Cooling Tower Water Treatment

comparison

Methodologies in Cooling Tower Water Treatments


Traditional Chemical Treatment

Method:

Crystal modification & sequester hardened to prevent formation of "scale deposits"


Scale and Corrosion Inhibition:
  • Phosphonates (HEDP, AMP, PBTC, others)
  • Polymers (TSO, others)
Biological Control:
  • Non Oxidizers (Isothiazolin, DBMPA, Gluteraldehyde, others)
  • Oxidizers (Bromine, Chlorine, Chlorine Dioxide, Ozone)
Key Issues:
  • COC limited by hardness, alkalinity, silica, and TDS
  • Concerns with chemical handling and discharge (non green)
  • Complex chemical feed and control systems and testing

LOW ROI (water and energy conserved)

NCD (Non Chemical Devices)

Method:

Precipitation of harness as non adhering crystals, deposition control to basin or separators


Magnetic Devices:
  • Electromagnetic Field: Electrostatic Devices
  • Catalytic Devices: Precipitates on a Core
  • Pulsed Power Technology: Electromagnetic Energy
  • Kinetic Energy: Hydrodynamic Cavitations
Key Issues:
  • COC limited by hardness, alkalinity, silica, and TDS
  • Precipitates deplete alkalinity-pH needed for corrosion control
  • Not effective with low hardness or variable water quality

Generally high capital expense with LOW ROI (water and energy conserved)

High TDS- Silica Based Technology

Method:

Remove hardness ions and utilize natural TDS and alkalinity (pH) to polymerize silica


High Efficiency Softeners - HES:
  • Removes scale ions
  • Tower water is biostatic with high TDS and pH
  • Sodium silicates for corrosion control form in tower water
Key Issues:
  • COC not limited, minimizes water use and blowdown
  • Exceptional corrosion protection with green and sustainable chemistry
  • Natural silica, alkalinity and TDS in raw water are useful for both corrosion inhibition and bio static control, more is better

LOW capital expense, HIGH ROI (maximum water and energy conserved)