Dust Suppression System Research Articles

Modelling for Air Quality Estimation for a Planned Coal Washery to Control Air Pollution

Tasra coal washery has been planned in Tasra block which is located in Jharia coalfield of Jharkhand state in India. In order to predict air pollution impact because of the proposed washery, modelling has been done using fugitive dust model. Dust levels (PM10 and PM2.5) have been assessed both for conditions of controlled and uncontrolled emissions from various sources of the washery. Baseline site specific air quality data (PM10 and PM2.5) of winter season and maximum coal washing capacity of 700 t h−1 have been considered for prediction of air quality in case of worst-case scenario. Based on modelling exercise, it has been predicted that PM10 concentration may increase from 0.058–51.333 and 0.039–17.485 μg m−3 under the conditions of uncontrolled and controlled emissions respectively at the air quality monitoring sites and the selected receptor locations in the nearby vicinity of the proposed washery. Similarly, PM2.5 concentrations may rise from 0.044–16.636 and 0.022–7.219 μg m−3 due to the uncontrolled and controlled emissions respectively. In order to minimize the fugitive dust levels from the washery site, installation of dry fog dust suppression system has been recommended at different dust generating sources in addition to implementation of other dust control measures in and around the coal washery.

Simulation analysis and engineering application of distribution characteristics about multi-stage atomization field for cutting dust in fully mechanized mining face

To improve the dust suppression efficiency of the external spray systems of shearers, a dust reduction method consisting of shearer external multi-stage atomization and dust removal fan was proposed. Computational fluid dynamics-based numerical simulation was combined with atomization experiments to analyze the migration and distribution of the cutting dust and multi-stage atomization field under airflow at the 2307 fully mechanized mining face of the Tangkou mine. The results show that with adding dust removal fan and multi-stage atomization points, the peak area of wind speed appeared on both sides of the shearer, and the wind speed was greater than 2.7 m/s, the dust concentration on the downside side of the shearer decreased, the spray coverage area increased significantly, and the droplet concentration at the shearer drum was the largest, exceeding 0.05 kg/m3. According to the research results, the multi-stage atomization arrangement of single-fluid water nozzles of shearer was put forward, and the field application was carried out. Compared with the engineering application results of the single-stage atomization dust suppression system, the total dust reduction rate of the synergistic effect of multi-stage atomization external spray with dust removal fan for the shearer is 87.12%, which is 38.59% higher than that of the conventional single-stage atomization dust suppression system.

Air quality modelling for prediction of dust concentrations in iron ore mines of Saranda region, Jharkhand, India

Air quality monitoring was conducted in 12 working, 29 closed and 18 proposed ion ore mines to assess the existing baseline air quality status in Saranda region of West Singhbhum district in the Jharkhand state of India. Air quality modelling was carried out to predict the dust concentrations that likely to arise as a result of the several mine operations. This modelling analysis enabled the effective mitigating measures to control mining related air pollution. It was observed that the main cause of particulate matter generation in the region is due to the road transportation of ore. Transportation of iron ore by conveyor belts from the pit head to the bunkers at the nearest railway siding, and thereafter from the bunkers to the user site by covered railway wagons demonstrated the best possible alternative mechanism for reducing particulate matter (PM10 and PM2.5) concentrations in the region. It was predicted that concentrations of PM10 and PM2.5 would be below or slightly higher than the National Ambient Air Quality Standard (NAAQS) in most of the surroundings and higher within mine leasehold areas. Air pollution levels can be minimized by implementing effective control measures. Consequently, it was suggested that all the existing working mines as well as proposed operative mines in the region should use the transportation from mine to the nearest railway siding by covered conveyor belts and bunker loading systems with the use of scientific dust suppression systems at transfer points.

Efficiency of Dust Suppression with Aerosol Guns–Fogging Machines with Air-and-Fluid Jets

The environment protection and dust control on washed-in waste piles is complicated by the continuous replenishment of tailings and, consequently, formation of new dusting layer on the pile surface. This problem can be solved using aerosol guns–fogging machines devices within the dust suppression system. The authors propose to place the aerosol dust suppression system on a platform–car moving along a tailings dump. This allows automating dust control and increasing volume of transported water. Grain-size composition of dust at tailing dumps of Kovdor Mining and Processing Plant is determined. From the laboratory experiments, it is found how intensity of dust transfer abates dust suppression. The experimental findings make it possible to calculate the required number of jets for an aerosol gun.

