High Dust Removal Research Articles

Study on the development and dust suppression performance of a novel composite dust suppressant for metal mines

The significant amount of dust generated during the metal mining process affects both personnel health and the environment. Some mines, such as magnetite mines, produce magnetic dust that is easily adsorbed onto equipment, causing equipment failure and other issues. To solve such problems, a composite dust suppressant was synthesized in this study using carboxymethyl cellulose sodium (CMC-Na), primary alcohol ethoxylate (AEO), and polyethylene glycol (PEG) as raw materials. Firstly, the optimal ratio was determined according to the response surface method. Subsequently, the performance and dust reduction efficiency of the suppressant was evaluated. According to the optimal formulation ratio, the dust suppressant exhibited a viscosity of 34.5 mPa·s and a surface tension of 28.46 mN/m. The wind erosion resistance, compressive strength, and water retention of the dust samples were improved following the dust suppressant application. The loss rates were only 0.025% and 0.9% at wind speeds of 3.5 m/s and 20 m/s, respectively. Simulation experiments indicated that the suppressant achieved a dust suppression efficiency of 82.7% for respirable dust and 90.91% for total dust. These results demonstrate that the suppressant possesses high dust removal efficiency and effective dust suppression, aligning with the application requirements of metal mines and contributing to the mitigation of dust issues during mining operations.

Effect of horizontal cartridges on the uniformity of flow field distribution inside a cartridge filter

Cartridge filters are widely utilized in industrial dust removal due to their advantages of high dust removal efficiency, compact size relative to bag filters, and the capacity to reuse collected dust. However, the conventional upright installation of the cartridges' front row directly faces the air inlet, which is directly impacted by the high-velocity dirt airflow and is often broken. This setup also disrupts airflow distribution, leading to uneven mass flow distribution and localized high velocity. To address these challenges, this study proposes horizontally installing the cartridges, by utilizing the bottom cone to buffer the airflow. This not only resolves issues of localized cartridge breakage but also promotes uniform airflow distribution, thereby prolonging filter service life. Computational Fluid Dynamics (CFD) is employed to simulate the changes in the flow field within the physical model, using finite element iterative calculations. This approach reduces experimental costs while providing precise data. Therefore, numerical simulation is used to verify the effectiveness of horizontal cartridges in improving the uniformity of the flow field distribution in the cartridge filter. The results showed that the horizontal cartridge filter improved the mass flow distribution uniformity by 54.9%, the peak velocity difference was reduced by 69.63%, and the maximum velocity was reduced by 68.42% compared to the upright cartridge filter. Horizontal cartridges have a more uniform flow field distribution, effectively avoiding problems such as abrasion and rupture of the filter media caused by excessive local air velocity.

Self-Powered Autonomous Electrostatic Dust Removal for Solar Panels by an Electret Generator.

Solar panels often suffer from dust accumulation, significantly reducing their output, especially in desert regions where many of the world's largest solar plants are located. Here, an autonomous dust removal system for solar panels, powered by a wind-driven rotary electret generator is proposed. The generator applies a high voltage between one solar panel's output electrode and an upper mesh electrode to generate a strong electrostatic field. It is discovered that dust particles on the insulative glass cover of the panel can be charged under the high electrical field, assisted by adsorbed water, even in low-humidity environments. The charged particles are subsequently repelled from the solar panel with the significant Coulomb force. Two panels covered with sand dust are cleaned in only 6.6min by a 15cm diameter rotary electret generator at 1.6ms-1 wind speed. Experimental results manifest that the system can work effectively in a wide range of environmental conditions, and doesn't impact the panel performance for long-term operation. This autonomous system, with its high dust removal efficiency, simplicity, and low cost, holds great potential in practical applications.

