Vacuum Flash Cooling

Vacuum flash cooling is a technique to rapidly cool any product which contains water. The driving force behind this technique is the use of evaporative cooling principles. As the vapor pressure of a liquid decreases, so does its boiling point. By rapidly reducing the pressure of a product wet with free standing water, the liquid water quickly evaporates. The water absorbs the required latent heat during its phase change from a liquid to vapor. As a result, the temperature of the product decreases. The cooking industry extensively uses this process where flash cooling greatly reduces the time required to cool the cooked product, increasing production. The cooling improves the product quality; thus, increases the shelf life of perishable products which makes this cooling technique popular in the food and baking industry.

Generally, Wintek would recommend using a liquid ring vacuum system for flash cooling applications. The liquid ring pump is robust and can be used to pull low vacuum levels, which is all that this application requires. Because water is usually the solvent being removed from the product, water can be used as the sealant and recovered. This lowers the operating cost by eliminating the need to provide fresh sealant to the liquid ring pump.