Impact of Alternative Electrode Designs

All three designs—rigid electrode, weighted wire, and rigid frame—can be employed in most applications. Any cost differential between designs will depend on the combination of vendor experience and site-specific factors that dictate equipment size factors. The rigid-frame design will cost up to 25% more than the wire and plate design if the plate height is restricted to that used in wire/plate designs. Several vendors can now provide rigid-frame ESPs with taller plates, and thus the cost differential can approach zero. The weighted wire design uses narrower plate spacings and more internal discharge electrodes. This design is being used less; therefore, its cost is increasing and currently is approximately the same as that for the rigid electrode ESP. Below about 15,000 ft2 of plate area, ESPs are not normally field-erected (erected at the installation site), and the costs will probably be higher than values extrapolated from Figure

Dry-type rigid electrode ESP flange-to-flange purchase price
versus plate area