CFD modeling for pipeline flow of fine particles at high concentration

2012 ◽  
Vol 43 ◽  
pp. 85-100 ◽  
Author(s):  
D.R. Kaushal ◽  
T. Thinglas ◽  
Yuji Tomita ◽  
Shigeru Kuchii ◽  
Hiroshi Tsukamoto
Keyword(s):  
Fine Particles ◽  
Cfd Modeling ◽  
High Concentration ◽  
Pipeline Flow

Optimization of Pipeline Flow of Fine Particles Slurry Using Genetic Algorithms

2015 ◽  
Vol 5 (1) ◽  
pp. 33-37
Author(s):  
Sanjay Kumar Srivastava ◽  
◽  
Rajesh Kumar ◽  
Prabhat Kumar Singh Dikshit ◽  
◽  
...  
Keyword(s):  
Genetic Algorithms ◽  
Fine Particles ◽  
Pipeline Flow

Vaporization and Ultra-Fine Particle Generation during the Plasma Spraying Process

1997 ◽  
Author(s):  
K.A. Gross ◽  
P. Fauchais ◽  
M. Vardelle ◽  
J. Tikkanen ◽  
J. Keskinen
Keyword(s):  
Fine Particles ◽  
High Concentration ◽  
Thermal Spray Process ◽  
Particle Generation ◽  
Spray Process ◽  
Ultra Fine Particle ◽  
Fast Cooling ◽  
Ultra Fine Particles ◽  
Plasma Spraying Process ◽  
Very High

Abstract The thermal spray process melts powder at very high temperatures and propels the molten material to the substrate to produce a coherent deposit. This heating produces a certain amount of vaporization of the feedstock. Upon exiting the plasma plume the fast cooling conditions lead to condensation of the vapor. An electrical low pressure impactor was used to monitor the concentration of ultra-fine particles at various radial and axial distances. Metal, namely iron powder, showed very high concentration levels which increase with distance. Ultra-fine particles from ZrO2-8Y2O3 reached a peak concentration at 6 cm. Use of an air barrier during spraying decreases the population of ultra-fine particles facilitating the production of a stronger coating.

scholarly journals An assessment of atmospheric deposition of metals and the physico -chemical parameters of a rainwater harvesting system in Rio de Janeiro Brazil, by means of statistical multivariate analysis

2020 ◽  
Vol 15 (4) ◽  
pp. 1
Author(s):  
Gabrielle Nunes da Silva ◽  
Letícia Delduque Alves ◽  
Isabella Escobar dos Santos ◽  
Daniele Maia Bila ◽  
Alfredo Akira Ohnuma Júnior ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Fine Particles ◽  
Rainwater Harvesting ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
High Concentration ◽  
Physico Chemical ◽  
Pearson Coefficient ◽  
Coefficient Corrélation ◽  
Pre Treatment

This study evaluates the rainwater harvesting system to determine the chemical quality of the water and allocate it for use. Samples were collected in the city of Rio de Janeiro at the points of Direct Precipitation (DP), First Flush (FF) and Reservoir (RR). The methodology involved carrying out an analysis of Ca, Cd, Cu, Na, Ni, Fe, K, Mg, Pb, Zn, conductivity, turbidity, pH and chloride. The R language was used for the principal component analysis, Pearson coefficient correlation, hierarchical cluster analysis, Tukey test and boxplot. The results show that when there is no interference from the catchment surface (DP), the rainwater has a low concentration of metals, although the first millimeters of rain have a concentration above what is permissible in the guidelines issued by the Ministry of Health (Ordinance n° 05/2017). The disposal system (FF) reduced the concentration of pollutants in the RR, but not enough to comply with legislation. It was noted that Ca, K and Na are the main metals found in rainwater. During the dry period, there were significant correlations between the physico-chemical and meteorological parameters. The high concentration of metals in the wet period suggests that rain assists the cleaning of the atmosphere and that most metals are present in the form of aerosols or fine particles suspended in the air. The findings reveal significant indications of acid rain and pre-treatment is recommended to ensure rainwater can be used safely for more mundane purposes.

scholarly journals Impacts of coal burning on ambient PM<sub>2.5</sub> pollution in China

2017 ◽  
Vol 17 (7) ◽  
pp. 4477-4491 ◽  
Author(s):  
Qiao Ma ◽  
Siyi Cai ◽  
Shuxiao Wang ◽  
Bin Zhao ◽  
Randall V. Martin ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Fine Particles ◽  
Transport Model ◽  
National Level ◽  
National Average ◽  
Primary Concern ◽  
High Concentration ◽  
Coal Burning ◽  
Average Contribution

