Search

In this work, a spike-tubular electrostatic device was developed for effectively removing particulate matter (PM) and VOCs, based on multi-stage electric field enhancement and expanded arc interface ratio of corona discharge. In the experiment, it was equipped with a portable 12 V D.C. power supply module and a fan module; PM from moxa smoke, mainly composed of submicron particles with a high penetrate rate, and HCHO were employed to test its electrostatic precipitation and oxidation ability, respectively. Additionally, CFD numerical simulation was adopted to investigate the characteristics of the electric field, the flow field, and the ozone generation. Experimental results showed that the electrostatic device could remove 99% of the fine particles at 2 m/s. Meanwhile, it could also remove HCHO of 2.14 × 103-1.07 × 104 μg/m3 concentration with 100% efficiency. By comparison, its oxidation capacity could be about 80 times that of ozone oxidation, revealing the enhanced oxidation ability of other short-living reactive species. Simulation results proved that the promising purification performance resulted from the locally enhanced electric field strength, up to 2 × 107 V/m in the central region, and sufficient contact between pollutants and the corona discharge region. Finally, as verified by the airtight chamber cycle experiment and case comparison, the device owns feasible purification ability and promising energy yield (0.79 g/kWh) in the application. Moreover, prospects and strategies for the device's practical application in air purification and disinfection were proposed, which may provide helpful enlightenment for air purification. [ABSTRACT FROM AUTHOR]

This paper develops a novel approach for evaluating charged particles' collision probability in the external electric field of a regular two-stage electrostatic precipitator based on Lagrangian particle tracking method, which overcomes itself difficulties and that of the Eulerian method. The numerical simulation aims to obtain the particles' accumulated displacement which is a parameter to reflect the efficiency of particle collision. The effect factors of frequency, gas velocity, plate spacing and applied voltage are also considered. Results indicate that the external electric field of R-AC is more beneficial to particle collision compared to the other waveforms of AC. Besides, frequency and plate spacing are not found to have obvious or regular effect on collision probability, but the promotion effect of applied voltage on it was obtained. The dimensionless coefficient analysis provides extremely useful information for the optimization of working conditions in different types of the external electric field. [Display omitted] • A novel method was proposed to investigate the particle collision in electric field. • The influence factors on the particle dynamic were analyzed systematically. • An optimization strategy for improving particle collision in the external electric field was put forward. [ABSTRACT FROM AUTHOR]

The high-voltage electric field can effectively capture charged aerosols and has the effect of killing microbial aerosols simultaneously. In this article, an innovative visualization method for investigating the dynamic characteristic of submicron-scale aerosol particles in the high-voltage electric field is developed. Based on reasonable working principles and reliable experimental schemes, the movement of submicron-scale aerosol particles is observed and visualization images in different working conditions are photographed. Besides, with the aid of numerical method and solution of related equations, simulation researches on flow field distribution, electrostatic field characteristics, particle charging and motion behavior characteristics are also carried out. Visualization results prove the linear motion law of aerosol particles in an electric field of 0–3 kV/cm unit. As for 1 µm diameter particle, its migration velocity in 1 kV/cm electric field is measured as 0.016 m/s and 0.019 m/s after positive and negative charging of 1.5 kV voltage, respectively. A reliable calculation formula (η = (V j q p L j) / (3 π μ D 2 u x d p)) for predicting collection efficiency is derived and established based on actual particle migration velocity. The researches on the migration and capture law of submicron-scale aerosol in the high voltage electric field gives a key reference for the development and design of efficient removal of microbial aerosol and air purification equipment. [Display omitted] • An innovative visualization method is developed. • It proves linear motion of particles in an electric field of 0–3 kV/cm unit. • Particle migration velocity after both positive and negative charging is obtained. • A reliable calculation formula is derived and established. [ABSTRACT FROM AUTHOR]