Cooling Tower Water Treatment

Why cooling tower water treatment is a chemistry problem

A cooling tower is an evaporator: pure water leaves as vapour, and everything dissolved in the make-up stays behind and concentrates. Left alone, that concentration drives the four failure modes every operator knows: scale on heat-exchange surfaces, corrosion of piping and fill, fouling by suspended solids, and biological growth, including Legionella, which Canadian public-health authorities treat as a registrable risk in several jurisdictions.

Cooling tower water treatment manages all four at once, because fixing one in isolation worsens another. Softening the make-up cuts scale but makes the water more corrosive; heavy biocide dosing controls slime but can attack galvanized fill. A working program balances:

• Cycles of concentration, set by conductivity-controlled blowdown; raising cycles from 3 to 6 cuts make-up water demand by roughly 10 percent and blowdown volume nearly in half
• Scale and corrosion inhibitors, phosphonates and azoles dosed to the recirculating volume
• Oxidizing and non-oxidizing biocides, alternated so biofilms never adapt
• Side-stream filtration, which removes the airborne dust a tower scrubs out of the atmosphere all day

Equipment for cooling tower and blowdown treatment

Our scope is the hardware that makes the chemistry work: chemical dosing skids with conductivity and ORP control, water meters on make-up and blowdown, side-stream sand or screen filters, and softeners or reverse osmosis on make-up where raw-water hardness is high. RO-treated make-up is increasingly common at Canadian plants chasing higher cycles, because it removes the silica that usually caps them.

Blowdown itself is a wastewater stream, and municipalities treat it as one. Sewer-use bylaws set limits on temperature, pH and total dissolved solids, and a tower running high cycles can breach them. We size neutralization and cooling for blowdown where the bylaw requires it.

Send us your make-up water analysis, tower tonnage and current cycles of concentration. We will quote a control-and-dosing package, with the water and chemical savings calculated against what you run today.