Optimization study on the application of induced dust suppression cover in primary crushing station of open-pit mine

Aiming at the problems of large dust production, high dust removal cost and poor dust suppression effect of primary crushing station in open-pit mine, the new type dry device-dust suppression cover was put forward, which induced dust to complete the circular clean movement with closed loop eddy current inside the enclosure by means of pressure balance and closed loop flow. After field application, it was found that the dust suppression effect of the device was not ideal and it was seriously affected by wind. By means of fluid dynamics simulation, the structure of the device was optimized for design and engineering application. The simulation results showed that the optimized device enhanced the overall upward movement trend of the internal air flow, weakened the transverse movement trend of air flow, and blocked the interference of ambient wind, which can effectively inhibit the driving effect of overdraft on dust dispersion. The monitoring results showed that the dust concentration around the optimized device was significantly lower than that before optimization, and the lowest concentration can reach 0.33 mg/m3, which met the requirements of environmental protection emission.

Pilot scale test of wet dust removal by high gravity intensification technology in fertilizer plant

Industrial dust can cause serious harm to the environment and human body. High gravity wet dust removal is a new type of high-efficiency dust removal technology, with the advantages of high dust removal efficiency, low economic cost, convenient operation and maintenance. In this work, a cross-flow rotating packed bed was used as the wet dust removal equipment, and a pilot scale dust removal experiment platform was built at the production site of the enterprise. The dust removal effect of high gravity wet dust removal technology on granulation waste gas in actual production was also studied. The second compound fertilizer plant of TianJi Group emitted dust-containing exhaust gas with a dust content of about 2500 mg/m3 during the production process. Different key parameters including high gravity factor, liquid flow rate and liquid circulation time were investigated on dust removal efficiency and fractional efficiency, and the mechanism of high gravity wet dust removal was analyzed. The obtained results suggested that under the conditions of gas flow rate of 400 m3/h, liquid flow rate of 0.5 m3/h and high gravity factor of 205.61, the dust removal rate was as high as 99.88% with an outlet concentration of less than 10 mg/Nm3. Under three hours of clean water absorption cycle, the dust concentration after purification could still be reduced to less than 10 mg/Nm3, and the dust removal efficiency could reach more than 99%. The relationship between the fractional efficiency of the cross-flow rotating packed bed and the dust particle size was nonlinearly fitted, which showed a good fit. High gravity wet dust removal technology increased the inertial force of particles in the gas through rotation, while atomizing the liquid into a micro liquid. The scales of the two were matched, and the inertial collision was effectively enhanced to improve the dust capture effect. Therefore, high gravity wet dust removal technology can effectively control industrial dust emissions and has a strong potential for industrial applications.

Catalytic filter for the removal of dust and NOx at low temperature

The catalytic filter was fabricated by supporting selective catalytic reduction (SCR) catalyst on the low-density ceramic (LDC) for the removal of dust and nitrogen oxides (NOx) in the flue gases at relative low temperature. MnOx–ZrO2/TiO2 catalyst was selected as SCR catalyst. The NOx and dust removal efficiency, filter resistance, regeneration performance and anti-sulfur performance were investigated. The result showed that the NOx removal efficiency at 180°C reached 98.4% (1 m/min filtration velocity) for 6 wt% MnOx–ZrO2/TiO2 catalytic filter with Mn/Zr molar ratio of 2. Furthermore, MnOx–ZrO2/TiO2 catalytic filter performed good anti-sulfur performance. In the presence of 10 vol% water vapor and 100 ppm SO2 at 180 °C, the NOx removal efficiency for MnOx–ZrO2/TiO2 catalytic filter could retain up to 83.2% and it could recover to 91.8% when the water vapor and SO2 were cut off. MnOx–ZrO2/TiO2 catalytic filter showed the high dust removal efficiency of 99.99% and the low filter resistance of less than 200 Pa. The filter resistance of MnOx–ZrO2 /TiO2 catalytic filter could maintain 235.7 Pa after 200 times pulse blowback. The result illustrated that MnOx–ZrO2/TiO2 catalytic filter showed good regeneration performance.

