Enhancing Dust Removal Efficiency in Electrostatic Precipitators with Homogeneous Flow

The removal of industrial dust is mainly realized by various dust removal equipment. The electrostatic dust remover can remove more than 99.5% of the dust particles of various diameters, but the dust removal effect of particulate particles is not significant. Among them, for the finer particles in the dust, the dust removal effect is poor. After measurement, the efficiency of electrostatic dust removal is 80%-85% for fine particles with a particle diameter of 10-1μm [1]. With our higher demand for particulate emissions, improving the removal of industrial fine particulates is imminent. In the process of dust generation, dust particles collide or come into contact through various paths, thereby combining to generate larger particles, and this process becomes the condensation of dust. The dust agglomeration technology is generally used as a pre-treatment of the flue gas in the field of flue gas dust removal. By enriching the fine particles, the fine particles become larger, and then the dust is removed through the dust removal device.

The wet electrostatic precipitator (WESP) overcomes the shortcomings of traditional electrostatic precipitators, such as dust re-entrainment and back corona. It can effectively remove high-specific-resistivity dust, with a good removal effect on PM2.5. It is proposed to adopt chemical agglomeration and humidification agglomeration technology in the wet electrostatic precipitators to achieve ultra-low dust emissions from coal-fired power plants. The results show that the addition of chemical agglomerates, surfactants, and water vapor all affect the dust diameter of coal-fired power plants. After adding sesbania gum (SG), the D50 of dust particles increases from 28.29 μm to 48.22 μm. And the D50 of dust particles is 36.46 μm when spraying 3.6 kg/h water vapor only. With the cooperation of chemical agglomeration agents and water vapor, the dust agglomeration effect and removal efficiency can be further improved. When 10 mg/L SG is synergistically combined with 2.9 kg/h water vapor, the D50 is 64.75 μm, and the dust removal efficiency reaches 97.88%. On this basis, by adding 5 mg/L of Hexadecyltrimethylammonium bromide (CTAB), the D50 is 83.06 μm, and the dust removal efficiency increases to 98.62%. The synergistic effect of chemical agglomeration and humidification agglomeration promotes the aggregation of dust from coal-fired power plants. It can improve the removal efficiency of WESP for fine particulate matter but has little impact on the operation of existing equipment. The synergistic effects of multiple agglomeration technologies are also the direction for future research on the removal efficiency of fine particulate matter.

The standards of the environmental protection which have critically become tougher in the last decades demand to look for constant ways of improving the systems of technological gases purification in industry. Currently acute problem of thin clearing of large amounts of gases from the dispersed particles. Dedusting is carried out with the help of special devices that can be integrated into the main equipment or placed outside the process. To clean the vented gases used the apparatus of different principle and construction: scrubbers, cyclones, dust-collecting chambers, electrostatic precipitators and others. According to the method of separating dust from the gas following dust control methods: a mechanical method (paleoscience camera, inertial dry dust collection, wet dust removal, filtration) physical method (electrostatic precipitators); physical-chemical method (absorption, adsorption, chemisorption, catalyzing the thermal method). When assessing the efficiency of the dust collectors take note: the overall efficiency of dust removal, or the amount of dust caught in the dust collector, in relation to the amount of dust contained in the in the dust-free gas; fractional efficiency, which determines the completeness of capture of the particles of a certain size; the residual dust content in the gas when leaving the scrubber; the distribution of residue of dust in the gas to particle size or velocity. Under the effective capture know capture efficiency of over 95 %. In the article we deal with the methods of firm particles and dust removal from technological gas during the use of the plant reactivation operation of black sulphuric acid. There is the short characteristic of an electrostatic precipitator. Also we consider the problems standing in a GTS of the industrial enterprises, which lead to decrease in overall performance of the dust and gas purificating equipment. Possible ways of these problems solution are suggested.

