Dust Pickup Research Articles

Performance testing of nanocomposite based coatings with high dust pickup resistance and solar reflective index for energy efficiency in built environment

Cool paints/coatings are passive solutions which enable reduction in energy loads and impart substantially in buildings owing to their reflective properties. The most common metric to assess their performance is the Solar Reflective Index (SRI). Higher SRI values for paints enable the reflectance of solar radiation and further aid in reducing the cooling load in buildings. This study presents the development and testing of a novel nanocomposite-based coating, NanoDPR, designed to offer high dust pickup resistance and solar reflective index for energy efficiency in the built environment. The research addresses the challenges of dust accumulation affecting the long-term performance of such cool coatings in arid climatic conditions of the UAE. The study includes experimental investigation, conducted over 1000 days, demonstrated that the NanoDPR coating exhibits superior resistance to dust pickup and a lower reduction in SRI values compared to a reference coating. The work further extends to modelling on a residential townhouse for energy savings evaluation. The results revealed a 5% reduction in energy consumption annually and an avoidance of 2.75 kg of CO2/m2 of exterior painted area with the NanoDPR coating in comparison with conventional reflective paints. Results show that the development and adoption of such coatings can significantly impact energy consumption and carbon emissions, ultimately promoting a more sustainable future.

STRATEGY TO IDENTIFY AND MITIGATE HAZARDS IN DEEP-LEVEL MINE VENTILATION SYSTEMS USING A CALIBRATED DIGITAL TWIN

Deep-level mines have complex and dynamic ventilation systems to ensure that sufficient air is provided to underground workers. Certain changes to the ventilation systems are continually implemented to enable the deepening of these mines. The three main hazards in ventilation systems are high temperatures, dust pick-up, and gas build-up. This means that avoiding hazards in these systems is important for the health and safety of workers. New technologies, such as digital twinning, can be used to simulate and plan the entire deep-level mine ventilation network with ease. In this study, a digital twin is used to identify high-risk areas in a deep-level mine that are susceptible to high temperatures, dust-pick-up, and gas build-up. The identified hazards can now be avoided by implementing various changes to help mitigate the possibility of their occurrence. This enables the mining industry to plan proactively and to manage the ventilation system for the entire life-of-mine (LOM). Keywords Deep-level mine; Digital twin; Ventilation; Hazard identification; Hazard mitigation

Source routing and detection of dust storm in the Salt Lake basin of Qom in Iran

In the last decades, the frequency of dust storms has increasingly emerged in the central regions of Iran. This study investigated the SDS sources in the Salt Lake basin of Qom using daily visibility, wind speed, dust weather codes and NCEP/NCAR data, and MODIS and Sentinel-1 sensor datasets. Sample SDS days were selected by daily visibility and dust weather codes with 3-h interval ranging from 2000 to 2017. These sample SDS days were related to the 19 synoptic stations of the Salt Lake basin. Dust entry trajectories were determined through the HYSPLIT model and evaluated with the MODIS Deep Blue aerosol optical depth and atmospheric patterns. SDS sources were identified using Sentinel-1 radar images of IW mode and SLC type through radar interferometry technique. Analysis of variability and frequency in dusty days and wind speed indicated that in high wind speed and dusty days, frequency increases in the second half of the course. SDS entry trajectories indicated that the SDS mainly entered in the study area during April and May from Iraq and eastern Syria and also during June and July from the east of Iran and the study basin. Study of the regional atmospheric circulation represented that the thermodynamic relationship between the thermal low pressure and trough at 500 hPa in spring provides instability and ascending air in Iraq and eastern Syria. In summer, the pressure gradient between thermal low pressure in the east of Iran and the Caspian high pressure intensifies the wind in the eastern part of Iran from the surface to 850 hPa level. Investigation of the dust pickup areas with radar interferometry technique revealed that as far as Iraq and eastern Syria were concerned, the eastern part of Al-Anbar province in the western desert of Iraq was the first source, desert areas in central and southern Iraq were the second source, and the eastern part of Syria ranked the third source of dust. In Iran, the main sources of SDS are located in the eastern regions of the Salt Lake basin as newfound region, the southeastern areas of Semnan province, the northwest of Yazd, and the northeast of Isfahan in the central desert of Iran. In recent years, there has been more abundance of dust originated from the eastern SDS trajectories.

