The Dow Chemical — Technical Presentation (September 2021)
31 slides from The Dow Chemical's technical presentation, September 2021
Slide 1: Dispelling the Myths of Heat Transfer Fluids
Dispelling the Myths of Heat Transfer Fluids Kevin Connor – The Dow Chemical Company
Slide 2: Heat Transfer – Chill Water Loop
Heat Transfer – Chill Water Loop Secondary Coolant Primary Refrigerant (Heat Transfer Fluid) Expansion Device Air Handler Evaporator Condenser Pump Compressor 2
Slide 3: The Need for “Antifreeze”
The Need for “Antifreeze” • Water is almost a perfect fluid… – Excellent heat transfer – Excellent health & safety – Low cost • BUT water freezes at 0oC / 32oF • Antifreeze protects system piping and components from damage caused by freezing – Volume expansion due to ice crystals generates pressure
Slide 4: Heat Transfer Fluid “Wish List”
Heat Transfer Fluid “Wish List” • Effective freeze protection – Freezing point below -40oC / -40oF • Efficient heat transfer over broad temperature range – -15oC to 125oC / 0oF to 250oF • No harmful effects (health, safety, environment) – Non-toxic, non-flammable, environmentally benign • Non-corros
Slide 5: Choice of Heat Transfer Fluids
Choice of Heat Transfer Fluids • Salt based (brines) • Alcohols & Glycols – Lithium bromide ̶ Methanol – Calcium chloride ̶ Ethanol – Magnesium chloride ̶ Ethylene glycol – Sodium chloride ̶ Propylene glycol – Potassium acetate ̶ 1,3-propanediol – Potassium formate ̶ Glycerin – Potassium carbonate •
Slide 6: Impact on Freezing Point
Impact on Freezing Point Data from Melinder 2007 “Thermophysical Properties of Aqueous Solutions Used as Secondary Working Fluids “ 6
Slide 7: Impact on Corrosion
Impact on Corrosion 15% Methanol 15% Propylene Water Glycol 7
Slide 8: Corrosion
Corrosion • All salts are very corrosive – Long term protection is impossible even with corrosion inhibitors • Glycols or alcohols (without corrosion inhibitors) are corrosive to most metals – Oxidize to form acids low pH acidic pH is corrosive – Must use correct type of corrosion inhibitor tech
Slide 9: Corrosion Control
Corrosion Control • Corrosion can be limited by control of key environmental variables ̶ Design & Operation ̶ Materials ̶ Temperature & exposure to O2 ̶ Fluid Chemistry ̶ Corrosion inhibitors & pH ̶ Fluid purity • Maintain metal in passive rather than active state – Corrosion rate 1000 times lower
Slide 10: Impact on System Efficiency
* Data from Melinder 2007 Impact on System Efficiency “Thermophysical Properties of Aqueous Solutions Used as Secondary Working Fluids “ Physical Properties @ 10oC/ 50oF Thermal Volumetric Heat Fluid Description Freezing Point Conductivity Capacity Viscosity (cP) ( oC ) (W / m.K) (kJ / L.K) water 0
Slide 11: System Performance
System Performance • Adding antifreeze to water negatively impacts system performance – Must trade performance for freeze protection • Reduced heat transfer efficiency ̶ Antifreeze decreases thermal conductivity & specific heat ̶ How much will system performance be reduced? ̶ Regrettably there is no
Slide 12: Impact on Health & Safety
Impact on Health & Safety • Methanol and ethylene glycol are classified as moderately toxic – About 125 mLs is lethal dose for typical sized adult • Industrial ethanol (not for consumption) is denatured – Can contain methanol, pyridine or other (toxic) denaturants • Only propylene glycol is formally
Slide 13: Fire Safety: Flash point temperature
Fire Safety RCRA hazardous OSHA hazardous waste (ignitable) material (flammable) 122 115 Flash point temperature [deg F] 109 103 LFL “pure” ethanol = 4% 99 Flash pt = 13oC / 55oF 96 93 91 89 84 86 Trademark of The Dow Chemical Company 13
Slide 14: Advantages of Using Glycol
Advantages of Using Glycol Effective Freeze Protection Non-corrosive (if properly formulated) Relatively Efficient Heat Transfer No Adverse HS&E Effects Heath – Low toxicity (PG fluids) Safety – Non-flammable Environment – Readily Biodegradable Relatively Low Cost 14
Slide 15: Advantages of Choosing Dow
Advantages of Choosing Dow • Dow heat transfer fluids are properly formulated with corrosion inhibitors and pH buffers which ̶ Passivate metal surfaces prevent corrosion ̶ Neutralize degradation compounds prevent pH drop ̶ Thermoxidatively stable provide long term protection • Avoid cooling tow
Slide 16: DOWTHERM™ SR-1 Fluid
