scholarly journals Influence of Exhaust System Setup on Working Zone Pollution by Dust during Sawing of Particleboards

Author(s):  
Bartosz Pałubicki ◽  
Luďka Hlásková ◽  
Tomasz Rogoziński

Air pollution by wood dust in furniture production sites is an important hygiene issue. The dust is created by all types of wood and wood-based material machining, and its concentration in the working zone surrounding the machining stand depends on the effectiveness of the dust exhaust system. In present research, three setups of the dust extraction system for a conventional table sawing machine are considered while machining particleboards. The results showed a high impact of the exhaust system connection setup on the dust concentration in the air surrounding the sawing machine work stand. The use of both main and auxiliary sawdust extraction connectors together ensured the highest clearness of the air, with only 0.5 mg/m3 of dust concentration. Closing the upper hood leads to a concentration five times higher, while disconnecting it results in a ten times higher dust content. The finest dust particles (<1 µm), however, are the most numerous in the case of closing the hood.

2021 ◽  
Vol 11 (15) ◽  
pp. 6874
Author(s):  
Miroslava Vandličkova ◽  
Iveta Markova ◽  
Katarina Holla ◽  
Stanislava Gašpercová

The paper deals with the selected characteristics, such as moisture, average bulk density, and fraction size, of tropical marblewood dust (Marmaroxylon racemosum) that influence its ignition risk. Research was focused on sieve analysis, granulometric analysis, measurement of moisture level in the dust, and determination of the minimum ignition temperatures of airborne tropical dust and dust layers. Samples were prepared using a Makita 9556CR 1400W grinder and K36 sandpaper for the purpose of selecting the percentages of the various fractions (<63, 63, 71, 100, 200, 315, 500 μm). The samples were sized on an automatic vibratory sieve machine Retsch AS 200. More than 65% of the particles were determined to be under 100 μm. The focus was on microfractions of tropical wood dust (particles with a diameter of ≤100 µm) and on the impact assessment of particle size (particle size <100 µm) on the minimum ignition temperatures of airborne tropical dust and dust layers. The minimum ignition temperature of airborne marblewood dust decreased with the particle size to the level of 400 °C (particle size 63 μm).


2021 ◽  
Vol 70 (2) ◽  
pp. 35-64
Author(s):  
Sebastian Dominik Dziubak

The paper presents the composition of atmospheric air as a mixture of gases that make up the solid and variable components, and the definitions of air pollutants are referenced. Gaseous and solid pollutants (dust) of the atmospheric air have been defined. Dusts were divided according to various criteria and their properties were given. Exemplary courses of immission of the fraction of solid particles are given, indicating a strong dependence of the immission on the seasons, days of the week and day and night. The sources and characteristics of artificial and natural pollutants in the atmospheric air are presented. It has been shown that the main sources of anthropogenic pollution in addition to industry and the automotive industry. Cars are a source of gaseous and particulate pollutants PM, and they also emit pollution from brake and clutch lining wear, as well as from tire and road wear. The main sources of natural air pollution were discussed, including volcanic eruptions, fires in landfills, forests, steppes and sand storms, as well as mineral dust (road dust) carried from the ground by vehicles. The properties of road dust are discussed: chemical and fractional composition, density, dust concentration in the air. It has been shown that the two basic components of the dust, silica and corundum, whose share in dust reaches 95%, also have the highest hardness, which may have a decisive influence on the wear of engine components. Various valuesof dust concentration in the air were presented depending on the type and condition of the ground and the conditions of use of vehicles. Keywords: mechanical engineering, internal combustion engines, air pollution sources, road dust


Author(s):  
Boris N. Filatov ◽  
Natalya I. Latyshevskaya ◽  
Natalya V. Krylova ◽  
Irina K. Gorkina ◽  
Yulya I. Velikorodnaya ◽  
...  

