Abstract—In this study, a software has been developed to predict the optimum conditions for drying of cotton based yarn bobbins in a hot air dryer. For this purpose, firstly, a suitable drying model has been specified using experimental drying behavior for different values of drying parameters. Drying parameters in the experiments were drying temperature, drying pressure, and volumetric flow rate of drying air. After obtaining a suitable drying model, additional curve fittings have been performed to obtain equations for drying time and energy consumption taking into account the effects of drying parameters. Then, a software has been developed using Visual Basic programming language to predict the optimum drying conditions for drying time and energy consumption. Keywords—Drying, bobbin, cotton, PLC control, Visual Basic. I. INTRODUCTION ARN bobbins must be dried after dyeing processes in textile industry. Inevitable after most dyeing or/and finishing processes, drying is a time consuming, energy intensive and expensive process and constitutes one of the major cost elements among the textile finishing operations. The purpose of drying is to remove the water inside the bobbin. A part of water in the bobbin is removed mechanically. But this mechanical process is not sufficient to remove water entirely. A convective air dryer is generally used after this process to remove water entirely. In this study a software has been developed to obtain optimum drying conditions for cotton based yarn bobbins. For this purpose, firstly, a suitable drying model has been specified in defining the drying behaviour of cotton bobbins by fitting the model coefficients to the experimental drying data. After that, further regression analyses have been performed to obtain drying time and energy consumption equations depending on the drying parameters. The developed software predicts the optimum drying conditions using these equations. Hilmi Kuscu is with the Trakya University, Mechanical Engineering Department, Edirne, TURKEY (phone: 0090-532-4953660; fax: 0090-284- 2261217; e-mail:hilmi@trakya.edu.tr). Ahmet Cihan is with the Trakya University, Mechanical Engineering Department, Edirne, TURKEY (phone: 0090-532-5221670; fax: 0090-284- 2261217; e-mail:acihan@trakya.edu.tr). Kamil Kahveci is with the Trakya University, Mechanical Engineering Department, Edirne, TURKEY (phone: 0090-532-5269058; fax: 0090-284- 2261217; e-mail:kamilk@trakya.edu.tr). Uğur Akyol is with the Namık Kemal University, Mechanical Engineering Department, Çorlu, TURKEY (phone: 0090-535-3080759; fax: 0090-282- 6529372; e-mail:uakyol@nku.edu.tr). II. MATERIAL AND METHOD The experiments were conducted in a PLC controlled pressurized hot-air bobbin dryer. The schematic view of the experimental setup is shown in Figure 1. Ambient air is directed to an electrical heater by a centrifugal fan and the needed air pressure is obtained by a compressor. After the heater, air enters to a bobbin carrier system where the bobbins are dried. The carrier consists of four parts and four bobbins can be placed at each part. So totally, 16 bobbins can be placed in the carrier. In the carrier, hot air is passed repeatedly 10 minutes from inside to the outside of bobbins and 10 minutes from outside to the inside of the bobbins in radial direction. After carrier, drying air enters to a cooling exchanger. The purpose of this process is to reduce relative humidity of the air. Afterwards, drying air enters to a separator. In the separator, water droplets hanging on the air are separated from the air. Drying air finally returns to the fan. The carrier is on a load cell. The conditions of air at different points in the carrier and weights of the bobbins can be monitored by a software program, and the process can be controlled by an automatic control system. Fig. 1 Schematic view of the experimental bobbin dryer Drying air is heated in a heating exchanger consisting of 10 electrical resistances of 2.5 kW power. Control of heating power is provided by a solid state relay adjusting the phase difference of sinusoidal wave. Haters are PID (Proportion Hilmi Kuscu, Ahmet Cihan, Kamil Kahveci, Ugur Akyol A Software for Calculation of Optimum Conditions for Cotton Bobbin Drying in a Hot-Air Bobbin Dryer Y World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering Vol:5, No:6, 2011 1020 International Scholarly and Scientific Research & Innovation 5(6) 2011 scholar.waset.org/1307-6892/61 International Science Index, Mechanical and Mechatronics Engineering Vol:5, No:6, 2011 waset.org/Publication/61