To address the issue of excessive soil content in straw feed after harvesting by a straw feed harvester, this study designed a dust removal apparatus. Its optimal operating parameters were determined through a combination of numerical simulations and field experiments. Using dust removal efficiency as the evaluation criterion, the Box-Behnken experiment and variance analysis revealed that the factors influencing the dust removal efficiency of the apparatus, in order of significance, were the number of dust removal drums, the aperture of the dust sieve, and the rotational speed of the dust removal drums. The optimal parameter combination consisted of 5 dust removal drums, a dust sieve aperture of 5 mm, and a drum rotational speed of 370 r/min. The dust removal efficiency obtained from numerical simulation using these optimal parameters was 94.1%, while the field verification test yielded an efficiency of 93.5%, with a relative error of 0.64% between the two results, confirming the accuracy of the numerical simulation parameters. The optimized dust removal apparatus significantly improves the quality of straw fodder by reducing dust content, which not only enhances the efficiency of straw recycling but also supports sustainable agricultural practices, promoting both mechanization and green development in the industry.

With their advantages of high dust removal efficiency and low drag characteristics, hybrid wet-filter precipitators have great potential for dust control in coal mines, but the underlying mechanisms are not well understood. In this study, to help fill this knowledge gap, a hybrid wet-filter precipitator consisting of a 40-layer metal filter and a defogger device is designed and a prototype is constructed. Experiments are conducted to investigate its drag characteristics under wind velocities from 0.85 to 5.68 m/s and its dust removal performance under wind velocities of 2 and 4 m/s. On the basis of results with the initial design, which show that the dust removal efficiency does not meet the target value of 99%, two rounds of improvement are implemented to enhance the dust removal efficiency. Results show that the defogger device contributes ∼80% of the total drag. The drag from the metal filters is found to increase by over 80% on average after sampling, since some of dust particles are left on the filters, decreasing their porosity. The installation of two-layer air filters on the leeside of the metal filter unit is found to increase the efficiency to 99.89% and 99.80% under wind velocities of 2 and 4 m/s, respectively, although this is at the cost of increased drags. Additionally, it is found that the replacement of the defogger by a 20-layer metal filter is not desirable, since this increases the downstream air humidity to more than 100%, which can cause damage to the centrifugal blower system. Therefore, new designs for the defogger device need to be examined in future studies.

Air pollution, especially particulate pollution, has become a serious issue with the acceleration of industrialization. Wet scrubbers are widely used in industries for air purification due to their advantages. However, most scrubber studies have predominantly focused on fillers and injection methods, neglecting the systematic investigation of the tower rotation angle and particulate physical properties on dust removal performance. In this study, the geometric model of the scrubber was established based on the actual equipment in a refinery. Computational fluid dynamics (CFD) was employed, along with the fluid volume (VOF) and discrete phase (DPM) models, to solve the relevant equations. The grid independence and model were verified. Particles with different diameters were injected into the scrubber with different angle steel tray arrangements (α = 15°, 30°, 45°), and the dust removal efficiency was calculated. The results show that the dust removal efficiency generally increases with the increase of particle diameter. When the particle diameter is 200–300 μm, the efficiency is consistent. Before 350 μm, the highest efficiency is achieved at α = 30°, and the lowest at α = 15°; above 350 μm, the highest is at α = 30°, and the lowest at α = 45°. The tray angle affects air distribution uniformity, and α = 45° shows more uniform air distribution. This research provides a scientific basis for optimizing scrubber design and operation. It systematically explores the influence of tray angle and particle diameter on dust removal efficiency, filling the research gap in this area and guiding the improvement of scrubber technology in industrial applications.

