Specialized Services for Ammonia Refrigeration
Airgas Specialty Products understands the unique needs of the industrial ammonia refrigeration industry. We are active members of the Refrigerating Engineers and Technicians Association (RETA), the International Institute of Ammonia Refrigeration (IIAR), and the International Association of Refrigerated Warehouses (IARW).
Offering a nationwide fleet of trucks dedicated to ammonia delivery, anhydrous ammonia safety training, and ammonia services, Airgas Specialty Products can help keep your business running smoothly.
Ammonia Contamination in Refrigeration Applications
The impurity difference between agricultural grade ammonia and refrigeration grade ammonia is only 0.48%, though this is enough contamination to have a negative effect on system components and efficiency. Less than a half a percent of contamination makes ammonia unsuitable for refrigeration and that means even small amounts of impurity can make your system less efficient. The financial impact of electrical inefficiency alone can be substantial.
For each degree Fahrenheit that suction temperature is lowered, compressor capacity is reduced approximately 2-½% for high stage and 3 % for boosters. If the average system costs $20.00 per hr. per compressor to operate there would be an additional cost of $4,380.00 per year for each high stage compressor and $5,256.00 for each booster compressor.
This net result is that lowering suction temperature by 1º can cost you $5,000 per year per compressor.
One obstacle to keeping the most efficient system possible is keeping your ammonia dry, or contaminant free. Even well maintained systems that haven’t experienced a contaminating event like a puncture in a water chiller will still collect water over time.
One reason is that air contains moisture. Air is introduced through a variety of ways including regular maintenance. While the air is evacuated by using an air purger, this process leaves the water behind to collect over time. The level of water and oil contamination in your system can be tested with a cold flo sample taken from the low side of your system. Contact Airgas or your refrigeration contractor to include sampling as a part of your maintenance program.
Should you find contamination, stop-gap measures like draining oil and water from the low parts of the system may partially address the contamination issue. Real improvement requires a system pump-out or ammonia purification process known as distillation. Water in the system can actually change the molecular structure of ammonia form NH3 to NH4OH. Your system may be able to function at a satisfactory level, but will have to work harder and consume more power to achieve the same level of cooling.
Start over…think about a system pump-out.
If pipe or equipment repairs are in order, a pump-out may be the perfect answer to getting your facility back to peak condition.
Expansions provide another opportunity to fill your system with 99.98% pure anhydrous ammonia. When considering a pump out, there are several important questions to ask including:
- Do you need to pull a vacuum on the system? If so, is your pump-out provider equipped to meet this need, and how long will it take?
- When do you need the pump-out? Do you require service over a holiday, on a week-end, or other special time frame?
- What does the service provider do with the ammonia? Is the ammonia recycled?
- Does the provide have a good record of safety?
Never underestimate the importance of questions such as these. Hiring an inexperienced or under equipped pump-out provider can result in high labor charges and poor results.
Can’t shut down? Try Distillation.
Airgas Specialty Products can remove contaminants such as oil or water without stopping the operation of an ammonia system with our Distillation Unit. The Distillation Unit has shown tremendous results in field tests – leaving ammonia virtually contaminant-free. The self-contained portable Distillation Unit allows customers to regain efficiencies lost due to oil or water contaminated ammonia. In fact, recent tests conducted at customer locations removed 96% of total contaminants on average.
Ammonia purity is critical to maintain system efficiency and operating costs. To maintain maximum efficiency, an ammonia monitoring procedure can be implemented. Should contamination build up in your system, energy savings, equipment function, and wear and tear are few of the reasons to request a system pump-out. For more information contact Airgas Specialty Products at (800) AMMONIA (800-266-6642) or email us here.