The Study of the Particles Size Influence on the Venturi Scrubbers Perfomance

The suspended particles in the air are a factor that causes chronic illnesses to the respiratory system, which go from allergy to severe pulmonary damage. Particulary, breathable particles (from 0,5 μm to 5,0 μm sizes) cause damages to the respiratory system. The penetration and the deposition are the reason for the damages to the pulmonary alveolus. The industrial activity is the main responsible for the most part of the breathable particles emission. Because of that, Venturi scrubbers have been incorporated to the industrial process due to their high efficiency for particle collection. Venturi scrubbers are gas-atomizing devices. They are mechanical devices which rely on shearing and impaction forces to break water into fine droplets. Those droplets in contact with the particles, will collected them. This work consists of a Venturi scrubber of circular section operating horizontally, with liquid injection through a single orifice located in the scrubber throat. The experiments will analyse the influence of the length throat, gas velocity, liquid flow and particles sizes on the Venturi´s collection efficiency.

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Effects of Operational Variables on the Performance of Venturi Scrubbers with Circular Section

Materials Science Forum ◽

10.4028/www.scientific.net/msf.530-531.298 ◽

2006 ◽

Vol 530-531 ◽

pp. 298-303

Author(s):

L. Meili ◽

M.O. Fernandes ◽

Carlos Henrique Ataíde ◽

João Jorge Ribeiro Damasceno

Keyword(s):

Liquid Flow ◽

Collection Efficiency ◽

Experimental System ◽

Factorial Experimental Design ◽

Small Particles ◽

Air Velocity ◽

Circular Section ◽

Operation Conditions ◽

Liquid Injection ◽

Operational Variables

The Venturi scrubbers have a high collection efficiency to remove very small particles from gaseous streams. The main purpose of this work is to determine the overall collection efficiency of Venturi scrubbers with circular section under different operation conditions. The experimental system consisted of a Venturi scrubber with circular section and liquid injection in the throat. A factorial experimental design was carried out; the overall collection efficiency was the response. Three variables were analyzed: the throat length, the air velocity and the liquid flow. The best values for efficiency were obtained for 15 m/s of air velocity and 300 mL/min of liquid flow and the throat length did not have influence.

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Performance of a cyclone scrubber on removal of fine particulate matter

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq181220022a ◽

2020 ◽

Vol 26 (1) ◽

pp. 31-40

Author(s):

Ana Achiles ◽

Vádila Guerra

Keyword(s):

Pressure Drop ◽

Sugar Cane ◽

Gas Flow ◽

High Efficiency ◽

Fine Particles ◽

Collection Efficiency ◽

Sugar Cane Bagasse ◽

Flow Ratio ◽

Liquid Injection ◽

Gas Flow Ratio

Cyclones are not classified as effective devices for removing fine particles, while high efficiency wet scrubbers usually have high operational costs. In order to achieve better performance, the aim of this study is to evaluate, for the first time, a cyclone scrubber design based on the dimensions of a Stairmand cyclone separator with the inclusion of liquid injection nozzles located in different positions to improve the separation of fine particles. Given the lack of studies considering the effect of liquid injection and other operational conditions in the removal performance of a cyclone scrubber with Stairmand dimensions, the present paper provides a complete evaluation of these effects for the separation of sugar cane bagasse ash from air. The parameters investigated were inlet gas velocity, liquid injection position, liquid-to-gas flow ratio and droplet size distribution. The cyclone scrubber performance was evaluated considering collection efficiency and pressure drop. Overall efficiency of almost 99% and low-pressure drop was achieved by employing a liquid-to-gas flow ratio of 0.43 L/m? for the collection of ash from the combustion of sugar cane bagasse. Grade efficiencies revealed that injecting droplets into cyclones significantly improved the removal of fine particles with an aerodynamic diameter less than 2.5 ?m.

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Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System

BioMed Research International ◽

10.1155/2015/524283 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Jun Ho Ji ◽

Jong Bum Kim ◽

Gwangjae Lee ◽

Jung-Hun Noh ◽

Se-Jin Yook ◽

...

Keyword(s):

Titanium Dioxide ◽

High Efficiency ◽

Collection Efficiency ◽

Particle Diameter ◽

Development Stage ◽

Bag Filter ◽

High Exposure ◽

Filter System ◽

Particle Collection ◽

Computational Fluid Dynamics Cfd

Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD).

