Chemical dosing for cooling tower water

[u/Trigathoras69]

Hello guys, junior engineer here. I was given the task to install a control panel to inject chemicals for cooling tower water and design the suitable piping pathway and where should the chemicals be injected into the cooling tower system. I was thinking of just directly inject the chemicals into the cooling tower basin, but since the cooled water in the basin is stagnant, im afraid the chemicals will not mix well inside the basin. My supervisor suggested do the piping to that the chemicals are injected into the header at recirculation pump discharge side. The constraint with this idea is that the header is made of stainless steel, and the chemical piping is PVC. I would like to ask for any ideas or comment from you guys, especially for those who are working with cooling tower. Is there any industry standard on how to inject the chemicals into the cooling tower system?

[u/Cyrlllc]

Injecting it into the basin seems like a bad idea I agree.

Maybe installing an inline mixer into the header is a good enough of a solution. 

You might even get away with dosing directly into the header using dosing pumps on the pipe a certain distance upstream to ensure good mixing. If your chemicials arw highly viscous and hard to mix you could look into dosing with intermediate concentrations using buffer tanks.

[u/Trigathoras69 → u/Cyrlllc]

all chemicals used are less dense than water so i think it can be directly injected to the header as you suggested