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 Wet Cake Filtration written by Harald Anlauf and published by John Wiley & Sons. This book was released on 2019-07-04 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Guides readers through the entire process of liquid filtrations, from a basic understanding and lab scale testing to advanced process applications and up-scaling of processes Wet Cake Filtration is a key method in solid-liquid separation and plays an important role in many industrial processes from the separation of solid products from a liquid, to removing contaminants in wastewater treatment. Furthermore, separation processes are rarely isolated and the integration as well as necessary pre-treatments in the process chain must be carefully considered and implemented. Supported by more than 40 years of research, development, and teaching, this book provides a comprehensive treatment of all relevant aspects in wet cake filtration as a key method in solid-liquid-separation. The first part of Wet Cake Filtration: Fundamentals, Equipment, Strategies discusses general principles and applications of wet cake filtration, determination of proper feed streams, and filter cake formation. The next chapters deal with variations of pre-treatment and process conditions, including necessary aspects of lab scale tests, up-scaling, and filter design. This is further strengthened with chapters examining particle purification, yield maximization, and cake deliquoring. Lastly, the filter media is discussed as the central piece of wet cake filtration. Beside the different possibilities of available filter media structures and process relevant aspects of filter media selection, the reliable characterization of pore sizes by porometry and innovative additional functionalities are introduced. -Provides information on wet cake filtration?the necessary pre-treatments and process considerations?to guide the reader to develop or improve their own processes -Offers the necessary tools that allow the engineer to transform a lab scale test into a scaled-up process -Presents cake filtration process-related topics like slurry characterization or slurry pretreatment, and special developments such as hyperbaric filtration or steam pressure filtration -Discusses promising new processes like gasless cake desaturation and shrinkage crack free cake desaturation Wet Cake Filtration is a must-have resource for every engineer working with wet cake filtration, including water chemists, catalytic chemists, food chemists, chemical engineers, biotechnologists, and process engineers.

Download or read book Principles of Filtration written by Chi Tien and published by Elsevier. This book was released on 2012-04-19 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers filtration in various modes of operation for both solid/gas and solid/liquid suspensions. It provides the necessary knowledge and background information to prepare and equip persons who are interested in serious filtration work. It is a useful reference/text for students and practicing engineers. It can also be adopted as an advanced text book for various engineering courses in chemical, environmental, mechanical and metallurgical engineering. The book presents analysis and treatment of filtration processes employing different filter media operating in various modes for both gas/solid and liquid/solid systems. Presents a concise overview of filtration enabling full understanding of the applications as well as theunderlying theoretical foundations Presents filtration techniques in its entirety, i.e. gas/solid and liquid.solid separations and outlines their differences, coverage not found in any of the existing publications Presents rational procedures for analysing experimental data in a clear and easy to understand fashion by students and engineers Includes numerous illustrative examples enabling understanding of the underlying theory and selection of the most suitable solution for the particular application Provides detailed filter parameters (efficiency coefficients) vital in the design of filters Includes problems and solutions at the end of each chapter connecting the theoretical concepts with the practical aspects for engineers Written by the top expert on the subject of filtration

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 Filtration of Ultra small Particles on Fibrous Filters written by Igor Evgenevich Agranovski and published by . This book was released on 1995 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The problem of filtration of liquid aerosols by both wettable and nonwettable filters has been extensively studied and the results of the theoretical calculations together with the experimental results are presented. More realistic models of filtration by both wettable and nonwettable filters have been developed and verified experimentally.--A new instrument has been developed, and used in the experiments, for the measurement of the absolute concentration of aerosols in the gas stream. This instrument is based on the measurement of the initial vapour content of the gas stream simultaneously with the measurement of the vapour content after the total evaporation of aerosol. The concentration of the aerosol is calculated as the difference between these two values. The instrument was developed to provide fast and accurate measurements of aerosol concentration. The main advantages of the instrument are: high accuracy, simplicity of measurement, possibility of use for a wide range of substances, perfect suitability of operation for automatic monitoring technologies, etc. All rights for this instrument have been reserved and the fully automatic version will be available in the near future.--It was found that the efficiency of filtration of aerosol on the wettable filter depends on the thickness of the liquid film on the fibre. This parameter was taken into account in the development of a theoretical model of filtration on wettable fibrous filters. The particle breakthrough problem has been solved by the optimisation of the aspect ratio (the ratio of the height by width) of the wettable filter. On this basis, industrial devices have been developed, patented, and implemented in industry. These devices provide a stable operating efficiency of higher than 99%.--It was found experimentally that the efficiency of filtration of aerosol on the nonwettable filter depends on the diameter of the drop suspended on the filter, and on the area of the filter blocked by drops: this influences the velocity of filtration. All these parameters were taken into account in the development of a theoretical model of filtration on nonwettable fibrous filters.--On the basis of this model, satisfactorily verified by the experiments, an industrial device has been developed. The harnessing of atomisers makes it possible to maintain the efficiency of filtration higher than 99%, even with a relatively high velocity of filtration of 2.7m/s. The new technology is tackling the problem of handling huge amounts of exhaust gases and this is particularly important for cramped installations when the space available for the air pollution control technology is quite limited.--A highly efficient gas cleaning technology has been developed. This technology is based on combining two stages (wet scrubber and filter) of currently utilised air pollution control devices by submerging the fibrous filter into the liquid on the plate. The new device provides an effective division of the main gas stream into ultra-small bubbles which increase the contact area between the gas and liquid phases. It was estimated theoretically and verified experimentally that the efficiency of the proposed 'combined' technology, is 45% higher than the efficiency of the two stages technology. The technology has been patented and will be offered for industrial implementation in the near future.

