A 630-megawatt coal-fired electric generation unit, the Cardinal Unit #3 Cooling Tower in southern Ohio was refitted with a new flue gas desulfurization (fgd) system that reduced its emissions.
The project was unique because of the size, height, and hyperbolic configuration of the cooling tower. The tower has a top inside diameter of 180 feet and is 430 feet above grade. The hyperbolic configuration complicated the already difficult rigging plan and implementation.
The cooling tower was constructed in 1974, so the project required the coating system to bond well to aged concrete and maintain adhesion over the 30-year planned remaining service life of the structure. The concrete surface was prepared with high-pressure water cleaning at a target pressure of 6,000 psi. A 100% solids epoxy primer and a trowel- applied epoxy surface were applied over the entire surface to fill all cracks and surface pores, and the coating system was completed with two coats of a high-build, high-solids, glass-filled epoxy finish.