Absorber tray retrofit project: Indianapolis Power & Light Company Petersburg Unit No. 4 FGD system

In October 1993, Indianapolis Power & Light Co. (IPL) decided to retrofit the internal packing on one of their dual-loop FGD absorber modules with a patented sieve tray. This retrofit was undertaken as an attempt to lower maintenance costs, improve reliability, gain longevity in run-time and still maintain adequate scrubber system performance. Full-scale testing, a performance review of packing versus the tray, and a calibration of the tray-equipped absorber to EPRI`s FGDPRISM computer model were conducted in 1994. Results of field testing activities, along with the long-term effects of the tray installation, are discussed. Site-specific issues that prompted IPL to seriously consider the installation of a tray device to improve long-term operation of their unit, and economic evaluation issues, are presented.