Fuzzy Control of Fabrics Drying on an Induction Heated Rotating Cylinder: Experimental Results

The removal of water from materials in textile industry and pulp and paper industries requires a high-energy consumption, increasing significantly the operating costs. Nevertheless, electromagnetic induction heating is an alternative with considerable potential for the thermal treatment of materials. Specifically, heating the surface of a metallic cylinder by electromagnetic induction has opened up a range of applications for continuos heating, pre-drying and drying of fibrous web. Otherwise, these news electrotechnologies with industrial applications have to be used under controlled operational conditions. The past few years witnessed a rapid growth in the use of fuzzy logic controllers for the control of processes, which are complex and ill defined. These control systems are inspired by the approximate reasoning capabilities of the process operator. The purpose of this paper is to improve and apply an digital control structure on the basis of fuzzy logic technique for the textile drying using a rotational cylinder heated by electromagnetic induction, manipulating the power supply to the inductors to control the exit humidity of the web. The proposed fuzzy logic controller was tested experimentally in a dryer pilot-scale plant and the results show the capability of the controller to reach the set point initially fixed at 20 g water/100 g dry fabric. Once reached the set point, continuing the trial, steps changes of the web-cylinder contact surface and the set point were done and the results shows the capacity of the proposed fuzzy logic controller in both perturbations.