An estimate of the dust pickup current at Enceladus

We demonstrate that the acceleration of submicron dust originating at Enceladus by a reduced co-rotating E-field is capable of creating a dust pickup current perpendicular to the magnetic field with values ranging from 3 to 15kA (depending upon the effective grain charge). Such a current represents a new contribution to the total pickup current in the region. As such, we suggest that dust pickup currents, along with ion and electron pickup currents, are all active within the plume.

Ion densities and magnetic signatures of dust pickup at Enceladus

Encedalus' plume of charged dust has been shown to strongly modify the plasma structures. Therefore, we analyze the magnetic signatures of dust to constrain the dust plume. For the first time, the mutual feedback between the nanograins and their plasma environment is investigated. Our model combines plasma simulations by means of the A.I.K.E.F. (Adaptive Ion‐Kinetic Electron‐Fluid) code with Monte Carlo simulations of the 3‐D profiles of the gas and dust plumes. Data from several instruments of Cassini are considered: the neutral plume model is in good agreement with INMS data, whereas theoretical predictions of the peak ion density are compared against CAPS data, and properties of the dust are obtained by comparing our results with MAG data from the recent E14–E19 flybys. Our main results are (1) due to the ion‐neutral chemistry, H3O+ is the predominant ion species within the plume; (2) the high nanograin densities observed by CAPS require an increased effective ionization frequency to fulfill quasi‐neutrality; (3) the nanograin pickup current makes only a minor contribution to the current systems; i.e., the major contribution of the dust arises from electron absorption; (4) the pickup of nanograins is clearly visible in the magnetic field signatures, even including the distant encounter E15; (5) MAG data indicate a southward extension of the charged dust plume of at least 4 Enceladus radii; (6) the modification of the currents by the nanograins is responsible for the surprising fact that Cassini did not detect a region with a reduced magnetic field strength.

Dynamic monitoring of the dust pickup efficiency of vacuum cleaners.

This study evaluated a new method that uses an optical aerosol photometer for dynamically monitoring dust pickup efficiency during vacuuming. In the first stage of this study the new method was compared with built-in dirt sensors installed by vacuum cleaner manufacturers. Through parallel testing it has been shown that the widely available built-in dirt sensors are not sensitive enough to register small (< 53 microm) dust particles. Therefore, only the optical photometer was used in the rest of the experiments of this study to monitor the dust pickup efficiency while the vacuum cleaner was operated with different nozzles on clean and soiled carpet and vinyl sheet flooring. This method also was used to monitor dust pickup efficiency when vacuuming carpets originating from lead-contaminated homes. The dust pickup efficiencies obtained with the optical aerosol photometer have been compared with the surface lead concentrations found during different stages of cleaning. Results indicate that the dust mass concentration registered with the optical aerosol photometer at the nozzle outlet correlates well with the dust mass collected in the vacuum cleaner filter bag and with the surface lead level. Therefore, dynamic dust pickup monitoring can provide valuable information about the efficiency of cleaning when a vacuum cleaner is used. This suggests that a small aerosol photometer similar to a light-scattering smoke detector would be beneficial in vacuum cleaners used for cleaning surfaces contaminated with leaded dust and biological particles (including allergens).

Dynamic Monitoring of the Dust Pickup Efficiency of Vacuum Cleaners

Dynamic Monitoring of the Dust Pickup Efficiency of Vacuum Cleaners

Test methods for evaluating the filtration and particulate emission characteristics of vacuum cleaners.

