Conventional filtration mechanisms struggle to meet ultralow emission requirements for fugitive particles in the iron and steel industry because of the penetration of fine particles. Leveraging the magnetic properties of these particles, a novel functional magnetic filter material loaded with cobalt ferrite nanoparticles was developed. To further enhance performance, an integrated dedusting system was designed combining an electroagglomeration unit with a magnetic filter material unit, thereby capitalizing on the performance enhancement provided by electromagnetic agglomeration in the filtration process.
The feasibility of this system is demonstrated through a segmented investigation. In the numerical simulation section, the electrocoagulation efficiency of oppositely charged particles under AC, DC, and no-field conditions was compared and analyzed using the computational fluid dynamics-population balance model (CFD-PBM). The particle agglomeration nucleus was defined through a user-defined function. Additionally, the dynamics of particle capture by magnetic fibers were computed based on the computational fluid dynamics-discrete phase model (CFD-DPM). The magnetic force exerted by magnetic fibers on particles was defined through UDF. The experimental results further confirmed that the filtration performance of the magnetic filter media was tested with and without the application of electrostatic agglomeration.
1) After the fugitive particles were bipolarly charged, the agglomeration effect of oppositely charged particles was most effective in AC electric fields, followed by DC electric fields, while it was weakest in the absence of an electric field. 2) Magnetic fibers can remarkably alter the movement trajectory of fugitive particles through magnetic force, causing directional migration toward the fibers and thereby enhancing the efficiency of particle capture. When the saturation magnetization of the magnetic fiber was 7950 A/m, and the magnetic susceptibility reached 0.025, the capture efficiency of PM1.0 can reach 1.256%. 3) The magnetic polyimide filter media can increase the filtration efficiency of particles with a diameter of less than 2.0 µm by approximately 20%. When the filtration rate reaches 5 m/min, the pressure difference is only approximately 9.0 Pa. The increase in pressure drop caused by loading cobalt ferrite nanoparticles can basically be ignored. 4) When the bipolar charge parameters were +18 kV/0.21 mA, -16 kV/0.04 mA, the magnetic polyimide filter material combined with electrostatic agglomeration significantly improved the filtration efficiency for fugitive particles in the 0.1–1.0 µm range, achieving an efficiency of over 90%. The filtration pressure drop of the magnetic polyimide filter material was greater than that of magnetic polyphenylene sulfide and magnetic glass fiber. This is much higher than that of the magnetic polyimide filter material or the polyimide filter material under electrostatic agglomeration. Comprehensive analysis suggests that applying an AC electric field on the basis of bipolar charging is anticipated to further enhance the filtration performance of the magnetic filter material.
This study presents a comprehensive exposition that encompasses the design concept, structural features, experimental procedures, and data analysis, providing a clear research paradigm for subsequent system design, parameter optimization, and performance validation. Furthermore, it proposes a novel research methodology that integrates experimental study with numerical simulation.
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