Because the coil never freezes and defrost cycles are not required, the leaving-air conditions remain constant. Liquid desiccant systems can be used with any type of refrigerant or refrigeration system. Calcium and lithium chloride use is not permitted with edible food product. The biggest problem with inorganic salt solutions is that they are highly corrosive. Thus, there is the potential for increased maintenance costs.
Propylene glycol is well-suited for liquid desiccant systems used in food processing operations.
Does not have corrosive characteristics. Is effective as a food preservative. Is more effective than the inorganic salts at lower temperatures. The temperature and concentration of the desiccant liquid determines the leaving dry bulb and dewpoint. In a glycol system, the concentrator portion monitors and adjusts the desiccant's concentration levels by removing excess moisture.