mass transfer resistance, drying, condensation, dishwasher
During the drying phase of a dishwasher, water evaporation and condensation phenomena take place. Some wet surfaces inside the dishwasher are above the local air dewpoint and will experience evaporation, while other surfaces are below the local air dewpoint and will experience condensation. In this study, the evaporation mass transfer resistance of a standard load used in a household dishwasher was experimentally measured. The standardized load measurements were taken in situ during a regular drying phase after the ordinary washing was complete. To determine the mass transfer resistance of condensation, a tub wall sample was cut from the interior of a commercially available dishwasher. The wall samples were tested ex-situ in a benchtop psychrometric chamber to determine the condensation heat and mass transfer coefficient. The wall samples were locally cooled using a thermoelectric module. The experimental results were compared to those from a heat and mass transfer resistance correlation. The measured evaporation and condensation mass transfer coefficients can be used to model the drying process in a humid and stagnated environment.