Download or read book Experiments Measuring Particle Deposition from Fully Developed Turbulent Flow in Ventilation Ducts written by and published by . This book was released on 2003 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle deposition in ventilation ducts influences particle exposures of building occupants and may lead to a variety of indoor air quality concerns. Experiments have been performed in a laboratory to study the effects of particle size and air speed on deposition rates of particles from turbulent air flows in galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. The duct systems were constructed of materials typically found in commercial heating, ventilating and air conditioning (HVAC) systems. In the steel duct system, experiments with nominal particle sizes of 1, 3, 5, 9 and 16 [mu]m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition rates of particles with nominal sizes of 1, 3, 5, 8 and 13 [mu]m were measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces (floor, wall and ceiling) at two straight duct sections where the turbulent flow profile was fully developed. In steel ducts, deposition rates were higher to the duct floor than to the wall, which were, in turn, greater than to the ceiling. In insulated ducts, deposition was nearly the same to the duct floor, wall and ceiling for a given particle size and air speed. Deposition to duct walls and ceilings was greatly enhanced in insulated ducts compared to steel ducts. Deposition velocities to each of the three duct surface orientations in both systems were found to increase with increasing particle size or air velocity over the ranges studied. Deposition rates measured in the current experiments were in general agreement with the limited observations of similar systems by previous researchers.
Download or read book Particle Deposition in Ventilation Ducts written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In ventilation duct flow the turbulent flow profile is commonly disturbed or not fully developed and these conditions are likely to influence particle deposition to duct surfaces. Particle deposition rates at eight S-connectors, in two 90{sup o} duct bends and in two ducts where the turbulent flow profile was not fully developed were measured in a laboratory duct system with both galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. In the steel duct system, experiments with nominal particle diameters of 1, 3, 5, 9 and 16 [mu]m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition of particles with nominal diameters of 1, 3, 5, 8 and 13 [mu]m was measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces. Deposition at S-connectors, in bends and in straight ducts with developing turbulence was often greater than deposition in straight ducts with fully developed turbulence for equal particle sizes, air speeds and duct surface orientations. Deposition rates at all locations were found to increase with an increase in particle size or air speed. High deposition rates at S-connectors resulted from impaction and these rates were nearly independent of the orientation of the S-connector. Deposition rates in the two 90{sup o} bends differed by more than an order of magnitude in some cases, probably because of the difference in turbulence conditions at the bend inlets. In straight steel ducts where the turbulent flow profile was developing, the deposition enhancement relative to fully developed turbulence generally increased with air speed and decreased with downstream distance from the duct inlet. This enhancement was greater at the duct ceiling and wall than at the duct floor. In insulated ducts, deposition enhancement was less pronounced overall than in steel ducts. Trends that were observed in steel ducts were present, but weaker, in insulated ducts.
Download or read book Particle Deposition in Ventilation Ducts written by Mark Raymond Sippola and published by . This book was released on 2002 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Deposition in Ventilation Ducts written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In ventilation duct flow the turbulent flow profile is commonly disturbed or not fully developed and these conditions are likely to influence particle deposition to duct surfaces. Particle deposition rates at eight S-connectors, in two 90{sup o} duct bends and in two ducts where the turbulent flow profile was not fully developed were measured in a laboratory duct system with both galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. In the steel duct system, experiments with nominal particle diameters of 1, 3, 5, 9 and 16 [mu]m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition of particles with nominal diameters of 1, 3, 5, 8 and 13 [mu]m was measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces. Deposition at S-connectors, in bends and in straight ducts with developing turbulence was often greater than deposition in straight ducts with fully developed turbulence for equal particle sizes, air speeds and duct surface orientations. Deposition rates at all locations were found to increase with an increase in particle size or air speed. High deposition rates at S-connectors resulted from impaction and these rates were nearly independent of the orientation of the S-connector. Deposition rates in the two 90{sup o} bends differed by more than an order of magnitude in some cases, probably because of the difference in turbulence conditions at the bend inlets. In straight steel ducts where the turbulent flow profile was developing, the deposition enhancement relative to fully developed turbulence generally increased with air speed and decreased with downstream distance from the duct inlet. This enhancement was greater at the duct ceiling and wall than at the duct floor. In insulated ducts, deposition enhancement was less pronounced overall than in steel ducts. Trends that were observed in steel ducts were present, but weaker, in insulated ducts.
Download or read book Particle Deposition from Turbulent Flow written by and published by . This book was released on 2002 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report reviews published experimental and theoretical investigations of particle deposition from turbulent flows and considers the applicability of this body of work to the specific case of particle deposition from flows in the ducts of heating, ventilating and air conditioning (HVAC) systems. Particle deposition can detrimentally affect the performance of HVAC systems and it influences the exposure of building occupants to a variety of air pollutants. The first section of this report describes the types of HVAC systems under consideration and discusses the components, materials and operating parameters commonly found in these systems. The second section reviews published experimental investigations of particle deposition rates from turbulent flows and considers the ramifications of the experimental evidence with respect to HVAC ducts. The third section considers the structure of turbulent airflows in ventilation ducts with a particular emphasis on turbulence investigations that have been used as a basis for particle deposition models. The final section reviews published literature on predicting particle deposition rates from turbulent flows.
Download or read book Particle Deposition in Ventilation Ducts written by Mark Raymond Sippola and published by . This book was released on 2002 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environment Energy and Climate Change I written by Elena Jiménez and published by Springer. This book was released on 2015-01-16 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a comprehensive overview of advanced research in the field of environmental green chemistry for air, soil and water pollutants, and presents emerging technologies on the chemical treatment of polluted sites and wastes. The 15 chapters, prepared by internationally respected experts, address the following topics: (1) monitoring of indoor and outdoor air pollutants; (2) atmospheric degradation processes and formation mechanisms of secondary pollutants; (3) the environmental assessment and impacts of soils polluted by heavy metals and hydrocarbons; (4) sustainable and emerging technologies for the chemical treatment of organic and animal wastes and wastewaters; (5) photocatalytic CO2 conversion methods for the mitigation of greenhouse effects; and (6) non-conventional methods in green chemistry synthesis. Lastly, the authors outline the future perspectives of each topic. Given its multidisciplinary approach, combining environmental analysis and engineering, the book offers a valuable resource for all researchers and students interested in environmental chemistry and engineering.
Download or read book Heating Ventilating and Air Conditioning written by Faye C. McQuiston and published by John Wiley & Sons. This book was released on 2004-08-06 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: HEATING, VENTILATING, AND AIR CONDITIONING Completely revised with the latest HVAC design practices! Based on the most recent standards from ASHRAE, this Sixth Edition provides complete and up-to-date coverage of all aspects of heating, ventilation, and air conditioning. You’ll find the latest load calculation procedures, indoor air quality procedures, and issues related to ozone depletion. Throughout the text, numerous worked examples clearly show you how to apply the concepts in realistic scenarios. In addition, several computer programs (several new to this edition) help you understand key concepts and allow you to simulate various scenarios, such as psychometrics and air quality, load calculations, piping system design, duct system design, and cooling coil simulation. Additionally, the load calculation program has been revised and updated. These computer programs are available at the book’s website: www.wiley.com/college/mcquiston Key Features of the Sixth Edition Additional new worked examples in the text and on the accompanying software. Chapters 6-9 have been extensively revised for clarity and ease of use. Chapter 8, The Cooling Load, now includes two approaches: the heat balance method, as recommended by ASHRAE, and the simpler RTS method. Both approaches include computer applications to aid in calculations. Provides complete, authoritative treatment of all aspects of HVAC, based on current ASHRAE standards. Numerous worked examples and homework problems provide realistic scenarios to apply concepts.
Download or read book Inhaled Particles written by Chiu-sen Wang and published by Elsevier. This book was released on 2005-01-20 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inhaled Particles integrates all that is known about inhaled particles in a unified treatment. It aims to provide a scientific framework essential to a reasonable understanding of inhaled particles. The emphasis is placed on demonstrating the key roles of lung morphology on airflow and particle transport as well as identifying physical and biological factors that influence deposition. Special attention is paid to maintaining consistency of treatment and a balance between theoretical modeling and experimental measurements. The book covers all important aspects of inhaled particles including inhalability, aerosol dispersion, particle deposition, and clearance. It reviews concisely the basic background of lung morphology, respiratory physiology, aerodynamics, and aerosol science pertinent to the subject. Essential aspects of health effects and applications are also included. An easy-to-read, self contained introduction to the field An excellent source of updated research information Useful for students and professionals in aerosol science, environmental health science, occupational hygiene, health physics and biomedical engineering
Download or read book Turbulent Aerosol Deposition in Large and Small Square Flow Passages written by William Dwight Gerstler and published by . This book was released on 2000 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Image Velocimetry written by Markus Raffel and published by Springer Science & Business Media. This book was released on 2007-08-09 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This immensely practical guide to PIV provides a condensed, yet exhaustive guide to most of the information needed for experiments employing the technique. This second edition has updated chapters on the principles and extra information on microscopic, high-speed and three component measurements as well as a description of advanced evaluation techniques. What’s more, the huge increase in the range of possible applications has been taken into account as the chapter describing these applications of the PIV technique has been expanded.
Download or read book Experimental Study on the Particles Deposition in the Sampling Duct written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high standard of protection against the harmful effects of radioactive aerosol dissemination requires a measurement, as representative as possible, of their concentration. This measurement depends on the techniques used for aerosol sampling and transfer to the detector, as well as on the location of the latter with respect to the potential sources. The aeraulic design of the apparatus is also an important factor. Once collected the aerosol particles often have to travel through a variably shaped duct to the measurement apparatus. This transport is responsible for losses due to the particles deposition on the walls, leading to a distortion on the concentration measurements and a change in the particle size distribution. To estimate and minimize measurement errors it is important to determine the optimal transport conditions when designing a duct; its diameter and material, the radius of curvature of the bends and the flow conditions must be defined in particular. This paper presents an experimental study in order to determine, for each deposition mechanism, the retained fraction, or the deposition velocity for different flow regimes. This study has pointed out that it exists a favourable flow regime for the particle transport through the sampling ducts (2 500
Download or read book Deposition of Submicron size Particles in Ventilation Ducts written by and published by . This book was released on 1963 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Turbulent Deposition Behaviour of Fine Particles Entrained in a Fully Developed Air Flow of a Round Duct Under Isothermal Conditions written by Panayiotis George Papavergos and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical and Experimental Investigation on Particle Deposition and Distribution in Ventilation Duct Bends written by Ke Sun and published by . This book was released on 2011 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Science written by Charles Norman Davies and published by . This book was released on 1966 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite work comprising a textbook on branches of aerosol science - covers theoretical and technical aspects of the generation, measurement and use of aerosols. References.