Experimental study on production and emission characteristics of PM2.5 from industrial fluidized bed boilers

Particle size distributions, concentrations, morphological characteristics, and elemental compositions of eight fluidized bed boilers with different capacities and different dust collectors were determined experimentally. The PM2.5 particle concentration and mass concentration were monitored in real-time before and after the boiler dust collector by electric low pressure impactor, and the physical and chemical properties of PM2.5 were analyzed by membrane sampling. We found that the PM2.5 particle concentration produced by industrial fluidized bed boilers displayed bimodal distributions, peaking at 0.2 ?m and 0.76 ?m, the formed mechanism of these two parts particles is vaporization-condensation of mineral matter and residual ash particles and the adsorbent wear or tear. Mass concentration exhibits a single peak characteristic with a peak at 0.12 ?m. The removal efficiency for PM2.5 of dust collectors varies with different dust removal mechanisms. The electrostatic precipitator and bag filter have high dust removal efficiency, and the water film dust collector has low dust removal efficiency. The normal operation of the bag filter has a great influence on the dust removal efficiency. The physical and chemical properties of PM2.5 showed that the single-particle morphology was mainly composed of irregular particles, containing a small amount of solid spherical particles and more agglomerates. The content of Si and Al in PM2.5 elemental analysis is the highest, which decreases after a dust collector. Some fluidized bed boilers use desulfurization in the furnace, which has great influence on the mass concentration of Ca and S elements, and the lowest Hg content in trace elements, about a few ppm. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI200901242E">10.2298/TSCI200901242E</a><u></b></font>

Study and application on foam-water mist integrated dust control technology in fully mechanized excavation face

The dust produced by the roadheader during the tunneling process will change with time. Water mist can achieve high dust removal efficiency when the dust production is relatively small, and foam technology can realize high efficiency in the treatment of large dust production. It is necessary to choose water mist and foam dust removal technology freely according to the dust yield. Therefore, this paper puts forward the research of foam and water mist integrated dust removal technology. According to the characteristics of dust production in excavating operation, a new type of flat fan foam nozzle is put forward. Through the internal channel of gradual change, the foam jet is transformed from a cylindrical fluid to a flat one and diffuses at a certain angle. And the outlet area of the nozzle is determined to be 120mm2, with the nozzle’s uniform angle of 6° and the compression angle of 25° as the final angle of the nozzle through simulation and field experiments. Combined with the characteristics of water mist, the function of water atomization is added to foam technology. On the basis of foam nozzle, 10 symmetrical water inlet channels with a diameter of 1.5mm are uniformly arranged on the side wall, and the original foam inlet is changed into air inlet. Through multi-stage atomization of air and water, water mist with fine atomization size and uniform distribution can be produced. Relevant atomization operation conditions are tested through experiments. The test results show that the new technology could greatly reduce the cost, achieve the goal of efficient dust removal, and guarantee the working environment and the health of the workers.

Preparation and properties of a rock dust suppressant for a copper mine

Dust lifting on copper mine transportation roads likely causes mechanical damage, environmental pollution, and human health hazards. Existing dust suppressants have the disadvantages of low dust suppression efficiencies, environmental pollution, and low pertinence. Therefore, an environmentally friendly and high-efficiency composite rock dust-moisturizing dust suppressant was developed in this study to suppress the dust on copper mine transportation pavements. We used sodium carboxymethyl cellulose, acrylamide, sodium silicate, and fatty alcohol polyoxyethylene ether as raw materials and determined the best ratio of the dust sample using evaporation resistance, hygroscopicity, permeability, pH, and solution viscosity analyses. The results show that the optimum composition of the dust suppressant is 0.55% carboxymethyl cellulose sodium-grafted acrylamide, 10% sodium silicate concentration, and 0.2% fatty alcohol polyoxyethylene ether. A simulated dust removal and reduction experiment was carried out using this composition. The experimental results show that the dust suppression agent has a high dust removal efficiency and good dust suppression effect.

