The company responded quickly. Key to resolving this problem was its portable, high-speed recovery-reclamation unit called the “RPS.”
Equipped with this unit, two CFC technicians were dispatched to the facility. Ideally, they would have pulled the charge and reclaimed refrigerant because it’s a faster procedure, removing all the oil in one pass.
This was not an option, however. The system could not be shut down, and the customer insisted that the technicians sidestream the refrigerant.
This process cooling system was unusual in that the compressor was used to subcool the refrigerant in the evaporator, then 40ÞF liquid refrigerant was pumped to air handlers throughout the facility.
The advantage of this liquid overfeed system lies in its ability to dehumidify huge amounts of air, and dehumidified air is critical to this particular facility.
CFC Refimax used the liquid pumps on the system to pump 2,000-lb batches of oil-laden, 40° liquid refrigerant into the RPS. The unit distilled and filtered the refrigerant to ARI 700-93 standards, then pumped the clean refrigerant back into the evaporator.
This process was repeated dozens of times until the 16,000 lb of refrigerant had been processed four or five times.
Oil removal (water too)
With each batch, the oil-saturated refrigerant was gradually diluted with ARI 700-quality refrigerant until the oil content of the remaining charge was down to about 1%.More than 100 gal of used refrigerant oil were removed from the refrigerant, approximately 4.5% of the refrigerant charge.
Industry experts estimate that a centrifugal chiller loses approximately 2% of its efficiency for every 1% of oil. This translates oil removal into significant energy savings and improved chiller performance.
After processing 65,000 lb of R-134a in just over two days, the recovery-reclaim firm removed the non-condensables from the system. A purge system eliminated the air and reduced the head-pressure and corresponding energy demands of the system.
Attention was then turned to a smaller, 3,000-lb R-134a system that had been giving the facility technicians some trouble. Using the RPS, technicians began evacuating the charge and discovered that the system was full of water. They had filled the recovery-reclaim unit with standing water and refrigerant!
The refrigerant and water were transferred to holding cylinders. Then the RPS was purged and dehydrated of all moisture. The water and refrigerant in the holding cylinders were run through a water separator to eliminate standing water, then reclaimed to ARI standards. Once cleaned, the refrigerant was transferred to a holding vessel.
When the chiller was opened, water streamed out of the bottom and facility personnel elected to get an eddy test done to determine its source.
While waiting on the eddy current results, the CFC technicians were asked to sidestream the refrigerant in another 3,000-lb system to remove oil, air, and “crud.” By the close of this assignment, three different chillers had been processed.
The benefits to the customer were said to be both immediate and long term.
CFC Refimax currently has operations in Orlando Fla., Houston, and Atlanta. The company may be reached at 1935 Delk Industrial Blvd., Marietta, Ga. 30067; 770-984-2292; 770-850-0862 (fax); or sales@refi max.com (e-mail).
