Sweet Success with Ammonia Refrigeration by Randy Williams, GCAP LLC October 1, 2008 ARTICLE TOOLS EmailPrintReprints Share Enlarge this picture Berkey Creamery produces more than 225,000 gal of frozen desserts each year. The ammonia refrigeration system creates the low and ultra low temperatures needed to freeze and store the creamery’s famous ice cream. Ammonia is proving to be a safe and cost-effective refrigerant solution for Berkey Creamery. Berkey Creamery at Penn State University in University Park, Pa., is the largest university creamery in the nation. Each year, approximately 4.5 million lb of milk pass through the creamery’s stainless steel holding tanks. About 75 percent comes from a 300-cow herd at the university’s Dairy Production Research Center, and the rest is purchased from two family farms in the nearby town of Bellefonte, Pa. All milk is sent to the creamery lab for quality control testing before it is processed; after processing, it is sent to various locations to produce products that are consumed on campus, sold from the university store, and marketed through the Internet. Approximately half of the milk is processed into beverage milk, and another 20 percent is used to produce sour cream, ricotta cheese, cream cheese, cheddar cheese and yogurt. But the creamery is most famous for its ice cream, which comprises the remaining 30 percent of its product line. More than 225,000 gal of ice cream are produced annually for university consumption and sales to the general public. Producing such a large quantity of ice cream requires a reliable refrigeration system. The creamery, which was founded in 1865, has a long history with ammonia refrigeration -- it was one of the first food processing plants to adopt ammonia refrigeration technology in 1931 as an efficient replacement for brine cooling. That system was updated in the 1950s and then maintained for the next five decades. By 2001, Berkey Creamery was ready to begin planning for a new manufacturing facility that would be completed in the fall of 2006. The creamery had a decision to make. Should it stick with ammonia or switch to the new Freons that were being touted by some in the industry as a safer alternative? “Folks from Penn State’s Environmental Health and Safety Board were advocating pretty strongly that we move away from ammonia,” says Tom Palchak, manager of the creamery. “They had some concerns relating to the safety of ammonia refrigeration, especially given our proximity to the more than 42,000 undergraduate students at the university, but most of those concerns were based on misinformation. We had a significant amount of experience with ammonia and were familiar with all of its benefits. We had to convince them that ammonia has a very safe track record.” A Safe, Efficient Option Enlarge this picture Dave Long inspects the liquid-line solenoid valve leading to the ice builder. Ammonia supplied to the ice builder creates the 33°F (0.6°C) chilled water used to cool pasteurized milk. Like the condensing system, the ice builder is mounted on the roof and covered to prevent cross-contamination. Palchak and his team were successful, and in September 2006, Berkey Creamery began production in its new ammonia refrigeration plant designed by Food Engineering Inc., Mechanicsburg, Pa. A continuous charge of about 5,000 lb of anhydrous ammonia runs through ice builders, freezers, tanks and other equipment built by Industrial Refrigeration Service Inc., Baltimore, Md. According to Palchak, ammonia was a logical choice for the creamery for a number of reasons. “Ammonia is environmentally responsible and cost-effective. The compressors for ammonia refrigeration systems are also much smaller than the compressors that are sized for refrigeration systems that operate with Freon -- approximately half the size -- which optimizes the space available in the plant. Additionally, the ammonia system is completely contained and self-alarming because of ammonia’s strong scent.” Ammonia also is the most efficient refrigerant for the ultralow temperatures used in the creamery. “We harden our ice cream at about -35°F [-37°C], and we store our ice cream at about -25°F [-32°C]. Ammonia is one of the few refrigerants that can handle those temperatures effectively,” Palchak says. But ammonia also is hazardous and safety is paramount. The creamery included an automatic purging capability. Also, working closely with Food Engineering, the creamery made sure to implement state-of-the-art safety controls in the new plant. The refrigeration system includes ammonia sensors, supplied by Honeywell Analytics Manning Systems, Lenexa, Kan., located strategically throughout the creamery. If a leak activates a sensor, the system goes into an automatic pump-down, and the room containing the leak is isolated. If a leak exceeds 35 parts per million (a strong odor), the local police department is notified automatically. “We built in a number of safety devices and a lot of redundancy as a way to proactively address some of the concerns about ammonia refrigeration,” Palchak explains. In fact, Berkey Creamery was so proactive that its equipment meets OSHA regulations and IIAR standards for plants that use 10,000 lb of ammonia -- more than twice what the plant is currently using. The additional capacity provides some room for expansion and also reassures those on the university campus that the system is designed for safety. “Safety is very important to us,” Palchak says. The Human Element Enlarge this picture Creamery manager Tom Palchak (left) and Dave Long, a maintenance engineer, examine the fan blades in the condensers. The condensing equipment is mounted on the roof of the building and requires periodic inspection to prevent buildup of dust, twigs, leaves and other debris on or near the fan turbines. While equipment safety features are important, they can only go so far. There is also a human element involved in the safety equation, and thorough training is a necessity for anyone who works with ammonia. Berkey Creamery began its training program about six years ago, shortly after it began discussing its new plant. Food Engineering Inc. recommended that Palchak contact Garden City Ammonia Program (GCAP LLC), an industrial refrigeration training firm based in Garden City, Kan. After sending several maintenance personnel to Garden City for hands-on training in GCAP’s laboratory, Palchak and Randy Gilliland, Berkey Creamery’s ammonia engineer, were impressed with the level of knowledge and confidence the individuals displayed when they returned to the plant. The training program, part of GCAP’s Industrial Operator I course, covered the basic engineering of a refrigeration system, the various stages of refrigeration, the uses for each stage, and the regulatory requirements and dangers of ammonia. For the next several years, as new employees joined the creamery or as experienced personnel required more advanced training, Palchak and Gilliland sent creamery staffers to GCAP for training. Then, in February 2008, the plant decided to take training a step further and bring GCAP into the Berkey Creamery facility so that employees could receive hands-on training on the plant’s own equipment. Enlarge this picture Tom Palchak and Dave Long take a reading on the auto-purge system. The auto-purge saves energy and lowers costs by removing noncondensable gases from the refrigeration system. “We had been compliant with our training in the past, but this program allowed us to take training to the next level and really give our maintenance employees the confidence they needed to have a better feel for their jobs and a higher level of confidence when they’re handling a hazardous material,” Palchak says. As with any manufacturing plant, cost was a consideration. Berkey Creamery has spent thousands of dollars on safety training over the past six years, and bringing GCAP to the Penn State campus for a training session was a considerable expense. But the payoff has been dramatic. Employees who undergo the training understand the principles of ammonia refrigeration and how it develops in various stages, such as a gas, a liquid, a high-pressure gas and a hot gas. They understand how to deal with pressurized systems and how to handle problems. “In one case, we had one of our liquid feed pumps fail and we had a small release,” Palchak explains. “It wasn’t substantial -- not enough to shut down the system -- but it was enough to show an indicator light on the ammonia sensor. Because the employees had been trained to handle this kind of situation, they knew exactly what to do. They handled the problem in a very thoughtful and procedural manner rather than just reacting to a leak. The training allowed them to deal with a situation that they don’t find themselves in very often. “I look at it this way: Is it more expensive to deal with training, or to pay the consequences because of a lack of training? Being proactive about training is definitely the better option,” Palchak adds. Ammonia refrigeration is helping Berkey Creamery cost-effectively produce hundreds of thousands of gallons of delicious ice cream and other dairy products each year. By remaining proactive in ammonia safety training, the creamery likely will maintain its leadership status in both dairy products and ammonia safety for years to come.