Honeycomb Wheel Desiccant Resin DryerProject Number ET 07.18 Organization SCE End-use Process Sector Industrial Project Year(s) 2007 - 2009
In most plastic fabrication processes, plastic resin has to be dried to a specific humidity level before using it for fabrication. The technology under consideration, a new type of dryer for plastic resins, uses a revolving circular bed of desiccant material in a honeycomb structure. This method of resin drying seems to have the potential for energy savings. Typically, hot dry air is passed through the resin during the drying process and the initial drying of the air is accomplished with desiccant material. In the new equipment, the desiccant wheel is divided into sections and while air passes through one section to get dried, another section of the wheel is in “regeneration mode,” i.e. at any time, one part of the bed will be in drying phase and the other in the regeneration phase. The desiccant wheel used in this technology has a honeycomb structure which improves the drying process and makes the drying process more uniform. Regeneration is the phase when the desiccant material gets rid of the water it absorbed during the drying process. The conventional technology (baseline) is a “twin tower” system of desiccant material. In this arrangement, while one side of the tower is in the drying phase the other undergoes “regeneration” – quite similar to the process described above. But it is anticipated that there will be energy savings associated with the new process due to the innovative, honeycomb structure of the desiccant bed, which results in reduced time for regeneration. This structure results in reduction in the amount of energy (heat) required for the process. The new technology is commercially available from several manufacturers.