Evaporation and settling behavior of metalworking fluid aerosols

Environmental and industrial hygiene issues have been receiving ever increasing attention. One important issue is metalworking fluid (MWF) mist formation since it can have a negative effect on workplace air quality. A model is presented to characterize the evaporation and settling behavior of a diluted water-soluble MWF mist under ambient conditions. The model is based on the Langmuir-Knudsen law and Stokes? law. The Langmuir-Knudsen law is employed to describe the evaporation process of each MWF droplet and allows for nonequilibrium effects associated with small droplet size. Stokes? law is applied to characterize the droplet settling mechanism at small Reynolds numbers. Experiments are performed to validate the model. Experiments show that the evaporation rate decreases to zero as the water in a droplet completely evaporates to produce a small nonvolatile oil drop. It is found that the evaporation and settling of a collection of MWF droplets can be predicted by the proposed model