Experimental comparison and optimization on granular bed filters with three types of filling schemes

Coal pyrolysis is an important way to realize the clean and efficient utilization of coal in China. However, the problem of dust removal from coal pyrolysis gas has restricted its development. Granular bed filters (GBFs) are among the most promising dust removal technologies because of their convenient and efficient filter material. To meet different dust removal requirements, an optimum filling scheme of the GBF must be determined. In this study, the filtration performance of GBFs with three types of filling schemes, single-layer GBFs with uniform-sized particles, single-layer GBFs with mixed-sized particles and double-layer GBFs with two sizes of particles, was tested and compared. The results showed that among the single-layer GBFs, the GBFs with medium-sized particles (1–3 mm) and the GBFs with mixed-sized particles are recommended because of their high efficiency and a low pressure drop. Double-layer GBFs yielded better filtration performances than single-layer GBFs and were suitable in applications with high dust removal requirements. However, the filtration performance of double-layer GBFs was correlated with filter material collocation, which primarily depends on the lower-layer granules. To achieve optimum filtration performance, the lower layer of a double-layer GBF should be filled with particles with sizes less than 1 mm. The optimum ratio of the lower-layer height to the overall height should be approximately 0.2, and the value can rise slightly with increasing upper-layer granular size. These results can be used as a guide for optimally filling GBFs under different requirements to further promote the development of clean coal utilization.

Study on the Change Characteristics of Dust Specific Resistivity and Electrostatic Precipitation Efficiency

Specific resistance is an important factor affecting the performance of ESP. For the dust resistance than the impact of electrostatic dust removal mechanism, the relationship between dust specific resistance and electrostatic dust removal efficiency, high dust specific resistance and low dust specific resistance in the electrostatic dust produced by the adverse effects. The method of controlling the specific resistance of dust is proposed, which reduces the specific resistance of high specific resistance dust by adjusting the flue gas humidity, changing the flue gas temperature and flue gas quenching. The surface modification technology is used to improve the low specific resistance dust. By controlling the dust specific resistance to 104 to 1010 Ω · cm, the electrostatic precipitator is kept at a high dust removal efficiency.

Activated Carbon-Coated Electrode and Insulating Partition for Improved Dust Removal Performance in Electrostatic Precipitators

The dust removal performance of two types of modified electrode electrostatic precipitator systems was evaluated and compared with that of a conventional aluminum plate electrode using laboratory-scale experiments. In the novel electrode systems, the electrode surface was coated with activated carbon using a mixed slurry containing carbon black, polyvinyl acetate, and methanol. The modification of the electrode surface improved dust precipitation by increasing the specific capacitance of the electrode. The modification also lowered the electrode’s resistance and increased its specific surface area. The optimum electrode spacing and electric voltage supply were determined using batch-type tests. In addition, dielectric insulators were applied as a partition between the oppositely charged electrodes equipped with the modified electrode plates. Multi-layered office paper cut to the same size as the electrodes was used as an insulating material. The addition of the insulator resulted in excellent improvement in the dust removal performance by minimizing the back-corona discharge phenomenon as well as doubling the dust collecting surface. Continuous dust removal tests with the three electrode systems revealed that whereas the conventional aluminum electrode exhibited 54 % dust removal, the activated carbon (AC)-coated system showed 85 % and AC-coated + insulator system showed 90 % and higher dust removal efficiency.

Dust Removal Using Electrode-Plates Coated with Activated Carbon

The main purpose of this research work was to evaluate dust removal efficiencies using electrode plates coated with activated carbon in dust removal chamber. The experiments were performed with electrode-plates coated with activated carbon with black carbon and poly vinyl acetate (PVA) as binding agent. Methanol was added into the coating mixture for lowering the viscosity and at the same time helped the activated carbon (AC) pores not to be blocked by PVA. After coating the electrode surface, it was tested to collect dust in cylindrical chamber with and without power supply. In both case, AC coated electrode showed higher dust removal efficiencies compared to conventional aluminum electrode. Continuous test for PM10 dust control revealed that removal efficiency gradually increased with time passage, and as increasing the distance from inlet, the removal efficiency becomes stable. However, where the interval between electrodes was as short as 1cm, and also at the back of the chamber, “back discharge” effect was observed, and resolved easily by the elevation of humidity level. Volatile organic compounds (VOCs) were controlled successfully with the AC coating material so that it proved both particular and gaseous contaminants can be treated with this AC-coated electrostatic precipitator.*Corresponding author (Kwang Soo Kim): Daehwa-Dong 283, Goyangdae-Ro, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 411-712, Korea / kskim@kict.re.kr / Tel. + 82 31 9100 299 / Fax. +82 31 910 0291