COOLING SYSTEMS WATER TREATMENT TRAINING Presented by A and W TECHNOLOGIES

Plant Refrigeration Costs Electricity 20% Equipment Depreciation 59% Labor Makeup Cost Sewer Cost 13% 5% Water Treatment 2% 1%

NUMBER 1 PRIORITY SAFETY THINK

COOLING WATER IMPURITIES TYPICAL IMPURITIES Ions Calcium, Magnesium, Sulfate, Silica, chlorides All can react to form harmful deposits pH Increasing pH - increased scale potential Decreasing pH - increased corrosion potential

COOLING WATER IMPURITIES Characteristics City Water Well pH 7.2 7.3 M alkalinity 0 ppm 71 Chorides 12 ppm 2.3 Hardness 17 ppm 68 Silica 4.2 ppm 23 Iron .05 to .5 ppm .5 Conductivity 60 mmhos 160 - 185 Copper .1 ppm .1

FORCED DRAFT TOWER Condenser Water EVAPORATION HOT WELL FAN Fill Solenoid valve MAKEUP water meter WELL & CITY Blowdown line to drain 3 Chillers COLD WELL Recirculation pumps

Forced Draft Tower A and W TECHNOLOGIES PROCESS Blowdown MAKEUP Water Meter PROCESS 74*F 90*F

NATURAL DRAFT TOWER 500,000 GPM 10* F Delta T - Approach 500’ 500,000 GPM 10* F Delta T - Approach Power Generating Station

? Water distribution Evaporative Evaporation Condensor Chillwater in the tubes or ammonia ? Makeup water To chemical feed center Recirculation pump Hey what the heck is that? BAC Evaporative condensor Chicken plants and food manufacturers

COOLING WATER OPERATIONAL FACTORS Evaporation = (Recirc. Rate x Delta T x .001) = GPM Pure water leaves Solids concentrate Requires fresh water makeup to be added Blowdown *Makeup = Equal to Evaporation Evap + BD Cycles - 1 Cycles Equal to Conductivity in Tower Conductivity in Makeup

Typical Specifications Evaporation 5000 x 10 x 70% x 24 x .06 = 50,400 GPD Blowdown 50,400 / 5-1 = 12,600 GPD Makeup = Evap + BD 50,400 + 12,600= 63,000 GPD

Typical Specifications Evaporation Credits 4220 x 10 x 60% x 24 x .06 = 36,461 GPD At 365 days per year this is 13,308,265 GPY Sewer charge is $2.75 per 1000 gallons 13,308,265/1000 = 13,308 x $2.75 = $36,597

Optimizing Cycles Cycles Blowdown Tower 5 10 15 20 25 30 35 40 1 2 3 4 5 10 15 20 25 30 35 40 1 2 3 4 6 7 Cycles Tower Blowdown

Saves Water 40 35 30 25 Tower Blowdown 20 15 10 5 1 2 3 4 5 6 7 Cycles

COOLING WATER PROBLEMS CORROSION Tendency for metal to revert to its natural state Electrochemical reaction Anode, cathode, source of electron flow and an electrolyte General thinning and/or pitting Galvanic corrosion

At the Anode Fe++ Anode e- e- e- e- e- Fe = Fe++ + 2e- One end of the “battery” Fe++ Anode e- e- e- e- e- Fe = Fe++ + 2e-

At the Cathode H2O OH- O2 Cathode e- e- e- e- e- The other end completes the circuit! H2O OH- O2 Cathode e- e- e- e- e- 1/2O2 + H2O + 2e- = 2OH-

Result: Corrosion Products Form OH- Fe++ OH- Cathode Fe(OH)2 Anode Fe++ + 2OH- = Fe(OH)2

COOLING WATER TREATMENT CORROSION CONTROL Without it.... Destruction of equipment Plant downtime due to equipment failure Decreased efficiency / decreased heat transfer

COOLING WATER TREATMENT CORROSION CONTROL Anodic inhibitors Cathodic inhibitors Continuous feed must be maintained to keep the protective film in place !! Control of blowdown / pH critical to success!!

