INTRODUCTION

Electrostatic precipitator (ESP) contains set of positively charged plates which are placed in parallel in the path of particulate emission. ESP also contains GD screens located within diffuser. It is very important that ESP plate bundle should receive uniform flow at its entry, hence main challenge was making the flow more uniform at plate bundle entry by keeping back pressure (pressure drop) across ESP within critical limit. Thus performance & life of ESP will depends on flow uniformity at plate bundle entry and it can be achieved by CFD.

CHALLENGES

• Detailed modeling and meshing of plate bundles and GD screen with all its holes.
• Effective design modifications for improving flow uniformity at plate bundle entry by keeping back pressure within critical limit.

THE SOLUTION

CFD analysis of ESP with GD screen was executed for determining flow parameters inside ESP. Due to presence of higher diffuser angle on upstream side of plate bundle, there was a flow separation & large recirculation regions in ESP. Using CFD, these locations and size of the dead regions were predicted. Based on initial CFD results, cost effective design optimization iterations were carried out which reduced the flow recirculation regions by delaying flow separation point. These improved flow uniformity at ESP plate bundle entry. This has further helped in increasing the life of ESP plates by reducing erosion rate of plates.

BENEFITS

• Quick turnaround time to fix existing problem of highly non-uniform flow at ESP plate bundle entry.
• Design optimization of system for efficient performance with prolonged life.
• Cost-effective design modifications.