scholarly journals Application of Acoustic Agglomeration Technology to Improve the Removal of Submicron Particles from Vehicle Exhaust

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1200
Author(s):  
Inga Garbarienė ◽  
Vadimas Dudoitis ◽  
Vidmantas Ulevičius ◽  
Kristina Plauškaitė-Šukienė ◽  
Artūras Kilikevičius ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Particle Number ◽  
Combustion Engine ◽  
Exhaust System ◽  
Ambient Air ◽  
Submicron Particles ◽  
Vehicle Exhaust ◽  
Scanning Mobility Particle Sizer ◽  
Symmetric Methods ◽  
Particle Sizer

The natural processes of interactions between aerosol particles in the ambient air through which they agglomerate is a vast area of chamber research and are inherent to many industries and are often inter-connected with transport engineering. Further improvement of symmetric methods for aerosol particle number and mass concentration reduction made it possible to create various synergic techniques. The study used a 1.9 TDI diesel internal combustion engine, which was supplied with diesel (D100) and second-generation biofuels (NExBTL100) with the EGR exhaust system on and off. Measurements were performed using a Bruel and Kjær “Type 9727” system for measurement of vibrations, a scanning mobility particle sizer (SMPS) and an original agglomeration chamber. The three modes of particle size distributions were observed in the size range from 10 to 470 nm for both D100 and NExBTL100 fuels with and without the use of the EGR system. The application of 21.3 kHz frequency sound with SPL 144.1 dB changed the NExBTL100 generated aerosol particle number concentration but did not sufficiently affect the concentration of D100 emitted particles. The greatest agglomeration effect (21.7 ± 10.0%) was observed in the range of extremely small NExBTL100 derived particles (10–70 nm) when used in combination with an EGR system.

scholarly journals Measurement of nonvolatile particle number size distribution

2016 ◽  
Vol 9 (1) ◽  
pp. 103-114 ◽  
Author(s):  
G. I. Gkatzelis ◽  
D. K. Papanastasiou ◽  
K. Florou ◽  
C. Kaltsonoudis ◽  
E. Louvaris ◽  
...  
Keyword(s):  
Size Distribution ◽  
Black Carbon ◽  
Biomass Burning ◽  
Particle Number ◽  
Number Concentration ◽  
Experimental Methodology ◽  
Particle Number Concentration ◽  
Scanning Mobility Particle Sizer ◽  
Number Size Distribution ◽  
Particle Sizer

Abstract. An experimental methodology was developed to measure the nonvolatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a nonvolatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol (OA; 40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50–60 % of the particles had a nonvolatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon with an 80 % contribution, while OA was responsible for another 15–20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.

scholarly journals Planning an experiment for cleaning exhaust gases with ultrasound

2021 ◽  
Vol 18 (1) ◽  
pp. 86-92
Author(s):  
A. S. Kadyrov ◽  
B. K. Sarsembekov ◽  
A. B. Kukisheva
Keyword(s):  
Motor Vehicle ◽  
Combustion Engine ◽  
Similarity Theory ◽  
Oscillation Amplitude ◽  
Exhaust System ◽  
Pressure Oscillation ◽  
Ultrasonic Frequency ◽  
Settling Rate ◽  
Vehicle Exhaust ◽  
Exhaust Gases

Introduction. The article deals with the protection of the environment from harmful components of the exhaust gases of a motor vehicle. In order to solve this problem, it is proposed to develop an additional device to the exhaust system of an internal combustion engine, based on the ultrasonic coagulation cleaning method.Materials and methods. Due to the need for an environmentally friendly vehicle exhaust system, an experiment is planned to determine the particle gas settling rate on the ultrasonic stand. The correct setting of the experiment requires a preliminary theoretical analysis and a reduction in the number of parameters influencing the experiment. At the time of the experiment, the number of parameters considered should reflect the main processes and their interactions fairly accurately. However, ultrasonic coagulation depends on most parameters, such as particle settling velocity, ultrasonic wave pressure, oscillation amplitude, ultrasonic frequency, particle radius, dynamic viscosity, gravity acceleration and particle mass, which can complicate and increase the time for experimentation. The method of similarity theory and dimensional analysis was used to reduce the set of variables. This method reduces the number of experiments and saves time, costs and other resources spent on the experiment with a large number of parameters.Results. As a result, a minimum number of dimensional criteria were obtained to improve the efficiency of the ultrasonic screen processing of experimental data.Conclusion. Thus, the dimensionless criteria obtained make it possible to draw up a plan for an experiment to determine the settling rate of car exhaust gas particles on an ultrasonic stand and confirm the applicability of the ultrasonic coagulation treatment method.

