AMMONIA CONDENSERS WATER TREATMENT BEST PRACTICES

PETER BRUNO JUSTIN SPRINGER DISTRICT MANAGER – WISCONSIN AREA MANAGER – SOUTHERN WISCONSIN

5/9/18

1 Agenda

 Why Treat Ammonia Condensers?

 Initial Passivation

 Galvanizing and White Rust Awareness

 Stainless Steel Condenser Considerations

 Treatment Options

 Questions Why Treat Ammonia Condensers

Ensure asset protection Optimize energy efficiency Manage water usage MICROBIO Minimize health risk CORROSION Evaporative Cooling – Common Issues

Typically poor water distribution - Makeup - Circulation - Mineral Concentration - Small basins

Blowdown and water chemistry control

Galvanized metallurgy Condenser Configuration - Common or Central Sump

• Multiple Condensers Blowdown • Common Sump Raw Water • Chemistry balance Make-up Trasar

The Common sump system makes it easier to chemically treat. Initial Passivation Best Practices for Galvanized Condensers

• 1ST option : Phosphate based treatment • 2ND option : Zinc based treatment (AZ Lite ) • Re-passivate after major shutdown or maintenance Initial Passivation Best Practices for Galvanized Condensers Galvanized Condensers

Galvanize passivation is not bullet proof. Even with good control some customers still experience white rusting.

Passivation just reduces the risk of white rusting.

15 Initial Passivation Best Practices for Stainless Steel Condensers

Clean and passivate based on other metallurgy in the system – Copper, Mild Steel etc.

If only stainless Steel in system

 First 72 hours of operation 1.5-2X the Scale and corrosion inhibitor

 Use Surfactant (Nalprep) during the first 72 ▪Removal of oils and biofilm GALVANIZED CONDENSERS Scale and Corrosion

17 HEAD PRESSURE Scaling and Fouling

 Insulates tube bundle

 Condensing less efficient

 Compressors must work harder to achieve liquid state (0.67 kw/ton)

 Higher compressor head pressure…more electricity consumed

 ~2.5% energy per 5-psi head pressure change

 1,000 tons refrigeration costs ~$400,000/yr in electricity

Reference : BAC bulletin SEN5M/03/00 HEAD PRESSURE Scaling and Fouling

Reference : BAC bulletin SEN5M/03/00 HEAD PRESSURE Scaling and Fouling

Reference : BAC bulletin SEN5M/03/00 HEAD PRESSURE Mist Eliminators

Reduces forced air flow

Condensing less efficient

Compressors must work harder to achieve liquid state

Higher compressor head pressure…more electricity consumed

~2% energy loss for plugged eliminators HEAD PRESSURE Spray Pattern Reduces condensing efficiency

Increases potential for scaling

Results in more condensers than needed HEAD PRESSURE Spray Nozzles Must have regular maintenance and inspection

Proper pressure and circulation

Recommend minimum quarterly inspection AMMONIA REFRIGERATION Other Challenges

Purge of non-condensable

Ammonia leak-nitrifying bacteria

Circulation capacity

Annual cleaning

External water leaks AMMONIA REFRIGERATION Galvanizing and White Rust

Porous zinc carbonate- rapidly formed in pH>8.3 AMMONIA REFRIGERATION Galvanizing and White Rust

White, fluffy or waxy non- protective zinc corrosion product

Can be removed mechanically AMMONIA REFRIGERATION Galvanizing and White Rust

Erodes over time leaving iron exposed

When zinc consumed, iron corrodes rapidly in aerated, warm environment STAINLESS STEEL CONDENSERS Stress Corrosion Cracking

29 Stress Corrosion Cracking

Stress Corrosion Cracking ▪The combination of a stress within the metal and a specific corrosive species that results in a crack ▪Cracking does not occur due to stress on its own or the corrosive species on its own. Both need to be present at the same time 31 Stress Corrosion Cracking

The cracks have a typical branching type structure Stainless Sandvik Risk Curve AMMONIA REFRIGERATION Acid Feeding and Ammonia Condensers

 Common sump only…never individual NH3 In

Ammonia Optional neat feed of acid to mix area or integral sumps Condenser(s) using dilution trough. NH3 Out

Recommended: Open tank Common Sump Kynar lined corp stop  Proper pump, tubing and connector (231-P6036.88)

material CirculatingCentrifugal pump Pump

Recommended: Polyethylene Tube (100-ft, 001-H00024.88)  Secondary containment of tubing Separate by 3-ft minimum

 Mixing required

Recommended: Sample Line for LMI 38 gpd Pump Trasar, pH, Conductivity, etc. B111-92S Minimum 10 gpm. (001-H02160.88) Recommended: Walchem WPH310 pH Controller Includes: Kynar head, SulfuricOpen Acid tank Drum (021-CL1008.88) injection valve, foot valve  Redundant controllers or 3D Corrosion/Scale Biocide and 16-ft of polyethylene Inhibitor tubing

Containment Basin Recommended: 2-drums controller (241-CW1012.88) 1. Acid feed is not recommended for systems without a common or remote sump. 2. pH controller must send alarm signal to light and/or alarm in both the sump area and plant engineering office. 3. Containment basin must be checked and logged daily for acid leaks. 4. Acid feed pump must be permanently mounted. 5. Acid feed tubing must be enclosed in Schedule 80 PVC pipe and graded to drain back to containment basin. 6. Acid feed pump must be tied to circulating pump control loop. No chemical feed is allowed if system in not  External alarm to light or horn circulating. 7. The recommended sample line is 3/4-Schedule 80 PVC pipe. AMMONIA REFRIGERATION If no Acid Feed Available

White Rust Inhibitor is an option ▪ Base feed of 50 ppm along with scale and corrosion inhibitor Summary

Good passivation is a must to minimizing white rust formation.

Follow the manufacturer guidelines for passivation and chemical control.

An program that utilizes acid may be the only solution for long term control of white rust.

35 Questions Thank You!

Peter Bruno Justin Springer District Manager - Wisconsin Area Manager – Southern Wisconsin 920-915-6618 608-770-9798