Close‐to‐streamline numerical study on gas velocity distribution in industrial scale electrostatic precipitator gas inlet hood

Abstract

AbstractThe uniformity of gas velocity distribution in gas inlet hoods is important to guarantee high dedust efficiency in electrostatic precipitators (ESPs), especially for high solid concentration applications. The close‐to‐streamline numerical method was developed to geometrically 1:1 simulate an industrial scale ESP gas inlet hood, which had complicated internal structures, such as dedust angle irons and gas distribution perforated plates with up to 10 000 holes. The realizable k‐ε model was used for the gas flow simulation. The numerical results of the gas velocity distribution show reasonable agreement with the field measurements. The outlet gas velocity distribution was non‐uniform, which was lower in the central region and higher in the near‐wall regions. The gas flow characteristics were analysed to reveal the main influence factors on gas velocity distribution and put forward corresponding modification methods. After the retrofit, the field measurements of the outlet gas velocities showed that the gas velocity distribution improved. The non‐uniform index of outlet gas velocity distribution decreased greatly from 0.355 to 0.244. The visible dust emissions from the chimney disappeared which indicated increased dedust efficiency. Therefore, the close‐to‐streamline method can simulate gas velocity distribution in complicated structures of ESP gas inlet hoods. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.