Dust Collection Research Articles

Analysis of the dust cleaning performance of a branch-type nozzle.

To solve the problem of uneven dust cleaning in filter cartridges, a simple and easy-to-install "branch-type" nozzle structure was designed to improve cleaning efficiency. In this study, numerical simulations, range analysis methods, orthogonal experimental design, back-blowing experiments, and powder cleaning experiments were conducted. By choosing the back-blowing uniformity as the evaluation index for cleaning performance, with the flow distribution coefficient A, length of branch pipe B, and outlet diameter of main pipe C as the factors, and ignoring the interaction between factors, an orthogonal experiment was designed to simulate the fluid flow field of nine different nozzle structures installed in the back-blowing model. The results were analyzed using range analysis methods, and the optimal nozzle structure parameter combination was determined to be A = 50%/40%/10%, B = 70 mm, and C = 18 mm. Based on the back-blowing experiment, the accuracy of the simulation results was verified, and the back-blowing uniformity was improved by 50.12%. In the powder cleaning experiment, a new method of measuring the mass of dust shaken off by a single pulse of cleaning to calculate the residual dust on the filter cartridge, rather than removing the filter cartridge and weighing it, was found to reduce experimental errors and make the conclusions more solid and convincing. The results showed that the "branch-type" nozzle increases the cleaning efficiency by 37.6% compared with no nozzle installed, proving that the "branch-type" nozzle can reduce the number of reverse cleaning required and extend the cleaning interval, thus optimizing the cleaning performance of the dust collector.

A Numerical Simulation of the Coal Dust Migration Law in Directional Air Drilling in a Broken Soft Coal Seam

Abundant industrial experiences have shown that directional air drilling technology is effective for gas drainage when drilling broken and soft coal seams. In this paper, the Eulerian–Eulerian model was used to simulate the gas–solid two-phase flow behavior of compressed air transporting coal dust in broken soft coal seams. The relationship between the degree of coal dust deposition, annular air pressure law, transportation of coal dust, aforementioned factors of rotational speed, particle size, and air volume could be determined. The results indicate that the particle size plays a significant role in the transport capacity of coal dust. Smaller particle sizes and a higher airflow result in a lower deposition degree of coal dust. When the particle size of coal dust is 1.69 mm and the airflow is 300 m3/h, in the case of coal dust generation at a rate of 0.24 m3/h, the deflection angle of the coal dust collection zone is increased by 130% as the rotational speed of the drill rod is increased from 0 to 120 rpm. Similarly, the deflection angle of the coal dust collection zone is increased by 12.8% in a 500 m3/h airflow under the same condition. Additionally, fine particle-sized coal dust is transported in a spiral line. The coal dust with larger particle sizes tends to be in the middle and lower parts of the hole and move along a specific trajectory. Industrial experiences of medium-air-pressure drilling confirm that a rotary drilling speed between 80 and 120 rpm, with a minimum air volume of 400 m3/h and preferably 500 m3/h, can promote a smooth hole drilling effect and enhance the construction safety in the gas drainage process.

Filter Cleaning System Modification to Improve Dust Colletor

The filter cleaning system is part of the dust collector which functions as a filter between dirty air and clean air. Blockage of the dust collector is due to a lack of maintenance to control the performance of filter cleaning components such as valves, jetspray tubes and bagcloth. Another cause is the less than optimal air pressure from the jetspray to dislodge the dust adhering to the bagcloth. So it is necessary to recondition both the layout of the filter cleaning components and the optimization of jet spray pressure. Determination of the capacity of the jetspray tube is adjusted to the specifications of the compressor and uses the ASME VIII Div I (Pressure Vessel) standard with dimensions of 1400mm x 8inch SCH20. The feasibility test of the jetspray tube is carried out by calculating the allowable thickness and the factor of safety based on the pressure operated on the jetspray tube. Determining the location of the filter cleaning components is based on aspects that make it easier for the operator to carry out the maintenance so that the performance of the filter cleaning components can be controlled properly. Based on the stress simulation using solidworks 2020 for the SCH20 pipe which has a thickness of 6.35mm operated with a pressure of 7 bar it is categorized as safe to use.

