A cooling tower is an open evaporative system: it concentrates dissolved solids, absorbs airborne dirt, and runs warm enough to grow biofilm. Dosing practice has to answer all three.
The Operating Reality
An open tower feeds scale inhibitor, corrosion inhibitor and biocide into the basin or the circulating line, with blowdown controlled by conductivity and make-up replacing what evaporation and drift remove.
Why Manual Dosing Falls Short
Cycles of concentration move with weather and load. A dose tuned in spring is wrong in August, and a biocide run on one mode selects for resistant organisms.
How Automatic Chemical Dosing Fits
- Dose should follow conductivity-driven blowdown, not a fixed timer, so inhibitor concentration tracks cycles.
- Biocide programmes should alternate modes to limit selection pressure on the biofilm population.
- Automatic dosing lifts concentration compliance from the 65-80% typical of manual feed to 98% or better, and cuts inspection rounds from 4 per day to about 0.2 per day.
Selection Checklist
- Define the control signal first (pH, ORP, conductivity or flow-proportional) before sizing the pump.
- Size the metering pump to the lowest expected dose with margin, not to the peak dose.
- Confirm chemical compatibility of wetted parts (316L, PVC, PVDF) with every product to be fed.
- Provide containment, leak detection and dry-running protection in the dosing room design.
- Integrate the skid with PLC, DCS or remote telemetry so dose is visible in the control room.
Related Products
- Automatic Chemical Dosing System
- Automatic Condenser Tube Cleaning System (ATCS)
- Constant Pressure Water Make-up System
FAQ
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