Effect of Duct Extension on Velocity Profile in a Multi-Tube Electrostatic Precipitator

Electrostatic precipitators are widely used for the removal of particulate matter from flue gases due to their high collection efficiency. In this study, a computational fluid dynamics approach was employed to analyse the influence of an upstream duct extension on the velocity distribution within a four-tube precipitator. Compared to a standard single- tube configuration, the multi-tube arrangement provides a 60% increase in collection area. However, this benefit introduces challenges in uniform flow across all tubes. Two configurations were examined: a baseline case without extension (Case 1) and a modified version incorporating a 500 mm duct extension before the ESP section (Case 2) for improving flow uniformity. Simulation results revealed that Case 1 exhibited significant velocity asymmetry, with two tubes carrying most of the flow. Case 2 demonstrated substantially improved flow uniformity, with more balanced velocities across all tubes. These findings highlight the importance of flow- conditioning measures in optimizing the electrostatic precipitator. Although the duct extension proved effective, its integration may be limited by spatial constraints in small-scale systems, prompting future investigation into compact alternatives such as internal deflectors or straighteners.