Diseño y Construcción de un Secador Rotatorio para la obtención de escamas PET

Abstract

The design and construction of a rotary dryer for obtaining PET flakes was carried out with the objective of substantially reducing the moisture content of the plastic. The aforementioned equipment will serve as a teaching tool in the Unit Operations Laboratory, School of Chemical Engineering, Faculty of Sciences of the Polytechnic School of Chimborazo to reinforce the theoretical knowledge about the drying of solids. For the design, tests were carried out in the laboratory acquiring different data, which were used to elaborate the engineering calculations for a correct dimensioning of the equipment, making a previous selection of the main elements that conform the equipment, these are: Drying chamber, motor, fan, heat source. The equipment was manufactured in AISI 304 stainless steel, and its dimensions are as follows: the drying chamber has a length of 80 cm, a diameter of 38 cm, a volume of 90 L and a capacity of 10 Kg/h; the motor power is ½ HP (373 W); the fan speed is 3600 RV, the optimum temperature of the heat source is 115C. With this equipment it was possible to achieve an efficiency of 87.6%, thus meeting the specification for this type of equipment. As results, a reduction of PET humidity from 28% to 1% was obtained, in a time of 0.3 hours and with a total drying speed of 5.36 kg/m2h. We conclude that the rotary dryer is in excellent conditions for the PET drying process, achieving a moisture reduction of 1%. We recommend that at the moment of using the equipment, a mask, gloves and apron should be worn for a good performance and to reduce the hazards that may occur in the laboratory.