scholarly journals Influence of different ventilation systems on inhalable and respirable dust particles concentrations distribution in weaning and finishing fattening pig houses

2003 ◽  
Vol 48 (2) ◽  
pp. 187-204
Author(s):  
Goran Topisirovic
Keyword(s):  
Experimental Treatment ◽  
Dust Concentration ◽  
Dust Particles ◽  
Breathing Zone ◽  
Airflow Velocity ◽  
Significant Decrement ◽  
Ventilation Ducts ◽  
Finishing Pig ◽  
Mechanical Extraction ◽  
Ventilation Systems

The application of different mechanical extraction ventilation systems in reducing and controlling dust concentrations in weaned and finishing pig houses was analyzed and discussed in this work. Dust concentrations and airflow velocities have been measured at 20 measuring points, smoothly positioned over the house cross section, in the net consisting of 4 horizontal and 5 vertical rows. The lowest horizontal row was positioned at the pigs breathing zone (40 cm above the floor), and the highest (fourth) horizontal row was positioned at the workers breathing zone (160 cm). Control values were measured in houses with closed doors and windows and all the fans switched off. These values were compared with three experimental sets of values achieved with: floor, roof and both ventilation systems. Dust concentrations were measured by konimeter (Konimeter 10, Karl Zeiss Jena), airflow velocity in ventilation ducts with a turbine anemometer and the airflow velocity at measuring points with hot wire anemometer. In the finishing house significant decrement of inhalable (F = 44.35, P << 0.01) and respirable (F = 43.82, P << 0.01) dust concentration was achieved in the third experimental treatment. In the weaned piglets house, significant decrement of inhalable (F = 49.43, P << 0.01) and respirable (F = 42.69, P << 0.01) dust concentration was achieved with floor ventilation.

scholarly journals Emission, transport, and radiative effects of mineral dust from the Taklimakan and Gobi deserts: comparison of measurements and model results

2017 ◽  
Vol 17 (3) ◽  
pp. 2401-2421 ◽  
Author(s):  
Siyu Chen ◽  
Jianping Huang ◽  
Litai Kang ◽  
Hao Wang ◽  
Xiaojun Ma ◽  
...  
Keyword(s):  
East Asia ◽  
Dust Emission ◽  
Dust Concentration ◽  
Dust Particles ◽  
Storm Event ◽  
Gobi Desert ◽  
Radiative Effects ◽  
Dust Aerosols ◽  
Budget Analysis ◽  
Westerly Jets

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.

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

2020 ◽  
Vol 17 (10) ◽  
pp. 3626 ◽  
Author(s):  
Bartosz Pałubicki ◽  
Luďka Hlásková ◽  
Tomasz Rogoziński
Keyword(s):  
Air Pollution ◽  
Exhaust System ◽  
High Impact ◽  
Dust Concentration ◽  
Dust Particles ◽  
Extraction System ◽  
Wood Dust ◽  
Dust Extraction ◽  
Working Zone ◽  
Machine Work

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.

scholarly journals Air Curtain Dust Removal Device Design and Dust Prevention Strategy in Heading Face

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xu Huang
Keyword(s):  
Base Plate ◽  
Dust Concentration ◽  
Prevention Strategy ◽  
Previous Model ◽  
Dust Removal ◽  
Device Design ◽  
Airflow Velocity ◽  
Air Curtain ◽  
Total Dust ◽  
Left And Right

Dust protection is a safety guarantee of heading face. The previous model of air curtain research was ideal, and the dust removal effect was rarely studied in the actual dust-producing face. This paper presents a method of air curtain dust removal (ACDR) in the actual heading face. The author designed an air curtain dust removal device (ACDRD). The law of total dust concentration, respiratory dust concentration, and respiratory dust ratio is obtained. The minimum outlet airflow velocity is analyzed using the flat-plane injection theory. The effect of the exhaust fan placement on the dust removal effectiveness is examined. Research indicates the following: The airflow speed at the upper, left, and right sides of the ∩-shaped slot is 17.39 m/s, 12.04 m/s, and 13.66 m/s, respectively. The minimum dust removal speed of the air curtain is 5.48 m/s. The total dust concentration is the highest in the spot of roadheader operator, and the concentration of respiratory dust decreases sharply within 20 m. When the indentation air duct is 2.1 m away from the base plate, the dust-proof effect is better. The results can provide theoretical bases and methods for air curtain analysis of the heading face.

