Why is it said that smoke tower integrated exhaust cooling towers pose a more serious problem than conventional cooling towers?

Thread Content

Why is it said that smoke-tower integrated exhaust cooling towers pose a more serious problem than conventional cooling towers? In the cooling water systems of power plant boilers, the smoke-tower integrated technology is generally used, and the corrosivity of the environmental conditions in such exhaust cooling towers is greater than that in conventional cooling towers. The flue gas that has been desulfurized and denitrified enters the naturally ventilated cooling tower through fiberglass flues, where it mixes with water vapor before being released into the atmosphere. The corrosive substances present in the flue gas (CO2, SO2, SO3, HCl, and HF) come into contact with water vapor; the condensed water droplets fall back into the cooling tower, forming large droplets on its walls. The droplets containing corrosive agents are weakly acidic (local pH≈1), and the cumulative effect over time can cause severe corrosion to the casing of the cooling tower. Therefore, anti-corrosion treatment must be applied to areas such as the surface of the cooling tower shell; this anti-corrosion treatment is crucial for the structural safety of the cooling tower. Although the flue gas discharged into the smoke exhaust cooling tower, after desulfurization and denitrification, is already clean, gases such as SO2, HCl, and large amounts of CO2, which cannot be completely removed, still possess strong corrosive properties when combined with water vapor. Conventional cooling towers are only affected by water vapor and subject to corrosion damage; therefore, smoke-cooling towers that combine smoking functions with cooling capabilities suffer more severe corrosion damage than conventional cooling towers.