I think this will not be a problem, as the salt would be continuously washed away with new water. But the corrosion would be a problem indeed.
Maybe some plastic/epoxy/glass casing would help, but it might also hinder recyclability.
Seriously: Maybe residue wouldn't be an issue if it was never allowed to dry, but the corrosion-proof construction, drainage system, and pumping costs would be considerable. Then there's the 100 problems we're not aware of yet...
Additionally power stations use steam turbines which require a lot of water. Some cooling water for misters would probably be a rounding error.
https://www.newindianexpress.com/states/kerala/2021/dec/13/c...