scholarly journals Climatic factors contributing to long-term variations of fine dust concentration in the United States

2017 ◽  
Author(s):  
Bing Pu ◽  
Paul Ginoux
Keyword(s):  
Great Plains ◽  
The United States ◽  
Dust Concentration ◽  
Dust Particles ◽  
Positive Trend ◽  
Fine Dust ◽  
Low Level ◽  
Low Level Jet ◽  
Long Term Variations

Abstract. High concentration of dust particles can cause respiratory problems and increase non-accidental mortality. Studies found fine dust (with aerodynamic diameter less than 2.5 microns) is an important component of the total PM2.5 mass in the western and central U.S. in spring and summer and has positive trends. This work examines factors influencing long-term variations of fine dust concentration in the U.S. using station data from the Interagency Monitoring Protected Visual Environments (IMPROVE) network during 1990–2015. The variations of the fine dust concentration can be largely explained by the variations of precipitation, surface bareness, and 10 m wind speed. Moreover, including convective parameters such as convective inhibition (CIN) and convective available potential energy (CAPE) better explains the variations and trends over the Great Plains from spring to fall. While the positive trend of fine dust concentration in the Southwest in spring is associated with precipitation deficit, the increasing of fine dust over the central Great Plains in summer is largely associated with an enhancing of CIN and a weakening of CAPE, which are related to increased atmospheric stability due to surface drying and lower troposphere warming. The positive trend of the Great Plains low-level jet also contributes to the increasing of fine dust concentration in the central Great Plains in summer via its connections with surface winds and CIN. Summer dusty days in the central Great Plains are usually associated with a westward extension of the North Atlantic subtropical high that intensifies the Great Plains low-level jet and also results in a stable atmosphere with subsidence and reduced precipitation.

The Application of Particle Motion Equation in Coal Handling System of Dissipation Dust Law

2013 ◽  
Vol 313-314 ◽  
pp. 702-705
Author(s):  
Shao Cheng Ge ◽  
Yao Xuan Feng ◽  
De Ji Jing
Keyword(s):  
Numerical Simulation ◽  
Field Test ◽  
Particle Motion ◽  
Theoretical Basis ◽  
Coal Dust ◽  
Motion Equation ◽  
Dust Concentration ◽  
Dust Particles ◽  
Space Application ◽  
Handling System

For getting the effectiveof application in dissipation dust law with particle motion equation atcoal handling system of belt machine tail, must be to proceed related numerical simulation in the way of dust particles motion incoal handling system of belt machine tail and dust concentration of diffusion inoperation space. Application particlemotion equation theory for numerical simulation to coal dustparticles, obtained dust coal dissipation law in coal handling system, at thesame time combine with the data of the field test of dust concentration andfallout dispersion for analyzing and comparing. The results of comparison showthat: the data of numerical simulation with particle motion equationin coal dust dissipation law is coincide with reality dissipation law. Accordingto the conclusion of this research, it is provides theoretical basis forprevention and treatment in coal mine of coal handling system of dustdissipation.

scholarly journals Reduction of Dust in the Longwall Faces of Coal Mines: Problems and Perspective Solutions

2021 ◽  
pp. 84-97
Keyword(s):  
Coal Mining ◽  
Renewable Energy Sources ◽  
Coal Mines ◽  
Mining Industry ◽  
Dust Concentration ◽  
Dust Particles ◽  
Coal Production ◽  
Mining Operations ◽  
Dust Composition ◽  
High Dust

