Enhancing fine particle separation by hybrid-electrostatic-turbulence coagulation: An experimental and numerical investigation

Yang, Zhen; Tong, Yongqi; Zhang, Lin; Bu, Shi; Huo, Guangtian; Fang, Jiamei; Ding, Hong; Xu, Weigang

doi:10.1016/j.apt.2022.103431

Cited by 12 publications

(5 citation statements)

References 22 publications

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“…The two particle streams of opposite signs flowing one after another are then agglomerated in DC or AC electric field [67,68]. In order to increase the probability of collision between oppositely charged particles, in some of the constructions a turbulent flow is induced by the obstacles crossing the gas flow by a high gas velocity, about 10 m/s [69][70][71][72]. The particles collide due to the Coulomb attraction forces between them, and are agglomerated.…”

Section: Electrostatic Particle Agglomeratorsmentioning

confidence: 99%

Hybrid electrostatic filtration systems for exhaust gas cleaning

Jaworek,

Sobczyk,

Marchewicz

et al. 2024

J. Phys.: Conf. Ser.

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Emission of submicron and nanoparticles by industrial processes, like coal or biomass combustion, solid waste incineration, cement kiln heating, and glass production is a serious environmental problem. The application of most effective bag filters is limited due to very high temperature of the exhaust gases from most of these processes, sometimes >1000 K, which the filter material cannot resists. Cyclones, which could be resistant to these temperatures, are not effective for PM2.5 particles removal, which are the most abundant in these processes. Electrostatic precipitators remove dust from flue gases with high mass collection efficiency, but in submicron range (~100 nm to 1 μm) the so called “penetration window” occurs, in which the fractional collection efficiency decreases even below 50% at minimum. Hybrid electrostatic filtration systems, which combines various conventional gas-cleaning devices were therefore proposed and tested in several research papers, in order to improve the overall collection efficiency of the precipitation processes. The heart in all of these devices is an electrostatic particle charger, which can be a conventional electrostatic precipitator, a corona-discharge particle precharger, or electrostatic particle agglomerator. After charging and/or agglomeration, the particles can be further removed by other devices like cyclones, electrostatic precipitators, or bag filters (after gas cooling to an allowable temperature). The paper reviews specific problems encountered in exhaust gas cleaning from various industrial processes, and the most interesting constructions designed for this goal. In particular, an example of a system comprising a unipolar electrostatic agglomerator, which simultaneously charges the particles and agglomerates them in alternating electric field, for the formation of aggregates of finer particles (PM1) with larger species, which could be removed by any conventional gas cleaning device, with sufficiently high collection efficiency, has been discussed in details.

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Section: Electrostatic Particle Agglomeratorsmentioning

confidence: 99%

Hybrid electrostatic filtration systems for exhaust gas cleaning

Jaworek,

Sobczyk,

Marchewicz

et al. 2024

J. Phys.: Conf. Ser.

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“…It is generally believed the complexity of turbulent motion does not affect the applicability of unsteady continuum equations and Navier-Stokes equations for common turbulent transient motion [27][28]. The flue gas can be regarded as an incompressible fluid, so its density can be taken as a constant, and the flow of flue gas in the ESC satisfies the mass conservation equation and the momentum conservation equation, which can be expressed as follows:…”

Section: Gas Flow Fieldmentioning

confidence: 99%

Influences of magnetic field on the removal of submicron particles in electrostatic cyclone at different temperatures

Zhang

Zhao

et al. 2022

Environmental Engineering Research

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Aiming at improving the capture performance of inner vortex electrostatic cyclone (ESC), which is widely used in the field of flue gas purification, magnetic field is introduced to remove submicron particles. The theoretical and physical models of electromagnetic dust removal were established, and the dust-removal efficiency of submicron particles under different temperatures and magnetic fields was numerically simulated by FLUENT. The results show that a rise in temperature leads to a reduction in the grade efficiency of submicron particles of ESC, a decrease in the number of escaped particles at lower temperature, and the differences of the rising amplitude in overall efficiency corresponding to the traditional cyclone, which were 36.7%, 34.8%, 33.8%, and 31.9% at four temperatures. The contribution of temperature to the capture of submicron particles decreases continuously with the increasing temperature, but that of magnetic field progressively increases at this time. The magnetic field environment is conducive to the capture of submicron particles, the removal effect is more obvious with the increase of magnetic flux density, but the ascended ranges of magnetic field and temperature both decrease when it reaches 0.5 T. These results can provide a theoretical basis and a technical reference for the design of ESC.

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“…The rate of electrostatic coagulation has been studied [25], and an empirical formula for particles in the size range of 50-500 nm was presented. The effect of the external electric field strength on electrostatic coagulation for charged submicron fly ash particles has been reported [26], and the effect of particle charge on turbulent coagulation has been studied for submicron particles [27]. Recently [28], the turbulence effect on particle coagulation in the electric field of corona discharge was confirmed for large particles with a median diameter of 4.32 μm and at a relatively high concentration of 600 mg/m 3 .…”

Section: Introductionmentioning

confidence: 98%