Sustainable Management Resources Inc Join SMRI as we work on: “Creating a Sustainable New Economy” SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Basics of Cooling Tower Water Treatment Cooling towers reduce water temperature through evaporation, a high-energy phase change Only water leaves the system as a vapor, mineral content remains Minerals dissolve until the saturation point is reached, then scale begins to form When the mineral content is twice the level of the makeup water supply- 2 cycles of concentration have been reached SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Basics of Cooling Tower Water Treatment Conductivity is the measure of dissolved solids pH is the measure of the relative acidity or basicity of the water These 2 parameters are convenient methods to monitor and control scale formation and corrosion SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Causes of lost efficiency Calcium carbonate is the most common type of scale Calcium Carbonate Scale- 1/10” causes loss of efficiency of up to 40% Corrosion- Causes loss of heat transfer and leaks Biological growth- causes loss of heat transfer and can cause disease SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Control through Water Treatment Scale inhibitors- increase solubility Acid reacts with carbonates and releases CO2, increases saturation point Softeners remove Ca and Mg (scaling cations) Corrosion inhibitors- coat or react specifically with certain metals Biocides- slug dosed or continuously fed for bacterial control SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Monitoring and Control Conductivity, pH, ORP and corrosion Chemicals levels and feed verification Temperatures- inlet and outlet of tower, inlet and outlet of chiller, chilled water, etc Flows- through tower, chiller, etc Pressures- chillers Makeup and bleed-off water meters-ROI SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Water Evaporation Credits Evaporation = (Tonnage) x (0.03) x (% load) Example tons x.03 x.70 = 21 gpm Based on a 12 hour day- evaporation = 15,120 gallons On a yearly basis (260 days) that is 3,931,200 gallons of evaporated water 3,931,000 gallons x $2.75 per 1000 gals of water* = $10, per year savings *Low estimate for most areas and increasing yearly SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Bleed-off Reduction Bleedoff = Evaporation Cycles of concentration-1 3,931,000 gallons = 2,620,666 gallons bleedoff annually 2.5 (cycles of conc)-1 Using acid or side stream softening: 3,931,000 gallons = 1,123,142 gallons bleedoff 4.5(cycles of conc)-1 1,497,524 gallons of water saved from the sewer= $4,118 At a cost of $4.00 per 1000 gallons of treatment= $5,990 Total saved from acid use or softening= $10,108 annually SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Typical Cooling Tower Installation DI In Corrosion 4-20mA In Cooling Tower schematic

SMRI, San Diego CA, ~ ~ Steve Kaplan ~

Thank you SMRI, San Diego CA, ~ ~ Steve Kaplan ~