Control strategies in drying processes aiming at energy efficiency and quality of agricultural products

• Grant number: 07/00502-5
• Support Opportunities: Regular Research Grants
• Duration: October 01, 2007 - March 31, 2010
• Field of knowledge: Agronomical Sciences - Agricultural Engineering - Process Engineering of Agricultural Products
• Principal Investigator: Barbara Janet Teruel Mederos
• Grantee: Barbara Janet Teruel Mederos
• Host Institution: Faculdade de Engenharia Agrícola (FEAGRI). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The use of control strategies using a combination of parameters involved in a process that aims for optimization represents, in practical terms, cost reductions, product quality, less task execution time and greater energy efficiency. Among the post-harvest processes, drying is one of the most costly due to energy demands for air movement and heating. This justifies the study of control strategies in drying processes aimed at energy efficiency and product quality. This need is even more accentuated when dealing with seeds, because this product is very sensitive to temperature and humidity, and to maintain the quality standards these parameters need to be rigorously controlled. There are few studies in Brazilian literature about automation and control aimed at energy efficiency in drying systems and product quality. Therefore, this is an area with great growth potential. A drying system will be studied using an experimental workbench equipped with instruments to measure temperature, humidity and drying air speed, electric power and product weight, all in real time. A supervision and control software will be developed that incorporates resources that permit visualizing product moisture content evolution during drying, water loss, energy consumption, evolution of relative humidity and air temperature and seed weight (this can be corn, wheat or soy bean, depending on the harvest and the experiments), visualizing data in graph and table format, creating process data files, treating signals, identifying the system, and other resources. Tests will be carried out that combine the variation in temperature and air flow parameters to establish control strategies that permit the system to work automatically, with different flows and temperatures, according to product demands and energy economy. After drying, germination and mechanical injury tests will be run on seed samples to test the influence of the drying process on seed quality. Modifications can be made on the workbench, according to the results obtained, which permit creating new control strategies and new measurement instruments. From this study, we expect to obtain subsidies that permit establishing control strategies for a drying process; develop software for the supervision and control of drying systems, for real time supervision of the process, altering the parameters involved both manually and automatically; optimize the drying process aimed at product quality and energy efficiency; obtain subsidies to transfer results and from the supervision and control software to the drying systems that can be used on an industrial scale; make the experimental workbench available for didactic purposes in undergraduate and graduate studies; develop new research seeking advances in the state-of-the-art of involved areas, such as the dissemination of results at events and in journals. (AU)