Effect of air humidity on the pulse-jet cleaning performance of cartridge filter for collecting hygroscopic adhesive dusts

Pulse-jet cartridge filters are widely used in industrial dust removal. However, the accumulation of highly sticky dust can cause irreversible blockage of cartridges. This is primarily due to the humidity of the air on the cleaning performance of the filter cartridge. Therefore, this article proposed a new method to solve it by changing the injection air source (nitrogen, compressed air after suction dryer treatment and compressed air after cold dryer treatment), the influence of humidity on system strength and dust residues was assessed. We define absolute humidity above 10 g m−3 as a high humidity condition and vice versa as a low humidity condition. The conclusions are that the injection effect only considers the water content of the injection air source: nitrogen > compressed air after suction dryer treatment > compressed air after cold dryer treatment. In low humidity conditions, the injection air source is the main influence factor, plus the water content of the injection air source, the greater the resistance of the system and the dust residues. In high humidity conditions, the humidity of the air is the most important influence. When the gas-solid concentration and filtration wind speed are constant, the system strength and dust residues increase with the increase in humidity. This study provides new ideas and reliable data sources for the industrial collection of adhesive dust.

Study of the leaching process for dust chamber sublimates followed by the extraction of niobium and zirconium into solution

The material composition of the sublimates from dust chambers in titanium chlorinators has been studied by chemical, X-ray and microprobe analysis methods. Studies of the phase composition of dust chamber sublimates have shown that the object consists of aqueous and anhydrous chloride phases to a greater extent. Two forms of niobium present, such as oxychloride and oxide niobium were found. The presence of zirconium in sublimates has a chloride and oxychloride nature. Experiments for the aqueous leaching of dust chamber sublimates were conducted to determine the optimal process conditions: S:L ratio = 1:8, leaching time = 1 hour, temperature = 25℃. Studies were conducted to choose an acidic reagent for cake leaching followed by the conversion of niobium and zirconium into a solution. A solution consisting of HF+H2SO4 was selected as an acidic reagent for cake leaching. Optimal conditions for the extraction of niobium and zirconium into solution were established, such as 25% [18M HF] +75% [7M H2SO4], S:L ratio = 1:3, temperature = 90 °C, duration of the leaching process = 120 minutes. Under these leaching conditions, the extraction of niobium, zirconium, and titanium into solution was 94.06%, 84.95% and 32.35%, respectively. The elemental and phase composition of the residue from acid leaching of cake were determined.

Influence of the inner diameter of the bottom plate on the cleaning performance of double-layer filter cartridges

Dust collectors are used in various industries to separate pollutants from the air. Filter cartridge dust collectors are favored for their stability and small footprint. However, conventional cleaning techniques make it difficult to solve the problem of incomplete cleaning of filter cartridges, which require frequent replacement. Inner cone double-layer filter cartridges are utilized to improve the incomplete cleaning of filter cartridges. The size of the inner diameter (ID) of the bottom plate is one of the main factors affecting the cleaning performance of the double-layer filter cartridge. Double-layer filter cartridges' inside flow field is investigated by numerical simulation in this work. Selection of evaluation indexes such as peak static pressure and comprehensive pressure to assess cleaning performance and analyze the effect of ID on cleaning performance. It was shown that increasing ID could optimize the upper section of the filter cartridges' static pressure distribution. Both larger (ID = 160 mm) and smaller (ID = 40 mm) filter cartridges ID possessed better bottom static pressure accumulation capacity. As the inner diameter of the bottom plate decreases, the cleaning performance increases and then decreases, and the best results were obtained at an ID of 140 mm, with a PC of 1175 Pa. Notably, IDs exceeding 160 mm have a significant negative impact on the cleaning performance of the filter cartridges.