Abstract. High concentration of fine particles (PM2.5), the primary concern about air quality in China, is believed to closely relate to China's large consumption of coal. In order to quantitatively identify the contributions of coal combustion in different sectors to ambient PM2. 5, we developed an emission inventory for the year 2013 using up-to-date information on energy consumption and emission controls, and we conducted standard and sensitivity simulations using the chemical transport model GEOS-Chem. According to the simulation, coal combustion contributes 22 µg m−3 (40 %) to the total PM2. 5 concentration at national level (averaged in 74 major cities) and up to 37 µg m−3 (50 %) in the Sichuan Basin. Among major coal-burning sectors, industrial coal burning is the dominant contributor, with a national average contribution of 10 µg m−3 (17 %), followed by coal combustion in power plants and the domestic sector. The national average contribution due to coal combustion is estimated to be 18 µg m−3 (46 %) in summer and 28 µg m−3 (35 %) in winter. While the contribution of domestic coal burning shows an obvious reduction from winter to summer, contributions of coal combustion in power plants and the industrial sector remain at relatively constant levels throughout the year.

Sedimentation of a Stratified Suspension in a Quiescent Fluid

2007 ◽  
Author(s):  
Takashi Mitsui ◽  
Shusaku Harada ◽  
Kuniomi Asakura
Keyword(s):  
Particle Size ◽  
Settling Velocity ◽  
Fine Particles ◽  
Small Particle Size ◽  
Fluid Interface ◽  
High Concentration ◽  
Particle Assembly ◽  
Sedimentation Behavior ◽  
Surrounding Fluid ◽  
Quiescent Fluid

The sedimentation of fine particles in a stratified suspension, which has both the upper and lower interfaces, is studied experimentally. We measure the settling velocity of particles and observe the diffusion behavior near the interfaces. Especially we examine whether the macroscopic or the microscopic natures of suspension is dominant during sedimentation, i.e., the particles settle as an particle assembly relative to surrounding fluid or as a continuous suspension. The experimental observation shows that the gravity-induced instability of suspension-fluid interface, which has been already reported, governs the particle motion for high concentration and small particle size. However, the microscopic nature of suspension comes out in case of larger particles. In our study, the dependency of the sedimentation behavior on the particle size and the concentration is discussed quantitatively.

The rheological characterization and pipeline flow of high concentration water-in-oil emulsions

2003 ◽  
Vol 112 (2-3) ◽  
pp. 101-114 ◽  
Author(s):  
I. Masalova ◽  
A.Ya. Malkin ◽  
P. Slatter ◽  
K. Wilson
Keyword(s):  
High Concentration ◽  
Rheological Characterization ◽  
Pipeline Flow ◽  
Oil Emulsions

scholarly journals Impacts of Coal Burning on Ambient PM<sub>2.5</sub> Pollution in China

2016 ◽  
Author(s):  
Qiao Ma ◽  
Siyi Cai ◽  
Shuxiao Wang ◽  
Bin Zhao ◽  
Randall V. Martin ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Fine Particles ◽  
Transport Model ◽  
National Level ◽  
National Average ◽  
Primary Concern ◽  
High Concentration ◽  
Coal Burning ◽  
Average Contribution

Abstract. High concentration of fine particles (PM2.5), the primary concern about air quality in China, is believed to closely relate to China’s large consumption of coal. In order to quantitatively identify the contributions of coal combustion in different sectors to ambient PM2.5, we developed an emission inventory for the year 2013 using up-to-date information on energy consumption and emission controls, and conducted standard and sensitivity simulations using the chemical transport model GEOS-Chem. According to the simulation, coal combustion contributes 22 μg m−3 (40 %) to the total PM2.5 concentration at national level (averaged in 74 major cities), and up to 37 μg m−3 (50 %) in Sichuan Basin. Among major coal-burning sectors, industrial coal burning is the dominant contributor with a national average contribution of 10 μg m−3 (17 %), followed by coal combustion in power plants and domestic sector. The national average contribution due to coal combustion is estimated to be 18 μg m−3 (46 %) in summer and 28 μg m−3 (35 %) in winter. While the contribution of domestic coal burning shows an obvious reduction from winter to summer, contributions of coal combustion in power plants and industrial sector remain at relatively constant levels through out the year.

scholarly journals Chemical characterization of aerosols at the summit of Mountain Tai in Central East China

2011 ◽  
Vol 11 (14) ◽  
pp. 7319-7332 ◽  
Author(s):  
C. Deng ◽  
G. Zhuang ◽  
K. Huang ◽  
J. Li ◽  
R. Zhang ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Fine Particles ◽  
Eastern China ◽  
Chemical Characterization ◽  
Northern China ◽  
Water Soluble ◽  
World Heritage Site ◽  
High Concentration ◽  
Central Eastern ◽  
The Impact