Almost all coal based thermal power plants (CTPP) in India use electrostatic precipitator (ESP) for reduction of particulate matter (PM) in flue gas generated due to the combustion of Indian coal. This coal is characterized by high ash content, low calorific value and low sulfur content resulting in the generation of a very large amount of highly electrically‐resistive fly‐ash; thereby requiring a very large size ESP to minimize the fly‐ash emissions. However, the flue‐gas particle size distribution analysis showed that 60% of the particles are above 15 μm size, which can be conveniently removed using a low‐cost inertial separator such as a cyclone separator. It is proposed that a cyclone be used, as a pre‐cleaner to ESP so that the large size fraction of fly‐ash can be removed in the pre‐cleaning and the remaining flue‐gas entering the ESP will then contain only small size particles with low dust loading, thereby requiring a small ESP, and improving overall efficiency of dust removal. A low efficiency (65%), high throughput cyclone is considered for pre‐cleaning flue gas and the ESP is designed for removal of the remaining 35% fly‐ ash from the flue gas. It is observed that with 100% dust load, the ESP requires six fields per pass, whereas with cyclone as a pre‐cleaner, it requires only five fields per pass. Introducing cyclone into the flue gas path results in additional head loss, which needs to be overcome by providing additional power to induced draft (ID) fan. The permissible head loss due to the cyclone is estimated by comparing the power requirement in the bag filter control unit and cyclone‐ESP combined unit. It is estimated that a head loss of 10 cm of water can be permitted across the cyclone so as to design the same for 65% efficiency.

Asphalt hot regeneration pavement maintenance vehicle is a type of in situ heating waste asphalt special vehicle equipment for mix and regeneration of aged asphalt. When waste asphalt mixture is heated and melted, a lot of organic fumes are typically produced, along with dust from the mixing process. Because of the complex composition of the exhaust gases produced by asphalt hot regeneration pavement maintenance vehicles, it can be difficult to purify and remove them using a single method. In order to effectively purify exhaust gas with complicated compositions, a multistage combined treatment dust removal system structure is presented that includes cyclone sections, spray sections, and adsorption sections. With an emphasis on the cyclone section structure with the dust-gas separation function, computational fluid dynamics (CFD) is used to analyze the internal flow field characteristics, turbulence intensity, tangential velocity, and velocity field vector characteristics. The results reveal that the more symmetrical the distribution of tangential velocity field and static pressure field is, the greater the cyclone dust collector’s dust removal efficiency is, the more stable the flow field is, and the lower the turbulence intensity is. Furthermore, the center cyclone’s growing speed is adversely connected with dust removal effectiveness. As a result, an antiventuri cyclone dust collector with a scrambling column was designed. When the inlet air speed is 6 m/s, the dust removal efficiency of the improved device is 97.0%, which is 5.1% higher than that of the original device, and when the inlet air speed is 8 m/s, the dust removal efficiency of the improved device is 97.3%, which is 4.16% higher than that of the original device. With the increase of the inlet air speed, the difference between them keeps decreasing.

Unmanned probes, mainly powered by solar panels, are effective tools for exploiting space resources to expand the human habitat. However, it remains a great challenge for the unmanned probes to actively repel multiscale dust particles in space. Inspired by the synergistic antifouling mechanism of fly wings and legs, a biomimetic dynamic antifouling surface (BDAS) was prepared based on a combination of self-assembly and template inversion. BDAS consists of flexible and controllable cilia with ultrahigh aspect ratio. Under the control of an external magnetic field, BDAS can perform three modes of dust removal tasks. The synergism of these three modes ensures that BDAS provides superior dust removal against multiscale dust particles in complex environments. Compared to conventional passive dust removal surfaces, the dust removal efficiency is increased by 941%. As proof of concept, BDAS was installed on a lunar probe and achieved effective removal of simulated lunar soil (up to 1158%).

Experimental study on the atomization characteristics and dust removal efficiency of a fan-shaped nozzle for purifying working environment