Fine Particulate Formation During Biomass/Coal Cofiring

2002 ◽  
Author(s):  
Linda G. Blevins ◽  
Thomas H. Cauley
Keyword(s):  
Coal Combustion ◽  
Fine Particle ◽  
Particle Number ◽  
Combustion Products ◽  
Particle Formation ◽  
Particle Loading ◽  
Scanning Mobility Particle Sizer ◽  
Fine Particulate ◽  
Particle Sizer ◽  
Mass Concentrations

Experiments to examine the effects of biomass/coal cofiring on fine particle formation were performed in the Sandia Multi-Fuel Combustor using fuels of pure coal, 3 combinations of switchgrass and coal, and pure switchgrass. A constant thermal input was maintained. The combustion products were cooled during passage through the 4.2 m long reactor to simulate the temperatures experienced in the convection pass of a boiler. Fine particle number densities, mass concentrations, and total number concentrations for particles between 10 nm and 1 μm at the reactor exit were determined using a Scanning Mobility Particle Sizer. The results indicate that the fine particle loading for cofiring is higher than that achieved with dedicated coal combustion but lower than that achieved with dedicated switchgrass combustion.

scholarly journals Heating system for measuring tanks of the cementing unit from the exhaust system of the base chassis

2020 ◽  
Vol 164 ◽  
pp. 03015
Author(s):  
Sergey Kireev ◽  
Marina Korchagina ◽  
Andrey Efimov ◽  
Valentin Stepanov
Keyword(s):  
Temperature Field ◽  
Internal Combustion Engines ◽  
Field Experiments ◽  
Combustion Engine ◽  
Exhaust System ◽  
Ambient Air ◽  
Internal Combustion ◽  
Exhaust Pipe ◽  
Heating Efficiency ◽  
The Cost

The purpose of this article is to increase the efficiency of the design process and reduce the cost of field experiments by using numerical analysis methods of the dimensional capacity heating efficiency of the internal combustion engine exhaust system. To solve the problem, a non-stationary nonlinear solver of gas dynamic processes (Siemens STAR-CCM+) was used, which allows to evaluate the correctness of the problem statement, significantly reducing the cost of full-scale tests. The paper considers the heating of a dimensional two-section tank in the layout of the cementing unit on the chassis with a triplex high-pressure pump and a drive from the power take-off box on the gear box of the chassis engine. The exhaust pipe structurally passes inside the measuring tank. According to the research results obtained graphic dependences of temperature change of liquid measuring cups to control points, the distribution of temperature field of the liquid in a volumetric tank, distribution of the temperature field of the surrounding air, stream lines and velocity field of the ambient air and the exhaust gases of internal combustion engines. The results of the calculations clearly show that the application of the method of heating the measuring capacity by entering the exhaust pipe directly into the liquid can be considered effective.

scholarly journals Characteristics of sub-10 nm particle emissions from in-use commercial aircraft observed at Narita International Airport

2021 ◽  
Vol 21 (2) ◽  
pp. 1085-1104
Author(s):  
Nobuyuki Takegawa ◽  
Yoshiko Murashima ◽  
Akihiro Fushimi ◽  
Kentaro Misawa ◽  
Yuji Fujitani ◽  
...  
Keyword(s):  
Particle Number ◽  
Ultrafine Particle ◽  
Civil Aviation ◽  
Scanning Mobility Particle Sizer ◽  
Particle Emissions ◽  
Particle Counter ◽  
Condensation Particle Counter ◽  
International Airport ◽  
Particle Sizer ◽  
Volatile Particle

