Cooking with steam and getting hot water in return
Hormel Foods is well known for its variety of meat products in microwaveable, refrigerated and canned formats. It makes a variety of canned poultry, pork and beef products including Hormel chili products, Dinty Moore hearty meals, Hormel chicken breasts and, of course, its legendary SPAM family of products.
The processor is also an industry leader in sustainability efforts. For instance, in 2010, the Hormel Foods Progressive Processing facility in Dubuque, IA became the first USDA-inspected refrigerated foods production plant to earn LEED gold certification.
The company’s canned, shelf-stable products are sterilized in their containers via a saturated steam retort process. “The typical saturated steam process includes a validated retort vent schedule in which steam rids the vessel of air. The steam is vented to the atmosphere through roof penetrations,” says Terry Miller, supervising staff engineer for Hormel Foods. But, what if that energy could be recovered and put to a better use rather than sending it “up the chimney?”
In 2010, Allpax, a Pro Mach business, developed a steam recovery system that captures the vented steam while complying with FDA/USDA requirements prohibiting back pressure on the vent discharge line. (Steam recovery units are currently supplied on new Allpax retort installations or can be added to existing retort lines.)
The recovery system utilizes the steam energy (that is normally vented into the atmosphere) to create 180°F hot water, which is subsequently used in plant operations. The system not only saves water, it saves the steam that would normally be required to heat ambient water for use in a plant.
The system installed at the Progressive Processing facility in Dubuque creates 60 to 70 gallons per minute of hot water at 180°F when the retorts are in the vent phase of the cycle. “The retort line accumulates a maximum of 480 minutes of venting time daily. This equates to a maximum of 33,600 gallons of hot water from the heat recovery system delivered by Allpax Products,” says Miller.
The steam recovery system uses a recapture tank outfitted with an internal steam condenser to create hot water. Instrumentation and valves ensure the unit meets FDA/USDA requirements. The system also can maintain the level in the hot water capture tank and provide hot water for use elsewhere in the plant. The system operation is PLC controlled and features a 15-in. color touchscreen for operator interface. Once installed, the system does not require an operator and is virtually maintenance free.
“Based on the hot water the system generates, the savings in water and steam represent a viable return on investment,” Miller says.