The overall filtration efficiency of a vacuum cleaner traditionally has been tested by placing the vacuum cleaner in a test chamber and measuring aerosol concentrations at the chamber inlet and outlet. The chamber test method was refined and validated in this study. However, this chamber test method shows an overall filtration efficiency of close to 100% for most of the industrial vacuum cleaners and for most of the newly developed household vacuum cleaners of midprice range or higher because all these vacuum cleaners have a high-efficiency particulate air (HEPA) or other highly efficient filter installed at the exhaust. A new test method was therefore developed through which the vacuum cleaner was probed in various internal locations so that the collection efficiency of the individual components could be determined. For example, the aerosol concentration upstream of the final HEPA filter can thus be measured, which permits one to estimate the life expectancy of this expensive component. The probed testing method is particularly suitable for field evaluations of vacuum cleaners because it uses compact, battery-operated optical particle size spectrometers with internal data storage. Both chamber and probed tests gave the same results for the aerosol filtration efficiency. The probed testing method, however, also gives information on the performance of the individual components in a vacuum cleaner. It also can be used to determine the dust pickup efficiency and the degree of reaerosolization of particles collected in the vacuum cleaner.

Development and operation of an improved turntable dust feeder

An improved version of a dry dispersion turntable aerosol feeder has been developed which provides greater variation, control, and reliability in aerosol output. The heart of the system is a rotating dust cylinder that permits steady delivery of dust to a turntable groove where it is picked-up by an adjustable aspirator. This design feature eliminates the need for vibrators and ensures a smooth dust flow to the dust pick-up point. Depending on the cylinder diameter, unattended operating time can be greatly increased. The aspirator incorporates an adjustable venturi and pick-up apparatus. By varying venturi adjustment and air pressure, dust pick-up under differing operating conditions can be assured. A large range in aerosol output can be achieved using different groove widths, locations, and turntable speeds. Operational performance tests show steady aerosol output over the delivery range of 100 mg/min to 50 g/min, depending on the size of the feeder. To date, two sizes of the turntable aerosol feeder have been utilized effectively resulting in dust concentrations ranging from 100 μg/m 3 to 560 mg/m 3.

Pollution Control in Fertilizer Manufacture

AbstractMost air pollution regulations can be met by existing technology available. However, technology has not yet been developed to cope with the particulate emission problems at ammonium nitrate and urea prilling towers. Considerable technical effort is being devoted to finding solutions to the prilling tower problems. One possible solution for new plants is to granulate ammonium nitrate and urea in equipment which is amenable to particulate emission abatement. There are some unsolved water pollution problems at fertilizer plants awaiting further development of abatement technology. Miscellaneous discharges comprise a significant proportion of the aqueous wastes, and much of this loss can be avoided by adherence to good engineering practices when fertilizer plants are designed and constructed. In some cases, nutrients collected as wastes can be returned to the manufacturing process. Dust scrubber effluents and plant washdown obtained at granular fertilizer plants can be converted into liquid fertilizers; however, the dust collecting system should be designed to avoid excessive dust pickup. Two waste materials—gypsum and fluorides—are not normally suited for reuse in the manufacturing process. These materials are potentially useful by‐products, and greater emphasis is being placed on their recovery as by‐products because of the environmental problems associated with their disposal as wastes. Much progress has been made toward recovery of by‐product fluorine, but by‐product gypsum recovery involves large capital investment and extensive market development.

Techniques for the Prevention and Elimination of Static from Polymer Coatings

I. INTRODUCTION The problems of static electricity in the polymer industry are many and varied (see Table 1). They range from the removal of unwanted charge during fiber spinning and processing in order to avoid charging the machine and to reduce handling problems and dust pickup (fog marking), through the physiological problems associated with synthetic fiber carpets and automobiles to the explosion hazards of aircraft refueling, hospital environments, and mines. This is not to imply that all static is bad; in xerography, for example, the latent electrostatic image is developed by using toner (dry ink) charged by tumbling against the carrier; electrostatic separators make use of triboelectrification to accomplish separations not possible by other techniques.