School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsux, China.
Department of Food, Agricultural, and Biological Engineering, the Ohio State University, Columbus, Ohio, USA.
J Air Waste Manag Assoc. 2022 Dec;72(12):1442-1453. doi: 10.1080/10962247.2022.2120564. Epub 2022 Oct 10.
Droplet charging is an effective method to enhance dust removal efficiency using an electrostatic spray scrubber (ESS). However, effects of the materials and dimensions of different electrodes on droplet charging efficiency have not been studied systematically. In this study, ring-shaped electrodes were selected to test effects of three types of electrode materials (copper, stainless steel, and graphite) with various dimensions on droplet charging efficiency. A Faraday pail charge measurement device was used to measure the droplet charge generated by the electrodes. A reduced factorial design with four factors was used in this study to investigate the charging efficiency affected by the factors. The four factors tested were electrode material, electrode diameter, nozzle height, and applied voltage. A 304L stainless steel electrode was found to achieve higher droplet charge-to-mass ratio (CMR) values than identically shaped electrodes made from either copper or graphite. The optimal stainless steel electrode inner diameter was 100 mm. The 304L stainless-steel electrode with this optimal diameter and a height of 45 mm achieved the highest mean CMR of 0.435 ± 0.002 mC kg at an applied voltage of -11 kV with the bottom of the nozzle tip positioned 15 mm below the top of the electrode. Currently, the low removal efficiency of submicron particles cannot meet the environmental control requirements of industrial applications that may have significant concentrations of particulate matter (PM) in this size range. As stricter environmental regulations are increasingly enforced, there is an urgent need to efficiently remove submicron dust particles from the air. Experiments show that the dust capture process is improved by charging droplets in the spray separator and reducing the secondary escape of dust particles in the electrostatic precipitatorAlthough high-voltage charging of droplets has been investigated in many studies, the effect of electrode material and size on droplet CMR is still not fully understood. The purpose of this study was to (1) quantify the performance of 304L stainless steel (304L SS), copper, and high-purity graphite electrodes for spray droplet CMR, (2) evaluate effects of the applied voltage, nozzle height, electrode material and dimension on CMR, and (3) optimize the specific values of key design factors and operating parameters that lead to the highest CMR. The results of this study aim to optimize electrostatic spray scrubbers to achieve high droplet CMR values.
液滴荷电是提高静电喷雾洗涤器（ESS）除尘效率的有效方法。然而，不同电极的材料和尺寸对液滴荷电效率的影响尚未得到系统研究。在本研究中，选择了环形电极，以测试三种类型的电极材料（铜、不锈钢和石墨）的各种尺寸对液滴荷电效率的影响。使用法拉第桶电荷测量装置测量电极产生的液滴电荷。本研究采用四因素析因设计来研究受因素影响的充电效率。测试的四个因素是电极材料、电极直径、喷嘴高度和施加电压。研究发现，304L 不锈钢电极比铜或石墨制成的相同形状的电极具有更高的液滴荷质比（CMR）值。最佳的不锈钢电极内径为 100mm。在施加电压为-11kV、喷嘴尖端底部比电极顶部低 15mm 的情况下，具有最佳直径和 45mm 高度的 304L 不锈钢电极获得了最高的平均 CMR，为 0.435±0.002mCkg。目前，亚微米颗粒的去除效率低，无法满足工业应用的环境控制要求，而这些应用中可能存在大量的颗粒物（PM）在这个尺寸范围内。随着越来越严格的环境法规的实施，迫切需要有效地从空气中去除亚微米粉尘颗粒。实验表明，在喷雾分离器中对液滴进行荷电并减少静电除尘器中粉尘颗粒的二次逸出，可以改善粉尘的捕集过程。虽然已经有许多研究对液滴的高压荷电进行了研究，但电极材料和尺寸对液滴 CMR 的影响仍不完全清楚。本研究的目的是：（1）量化 304L 不锈钢（304LSS）、铜和高纯石墨电极对喷雾液滴 CMR 的性能；（2）评估施加电压、喷嘴高度、电极材料和尺寸对 CMR 的影响；（3）优化导致最高 CMR 的关键设计因素和操作参数的具体值。本研究的结果旨在优化静电喷雾洗涤器以获得高液滴 CMR 值。