A and W Cooling Products

A and W Technologies Three-Part Corrosion Protection Deposit Protection Molybdate Tracer Medium to High pH

A and W Inhibitors. . . Reliable Corrosion Protection A and W Passivates Anodic Sites Protects Cathodic Sites Shields Copper Surfaces Reliable Corrosion Protection A and W To Protect and to Serve

------------------------ -iron oxide----------------------- 1. Anodic Protection O2 O2 ------------------------ -iron oxide----------------------- e- e- A and W Inhibitors Passivate the Steel

With A and W . . .

COOLING WATER PROBLEMS SCALE Crystalline structure Combinations of cations and anions Water analysis can provide scaling indices to determine scale forming potential Inversely soluble As temperature increases solubility decreases (scale can come out of solution)

COOLING WATER PROBLEMS FOULING Accumulation of organic / inorganic material Examples: Biological slimes Algae Corrosion products Airborne dirt and debris Subject to flow velocities Organic fouling can be found throughout

Suspends Contaminants A and W Inhibitors . . . Technology Suspends Contaminants

Suspends Contaminants Inhibits Scale Formation A and W Inhibitors . . . Patented Technology Suspends Contaminants Inhibits Scale Formation

Suspends Contaminants Inhibits Scale Formation A and W Inhibitors . . . Patented Technology Suspends Contaminants Inhibits Scale Formation Allows High Cycles

Suspends Contaminants Inhibits Scale Formation Maintains Heat Transfer A and W Inhibitors . . . Patented Technology Suspends Contaminants Inhibits Scale Formation Allows High Cycles Maintains Heat Transfer Efficiency

A and W CHEMICAL FEED CONDENSER WATER A and W AWC AWC AWC AWC TECHNOLOGIES All pumps plug into controller. Blowdown solenoid also plugs into controller. Signal from water meter back to controller if used. Power needs to be supplied to the controller. 110VAC @ 10 amps. 3/4 INCH SCH. 80 PVC Return to Tower USE SCREWED TEES AT INJECTIONS Supply line CONTROLLER A and W CORROSION COUPON RACK 3/4 inch PVC pipe and screwed tees. Notice orientation, with flow. Can be constructed on site. *Presently No Coupon Studies! AWC AWC AWC AWC Awc 310 M-1015 M-1202 CL-1 & M92

COOLING WATER TREATMENT BIOLOGICAL CONTROL Cooling water systems provide an excellent environment for microbio activity Fouling and underdeposit corrosion Toxicant evaluations can determine the most effective biocide BUGS ALGAE

COOLING WATER TREATMENT BIOLOGICAL CONTROL Oxidizing biocides - “BURNS THE BUGS” Chlorine, bromine, sodium hypochlorite Provides quick kill Fed at a rate exceeding the chlorine demand plus 0.5 to 1 ppm free chlorine residual for one to four hours

COOLING WATER TREATMENT BIOLOGICAL CONTROL Nonoxidizing biocides – “POISONS OR STARVES ‘EM” Used where chlorine demand is high or... Supplemental biocide for chlorine Remain in the system longer than oxidizing biocides Provides longer contact time for kill

TESTING AND CONTROL SYSTEM TESTS Conductivity (All systems) pH (City, Tower, All closed loops) Molybdenum (Tower, All closed loops) Cycles (Tower) Microbiological (Tower) Data should be entered in log book or monitored with computer trending

TROUBLESHOOTING Low levels Algae in tower Tower losing water Closed loops losing water High head pressure on chillers Leaks on chemcials Bugs in Chillwater

Cooling Service Program Lab Analysis Water Deposit Metallurgical Test HX Equipment Corrosion studies Chiller efficiency studies Micro-biological studies Cooling tower wood analysis LSI Calculations Quality Assurance

Thank you for the opportunity AT&T A and W Technologies Thank you for the opportunity