Minimizing Cooling Tower Blowdown
OTHER PARTS OF THIS ARTICLEPt. 1: The First Step in Evaluating Cooling Tower EfficiencyPt. 2: How To Track And Measure Cooling Tower Efficiency ImprovementsPt. 3: This PagePt. 4: Water Savings From Cooling Tower Efficiency StrategiesPt. 5: Cooling Tower Efficiency Leads To Other Efficiencies
How much are you limited by blowdown? How can you mitigate its effects?
Generally, the goal is to minimize cooling tower blowdown because that means you are running at a higher cycle of conentration and therefore the system is operating more efficiently. Another benefit of reducing blowdown is the corresponding reduction in the volume of chemicals being discharged to waste. This has both economic and environmental benefits. That said, there is a practical limit to how much the blowdown volume can be reduced as cooling towers are excellent air washers and a minimal blowdown rate is necessary to control suspended solids fouling contributed by airborne debris. Often the use of filters such as a side stream filtration system can help remove these solids from the water.
Answers provided by Bill Harfst from the AT&T-EDF project team. Harfst is an independent water management consultant with Harfst and Associates, Inc. He has 40 years of experience in water treatment.