We continue our discussion from Part One on the vacuum vapor degreasing method by focusing on the subject of part drying.
In aqueous systems, heated air-drying is the most common method used for water removal. However, it is fair to say that most aqueous washers do a poor job of effective drying. Generally ambient air is employed, which depending on the relative humidity can contain significant water vapor to begin with. Upon heating the air becomes saturated and if the temperature can be maintained, can evaporate a considerable amount of water. The problem, however, is not usually in the saturation levels of the air, rather in the heat and mass transfer operations required to accomplish the water removal.