Respirable Coal Mine Dust in the Vicinity of a Roof Bolter: an Inter-laboratory Study to Compare Wet Versus Dry Dust Collection Systems

Respirable Coal Mine Dust in the Vicinity of a Roof Bolter: an Inter-laboratory Study to Compare Wet Versus Dry Dust Collection Systems

The influence of pipeline deposited dust on the explosion propagation of dust collector

An explosion experiment involving corn starch was conducted using a small tank directly connected to the pipeline. The objective was to investigate how the mass and location of deposited dust in the pipeline affect the explosion pressure and flame propagation characteristics of the dust cloud. The results revealed that when the container was at the optimum dust explosion concentration, as the mass of deposited dust increased, the maximum explosion pressure of both the container and pipeline increased and then decreased. Additionally, the maximum flame propagation velocity and flame propagation length gradually decreased as deposited mass increased. Furthermore, as the distance between the location of deposited dust in the pipeline and the container increased, the maximum explosion pressure increased and then decreased. Similarly, the maximum flame propagation velocity demonstrated a similar trend, whereas the flame propagation length gradually increased. In conclusion, the study's findings offer a theoretical foundation for scientifically assessing and effectively preventing and controlling explosion disasters in dust removal systems.

CHEMISTRY IN NANOMATERIALS OF HIGHWAYS

Summary: The article presents a variety of building materials, structures and products obtained using nanotechnology, which have improved physical and mechanical characteristics compared to traditional ones: they have greater strength, wear resistance, plasticity, heat resistance, and have significantly higher flash resistance. They are lighter in weight, more rational and safer to use and more durable. The use of nanotechnologies and nanomaterials is becoming more widespread in various spheres of human life. With unique properties, they are used for industrial and consumer applications, and their various types have found their place in many sectors: agriculture, energy, aerospace, cosmetics, food, medicine, construction, transportation, electronics, etc. But at the same time, it creates new risks and increases the impact on the environment. This effect is not visible to the eye, but it is noticeable for human health and the environment. It is necessary to properly use all safety measures and take care of the state of the atmosphere, water, soils and people during production, application, processing, packaging, construction work, transportation, storage, repair or demolition. This is provided by individual means of protection, ventilation systems, and dust collection during storage, construction, demolition, and waste disposal. One of the promising areas of environmental protection and cleaning is the bioutilization of nanoparticles by microorganisms and plants due to their battery capacity. Key words: Nanomaterials, nanotechnologies, road construction, environmental protection, emissions.

Innovative technologies combating with dust emission releasing into the atmosphere

An examination of various approaches, methods, and technologies recommended as optimal for safeguarding atmospheric air against dust pollution has led to the identification of the distinct advantages associated with vortex inertial dust collectors utilizing swirling currents. These collectors, referred to as Cyclone Separation Fans (CSF), have been determined to serve as primary and auxiliary equipment in dust removal systems within the production of building materials and other industries. Traditionally employed circuit designs for dust collection systems were also subject to analysis, revealing two prevalent types: open and partially closed air circulation systems. In the latter, a portion of the cleaned airflow is reintroduced into the system, representing a key feature of the design. This assessment underscores the significance of vortex inertial dust collectors, specifically CSFs, as instrumental components in dust removal systems across various industrial sectors. Their effectiveness in mitigating dust pollution, coupled with their versatility as both primary and supplementary equipment, positions them as recommended technologies for atmospheric air protection in the production of building materials and other related industries. The recognition of open and partially closed air circulation systems in traditional dust collection circuit designs further contributes to refining and optimizing dust removal processes for enhanced environmental protection.

An on-site inspection system for explosives in a container using dust collection through a vent cover and ion mobility spectrometric detection.

Rapid and accurate cargo-inspection systems are required for shipping containers, because illegal and hazardous items, such as explosives and drugs, can be easily concealed in large containers. Dust in a container is suspended in the air and deposited in vent covers. The vapor and particulate matter of explosives can be adsorbed onto the dust. In this study, a model vent cover system was developed for a container and explosive-adsorbed dust specimens were modeled using organic [cotton fabric (CF) and sawdust (SD)] and inorganic substances [clay (CL) and silica (SL)]. The dust was placed in the inner part of the vent cover and collected through the vent holes, and the explosive components present in the dust were rapidly analyzed using ion mobility spectrometry (IMS). Three explosives, namely 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and pentaerythritol tetranitrate (PETN), were investigated along with two different collection filters, namely poly(tetrafluoroethylene) (PTFE) and lens cleansing paper (LCP). The dust collection rate decreased when the dust was located away from the vent holes. The order of the dust collection rate was SD > CF > SL > CL. The limit of detection (LOD) of TNT was considerably lower than those of RDX and PETN. The LODs of the explosives when using the LCP collection filter were lower than those when using the PTFE filter. The LOD order was CF < SD < CL < SL for the PTFE collection filter and CL < SL < CF < SD for the LCP filter. The technique developed in this study can be employed as a rapid and accurate cargo inspection system for shipping containers.