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Experimental Investigation of the Effects of Helical Roof on the Performance of Stairmand High Efficiency Cyclone

International Journal of Chemical Engineering ◽

10.1155/2021/7207994 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Aykut Karadeniz ◽

Selami Demir

Keyword(s):

Pressure Drop ◽

Treatment Cost ◽

High Efficiency ◽

Negative Impact ◽

Collection Efficiency ◽

Operating Conditions ◽

Reduced Pressure ◽

Particle Collection ◽

Standard Design ◽

Roof Design

Cost-effectiveness of a standard and a modified Stairmand high-efficiency type cyclone was compared at various inlet gas velocities. The modified design was obtained by replacing the roof of the standard design with a helical roof. Experiments were conducted by both standard and helical roof designs at the same operating conditions. Results showed that helical roof leads to reduced pressure drop in cyclones while having a negative impact on particle collection efficiency. Reductions in pressure drop can reach up to 30%, while particle collection efficiency is reduced by up to 8% simultaneously. Overall, the treatment cost of a cyclone separator can be reduced by 14.1–20.8%. Results indicated that helical roof design cyclones can be used to reduce overall treatment cost by cyclone separators.

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DETERMINATION OF AEROSOLS POLLUTANTS ON MEMBRANES. EVALUATION OF PARTICLE COLLECTION EFFICIENCY AND LEAD CONCENTRATION IN AEROSOLS

Environmental Engineering and Management Journal ◽

10.30638/eemj.2011.085 ◽

2011 ◽

Vol 10 (5) ◽

pp. 621-627

Author(s):

Mihaela Emanuela Craciun ◽

Niculina Nina Badea ◽

Ovidiu Gales ◽

Florian Aldea

Keyword(s):

Lead Concentration ◽

Collection Efficiency ◽

Particle Collection

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Tailoring the Geometry of Bottom-Up Nanowires: Application to High Efficiency Single Photon Sources

Nanomaterials ◽

10.3390/nano11051201 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1201

Author(s):

Dan Dalacu ◽

Philip J. Poole ◽

Robin L. Williams

Keyword(s):

Quantum Dot ◽

High Efficiency ◽

Emission Rate ◽

Single Photon ◽

Collection Efficiency ◽

Photon Emission ◽

Device Performance ◽

Bottom Up ◽

Selective Area ◽

Photon Generation

For nanowire-based sources of non-classical light, the rate at which photons are generated and the ability to efficiently collect them are determined by the nanowire geometry. Using selective-area vapour-liquid-solid epitaxy, we show how it is possible to control the nanowire geometry and tailor it to optimise device performance. High efficiency single photon generation with negligible multi-photon emission is demonstrated using a quantum dot embedded in a nanowire having a geometry tailored to optimise both collection efficiency and emission rate.

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Uncertainty assessment of current size-resolved parameterizations for below-cloud particle scavenging by rain

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-5685-2010 ◽

2010 ◽

Vol 10 (12) ◽

pp. 5685-5705 ◽

Cited By ~ 83

Author(s):

X. Wang ◽

L. Zhang ◽

M. D. Moran

Keyword(s):

Size Distribution ◽

Collection Efficiency ◽

Theoretical Calculations ◽

Terminal Velocity ◽

Moderate Intensity ◽

Size Spectrum ◽

Cloud Particle ◽

Particle Collection ◽

Particle Scavenging ◽

Empirical Size

Abstract. Current theoretical and empirical size-resolved parameterizations of the scavenging coefficient (Λ), a parameter commonly used in aerosol transport models to describe below-cloud particle scavenging by rain, have been reviewed in detail and compared with available field and laboratory measurements. Use of different formulations for raindrop-particle collection efficiency can cause uncertainties in size-resolved Λ values of one to two orders of magnitude for particles in the 0.01–3 μm diameter range. Use of different formulations of raindrop number size distribution can cause Λ values to vary by a factor of 3 to 5 for all particle sizes. The uncertainty in Λ caused by the use of different droplet terminal velocity formulations is generally small than a factor of 2. The combined uncertainty due to the use of different formulations of raindrop-particle collection efficiency, raindrop size spectrum, and raindrop terminal velocity in the current theoretical framework is not sufficient to explain the one to two order of magnitude under-prediction of Λ for the theoretical calculations relative to the majority of field measurements. These large discrepancies are likely caused by additional known physical processes (i.e, turbulent transport and mixing, cloud and aerosol microphysics) that influence field data but that are not considered in current theoretical Λ parameterizations. The predicted size-resolved particle concentrations using different theoretical Λ parameterization can differ by up to a factor of 2 for particles smaller than 0.01 μm and by a factor of >10 for particles larger than 3 μm after 2–5 mm of rain. The predicted bulk mass and number concentrations (integrated over the particle size distribution) can differ by a factor of 2 between theoretical and empirical Λ parameterizations after 2–5 mm of moderate intensity rainfall.

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Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.785.576 ◽

2015 ◽

Vol 785 ◽

pp. 576-580 ◽

Cited By ~ 3

Author(s):

Liaw Geok Pheng ◽

Rosnani Affandi ◽

Mohd Ruddin Ab Ghani ◽

Chin Kim Gan ◽

Jano Zanariah

Keyword(s):

High Efficiency ◽

Combustion Engine ◽

Renewable Energy Sources ◽

Stirling Engine ◽

Energy Sources ◽

Heat Engines ◽

Stirling Engines ◽

Parabolic Dish ◽

Mechanical Devices ◽

And Control

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

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