Abstract. PM2.5 and TSP samples were collected at the summit of Mountain Tai (MT) (1534 m a.s.l.) in spring 2006/2007 and summer 2006 to investigate the characteristics of aerosols over central eastern China. For comparison, aerosol samples were also collected at Tazhong, Urumqi, and Tianchi in Xinjiang in northwestern China, Duolun and Yulin in northern China, and two urban sites in the megacities, Beijing and Shanghai, in 2007. Daily mass concentrations of TSP and PM2.5 ranged from 39.6–287.6 μg m−3 and 17.2–235.7 μg m−3 respectively at the summit of MT. Averaged concentrations of PM2.5 showed a pronounced seasonal variation with higher concentration in summer than spring. 17 water-soluble ions (SO42−, NO3−, Cl−, F−, PO43−, NO2−, CH3COO−, CH2C2O42−, C2H4C2O42−, HCOO−, MSA, C2O42−, NH4+, Ca2+, K+, Mg2+, Na+), and 19 elements of all samples were measured. SO42−, NO3−, and NH4+ were the major water-soluble species in PM2.5, accounting for 61.50 % and 72.65 % of the total measured ions in spring and summer, respectively. The average ratio of PM2.5/TSP was 0.37(2006) and 0.49(2007) in spring, while up to 0.91 in summer, suggesting that aerosol particles were primarily comprised of fine particles in summer and of considerable coarse particles in spring. Crustal elements (e.g., Ca, Mg, Al, Fe, etc.) showed higher concentration in spring than summer, while most of the pollution species (SO42−, NO3−, K+, NO2−, NH4+, Cl−, organic acids, Pb, Zn, Cd, and Cr) from local/regional anthropogenic emissions or secondary formation presented higher concentration in summer. The ratio of Ca/Al suggested the impact of Asian dust from the western deserts on the air quality in this region. The high concentration of K+ in PM2.5 (4.41 μg m−3) and its good correlation with black carbon (r = 0.90) and oxalic acid (r = 0.87) suggested the severe pollution from biomass burning, which was proved to be a main source of fine particles over central eastern China in summer. The contribution of biomass burning to the fine particle at MT accounted for 7.56 % in spring and 36.71 % in summer, and even reached to 81.58 % on a day. As and Pb were two of the most enriched elements. The long-range transport of aerosols spread the heavy pollution from coal-mining/coal-ash to everywhere over China. Anthropogenic air-pollution was evidently rather severe at MT, though it has been declared by UNESCO to be a World Heritage site.

scholarly journals Influence of Ammonium Sulfate Seed Particle on Optics and Compositions of Toluene Derived Organic Aerosol in Photochemistry

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 961
Author(s):  
Tingting Lu ◽  
Mingqiang Huang ◽  
Weixiong Zhao ◽  
Changjin Hu ◽  
Xuejun Gu ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Light Absorption ◽  
Radiative Forcing ◽  
Fine Particles ◽  
Complex Refractive Index ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Seed Particle ◽  
Optical Parameters ◽  
High Concentration

Aromatic secondary organic aerosol (SOA) particles are known to contribute to radiative forcing and light absorption of atmosphere. However, the complex refractive index (CRI), single-scattering albedo (SSA) and other optical parameters of aromatic SOA are not well understood. SOA generated from photooxidation of toluene with a variety concentration of ammonium sulfate ((NH4)2SO4) seed particles in a smog chamber were investigated in the current study. The real part CRI of toluene SOA without seeds derived and based on aerosol albedometer measurements is 1.486 ± 0.002 at λ = 470 nm, showing a good agreement with available experimental data, and its SSA was measured to be 0.92 ± 0.02 at λ = 470 nm, indicating that the SOA particles without seeds have strong scattering ability. The SSA of SOA formed in the presence of 300 μg/m3 (NH4)2SO4 seed was 0.81 ± 0.02 at λ = 470 nm, less than the SSA of SOA without seed. SSA of SOA decreased, while the imaginary part of CRI (k) of SOA increased with increasing concentration of (NH4)2SO4 seed, demonstrating that the adsorption capacity of SOA formed in the presence of (NH4)2SO4 seed is enhanced. Different from the carboxyl compounds measured in the SOA without seed, imidazoles with strong chromophores of C=N that are responsible for the light absorption were detected as the principal constituents of SOA formed in the presence of (NH4)2SO4 seed. These would provide valuable information for discussing the optics and components of aromatic SOA in the urban atmosphere containing a high concentration of (NH4)2SO4 fine particles.

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