In order to reduce the dust pollution produced by metal mine tunneling after blasting operations, as well as to solve the optimization problem of hybrid ventilation and dust removal parameters, to enhance the working conditions at the construction site and safeguard the health of workers, a study was conducted focusing on a metal mine in Yunnan. The study developed a hybrid ventilation model for roadway blasting and tunneling, using Fluent software to examine airflow distribution, dust dispersion, and sedimentation behavior in the tunnel. The study also examined how varying distances between air inlets and outlets, as well as different air volumes, affect dust distribution under hybrid ventilation. Additionally, gray correlation analysis was used to examine the connection between the time needed to lower dust concentration to safe levels and the relevant influencing factors. Findings indicate that with hybrid ventilation, the airflow in the roadway is segmented into three zones: vortex, transition, and stable areas, and the average wind speed of the roadway section will show a trend of increasing and then decreasing, and then decreasing to about 0.22 m/s and gradually stabilizing. Before ventilation 1 min, dust diffusion speed is faster, after ventilation 1 min, dust diffusion speed is slower. Dust with particle size above 35 μm from blasting will be settled closer to the face, while dust particles smaller than 35 μm are carried away by the airflow or extracted from the tunnel due to the influence of the wind. Through comparative analysis, it can be seen that the air outlet of the press-in type wind pipe is 10 m away from the face of the excavation, when the air inlet of the exhaust-type wind pipe is positioned 5 meters from the excavation face, the ventilation and dust removal efficiency is significantly improved. Additionally, a pressure-to-extraction ratio (m) of 0.8 to 1 yields better dust control results. Their respective gray correlation coefficients are 0.732, 0.648, 0.630, and 0.621.To enhance the post-blasting environment in the roadway, optimizing hybrid ventilation and dust removal parameters should prioritize adjusting the air volume at the outlet of the press-in type wind pipe to improve dust removal efficiency.

In China, the particulate matter (PM) pollution has caused serious environmental and health concerns, and it is still a huge challenge to control PM pollution. In order to alleviate the hazardous of PM pollution, the dust collector is widely used to separate PM from gas streams. However, after a period of operating, whether the removal efficiency of the dust collector still meet the requirement of the emission limit is unknown. The dust removal efficiency test device was designed and its performance was investigated in this study. The flow field simulation result showed that the test device had a good uniformity, which was consistent with previous measured result. Moreover, it found that the linear relationship between the light scattering concentration and the filtration membrane weighed concentration was y=2.285x, and when the inlet wind speed was about 0.5 m/s, the dust removal efficiency of the dust collector was more than 99.73%, the outlet dust concentration was (0.03-0.04) mg/m3, which was below the emission limit of 15 mg/m3. When the inlet dust concentration was about 200 mg/m3 and the inlet wind speed was (0.25-0.75) m/s, the dust removal efficiency was more than 99.98%. To sum up, the designed test device can be used to estimate the dust removal efficiency of various types of dust collectors.

Dust removal efficiency of high pressure atomization in underground coal mine

A special conical diffuser was presented and fixed on the top of the filter cartridge to improve the flow field. The existence of the diffuser can disperse the jet flow from the nozzle, and the high-speed airflow can act on more areas of the filter cartridge, including the top area of the filter cartridge. To improve the cleaning efficiency, the present study is aimed at optimizing the structure of the filter cartridge. The DPM model was used to simulate the dust dispersion process and the falling dust sedimentation from the filter under the action of the pulsed airflow. To validate the established model, the pressure values at the monitoring points were analyzed and compared with the related experimental results. It is found that the pressure values are consistent with the experimental results. Moreover, the installation distance and the size of the diffuser were studied and their influence on the dust distribution on the surface of the filter cartridge. It is found that the dust removal effect is relatively better when the installation distance is 90mm and the size radius is 25mm. The maximum dust concentration can be reduced by 15mg/m3. The present research results can provide theoretical guidance for the cleaning process of the filter cartridge and finally improve the dust-removal efficiency of the dust collector.

In order to solve the problem of dust pollution in the comprehensive excavation face, the matching relationship between the long forced ventilation and the short dust removal sucking was grasped, and reasonable control dust removal process parameters were obtained. In this paper, the 3-1 coal return air roadway in Hongliulin Coal Mine is taken as the research object. By establishing the working face physical model and adopting the numerical simulation method, the different axial diameter outward air ratio is compared and analyzed. Combined with the field measurement, it is verified to obtain the optimal range of dust axial diameter outward air ratio. The application results show that a swirl air curtain is formed along the sidewall of the roadway after the adoption of the attached air duct, and a dust control air curtain pointing to the head is gradually formed after entering the section of the roadheader. When the axial diameter outward wind ratio is 1:2∼1:3, the breathing dust at the driver's position can be controlled within 17 mg/m3, and the dust removal efficiency can be increased to more than 93%, which greatly improves the working environment and ensures the occupational health and safety of workers.