In this case, Honeywell GenetronÂ® AZ-50Â® R-507 was the chosen refrigerant. According to Honeywell, the retrofit was one of the largest of its kind and required more than 27,000 pounds of its product.
The project was a collaborative effort with RSD-Total Control and Chill-Tek Inc. RSD-Total Control, of Lake Forest, Calif., is a regional wholesaler of refrigerants, refrigeration and air conditioning components, and control systems. In operation since 1933, RSD-Total Control is a major distributor of Honeywell refrigerants and is said to have purchased the first cylinder Genetron made more than 50 years ago.
Headquartered in Manhattan Beach, Calif., Chill-Tek Inc. is an EPA-certified refrigerant recovery and reclamation company. It provides a range of technical services such as recovery of low- and high-pressure refrigerants, on-site cylinder evacuation, refrigerant and oil analysis, and mixed refrigerant disposal. Chill-Tek serves a broad customer base that includes contractors, wholesalers, and municipalities.
"This project took the experience and expertise from all companies involved," said Gary Lawson, CEO of Race Engineering. "This was a massive retrofit, but the collaborative effort made it a success."
Race was tasked with completing the retrofit with minimum production downtime. To accomplish this task, they first planned to evacuate the alkyl benzene oil charge, replacing it with polyol ester oil, designed to provide proper solubility and lubrication when paired with an HFC refrigerant. According to Lawson, Chill-Tek was instrumental in performing the oil change while the system was still operating on R-22. This contributed greatly to minimizing production downtime, he said.
They first pumped down the refrigerant into the in-line liquid receivers during the weekend of the conversion. Chill-Tek was then able to recover more than 24,000 pounds of R-22. While the recovery was underway, Race installed larger liquid lines and replaced the thermal expansion valves.
R-507 is an HFC refrigerant that is labeled as nonozone depleting and is considered environmentally friendlier than CFC and HCFC refrigerant products. The production and use of HCFC R-22 is being phased out in accordance with the Montreal Protocol, and refrigeration-dependent industries continue to retrofit systems using environmentally friendlier products such as HFC refrigerants.
To complete the retrofit, Race charged the system with 27,200 pounds of Genetron AZ-50. The technical team completed the retrofit in just 72 hours.
"We have experienced compressor capacity increases, along with motor rating increases, which required load-limiting control modifications," said Lawson. "We also expect the food manufacturer will experience oil separator gas velocity increases."
Race evaluated a number of potential refrigerant products for the retrofit, including R-404A and R-417A, taking into account issues such as flooded evaporators used in the system. Race said he selected R-507 because it is an azeotrope (a blend that acts as a pure fluid), and because it offered the cooling capacity and efficiency necessary to meet the critical needs of the customer.
For more information, visit www.honeywell.com/genetron.
Publication date: 05/29/2006