IMPROVEMENT OF THE CLEANING SYSTEM OF OIL GAS FLOWS USING AN AERODYNAMIC INSERT

Air pollution is becoming a problem due to inefficient technological processes that accompany the mechanical processing of solid materials in various industries, including metalworking and woodworking, coal enrichment, coal burning in thermal power plants, metallurgy and construction materials industries. The problem is relevant for cement factories, since some of them use outdated equipment. Fine dust in this context becomes particularly important because the particle size of this dust affects the quality and grade of the concrete produced. Given the specifics of cement production and the goals of our research, which are to effectively collect small particles, it is important to note that wet cement production methods are not the best solution. The ideal solution for the problem of cleaning dust and gas flows in the cement industry is the use of a two-stage dust collection system, which combines an advanced cyclone and a bag filter. The system's periodic shaking mechanism allows for effective capture and control of fine dust particles, ensuring high quality cement production and reducing environmental impact. The combination of a cyclone, an acoustic coalescer and a block of bag filters, which is equipped with a periodic cleaning mechanism, as well as the addition of a system for collecting fine dust using a collector funnel, will split the collected dust into two fractions: fine (a = 10−5 to 10−7m) and coarse (a &gt; 10-4m). The first fraction can be used to produce high-quality cement of high cost in the cement industry. The second fraction returns to the main technological process at its finishing stage.

The Impact of Power Quality on VFD Application in Motor Fan Dust Collector

The technology to control the motor speed according to load requirements is variable frequency drive (VFD). The motor fan dust collector operates using a VFD to reduce the speed during idle smelting conditions. In addition to energy efficiency, the power quality of the electrical energy system is important to consider. Nonlinear loads from VFDs cause harmonics in the industry that affect electrical power. Power quality measurement and analysis to determine the harmonic and unbalance values of voltage and current are important for improving power quality. This paper discusses the effect of VFDs on power quality, as a real case study, data from existing VFDs in the steel industry are taken to analyze power quality. A large current harmonic of 45% occurs when the VFD decrease the motor speed during idle smelting operation and drops to 5% when the motor speed returns to full speed during smelting operation on. The average maximum current unbalance value is 10.8% and the voltage unbalance is 0.36%, which is still below the standard maximum limit whether the motor is at full or low speed.

Testing the operation of the developed swirling scrubber

The article presents a study on the intensification of gas purification from solid particles using the hydrodynamic effect of centrifugal forces. An effective vortex dust collector design has been developed and is being implemented in production for cleaning from harmful impurities. The results of tests conducted at the facility to determine the efficiency of dust collection in a vortex apparatus with a tangential inlet of gas and liquid flow at various operating parameters are presented. The study found that the efficiency of the device increases with an increase in dust concentration. In the vortex apparatus, the efficiency of dust collection increases significantly with an increase in the axial flow velocity, which is characterized by an increase in centrifugal force and separation factor. The optimal operating modes of the developed vortex apparatus have been established in terms of the efficiency of dust collection.

