Novel hybrid composite discharge electrode for electrostatic precipitator

ABSTRACT

Over the last few decades, electrostatic precipitators (ESPs) have emerged as effective air pollution control devices for treating coal-fired power plant exhausts. Among the components of the ESP, the discharge electrodes are extremely important in determining the collection efficiency of the ESP. Typically, in wet ESPs, the discharge electrodes used must be made of corrosion-resistant alloys, which makes them extremely expensive and heavy. Hybrid composite discharge electrodes have the potential to be lightweight and corrosion-resistant substitute for traditional metal alloy electrodes used in wet ESPs. In this experimental study, a novel hybrid composite electrode (recently patented at Ohio University) is presented as a substitute for traditional metal electrodes in wet ESPs. The samples of hybrid electrodes were fabricated by using carbon fiber composites, combined with metal mesh, in the shape of a long and thin tape. The electrode’s electrical response was evaluated in open atmospheric conditions, while connected to a transformer-rectifier unit to generate a corona current at voltages exceeding 50 kV. Results of these hybrid electrodes were compared with traditional metal electrodes. The hybrid composite discharge electrode produced a uniform corona at comparable power levels to that of metal electrodes, with additional advantages of being compact, lightweight, and highly corrosion resistant. In addition, hybrid composite electrodes exhibited lower corona onset voltage as compared with metal electrodes. The preliminary experimental data are encouraging and show significant potential for this new inexpensive hybrid electrode to replace metal electrodes in wet ESPs, providing comparable (and in some cases exceeding) collection efficiencies with lower ozone generation.

Implications: The newly invented hybrid composite electrode (HCE) performance was evaluated through experimentation with conventional metal electrodes. The HCE performance was comparable to the metal electrodes. The HCE also exhibited uniform corona fields and steady power while maintaining similar and in some cases superior electrical performance as compared with metal electrodes and thus shows a significant potential to substitute metal electrodes in wet ESP systems.

Acknowledgment

The authors would also like to thank the anonymous referees for providing useful, constructive, and insightful feedback that resulted in a significant improvement of the original manuscript.

Funding

This work was completed in Ohio University’s Electrostatic Precipitator Laboratory, Athens, Ohio, and was supported through funds provided by the Babcock and Wilcox Company (GR-020-3200-08150), Ohio University Research Office, and Ohio University’s Russ College of Engineering and Technology.

Additional information

Funding

This work was completed in Ohio University’s Electrostatic Precipitator Laboratory, Athens, Ohio, and was supported through funds provided by the Babcock and Wilcox Company (GR-020-3200-08150), Ohio University Research Office, and Ohio University’s Russ College of Engineering and Technology.

Notes on contributors

M. Ali

M. Ali and K. Alam are professors in the Department of Mechanical Engineering at Ohio University, in Athens, OH, USA.

K. Alam

M. Ali and K. Alam are professors in the Department of Mechanical Engineering at Ohio University, in Athens, OH, USA.

Y.T.A. Al-Majali

Y.T.A. Al-Majali and M. Kennedy are graduate research assistants in the Department of Mechanical Engineering at Ohio University, in Athens, OH, USA.

M. Kennedy

Y.T.A. Al-Majali and M. Kennedy are graduate research assistants in the Department of Mechanical Engineering at Ohio University, in Athens, OH, USA.