Chemical Treatment Cost

The second line of any cooling-water budget: mass of product times unit price. A tower consuming 4380 lb of inhibitor a year at $3.25/lb delivered is a $14,235 chemical line, and that is the number a service contract is actually bid on. Cooling inhibitors typically run $2–6/lb depending on actives and drum quantity, oxidising biocides much less, non-oxidising biocides and specialty dispersants considerably more, so a program's cost is driven far more by which products are in it than by how many pounds move. As everywhere on this site, the answer is in whatever currency the unit price was entered in — there are no exchange rates here, so a price typed in CAD returns CAD.

The trap is the mass, not the price. Chemical is consumed by the water that leaves as liquid — blowdown plus drift — and not by makeup, because evaporation leaves every molecule of inhibitor behind in the basin; budgeting on makeup overstates consumption on a typical tower by a factor of three or four. Then check the basis of the ppm you multiplied: 100 ppm of a 20% active blend is 20 ppm of active, and pricing a product dose as though it were an active dose is a five-fold error in the same direction. Finally, watch what the price is quoted per: liquid products are sold by the drum, the tote and sometimes by the gallon, and converting a per-gallon price to a per-pound price needs the product density off the label — 9.5 lb/gal is typical, and assuming water at 8.34 puts you 14% out before you start.