Analysis and optimization of industrial engineering and management operating environment based on human factors engineering

Abstract In today’s society, which attaches great importance to humanization, human factors engineering has become a hot topic of research in industrial engineering to improve enterprises and factory sites. This paper aims to optimize the efficiency of industrial engineering by adopting industrial engineering (IE) methods, combing the methodological study of the production process and applying job measurement methods to improve engineering efficiency. The study results show that after the improvement of two-handed operation, the left and right-handed operation time is reduced to 25.78 seconds, which is 31.8% lower compared to the pre-improvement period. The overall process was optimized to minimize the bottleneck beat time from 1.379 seconds/piece to 1.333 seconds/piece, and the maximum production capacity increased from 51,308 pieces/day to 52,204 pieces/day. In addition, labor requirements in the industrial workflow were reduced by 20%, from 610 to 486 people. As for the improvement of the operating environment, the noise levels were kept below 73.9 dB(A), especially for the dust collector, which was significantly reduced from 86.4 dB(A) to 72.9 dB(A). This optimization of industrial engineering and its operating environment by applying human factors engineering principles ensures the production quality. It achieves the maximum output with minimum resource input, laying a solid foundation for the continuous optimization of industrial engineering.

Quality Improvement Effect of Waste Concrete Fine Powder by Applying Exfoliation Technology

Since the main components of waste concrete fine powder generated in the process of converting waste concrete into recycled aggregate are essentially the same as the main ingredients of cement-clinker, it is possible to use it as a raw material for cement. In addition, because waste concrete fine powder is a decarbonated salt, using it as a raw material for cement clinker is a very important carbon-neutral technology that can be expected to reduce process-derived carbon emission generated during cement manufacturing. However, waste concrete fine powder has a low calcium oxide content of around 10%, so its usability as a clinker raw material is very low. In order to use waste concrete fine powder as a raw material for clinker, the calcium oxide content must be increased to more than 35%. Separating the hardened cement paste from the aggregate while reducing the crushing ration of the aggregate during the crushing process is an important means of increasing the calcium oxide content of waste concrete fine powder. Accordingly, this study conducted an experimental study to increase the calcium oxide content of waste concrete fine powder using exfoliation grinding technology. The characteristics of waste concrete fine powder recovered through the exfoliation grinding technology were examined for waste concrete collected from a domestic intermediate processing company, model concrete manufactured in a laboratory, and commercially available cement bricks. As a result of the experiment, it was possible to recover the waste concrete fine powder with a higher CaO content by applying exfoliation grinding technology, compared to the dust collection fine powder that could be recovered through the crushing and grinding process.

A Study on Failure Rate, Reliability, and Collection Efficiency Trend of Bag Filters in a Cement Plant

This thesis presents a comprehensive study on the failure rate, reliability, and collection efficiency trends of bag filters in a cement plant over 15 years. Bag filters are vital pollution control equipment used in various industries, including cement plants, to maintain environmental compliance. Understanding their performance and failure patterns is crucial to ensure efficient and reliable operation while adhering to stringent pollution control standards. The research findings reveal that the failure rate trend of bag filters closely follows the bathtub curve, with an initial high failure rate, a period of lower failures, and a subsequent increase in failures as the equipment nears the end of its life cycle. Reliability trends align with Madhab's Hat curve, exhibiting higher reliability during the first 10 to 12 years of operation, followed by a decline in reliability. The collection efficiency of bag filters declines as the equipment ages, with the efficiency decreasing from 99.998% in the early years to 95.05% in the 15th year. This emphasizes the importance of maintenance and retrofitting for older dust collection equipment to maintain high collection efficiency. The study concludes that the typical life span of bag filters ranges from 10 to 15 years, after which major maintenance interventions are necessary to minimize failure rates. The research provides valuable insights for maintenance engineers, design engineers, and reliability engineers, enabling them to improve the performance of pollution control equipment, such as bag filters, reverse air bag houses (RABH), and electrostatic precipitators (ESP), to meet the pollution control standards set by regulatory authorities.

Performance of the porous media model for simulating flow through an electrostatic precipitator

An electrostatic precipitator (ESP), which filters the fine particles present in the exhaust gas generated from a power plant, has a better particle-collection efficiency when there exists a uniform flow in the dust collection chamber. However, most former investigations examined the flow distribution via numerical approaches that modeled the perforated plates within the inlet diffuser as porous media, which have not been adequately validated. Therefore, the aim of this study was to examine the performance of the porous media model for simulating the flow through perforated plates of an ESP diffuser by numerical simulation and experiment. Simulation results using the porous media model were compared with those obtained with a fully resolved mesh precisely describing the complete geometry of the entire perforated plate. The results obtained with both these methods were consistent with experimental results obtained upstream of the inlet diffuser, but the porous media model could not accurately simulate the flow distribution across the perforated plates. Overall, this model failed to predict the deflection of incoming flow on the solid bars and the wakes behind the bars, and could not reflect the vena contracta phenomenon occurring within the holes of the plate. As a result, the simulated flow distribution at the entrance of the main dust-collection chamber differed from that observed in the experiment, which resulted in poor prediction of the flow field inside the chamber. Therefore, this porous media model requires further improvement for wide-scale adoption in industrial practical applications, e.g., ESP for flue gas treatment in power plants.