Despite the increasing reliance on alternative and renewable energy sources in recent years, coal is set to continue being the most vital element of the global energy sector. The world coal supply (1,070 billion tons) shall last for 130 years with the current mining levels. In contrast to some large countries (such as the USA and Germany) reducing their coal production and consumption, Russia plans to increase the coal production levels as part of its strategy regarding the future of the coal mining industry. The annual volume of coal output is more than 440 million tons, 1/3 of which is extracted underground. The current and projected levels of underground coal mining present a set of issues pertaining to elevated dust concentration in the air and increased dust dispersion. High dust concentration in the air leads to damage to the skin, mucous membranes and respiratory organs of workers. Also, with high dust content, visibility in the longwalls decreases, the risk of injury and accidents increases. The present article deals with the formation of detrimental dust conditions that happen in the course of cleaning and preparatory mining operations in coal mines. The article reviews the international practices on dust reduction in coal mining operations and provides an overview of studies on dustiness levels and airborne dust composition in longwall faces of coal mines. It also presents mathematical models dealing with projections on dust composition, including projections on most hazardous dust particles the size of 0.1-10 and 0.1-35 μm. The article also presents a newly developed wetting method showing increased effectiveness.

Ice nucleating particle concentrations in Dust Regional Atmospheric Model (DREAM) – going one step further

2021 ◽  
Author(s):  
Luka Ilić ◽  
Eleni Marinou ◽  
Aleksandar Jovanović ◽  
Maja Kuzmanoski ◽  
Slobodan Ničković
Keyword(s):  
Field Experiments ◽  
Mineral Dust ◽  
Atmospheric Model ◽  
Dust Concentration ◽  
Saharan Dust ◽  
Dust Particles ◽  
Vertical Profiles ◽  
Regional Atmospheric Model ◽  
Immersion Freezing ◽  
The Mediterranean

&lt;p&gt;Mineral dust particles in the atmosphere have a large influence on the physical properties of clouds and their lifecycle. Findings from field experiments, modeling, and laboratory studies suggest that mineral dust particles are very efficient ice-nucleating particles (INPs) even in regions distant from the desert sources. The major sources of mineral dust present in the Mediterranean basin are located in the Sahara Desert. Understanding the significance of mineral dust in ice initiation led to the development of INPC parameterizations in presence of dust for immersion freezing and deposition nucleation processes. These parameterizations were mineralogically indifferent, estimating the dust ice nucleating particle concentrations (INPCs) based on dust concentration and thermodynamic parameters. In recent studies, feldspar and quartz minerals have shown to be significantly more efficient INPs than other minerals found in dust. These findings led to the development of mineralogy-sensitive immersion freezing parameterizations. In this study, we implement mineralogy-sensitive and mineralogically-indifferent INPC parameterizations into a regional coupled atmosphere-dust numerical model. We use the Dust Regional Atmospheric Model (DREAM) to perform one month of simulations of the atmospheric cycle of dust and its feldspar and quartz fractions during Saharan dust intrusion events in the Mediterranean. EARLINET (European Aerosol Lidar Network) and AERONET (AErosol RObotic NETwork) measurements are used with POLIPHON algorithm (Polarization Lidar Photometer Networking) to derive cloud-relevant dust concentration profiles. We compare DREAM results with lidar-based vertical profiles of dust mass concentration, surface area concentration, number concentration, and INPCs. This analysis is a step towards the systematic analysis of dust concentration and INPC parameterizations performance when compared to lidar derived vertical profiles.&lt;/p&gt;

EXPERIMENTAL STUDIES OF CARBON DIOXIDE INTAKE INTO THE ROOM FROM A PERSON ENGAGED IN MENTAL WORK

2021 ◽  
pp. 30-38
Author(s):  
Дмитрий Валерьевич Лобанов ◽  
Игорь Иванович Звенигородский ◽  
Александр Александрович Мерщиев ◽  
Роман Александрович Шепс
Keyword(s):  
Carbon Dioxide ◽  
Experimental Studies ◽  
Individual Characteristics ◽  
Mental Activity ◽  
Operating Costs ◽  
Breathing Zone ◽  
Climate Control ◽  
Mental Work ◽  
The Individual ◽  
Ventilation Systems