Abstract. The characterization of ultrafine particle emissions from jet aircraft equipped with turbofan engines, which are commonly used in civil aviation, is an important issue in the assessment of the impacts of aviation on climate and human health. We conducted field observations of aerosols and carbon dioxide (CO2) near a runway at Narita International Airport, Japan, in February 2018. We used an ultrafine condensation particle counter (UCPC) and a condensation particle counter (CPC) with unheated and 350 ∘C heated operation modes to investigate the contributions of sub-10 nm size ranges to the total and the non-volatile particle number concentrations. The performance of the 350 ∘C heated mode was tested in the laboratory to verify the consistency with existing methods for non-volatile particle measurements. We also used a scanning mobility particle sizer with unheated and 350 ∘C heated modes and an engine exhaust particle sizer for the measurements of particle number size distributions. Spiked increases in the particle number concentrations and CO2 mixing ratios were observed to be associated with the directions of wind from the runway, which can be attributed to diluted aircraft exhaust plumes. We estimated the particle number emission indices (EIs) for discrete take-off plumes using the UCPC, CPC, and CO2 data. The median values of the total and the non-volatile particle number EIs for diameters larger than 2.5 nm as derived from the UCPC data were found to be 1.1×1017 and 5.7×1015 kg per fuel, respectively. More than half the particle number EIs were in the size range smaller than 10 nm for both the total and the non-volatile particles in most of the cases analyzed in this study. The significance of sub-10 nm size ranges for the total particles in the diluted plumes was qualitatively consistent with previous studies, but that for the non-volatile particles was unexpected. Possible factors affecting the similarities and differences compared with the previous findings are discussed.

scholarly journals Estimation of aerosol particle number distributions with Kalman Filtering – Part 1: Theory, general aspects and statistical validity

2012 ◽  
Vol 12 (24) ◽  
pp. 11767-11779 ◽  
Author(s):  
T. Viskari ◽  
E. Asmi ◽  
P. Kolmonen ◽  
H. Vuollekoski ◽  
T. Petäjä ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Aerosol Particle ◽  
Particle Number ◽  
Observation Time ◽  
Kernel Matrix ◽  
Size Distributions ◽  
Aerosol Model ◽  
Particle Mobility ◽  
Particle Sizer ◽  
General Aspects

Abstract. Aerosol characteristics can be measured with different instruments providing observations that are not trivially inter-comparable. Extended Kalman Filter (EKF) is introduced here as a method to estimate aerosol particle number size distributions from multiple simultaneous observations. The focus here in Part 1 of the work was on general aspects of EKF in the context of Differential Mobility Particle Sizer (DMPS) measurements. Additional instruments and their implementations are discussed in Part 2 of the work. University of Helsinki Multi-component Aerosol model (UHMA) is used to propagate the size distribution in time. At each observation time (10 min apart), the time evolved state is updated with the raw particle mobility distributions, measured with two DMPS systems. EKF approach was validated by calculating the bias and the standard deviation for the estimated size distributions with respect to the raw measurements. These were compared to corresponding bias and standard deviation values for particle number size distributions obtained from raw measurements by a inversion of the instrument kernel matrix method. Despite the assumptions made in the EKF implementation, EKF was found to be more accurate than the inversion of the instrument kernel matrix in terms of bias, and compatible in terms of standard deviation. Potential further improvements of the EKF implementation are discussed.

scholarly journals Real-Time Aerosol Density Determination Utilizing a Modified Scanning Mobility Particle Sizer—Aerosol Particle Mass Analyzer System

2009 ◽  
Vol 43 (7) ◽  
pp. 673-678 ◽  
Author(s):  
Quentin G. J. Malloy ◽  
Shunsuke Nakao ◽  
Li Qi ◽  
Rebecca Austin ◽  
Clayton Stothers ◽  
...  
Keyword(s):  
Real Time ◽  
Aerosol Particle ◽  
Particle Mass ◽  
Mass Analyzer ◽  
Scanning Mobility Particle Sizer ◽  
Density Determination ◽  
Particle Sizer

Fine Particulate Formation During Switchgrass/Coal Cofiring

2005 ◽  
Vol 127 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Linda G. Blevins ◽  
Thomas H. Cauley
Keyword(s):  
Coal Combustion ◽  
Fine Particle ◽  
Mass Concentration ◽  
Particle Number ◽  
Fine Particles ◽  
Combustion Products ◽  
Scanning Mobility Particle Sizer ◽  
Fine Particulate ◽  
Particle Sizer ◽  
Mass Concentrations

