Investigation of drying conditions for dental practice loads

Abstract

This thesis investigates different drying techniques for dental practice loads experimentally and numerically. Several experiments are carried out by changing both top and bottom wall temperatures while changing the ranges of the pressure pulses during the drying phase. The studies show that both cases result in the best drying quality with only 2 grams of water remaining on the pouches at the end of the cycle under the conditions where the pressure pulse ranges from 14 to 16 kPa at a wall temperature of 170ºC and when the pressure ranges from 14 to 18 kPa at a top wall temperature of 160ºC and a bottom temperature of 170ºC, respectively. In addition, several simulations are presented using the COMSOL Multiphysics software to study the effect of fluid velocity on the evaporation rate of water droplets. Also, the effects of changing the top and bottom wall temperatures on the natural circulation and thus on the average velocity inside the chamber. Finally, the effects of changing both the wall temperatures and the pressure pulses range from 15 kPa to 20 kPa after one complete pressure pulse is presented. The maximum energy and exergy efficiencies are obtained as 78.29% and 30.3%, respectively.