Vacuum drying is the process of removing bulk moisture from a wet solid by exposing the mixture to high levels of vacuum. Drying is an essential operation in many different processes and is commonly seen in the food processing, pharmaceuticals, agriculture, powders and textiles industries.
A vacuum system is generally configured to pull vacuum on a large drying vessel. As the pressure within the vessel lowers to the vapor pressure of the liquid, the moisture will vaporize. Vacuum dryers are sometimes equipped with heaters to increase the temperature of the vessel. This increase in temperature coupled with the decrease in pressure allows for very high evaporation rates to occur. Once in vapor form, the moisture is removed from the dryer by a vacuum system and can be condensed and recovered, if desired.
Wintek has extensive experience in the vacuum drying industry and works closely with many of the dryer manufacturers.
Generally, Wintek recommends liquid ring vacuum systems for dryer applications because they are more rugged and can handle liquid and solid process carryover better than other types of vacuum pumps. While most dryers are equipped with some filtration to prevent their product from leaving the vessel, there is often a small amount of product that is not captured. Wintek’s process vacuum systems are ideal in these scenarios. In the case of a dryer not being equipped with filtration, Wintek can provide systems with knockout pot filtration vessels to be included in the system package to protect the system from process carryover.