Умственный труд достаточно разнообразен и характеризуется различной степенью ответственности, монотонности, внимания, уровнем эмоционального напряжения. Для обеспечения комфортных условий пребывания человека на постоянном рабочем месте, необходимо в том числе организовывать системы климатизации. Наиболее перспективными для указанной деятельности, являются персональные системы вентиляции, обеспечивающие качественную воздушную среду в зоне дыхания человека при одновременном снижении капитальных и эксплуатационных затрат по сравнению с традиционными видами систем вентиляции (смешивающая, вытесняющая вентиляция). Однако, при проектировании таких систем следует ориентироваться не на «среднего условного человека», а учитывать индивидуальные особенности работника (возраст, пол и др.), выполняющего конкретный вид умственной деятельности. С целью уточнения фактической величины углекислого газа, выделяемого человеком при определенной умственной работе, проведены натурные экспериментальные исследования, результатом которых является подтверждение характера и динамики изменения углекислого газа в помещении при отсутствии (бездействии) вентиляционных систем (линейная зависимость), а также уточнение величины выделяющейся двуокиси углерода при конкретном виде умственной деятельности (исследовался труд инженера-проектировщика). Intellectual work is quite diverse and is characterized by different degrees of responsibility, monotony, attention, the level of emotional tension. In order to ensure comfortable conditions for a person staying at a permanent workplace among other things it is necessary to arrange climate control systems. The most promising ventilation systems for the above activities are personal ones that provide high-quality air environment in the breathing zone of a person while reducing capital and operating costs compared with traditional types of ventilation systems (mixing, displacement ventilation). However, the design of such systems should be guided not by the "average conditional person" but by the individual characteristics of the worker (age, gender, etc.) performing a particular type of mental activity. In order to clarify the actual value of carbon dioxide emitted by a person doing a particular mental work, we conducted a series of field experimental studies. They resulted in confirmation of the nature and dynamics of changes in carbon dioxide in the room in the absence (inactivity) of ventilation systems (linear dependence). As well we clarified the value of emitted carbon dioxide at a particular type of mental activity (in this article we studied the work of an engineer-designer).

Respiratory Protection Provided by Negative Pressure Half Mask Filtering Respirators in Coal Mines

2018 ◽  
Vol 277 ◽  
pp. 232-240 ◽  
Author(s):  
Sergiy Cheberiachko ◽  
Olena Yavors’ka ◽  
Dmytro Radchuk ◽  
Andrii Yavorskyi
Keyword(s):  
Negative Pressure ◽  
Occupational Diseases ◽  
Coal Mines ◽  
Dust Concentration ◽  
Respiratory Protection ◽  
Breathing Zone ◽  
Sampling System ◽  
Total Dust ◽  
Exposure Limit ◽  
Low Efficiency

Two studies were conducted in the coal mines to evaluate worker exposures to a dust, and the effectiveness of air-purifying negative-pressure half mask respirators and was found that miners’ protection were insufficient. An elastomeric and filtering half-mask negative pressure respirators with (mid-efficiency) filters P2 (FFP2) were studied. Measurements of total dust concentrations in the in-mask and outer air were conducted simultaneously. Not identical sampling system led to an underestimation of the actual total inside dust concentration in the first study. The results have been corrected to reduce the systematic error. The inside total dust concentrations Ci exceeded national Permissible Exposure Limit (PEL) in most cases in both studies; in first GM Ci=24.7 mg/m3; in second 8.6 mg/m3. Protection factors were: from 2.9 to 6.9 in first study; and from 5.6 to 34 in second. Low efficiency of respirators can be caused by its non-continuous usage. High risk of miners’ occupational diseases should be reduced by decreasing the dust concentration in the breathing zone. It is advisable to check the possibility of improving respiratory protection of miners by powered air-purifying respirators.

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