was released on 1993-11-02 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for clean air has probably never been greater. Many industrial employees need to avoid exposure to airborne particulates, while certain industrial processes demand clean air of exceptional quality. Medical and biological fields rely on sterile air, while filtration can improve air quality in offices, homes and all types of transport. Filters act in a variety of complex and subtle ways. Each chapter introduces its subject matter simply, before tackling the problem in greater depth. The book therefore provides an excellent basis for detailed study, but is also invaluable to anyone needing an overview of the subject.
Download or read book An Investigation of Aerosol Filtration Via Fibrous Filters written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The most common method of removing particles from a gas stream is via fibrous filters. However, most of the previous studies have been limited to systems consisting of rows of fibers (often in two-dimensional geometries) perpendicular to the flow direction. The current work is aiming to develop an understanding of the role of filter?s microstructure and manufacturing process. In the first part of this study, pressure drop and nanoparticle collection efficiency of lightweight spun-bonded media are simulated by solving the Navier-Stokes equations inside three-dimensional geometries resembling the microstructure of such media. These pressure drop and collection efficiencies showed a perfect agreement with experimental data. In the second part of this work, the influences of fiber length and compaction ratio of filter media on the pressure drop are discussed. Simulation data of staple fiber media have shown good agreement with Davies? empirical equation. Such an agreement indicates that, within the range of dimensions considered, the fiber length has no significant influence on the materials? through-plane permeability as long as the SVF remains constant. Our simulation results for nonwovens with different compaction ratios, together with our experimental data, indicate that pressure drop of the porous media increases with increasing the compaction ratio or temperature of the calender rolls. In the third part of this work, we presented our approach for modeling permeability of fibrous filters with bimodal fiber size distributions (referred to as bimodal filters in this context). The three-dimensional microstructures resembling bimodal filter media with random in-plane fiber orientation distribution were generated to compute their permeability constants. These results were compared with the previous analytical and numerical models as well as our experimental data. Here we concluded that there exists an area-weighted equivalent average diameter for each bimodal filter tha.
Download or read book A Fundamental Study of Air Filtration for Respiratory Protection written by Behzad Fardi and published by . This book was released on 1988 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 34 (thesis year 1989) a total of 13,377 theses titles from 26 Canadian and 184 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 34 reports theses submitted in 1989, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Download or read book Research on Air Filtration written by Ming Ouyang and published by . This book was released on 1995 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Particle Filtration and Caking in Fibrous Filter Media written by Seyed Alireza Hosseini and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is aimed at developing modeling methodologies for simulating the flow of air and aerosol particles through fibrous filter media made up of micro- or nano-fibers. The study also deals with modeling particle deposition (due to Brownian diffusion, interception, and inertial impaction) and particle cake formation, on or inside fibrous filters. By computing the air flow field and the trajectory of airborne particles in 3-D virtual geometries that resemble the internal microstructure of fibrous filter media, pressure drop and collection efficiency of micro- or nano-fiber filters are simulated and compared with the available experimental studies. It was demonstrated that the simulations conducted in 3-D disordered fibrous domains, unlike previously reported 2-D cell-model simulations, do not need any empirical correction factors to closely predict experimental observations. This study also reports on the importance of fibers' cross-sectional shape for filters operating in slip (nano-fiber filters) and no-slip (micro-fiber filters) flow regimes. In particular, it was found that the more streamlined the fiber geometry, the lower the fiber drag caused by a nanofiber relative to that generated by its micron-sized counterpart. This work also presents a methodology for simulating pressure drop and collection efficiency of a filter medium during instantaneous particle loading using the Fluent CFD code, enhanced by using a series of in-house subroutines. These subroutines are developed to allow one to track particles of different sizes, and simulate the formation of 2-D and 3-D dendrite particle deposits in the presence of aerodynamic slip on the surface of the fibers. The deposition of particles on a fiber and the previously deposited particles is made possible by developing additional subroutines, which mark the cells located at the deposition sites and modify their properties to so that they resemble solid or porous particles. Our unsteady-state simulations, in qualitative agreement with the experimental observations reported in the literature, predict the rate of increase of pressure drop and collection efficiency of a filter medium as a function of the mass of the loaded particles.