DOWTHERM™ SR-1 Fluid • Ethylene glycol-based fluid (95%) • Fluorescent pink • Efficient heat transfer – -28° to 120° C • Provides freeze / burst protection – -51° C / -60° C (depending on concentration) • Dow is the oldest back-integrated supplier of glycol based heat transfer fluids: – DOWTHERM™ SR
Slide 17: DOWFROST™ Fluid
DOWFROST™ Fluid • Propylene glycol-based fluid (96%) • Water white • Low toxicity – fully complies with FDA & NSF regulations – Made with DOW PuraGuard™ Propylene Glycol USP/EP • Efficient heat transfer – -18° to 120° C • Provides freeze / burst protection – -51° C / -60° C (depending on concentrati
Slide 18: Advantages of DOW PuraGuard
Advantages of DOW PuraGuardTM • DOWFROST™ is the only inhibited glycol made with DOW PuraGuard™ Propylene Glycol USP/EP, a pharmaceutical grade of monopropylene glycol with a specified purity of 99.8% or greater • Competitive products are made with lower quality PG ̶ Fluid lifetime & safety are comp
Slide 19: DOWFROST™ HD Fluid
DOWFROST™ HD Fluid • Propylene glycol-based fluid (94%) • Fluorescent yellow • Fortified inhibitor package versus regular DOWFROST™ – Does not have same FDA / NSF approval • Efficient heat transfer – -18° to 135° C • Provides freeze / burst protection – -51° C / -60° C (depending on concentration) •
Slide 20: DOWFROST™ GEO 20
DOWFROST™ GEO 20 • Propylene glycol-based fluid (20 vol%) – Fluorescent yellow • Designed for Geothermal Heat Pumps – Lower concentration means lower pumping cost & higher heat transfer efficiency – Excellent corrosion protection – Bio-static concentration (will not support bio-degradation / bio- fo
Slide 21: Which Product Do I Choose?
Which Product Do I Choose? • Ethylene glycol (EG) is moderately toxic – ~½ cup is lethal to an average size adult • Propylene glycol (PG) is essentially non-toxic – Approved by FDA as direct food additive • Use DOWFROST™ for low toxicity needs – Food processing (DOWFROST™ only) – Schools or hospital
Slide 22: Avoid Poorly Formulated Products
Avoid Poorly Formulated Products Metal Test ASTM Data Limit Copper 1.6 10 Solder 9.2 30 Brass 3.7 10 Steel 199 10 Cast Iron 297 10 Aluminum 88 30
Slide 23: Tips for Proper Operation
Tips for Proper Operation • Use purified water (distilled, de-ionized) for dilution • Install and maintain “correct” glycol concentration – Over-dilution causes corrosion & bio-fouling – Too concentrated causes poor heat transfer • Operate within recommended temperature ranges – Over-heating c
Slide 24: Water Quality
Water Quality • Salts cause corrosion • Hardness causes scales & sludge • Requirements for dilution water ̶ Chlorides <25 ppm ̶ Sulfates <25 ppm ̶ Total hardness (as CaCO3) <100 ppm
Slide 25: Over-Dilution
Over-Dilution • Over-dilution causes corrosion and bio- fouling ̶ Glycol degradation ̶ Unpleasant odors • Minimum concentration ̶ 20% - 25% Bio-fouling - customer sample with • Maximum concentration 11% propylene glycol ̶ 60% - 65% 25
Slide 26: Over-Heating
Over-Heating • Fluid degradation and corrosion increase as temperature increase ̶ Fluid life compromised • Temperature limits ̶ Max bulk: 250 F to 350 F ̶ Max film: 300 F to 400 F Increased time / temperature, exposure to 02 / air
Slide 27: Dow Analytical Service
Dow Analytical Service • Free service if system contains more than 250 gallons of DOWTHERM™ SR-1 / DOWFROST™ • Sample analysis kits are available from Dow – “2 PAK’s” and “6 PAK’s” • Send samples to Dow laboratory and receive comprehensive analysis & report within 2 weeks • Detailed analysis: – Glyc
Slide 28: Sample Kits
Sample Kits Speer wren atu ne Fiurw ANALYSIS Krr Heat Transfer Fluids
Slide 29: Example Report
Example Report The DOW CHEMICAL COMPANY DOW FROST* Moat Trameter Flutie DOW FROST* Sample Analysis Repert —e Ramuyple Received. 01/04. 2002, TENAS OFPRATIONS, 2301 BRAZOSPORT Sample Number 2002-001-0036 EREEPORT. Togin Number (12-2062 0007 Report Date: Daa 2002 This is a copy of the report for: Dist
Slide 30: The Bottom Line
The Bottom Line • Glycol based fluids provide excellent overall protection • Understand the impact that glycol has on water • Trade off between performance versus freeze protection • Select and use a properly formulated glycol based fluid • Specifically designed for HVAC applications • Correctly ins
Slide 31: www.dowfrost.com
www.dowtrost.com Solutions for life.
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