Download or read book Filtration written by Clyde Orr and published by Marcel Dekker. This book was released on 1977 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Air Filtration written by Charles Norman Davies and published by . This book was released on 1973 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Filtration written by Nicholas P. Cheremisinoff and published by Butterworth-Heinemann. This book was released on 1983 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a state-of-the-art review of liquid filtration in the chemical process and allied industries. Interpretations of the phenomenological observations of the hydrodynamics of filtration are given in the hopes of establishing more theoretical and generalized bases of design methodology. Specific design and selection criteria are reviewed, and typical industrial problems and their solutions are presented. Nicholas Cheremisinoff is known internationally as one of the foremost engineers with Exxon and as the author of numerous books, articles and periodical contributions. Most recently his international consulting role has seen him active the Ukraine, part of the former Soviet Union, where the modernising of these industrial processes has been key. Liquid Filtration is a fundamental unit operation extensively practiced throughout the chemical process, petroleum, and allied industries. It involves the separation, removal, and collection of a discrete phase of matter existing in a dispersed or colloidal state in suspension. This separation is most often performed in the presence of a complex media structure in which physical, physiochemical and/or electrokinetic forces interact. Guide to an essential industrial operation Single reference source for many industries Author has world-wide experience and reputation

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 Modelling Micro scale Coalescence and Transport Processes in Liquid Aerosol Filtration written by Mead-Hunter Ryan and published by . This book was released on 2012 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has examined the physico-chemical properties of coalescing filters on a micro-scale, considering them as either a capillary system or a fibre-droplet system. This work has developed a validated theoretical model for droplet-fibe forces in both phillic and phobic systems and a computational fluid dynamics solver for droplet-fibre systems. This work will significantly improve the design and optimisation of coalescing filter systems.

Download or read book A Theoretical Study of Particle Capture Efficiency in Liquid Filtration by Nonwoven Fibrous Filters written by Majid Zia and published by . This book was released on 1990 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Improving Performance and Drainage of Coalescing Filters written by Shagufta Usman Patel and published by . This book was released on 2010 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pure air or gas is very critical to many industrial applications. Gas streams contain impurities in the form of solid and liquid aerosols of micron and submicron sizes. It is very important to remove these aerosols for improving the economy and reliability of industrial processes and equipment as well as protecting our health and environment. Among different filters being used, coalescing filters are effectively used to remove liquid aerosols from gas streams and hence has numerous industrial applications. The performance of the filter affects the economy of the process. A coalescing filter captures the oil droplets and the captured liquid typically drains from the filter by action of gravity. The saturation or hold-up of liquid in the filter constricts the gas flow, increases pressure drop, and increases the operating costs of the filter. The filter loaded with liquid droplet indicates limited filter life and needs to be replaced which increases the cost of process. Filter performance and filter life can be improved if the liquid saturation is reduced without reduction in capture efficiency. In this research work filter media are modified with drainage structures to reduce saturation and to reduce drag resistance. The media are tested in horizontal and vertical orientations to determine whether their orientation with gravity influences the performance. The experimental results show that with no drainage channels the media oriented with flow vertically downward operates the best whereas with drainage channels the horizontally oriented media had the best performance. The results also show filter geometries developed by embedding low surface energy woven drainage channels at 45 degree downward angles have the overall best performance. Adding nanofibers to improve the performance of the filter media is an effective way of improving filter media's capture efficiency with moderate increase in pressure drop. Nanofiber augmented filter media indicated higher pressure drop but when the drainage channels are incorporated in the filter, the increase in the pressure drop is significantly low. The pressure drop increase will be significant for a nanofiber augmented filter media without the drainage channels. Filter geometries developed by incorporating drainage channels at downward angles indicate significantly low pressure drop, the drainage channels create a path of lower resistance and hence maximum flow goes through the drainage channel improving the filter performance and drainage. This research work allows to develop cost effective filter geometries which will significantly increase filter performance as compared to the glass fiber filter media which are commonly used in the industry.

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 Wetting and Wicking in Fibrous Materials written by A. Patnaik and published by Woodhead Pub Limited. This book was released on 2006-01 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Textile Progress monograph series provides a critical and comprehensive examination of the origination and application of developments in the textile industry and its products. This issue reviews the developments in wicking and wetting of fibrous materials, including fibres, filaments, yarns and fabrics.

Download or read book Current Awareness in Particle Technology written by and published by . This book was released on 1994 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: