Written in English
A multitude of inertial sampling methods currently permit the selection of nearly any size of particle from the gas phase of an aerosol. Despite their success and high efficiency, these systems are challenged by intrinsic restrictions on operating pressures and flow rates, which necessitate designs that are sometimes extreme in their complexity and physical requirements. This work proposes the use of electrostatic methods as a promising alternative, and presents several novel designs for charge-based selection.A series of recommendations for future applications of electrostatic selection methods is offered in conclusion. A pilot study developed and tested a prototype electrostatic aerosol concentrator with very promising initial results, including a highly desirable inversion of the performance curve, and strongly recommends the further development of additional novel applications of electrostatic selection methods.A novel design for a corona particle charger was coupled with an electrostatic lens to produce a prototype electrostatic aerosol collimator. This charge-based sampling system was used to generate an aerosol beam from airborne particles. The beam produced was more acute (less than 350 microns in diameter) than any inertial beam reported to date. Furthermore, the performance of the ES collimator reversed the size bias of the inertial collimator, and preferentially sampled smaller particles.Using ions as an analog for ultrafine particles, a novel electrostatic lens was produced to demonstrate the advantage electrostatic methods offer over inertial sampling. The lens also provided a 100-fold improvement over existing ion sampling technology and was used to collimate ion source currents ranging from 30 pA to 7 nA, increasing the ion signal strength at the target by factors of 20 to 130 times that of the unaided signal.The inertial collimator commonly used in online aerosol sampling displays the size-dependent particle selection characteristic of all mass-based sampling methods. In this work, a custom-built inertial aerosol collimator illustrated this inherent size bias using a procedure specially developed to visualise sampling behaviour. By this means, the inert ially-generated aerosol beam was found to display a highly size-dependent radial distribution of its constituent particles. The observed tendency for particles to retain their collimation was limited to those larger than one micron in diameter.
|The Physical Object|
|Number of Pages||178|
Aerosol particles are an essential component of the atmosphere, with about MT of particulate matter produced or suspended in the troposphere each year .These particles contribute to air quality , soil fertilization (e.g., of the Amazon ) and cloud formation .By interacting with clouds, they contribute significantly to the water cycle and the Earth’s radiation balance .Author: Pascal Lemaitre, Mamadou Sow, Arnaud Quérel, Alexis Dépée, Marie Monier, Thibaut Menard, Andrea Flos. The specific charge on the fine particle dose of budesonide from Turbohaler corresponded to approximately electronic charges per particle, a value which is known to affect both total and. It is found that the collection efficiency of both ESP and RABH is dependent on the size of the incoming dust load. In ESP the collection efficiency is higher when the particle size is smaller than μm (PM) and larger than 1 μm i.e., PM and PM The collection efficiency is lower when the particle size lies between and 1 : Madhab Chandra Jena, Sarat kumar Mishra, Himanshu Sekhar Moharana. The APS measures the size distributions of particles from to μm and the FMPS measures the particle size distribution from nm to nm. The sampling of nanoparticles occurs via electrostatic precipitation, with a commercial electrostatic precipitator (ESP) for subsequent physicochemical and toxicological analysis.
An adjustable fan generates the gas flow through the ESP. Particle analysis is done by isokinetic sampling. To measure the dust concentration, a gravimetric method is used. For measuring the particle size distribution, different devices have been used. A light scattering analyser (Palas) covers the size range between and 40 μm. Abstract. Hygroscopicity is one of the most important physicochemical properties of aerosol particles and also plays indispensable roles in many other scientific and technical fields. A myriad of experimental techniques, which differ in principles, configurations and cost, are available for investigating aerosol hygroscopicity under subsaturated conditions (i.e., relative humidity below  The Aerodyne Aerosol Mass Spectrometer (AMS) has been designed to measure size‐resolved mass distributions and total mass loadings of volatile and semivolatile chemical species in/on submicron particles. This paper describes the application of this instrument to ambient aerosol sampling. The AMS uses an aerodynamic lens to focus the particles into a narrow beam, a roughened cartridge. Liao B-X, Gong W-C, Li Z, Tsai C-J () A mass correction method for the aerosol particle mass analyzer to measure the particle mass of sub nm nanoparticles. Aerosol Science and Technology 53(9)–
A Novel Method for Particle Sampling and Size-classified Electrical Charge Measurement at Power Plant Environment Ville Niemelä, Erkki Lamminen, Ari Laitinen Agglomeration Modelling of Sub-micron Particle During Coal Combustion Based on the Flocculation Theory K. Zhang, J. Zhang, H. Li, Y. Zhao, L. Zhang, C. Zheng The inertia theory for fine particle sampling has been confirmed through comparison with experiments. However, the amount of particle adhesion in a sampling probe and a sampling tube is quite significant and leads to erroneous results if neglected. Reduction of the electrostatic charge of aerosols as an important part of aerosol generation. Jeong C-H., Evans, G.J. “Inter-Comparison of a Fast Mobility Particle Sizer and a Scanning Mobility Particle Sizer incorporating an Ultrafine Water-based Condensation Particle Counter” Aerosol Sci. Technol. , () DOI: / An aerosol (abbreviation of "aero-solution") is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or es of natural aerosols are fog, mist, dust, forest exudates and geyser es of anthropogenic aerosols are particulate air pollutants and smoke. The liquid or solid particles have diameters typically less than 1.