The presence of grinding, mixing, and fractionation of solid components of formulations leads to the formation of aerosols in the air of the working area with a wide range of dispersion of the solid phase - all this characterizes the organization of technological processes for the production of energy-intensive materials. The study aims to give a qualitative assessment of possible air pollution of the working area of energy-intensive materials production by nanoscale aerosols with a solid dispersed phase. The researchers carried out the sampling of the working area air and flushes from solid horizontal surfaces to produce energy-intensive materials. We carried out the sampling by forced circulation of the test air through the absorption devices of Polezhaev. Scientists used Triton TX-114 solution with a mass concentration of 2.0 mg/dm3 as an absorption medium. The researchers performed flushing from surfaces using cloth tampons moistened with Triton TX-114 solution with a mass concentration of 2.0 mg/dm3. We determined the particle sizes in the samples using NanotracULTRA (Microtrac). Scientists found aluminum and nitrocellulose particles with sizes from 36 to 102 nm in the air of the working area and flushes from horizontal surfaces. The study of the fractional composition of RDX and aluminum powders of the ASD-1 brand showed the presence of nanoscale particles in them. Nanoscale dust particles pollute the air of the working area and solid horizontal surfaces at certain stages of the production of energy-intensive materials. There are nanoscale particles in the composition of powders of some standard components of formulations. Flushes from solid horizontal surfaces are an adequate qualitative indicator of the presence of nanoaerosols in the air of the working area.


2017 ◽  
Vol 17 (3) ◽  
pp. 2401-2421 ◽  
Author(s):  
Siyu Chen ◽  
Jianping Huang ◽  
Litai Kang ◽  
Hao Wang ◽  
Xiaojun Ma ◽  
...  

Abstract. The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m−2 s−1, which was similar to that over the GD (29 ± 3.6 µg m−2 s−1). However, the transport contribution of the TD dust (up to 0.8 ton d−1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d−1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m−3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust was estimated to be −3 and −7 W m−2 at the top of the atmosphere, −8 and −10 W m−2 at the surface, and +5 and +3 W m−2 in the atmosphere over the TD and GD, respectively. This study provides confidence for further understanding the climate effects of the GD dust.


2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Jehosua Sinolungan

Abstract: The increasing number of vehicles which increase air pollution has negative impacts on  global health, especially that of lung problems. Nowadays, people’s mobility is fast and variable, needing better and more environmentally friendly transportation, without neglecting the socio-economic aspect. These are the reasons to develop better and more environmentally related transportation facilities. By understanding air pollution mechanisms, and kinds of particles and pollutants from vehicles, we will appreciate and pay more attention to our environment, especially in urban areas. Collaboration among health and government related departments has to be improved to regulate the use of inner city vehicles, so that it can decrease lung problems. Key words: air pollution, transportation, dust particles, urban environment.     Abstrak: Bertambahnya jumlah kendaraan bermotor seiring dengan bertambahnya polusi udara, dan menimbulkan masalah global, yang berdampak negatif antara lain masalah kesehatan paru. Mobilitas manusia semakin beragam sehingga diperlukan dukungan sistem transportasi yang makin baik pula serta akrab lingkungan, tanpa mengabaikan segi sosio-ekonomi. Oleh karena itu sistem transportasi ini perlu dikembangkan menjadi sistem transportasi yang berkelanjutan. Diharapkan dengan mengetahui batasan polusi udara, jenis, serta dampak partikel debu dan gas kendaraan bermotor bagi kesehatan manusia akan  membuat kita lebih mencintai dan memperhatikan lingkugan hidup kita, khususnya sekitar perkotaan. Perana kerjasama lintas sektoral untuk mengatasi polusi partikel debu dan gas buangan perlu ditingkatkan Pengaturan kendaraan layak beroperasi akan menekan mening-katnya kasus infeksi atau gangguan saluran napas. Kata kunci: polusi udara, transportasi, partikel debu, lingkungan perkotaan.


