Brewery Refrigeration
Chillers
Brewery chillers consist of a closed-loop tubing attached to the heat exchanger of a beermaking vessel (Figure 22.2). Chillers contain an evaporator, a compressor, a condenser, and an expansion unit. Glycol or a mixture of water/glycol or brine flows through the circuit and cools the vessel by extracting heat from the heat exchanger.
Sizing the Chiller
Because of the wide range of temperatures (loads) required in producing beer, the system must be designed to handle all the different loads as efficiently as possible. The most important issue therefore is to size the chiller accordingly. For most breweries, sizing a chiller means getting the proper tonnage of capacity, and this means breweries should probably involve refrigeration consultants.
Glycol
Water is an excellent secondary coolant because of it is inexpensive and has favorable thermodynamic properties, and is used in some breweries at about 2 to 5 degrees C (36–41°F). However, water has a freezing point of 0 degrees C, (32°F) which limits its use in the brewery, i.e., it cannot be used for cold-stabilization. Another option is glycol, a coolant which has a freezing point at about -12.9 degrees C (8.9°F).
Water/Glycol Mixture
Most breweries use a 30 to 45 percent glycol mixture, depending on the application, for their coolant liquid as it provides several benefits over just normal water:
Distribution System
The distribution system consists primarily of water/glycol piping and a pump, or pumps depending on demand. The pump pulls glycol from the storage vessel and cycles it through all equipment to be temperature controlled before returning it back to the storage vessel. This process transfers heat back into the glycol storage vessel. The pump(s) should have a manifold with a non-return valve that stops any flow when the pump is not operating.
Portable Chillers
For many small breweries, the issue with refrigeration has long been the size of the equipment and the cost. Typically, large, stationary systems may be beyond their means; and as a new brewery, they might not have a completed structure to house mechanicals and related plumbing.
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