Numerical simulation of ventilation and dust suppression system for open-type TBM tunneling work area

In order to study the characteristics of the ventilation and dust suppression system for open-type TBM tunneling work area in a Ø8.53 diversion project, the numerical simulation method is adopted, and a three-dimensional steady airflow model, a dust flow model as well as other related flow characteristic equation models are established by considering the dust production mechanism of TBM construction. Besides, corresponding simulation models validated by experiment are established using CFD software, and the impacts of the main vent location, the air baffle length in the main beam and the exhausting air flow quantity on flow field distribution and dust flow behavior in open-type TBM tunneling work area are investigated. The results show: when the main vent is located 70–80m away from the working face, the ventilation in TBM tunneling work area is optimal; when the air baffle is as long as the main beam, the dust collection efficiency is the highest, reaching 89.4%; under the condition that the exhausting air flow quantity is less than half of the ventilation air flow quantity required by energy consumption and the minimum backflow velocity, the best dust suppression effect can be achieved when the exhausting air flow quantity is 40% of the ventilation air flow quantity.

The Development of the Water-Saving and Haze-Preventing Integrated System on Gantry Crane

With the frequent appearance of haze weather, haze-preventing has become one of the serious environmental problems. Among all measures, preventing inhalable particulate matter from the source is one of the most effective ways to eliminate haze. Based on the traditional water mist dust suppression technology, this paper developed a water-saving integrated system, by exploiting PROFIBUS-DP to connect water mist dust suppression system to gantry crane in port. This integrated system was demonstrated accurately spraying water mist while the crane dropping down coal. In this way, the suspended particulate matter is successfully inhibited, while fresh water is saved.

Novel Approach for Suppressing Cutting Dust Using Foam on a Fully Mechanized Face with Hard Parting

The cutting dust created by the shearer drum is the main source of dust on a fully mechanized coal face. However, overexposure to respirable dust may cause pneumoconiosis in coal workers, while coal dust may lead to serious explosions. The fully mechanized face known as II1051 Face, found at the Zhuxianzhuang Coal Mine located in east China, generates dust by way of the drum on a high-power shear. The coal seam involves hard rock parting so there is a high concentration of cutting dust when the shearer is working. Thus, we developed a new foam dust suppression method with an air self-suction system based on an analysis of the dust generation characteristics that suppressed the shearer cutting dust level. The new foam system was evaluated in a field test where the dust concentration was measured at two points. The results showed that the foam reduced the cutting dust concentration significantly. The respirable dust exposure levels were reduced from 378.4 mg/m3to 53.5 mg/m3and the visibility was enhanced dramatically. Thus, we conclude that our new foam system is highly efficient at capturing cutting dust, and it has a much lower water consumption. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: Contact angle of cutting dust sample, migration trajectory of cutting dust, technological process for suppressing shearer cutting dust using foam, the layout of the foam dust suppression system on coal face, real object of the air self-suction type foam generator, the special foam nozzle used for shearers, relevant experimental results of the air self-suction foam system.]

Development of a compact excavator mounted dust suppression system

This paper reports on the investigation of an excavator mounted dust suppression system for demolition and construction activities. Ever increasing pressure is placed on contractors to improve their environmental performance, especially dust emissions. Current methods of dust suppression have been investigated and each of the methods has also been critically analysed to determine their advantages and disadvantages. The investigation also examined the requirements of such a system and a concept system proposal was produced. A working prototype has been constructed for a mini excavator complete with a hydraulic breaker. The proposed system was rigorously tested in various configurations to determine its efficiency and effectiveness in comparison with current suppression techniques. The resulting benefits such as the reduction of water usage and cost are highlighted.

Submicron Particle Monitoring of Paving and Related Road Construction Operations

This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers’ breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000–60,000, 28,000–70,000, and 23,000–37,000 particles/ cm3 for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000–111,000, 28,000–81,000, and 19,000 particles/cm3 for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm3 in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of paver ventilation systems; diesel fume engineering controls; reduced idling; provision of cabs for the operators; and improved dust suppression systems on the milling machine. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing recommendations for controlling fumes and dust during road repair and a report on an investigation of the New York City Department of Transportation road repair operations.]

Alternate Solution for effective Dust Suppression in Thermal Power Plant

Many thermal power plants use coal as their fuel. To handle the coal, each power station is equipped with a coal handling plant. The coal has to be sized, processed, and handled which should be done effectively and efficiently. While working in the coal handling plant the major factor which reduces staff efficiency is the working environment i.e. a dusty atmosphere. Lots of care is always taken to reduce dust emission. Generally all systems used in power station coal handling plants are wet dust suppression systems. In this paper the reasons for failure of these type of dust suppression system are discussed. The remedy for the improvement of this system is also given in this paper. The existing system can be easily modified by using ultrasonic system. The spray discharge should be proportional with dust emission. The solenoid valve should be open with proportion with quantity of dust generation. The possibility of such type of this system is discussed in this paper.

