Shutting down the chiller system, which cools 10,400 gal of honing oil used in the engine-block cutting process at Ford Motor Co.'s mammoth Essex Engine Plant in Windsor, Ont., would run up costs in service and parts, including a reduction in plant productivity. The best-case repair scenario for the V-6 engine production plant was a projected five-day disassembly of the 24-ton system with hopes that necessary replacement parts were readily available once the leaking component was found. The worse-case scenario was waiting one or two weeks for parts and subsequently renting mobile chillers.
Gerry Miller, the plant's compression-equipment engineer, hadn't heard of refrigeration leak sealants prior to the incident, so he was wary of putting any foreign substance in the system.
“I like only refrigerant and oil in my systems, and that's all, but I had run out of alternatives,” says Miller, a 28-year veteran of refrigeration service.
Previous attempts with electronic leak detection and liquid soaping connections didn't reveal the leak location, but did confirm two realities: The leak most likely was inside the chiller's evaporator in an enclosed tank, and repairing the leak wasn't going to be easy.
To maintain Ford's stringent environmental policies on refrigerant leaks, Miller was preparing a fast-track plan to tear apart the system until Paul Appler, a power engineer and director of research and development for the HVAC/R division of Cliplight Manufacturing Corp., Toronto, suggested using a sealant made especially for refrigeration system leaks.
The relatively new chiller is a 48-ton model with two 25-hp, 24-ton semi-hermetic reciprocating Carlyle compressors with filter driers and expansion valves. The system operates with DuPont R22 refrigerant and Suniso 150-viscosity refrigerant oil.
The unit supplies 55°F (13°C) chilled water to a 50-ton plate heat exchanger that in turn cools the 100°F (38°C) --or higher -- honing oil to an ambient 70°F (21°C). Before the repair, the chiller was operating with:
- 195 psig discharge pressure.
- 219°F (102°C) discharge temperature.
- 212°F (100°C) shell temperature.
- 40 psig suction pressure.
- 77°F (25°C) suction temperature.
- 60° superheat.
Miller exercised a controlled methodical approach to using the sealant. A trial dose of three ounces of Cliplight's industrial strength sealant, Super Seal 3 Phase, designed for five-ton and larger systems, was administered. Because the trial dose stopped 80 percent of the leak without any adverse effects to the refrigeration system components, Miller opted to inject an additional three-ounce dose of sealant. The second injection completely halted the leak, based on system operation statistics of:
- 208 psig discharge pressure.
- 103°F (39°C) discharge temperature.
- 162°F (72°C) shell temperature.
- 68 psig suction pressure.
- 53°F (12°C) suction temperature.
- 13° superheat.
A year later, analysis showed “crystal clear” oil and an acid-free sample, according to Miller. “If there was going to be a problem, it would have surfaced by now,” he says.
For more information, contact Cliplight at (866) 548-3644 or firstname.lastname@example.org.