Experiments to examine the effects of biomass/coal cofiring on fine particle formation were performed in the Sandia Multi-Fuel Combustor using fuels of pure coal, three combinations of switchgrass and coal, and pure switchgrass. For this work, fine particles with aerodynamic diameter between 10 nm and 1 μm were examined. A constant solid-fuel thermal input of 8 kW was maintained. The combustion products were cooled from 1200 to 420°C during passage through the 4.2 m long reactor to simulate the temperatures experienced in the convection pass of a boiler. Fine particle number densities, mass concentrations, and total integrated number and mass concentrations at the reactor exit were determined using a scanning mobility particle sizer. The fine particle number concentrations for cofiring were much higher than those achieved with dedicated coal combustion. However, the total integrated mass concentration of particles remained essentially constant for all levels of cofiring from 0% coal to 100% coal. The constant mass concentration is significant because pending environmental regulations are likely to be based on particle mass rather than particle size.

scholarly journals Analysis of particle size distribution changes between three measurement sites in northern Scandinavia

2013 ◽  
Vol 13 (23) ◽  
pp. 11887-11903 ◽  
Author(s):  
R. Väänänen ◽  
E.-M. Kyrö ◽  
T. Nieminen ◽  
N. Kivekäs ◽  
H. Junninen ◽  
...  
Keyword(s):  
Mass Transport ◽  
Aerosol Particle ◽  
Growth Rates ◽  
Particle Number ◽  
Particle Growth ◽  
Size Distributions ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Dynamics ◽  
Particle Sizer

Abstract. We investigated atmospheric aerosol particle dynamics in a boreal forest zone in northern Scandinavia. We used aerosol number size distribution data measured with either a differential mobility particle sizer (DMPS) or scanning mobility particle sizer (SMPS) at three stations (Värriö, Pallas and Abisko), and combined these data with the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) air mass trajectory analysis. We compared three approaches: analysis of new particle formation events, investigation of aerosol particle number size distributions during the air mass transport from the ocean to individual stations with different overland transport times, and analysis of changes in aerosol particle number size distributions during the air mass transport from one measurement station to another. Aitken-mode particles were found to have apparent average growth rates of 0.6–0.7 nm h−1 when the air masses traveled over land. Particle growth rates during the new particle formation (NPF) events were 3–6 times higher than the apparent particle growth during the summer period. When comparing aerosol dynamics for different overland transport times between the different stations, no major differences were found, except that in Abisko the NPF events were observed to take place in air masses with shorter overland times than at the other stations. We speculate that this is related to the meteorological differences along the paths of air masses caused by the land surface topology. When comparing air masses traveling in an east-to-west direction with those traveling in a west-to-east direction, clear differences in the aerosol dynamics were seen. Our results suggest that the condensation growth has an important role in aerosol dynamics even when NPF is not evident.

scholarly journals Investigations on nano- and submicron-particle generation by spray painting processes

2017 ◽  
Author(s):  
Qiaoyan Ye ◽  
Oliver Tiedje ◽  
Shreyas Rohit Srinivas ◽  
Thomas Noest ◽  
Uhrrich Uhrner
Keyword(s):  
Particle Size ◽  
Particle Deposition ◽  
Turbulence Models ◽  
Nano Particles ◽  
Submicron Particles ◽  
Scanning Mobility Particle Sizer ◽  
Manufactured Nanomaterials ◽  
Spray Booth ◽  
Particle Sizer ◽  
Spray Gun

This paper presents experimental and numerical studies to determine the particle size distributions (PSD) and concentrations in paint overspray. Two kinds of paint materials, solvent borne and water borne paints, both with and without manufactured nanomaterials (pigments), and an industrial spray gun were used. Different aerosol measuring techniques, namely the Spraytec Fraunhofer type particle sizer for micro-sized droplets in the spray jet and the Scanning Mobility Particle Sizer (SMPS) for nano particles in paint overspray were applied. It was found, that solvent borne clear coats create significantly higher number concentration of nano-sized droplets than the water borneprimers. Only small differences in PSD between paints with and without manufactured nanomaterials were found. Numerical simulations of droplet trajectories within the spray booth, for both micro and nano sized droplets, were carried out. Based on the experimental and numerical results, a representative particle size distribution (smaller than 1 μm) for the given spray gun was obtained. Effects of turbulence models on the particle deposition on targets, especially for submicron particles, have been analysed in detailed.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4666

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