Environments ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 114
Author(s):  
Jiří Bílek ◽  
Ondřej Bílek ◽  
Petr Maršolek ◽  
Pavel Buček

Sensor technology is attractive to the public due to its availability and ease of use. However, its usage raises numerous questions. The general trustworthiness of sensor data is widely discussed, especially with regard to accuracy, precision, and long-term signal stability. The VSB-Technical University of Ostrava has operated an air quality sensor network for more than two years, and its large sets of valid results can help in understanding the limitations of sensory measurement. Monitoring is focused on the concentrations of dust particles, NO2, and ozone to verify the impact of newly planted greenery on the reduction in air pollution. The sensor network currently covers an open field on the outskirts of Ostrava, between Liberty Ironworks and the nearby ISKO1650 monitoring station, where some of the worst air pollution levels in the Czech Republic are regularly measured. In the future, trees should be allowed to grow over the sensors, enabling assessment of the green barrier effect on air pollution. As expected, the service life of the sensors varies from 1 to 3 years; therefore, checks are necessary both prior to the measurement and regularly during operation, verifying output stability and overall performance. Results of the PMx sensory measurements correlated well with the reference method. Concentration values measured by NO2 sensors correlated poorly with the reference method, although timeline plots of concentration changes were in accordance. We suggest that a comparison of timelines should be used for air quality evaluations, rather than particular values. The results showed that the sensor measurements are not yet suitable to replace the reference methods, and dense sensor networks proved useful and robust tools for indicative air quality measurements (AQM).


2021 ◽  
Author(s):  
Gabriela Iorga ◽  
George-Bogdan Burghelea

&lt;p&gt;Present research contributes to scientific knowledge concerning spatial and temporal variation of major air pollutants with high resolution at the country scale bringing statistical information on concentrations of NOx, O&lt;sub&gt;3&lt;/sub&gt;, CO, SO&lt;sub&gt;2&lt;/sub&gt; and particulate matter with an aerodynamic diameter below 10&amp;#160;&amp;#956;m (PM&lt;sub&gt;10&lt;/sub&gt;) and below 2.5&amp;#160;&amp;#956;m (PM&lt;sub&gt;2.5&lt;/sub&gt;) during the pandemic year 2020 using an observational data set from the Romanian National Air Quality Network in seven selected cities spread out over the country. These cities have different level of development, play regional roles, might have potential influence at European scale and they are expected to be impacted by different pollution sources. Among them, three cities (Bucharest, Bra&amp;#537;ov, Ia&amp;#537;i) appear frequently on the list of the European Commission with reference to the infringement procedure that the European Commission launched against Romania in the period 2007-2020 regarding air quality.&lt;/p&gt;&lt;p&gt;Air pollutant data was complemented with local meteorological parameters at each site (atmospheric pressure, relative humidity, temperature, global solar radiation, wind speed and direction). Statistics of air pollutants provide us with an overview of air pollution in main Romanian cities.&amp;#160; Correlations between meteorological parameters and ambient pollutant levels were analyzed. Lowest air pollution levels were measured during the lockdown period in spring, as main traffic and non-essential activities were severely restricted. Among exceptions were the construction activities that were not interrupted. During 2020, some of selected cities experienced few pollution episodes which were due to dust transport from Sahara desert. However, in Bucharest metropolitan area, some cases with high pollution level were found correlated with local anthropogenic activity namely, waste incinerations. Air mass origins were investigated for 72 hours back by computing the air mass backward trajectories using the HYSPLIT model. Dust load and spatial distribution of the aerosol optical depth with BSC-DREAM8b v2.0 and NMBM/BSC-Dust models showed the area with dust particles transport during the dust events.&lt;/p&gt;&lt;p&gt;The obtained results are important for investigations of sources of air pollution and for modeling of air quality.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgment:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The research leading to these results has received funding from the NO Grants 2014-2021, under Project contract no. 31/2020, EEA-RO-NO-2019-0423 project. NOAA Air Resources Laboratory for HYSPLIT transport model, available at READY website https://www.ready.noaa.gov &amp;#160;and the Barcelona dust forecast center for BSC-DREAM8b and NMBM/BSC-Dust models, available at: &amp;#160;https://ess.bsc.es/bsc-dust-daily-forecast are also acknowledged. The data regarding ground-based air pollution and meteorology by site was extracted from the public available Romanian National Air Quality Database, www.calitateaer.ro.&lt;/p&gt;


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