C4: CRITICAL CLEANING FOR CONTAMINATION CONTROL: The Basics of NON- Evaporative Parts Drying

摘要

In last month's column about the basics of drying, we covered removal of water from surfaces by evaporation. For most managers of critical cleaning operations, drying may not be synonymous with evaporation. Drying of rinse water by evaporation can be the most costly, energy, and time-consuming stage in the cleaning of parts. Even worse, whatever is non-volatile in the rinse water (minerals, detergents, ions), is left behind as surface imperfections. In some critical applications that can be fatal; the point of cleaning work, after all, is to remove surface imperfections--not generate them. The second general method for drying parts of liquid films is to apply force to the films so as to dislodge them from surfaces. At least three types of force may be used: centrifugal, mechanical, and surface tension.