Prospective healthcare-associated links in transmission of nontuberculous mycobacteria among people with cystic fibrosis (pHALT NTM) study: Rationale and study design.

Healthcare-associated acquisition and transmission of nontuberculous mycobacteria (NTM) among people with cystic fibrosis (pwCF) has been described, and remains a concern for both patients and providers. This report describes the design of a prospective observational study utilizing the standardized epidemiologic investigation toolkit for healthcare-associated links in transmission of NTM among pwCF. This is a parallel multi-site study of pwCF who have infections with respiratory NTM isolates and receive healthcare within a common CF Care Center. Participants have a history of one or more NTM positive airway cultures and have been identified as having NTM infections suggestive of a possible outbreak within a single Center, based on NTM isolate genomic analysis. Participants are enrolled in the study over a 3-year period. Primary endpoints are identification of shared healthcare-associated source(s) among pwCF in a Center, identification of healthcare environmental dust and water biofilm NTM isolates that are genetically highly-related to respiratory isolates, and identification of common home of residence watersheds among pwCF infected with clustered isolates. Secondary endpoints include characterization of healthcare-associated transmission and/or acquisition modes and settings as well as description of incidence and prevalence of healthcare-associated environmental NTM species/subspecies by geographical region. We hypothesize that genetically highly-related isolates of NTM among pwCF cared for at the same Center may arise from healthcare sources including patient-to-patient transmission and/or acquisition from health-care environmental dust and/or water biofilms. This study design utilizes a published, standardized, evidence-based epidemiologic toolkit to facilitate confidential, independent healthcare-associated NTM outbreak investigations within CF Care Centers. This study will facilitate real-time, rapid detection and mitigation of healthcare-associated NTM outbreaks to reduce NTM risk, inform infection prevention and control guidelines, and characterize the prevalence and origin of NTM outbreaks from healthcare-associated patient-to-patient transmission and/or environmental acquisition. This study will systematically characterize human disease causing NTM isolates from serial collection of healthcare environmental dust and water biofilms and define the most common healthcare environmental sources harboring NTM biofilms. ClinicalTrials.gov NCT05686837.

Fugitive Emission Characteristics of Fume and Dust from Short-Process Electric Furnace Tap Hole and Optimization of Dust Hood

Due to the advantages of a short cycle, low investment and low energy consumption per ton of steel, short-process electric furnace steelmaking is about to welcome a golden period of rapid development in China. During the operation of the electric furnace, a large amount of smoke and dust is generated. Most studies focus on organized emissions, and the impact of unorganized emissions in workshops on the environment cannot be ignored. This paper evaluates the thermal environment in the electric furnace steelmaking workshop based on the analytic hierarchy process and obtains the influence weight of the fugitive emission location. The mass concentration of dust at each measuring point increased by 1.17 mg/m3 on average, and the concentration of unorganized emission dust near the outlet was 23.572 mg/m3. The numerical simulation calculation model is established by the CFD method, a fixed initial jet velocity is set, the initial velocity of the ladle soot plume is changed, and the inclination angle, arrangement height and dust removal air volume of the dust hood are respectively adjusted in different tapping periods. The impact of simulation on the efficiency of dust collection for different dust removal hood configurations was investigated, considering variations in inclination angle, arrangement height and dust removal airflow. The optimal structural parameters for the dust removal hood were determined to be an inclination angle of 60° and an arrangement height of 2.4 m, and an optimal dust removal airflow was determined to be 110,000 m3/h. This study provides a theoretical foundation for engineering practice.