Assessment of Distribution and Composition of Quarry Mine Dust: Case of Pomona Stone Quarries, Harare

The study aimed at assessing the distribution and composition of dust produced at Pomona Stone Quarry mine in Harare, Zimbabwe. The source contribution to ambient PM2.5 and PM10 dust levels were quantified and their spatial distribution from the quarry to the receptor (community). The study also analysed the pH of soils around the mine, SiO2 and Al2O3 levels in quarry dust. Data was collected through direct observations, personal communications, experiments, soil and dust sampling and analyses. Dust sampling was done in January, April and August, to assess the effect of meteorological conditions on dust concentrations in two phases. Phase 1 was conducted during plant shut down (baseline measurements) while phase 2 was carried out during full plant operations (normal operating conditions), to assess the effect of quarry operations on the surrounding areas. Within the quarry production processes, crushing stage was the most dust emitting stage. Phase 1 dust results showed that both respirable (PM2.5) and inhalable (PM10) dust at all stages were below the legal limit, thus below 35 mg/m3 (respirable) and 180 mg/m3 (inhalable). Highest dust levels (209.9 mg/m3 inhalable and 69.01 mg/m3 respirable) were recorded in August, followed by April (206.9 mg/m3 inhalable and 67.52 mg/m3 respirable) then January (206.82 mg/m3 inhalable and 65.27 mg/m3 respirable). At all stages, highest dust concentrations for both parameters were recorded near the plant and decreased with increasing distance from the plant ( ranging from 209.9 mg/m3 - 19.41 mg/m3 inhalable and 69.01 mg/m3 - 14.23 mg/m3 respirable). This was attributed to the effect of particle size. August recorded the biggest area for both parameters falling within the non-permissible category, followed by April then January. The findings also revealed that the quarry dust contained higher levels of SiO2 (0.752 mg/cm3) which were 7 times higher than the recommended 0.1 mg/cm3 (NSSA). Low Al2O3 levels of 0.102 mg/cm3 were recorded and this was considered as environmentally safe. Soils were slightly acidic-alkaline and the t-test results at 95% confidence interval showed no significant difference between the results from site A and B (p = 0.526). It was concluded that quarry dust from Pomona had no significant effects on soil pH but possible health impacts on the receiving community. The study recommended that dust suppression systems such as water sprays, vegetation, air nets and enclosed production process must be implemented to curb dust emissions.

Retrofitting Sprinkler Systems for Suppressing Dust Generated by Moving Vehicles Inside Farms

Abstract Fugitive dust is one of the well known problems in agriculture and it affects both humans and machine producing quality. Dust problems can seriously cause harmful diseases to workers and ruin expensive equipments. In this study, a dust formation generated in open environment by vehicles was analyzed on unpaved roads. Formed dust was measured by calculating total forces on the PM 10 (airborne particles smaller than 10 mm) of dust particles, such as air velocity, gravity forces and air turbulence generated by the moving vehicle. The water fogger nozzle discharge was measured to determine the approximate droplets quantity in the air. The foggers were used to suppress the generated dust in an open environment via installing a proposed automatic suppression system which opens automatically when vehicles pass under the system. The relationship between water droplet speed and ability of collecting fugitive dust showed that high air temperature above 40°C and wind speed above 10 m s −1 have negative effects on the system's ability of collecting dust due to evaporation of small radius droplets and/or drifting water droplets away from the effective area. The overall system efficiency was found to be 85% and the proposed dust suppression system was found to be a satisfying solution for reducing fugitive dust hazards.

New Respirable Dust Suppression Systems for Coal Mines

Abstract Dust suppression in coal mines is a worldwide problem which has not been solved effectively. The application of negative pressure secondary dust removal (NPSDR) is a breakthrough in the coal mine safety field. In this paper, NPSDR technology and ultrasonic dust suppression systems are introduced. High pressure water is supplied to the NPSDR device which is mounted on the shearer. A negative pressure field is formed in the device. At the same time, the dusty air around the shearer drum will be sucked into, and purged from, the NPSDR device by the negative pressure field. An ultrasonic dust suppression system uses water and compressed air to produce micron sized droplets which suppress respirable coal dust effectively. The NPSDR technology can be used for shearer dust suppression while ultrasonic dust suppression can be applied in areas such as the transportation positions. These dust suppression methods have the following advantages: high efficiency, wide applicability, simple structure, high reliability and low cost.

