I'm trying to explain to a client

From John K…a consultant to plastics processors.


Question:


I'm trying to explain to a client the finer points of resin drying and can not get a good answer to a question related to the return air temperature of a dryer and how it affects desiccant performance. How does high return air temperature experienced running PET affect the desiccant's ability to adsorb more moisture?


Answer:


The optimum performance of a desiccant occurs at near ambient temperatures.  Temperatures in excess of this lower the desiccant capacity and require that the air be cooled before going to the desiccant.  This cooling of the air, for better adsorption, means that you have heated the air unnecessarily and thrown that heat into cooling water which requires more process heat to be re-added.  
Novatec’s Power Guard systems continuously monitor the return air temperature and adjust the process air flow for optimum drying and the minimum energy usage through a patented process that also adjusts the set point based on resin temperature.


Mark Haynie...Sales Manager – Dryer Products, Novatec, Inc.