To reduce energy consumption and improve the performance of its beer cooling process, the Stroh Brewery Co. analyzed the glycol circulation system used for batch cooling of beer products at its Heileman Div. brewing facility in La Crosse, WI. By simply reducing the diameter of the pump impeller and fully opening the discharge gate valve, cooling circulation system energy use was reduced by 50%, resulting in savings of $19,000 in the first year. With a cost of $1,500, this project realized a simple payback of about one month.
Brewing at the La Crosse facility is conducted on a weekly cycle beginning Sunday night, though not all tanks are cycled each week. After brewing is completed, the beer is cooled in a heat exchanger to 54°F (12°C) and moved to storage tanks. The beer is further cooled in the storage tanks by a glycol cooling system. A solution of water and 36% propylene glycol is pumped through a 400-ton chiller that uses ammonia from the central refrigeration plant to cool the solution to 22 to 24°F (-4 to -5°C). The glycol solution then is channeled through an intricate piping and pumping system to cool the beer storage tanks. This pumping system was the focus of the energy-saving efforts.