Improved dust capture methods for crushing plant

The use of compressive crushing equipment such as gyratory crushers within minerals processing plants can potentially generate large quantities of dust. Remedies to this problem include the retrofitting of shrouds, enclosures, local exhaust ventilation (LEV) systems and water suppression systems. The single or combined application of these systems must be optimised to ensure they operate efficiently. It is desirable that the future design planning of such facilities include integrated dust suppression and/or removal systems to ensure material delivery rates are maintained and the welfare of the workforce is protected. The tipping of mineral ore into the crusher feed bin is investigated by the construction and solution of computational fluid dynamic (CFD) models validated by data obtained from scale experiments. A 3D computational model was constructed using the Fluent™ CFD software to represent the background ventilation regime within an underground crushing installation. The falling ore is represented as a continuum granular fluid falling under gravity from the raised bed of the dump truck. Transient path lines are computed to simulate the updraft airflow generated by the tipping process and indicate the dispersion path of any entrained dust. The relationships between the falling ore material, the displaced air and the shear induced flow are determined by an analysis of the computed volume/mass flow rates predicted across the crusher opening. A parametric study has been performed on the model of the tipping process to investigate the influence on dust dispersion of; the orientation of the dump truck, the surrounding ventilation characteristics and the material tipping rate, volume and initial fill level of the crusher bin. The operation of LEV systems has also been simulated to identify the influence of such systems on the airflow characteristics in and around the crusher feed bin. An analysis of the airflow patterns predicted by the CFD simulation models indicates strong shear flows induced between the tipped material and the surrounding airflow in the vicinity of the crusher during tipping, and a strong influence of the background ventilation regime on the path taken by this shear flow. Scale experimental studies were conducted to characterise the induced shear flow and visualise the potential entrainment and transport of dust. An analysis of these preliminary experiments is presented.

The ventilation of an underground crushing plant

The use of compressive crushing plant such as gyratory crushers within minerals processing operations can generate large quantities of dust as large volumes of ore are tipped into the crusher feed bins. Methods to reduce these dust emissions include the retrofitting of shrouds, enclosures, local exhaust ventilation (LEV) systems and water suppression systems. The operation of these ancillary systems should be optimised to offer maximum performance. It is desirable that the future planning of such facilities include sufficient dust suppression and/or removal systems to ensure that material delivery rates are maintained and the welfare of the workforce is protected. This paper presents the results of an investigation of the tipping process through the application of computational fluid dynamic (CFD) methods and validation using data obtained from scale experiment. A 3-D computational model has been constructed using the Fluent™ <www. fluent. co. uk> modelling software to represent the ventilation regimen within an underground crushing installation. The falling ore has been represented as a granular fluid continuum falling under gravity from the bed of the dump truck. Transient streamlines are used to represent the dispersion of dust due to the updraft airflow generated by the tipping process. A parametric analysis has been performed on a model of the tipping process to investigate the influence on dust dispersion of; the orientation of the dump truck, the surrounding ventilation characteristics and the material tipping rate and volume. The CFD models predict a strong shear-induced flow in the region of the crusher during tipping and a high sensitivity to the surrounding ventilation regimen. These results indicate the need for further experimental studies to characterise the entrainment and transport of dust-laden air into the induced shear flow. An experimental rig has been designed and evaluated for the purposes of conducting validation studies and gaining further insight into this phenomenon. Results of these investigations are presented.

Dust Control for Material Handling Operations: A Systematic Approach

Material handling operations are used widely in industry. Often they produce unacceptable levels of dust. This article proposes a systematic approach to dust control for material handling operations. It focuses on the appropriate dust control technologies for the wide range of material handling operations. Both dust collection and dust suppression systems are considered. Comparisons are made between competing technologies using available information. Relevant literature resources are compiled and synthesized to provide the reader with the most recent design and operational information. Important areas requiring further research and development work are identified.

Characterization of the aerosol in turkey rearing confinements

A study was conducted to characterize the aerosol found in turkey rearing confinements, to study biological response to inhalation of the aerosol, and to evaluate a water spray, dust suppression system in one confinement as compared to a control barn. A significant reduction in aerosol concentration in the "sprayed" barn was inferred by many environmental and biological sampling parameters. Similarity of physical and biological factors in both study populations, with the exception of the dust suppression system, implied that a mortality rate increase of 1.74 of control versus "sprayed" barn was directly related to aerosol concentration.