Enhanced high-temperature particle capture through an electrostatic precipitator with assistant electrodes

Abstract

High-temperature electrostatic precipitators (ESPs) are a potentially effective technology for purifying high-temperature gases. In this study, a comprehensive numerical model was developed to investigate the electric field and particle migration characteristics of an ESP at temperatures ranging from 400 to 600 °C. Moreover, an optimized ESP with assistant electrodes for improved high-temperature particle capture was proposed. The electric field, flow field and particle capture characteristics of the two types of ESPs were compared to demonstrate the superiority of the optimized ESP. Results indicated that high temperatures had a negative impact on ESP performance. As the temperature increased, the operating voltage of the ESP decreased, leading to decreases in both the electric field strength and space charge density. The effective migration velocity of the particles also decreased with increasing temperature, and the inhibitory effect of high temperature on particle capture increased with increasing particle size. The optimized ESP with assistant electrodes exhibited more favorable electric field and flow field characteristics for particle capture compared to those of the conventional ESP. The optimized ESP exhibited higher electric field strength, which increased the electric field force on the particles and promoted particle capture. Meanwhile, the space charge density of the optimized ESP was lower, effectively inhibiting the occurrence of back corona. Moreover, the optimized ESP enhanced the ionic wind downstream of the discharge electrode, thereby promoting particle migration towards the collection electrode. Consequently, the ESP with assistant electrodes effectively improved the collection efficiency.