(203b) Infrared Temperature Experiments and DEM Simulations of Heat Transfer in an Agitated Dryer
AIChE Annual Meeting
Tuesday, November 17, 2020 - 8:00am to 8:15am
In this work, we isolate the heat transfer element of drying and focus on studying it on its own. The idea is that if we can decouple the different facets of drying and understand them on their own first, we can eventually study their combined interactions more easily. We conduct heat transfer experiments using a laboratory scale agitated dryer and an infrared camera to measure the temperature of the surface of a particle bed over time. The temperature data collected by the thermal camera is used to compute the heat transfer coefficient for the system as well as the temperature standard deviation, giving information about both the mean temperature of the bed and its temperature uniformity. Using this methodology, we investigate how operating conditions, such as the impeller rotation rate, influence heat transfer. The experiments are carried out using glass beads as well as more pharmaceutically relevant materials such as citric acid. Next, we present a comparison between the experimental results and discrete element method (DEM) simulations. The model makes use of a particle-particle and particle-wall conductive heat transfer model to describe the system. Overall, despite the simplicity of the heat transfer model, we find a fairly good agreement between the simulations and the experiments. This suggests that the model can serve as a good starting point towards better understanding how the rate of heat transfer and the temperature uniformity of a particle bed can be optimized in an agitated dryer.