Download or read book Aerosol Filtration written by Qisheng Ou and published by . This book was released on 2013 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle control technologies are essential in many manufacturing industries (electronic and chemical industrial, mineral processing, and food and beverages) as well as in pollution abatement and environmental control (for example, post processing of power plant emissions and clean rooms). A variety of particle control technologies using various mechanisms have been developed. Among these technologies, filtration is known as the most economical for achieving high removal efficiency of fine aerosol particles. In numerous existing studies on the loading process of particle filtration, two assumptions are usually made: (1) particles are spherical or nearly spherical in shape and (2) particles are uniformly deposited on filter medium. However, in practical applications, these two assumptions are not always met. Agglomerate particles with non-spherical shape are ubiquitous in industrial processing and ambient environment, and non-uniform particle depositions are often met. The overall objective of this dissertation is to advance our current knowledge on these two specific areas of aerosol filtration: (1) agglomerate particle filtration and (2) particle deposition uniformity. For the first part, Agglomerate Particle Filtration, a system which is able to generate stable and controllable agglomerate particles was developed. Both branch-like and chain-like agglomerate particles were generated through the system, and their morphologies were characterized using both online and offline methods. Series of filter loading experiments were performed to study the filtration behavior of fibrous filters loaded with agglomerate particles over the entire filter lifetime, including the initial filtration, depth filtration, transition filtration and surface filtration. The filtration and loading of agglomerate particles exhibited different behaviors than those of spherical particles. Different effects, including filter media, fractal dimension of agglomerate particles, and the overall mobility size of agglomerate particles, on the loading behavior were explored. Moreover, for predicting the loading behavior of agglomerate particles, two semi-empirical models were proposed by modifying existing models. Good agreements were found for both of them. For the second part, Particle Deposition Uniformity, particle depositions under two scenarios were investigated. In the first scenario, particle deposition along pleated filter panels was studied using a COMSOL-Matlab based numerical model. The evolutions of particle deposition profile and pressure drop of pleated filter panels during dynamic particle loading process were investigated. The model was validated by experimental loading tests. In the second scenario, particle deposition uniformity on HVAC entrance filter panels installed in an aircraft was studied by a computational fluid dynamics model. The flow fields around entrance filter panels and particle depositions on them were investigated. Factors affecting particle deposition uniformity were identified and explored.
Download or read book Fluid Filtration Gas written by Robert R. Raber and published by ASTM International. This book was released on 1986 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fibrous Filter Media written by Philip Brown and published by Woodhead Publishing. This book was released on 2017-06-16 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibrous Filter Media comprehensively covers the types, manufacture, applications, performance, and modeling of fibrous filter media. Part I introduces the principles of gas and liquid filtration, while Part II presents an overview of the types of fibrous filters, including details of fiber types, fabric construction, and applications. Part III covers a variety of filtration applications in which fibrous assemblies are used, with examples ranging from filtration for improving air quality, to medical filters, to industrial waste-water filtration. Finally, Part III covers the properties and performance of fibrous filters, including chapters on filter performance and simulation. With its expert editors and international team of contributors, this important book provides information on fibrous filters relevant to fiber and textile scientists, and is also ideal for academics and industry professionals working in the field of filtration. Dr. Philip Brown is Sweetenburg Professor of polymer and textile engineering at Clemson University, USA. Dr. Christopher Cox is Professor of mathematical sciences at Clemson University, USA. Systematic and comprehensive coverage of the trends and new technologies being developed in the field of fibrous filter media Focused on the needs of the textiles and filtration industries, with a clear emphasis on applied technology Contains contributions from an international team of authors edited by an expert in the field
Download or read book Numerical Study of Atmospheric Aerosol Sampling Process by Fibrous Filters written by Zhili Liu and published by . This book was released on 1993 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Filtration by Fibrous Filters written by B. Hanna and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
