IMPACT STUDIES OF THE AIR-FLUE GASES MIXTURE IN THE CORN DRYING PROCESS

摘要

The present paper focuses on the necessity of the drying process of the grains through convection, using the actual storage technology, keeping the standards for quality and nutritional safety, in the present context of Romanian integration in the European Union. Drying seed grains, with the purpose of storage for long periods, is a method used in food industry on large scale, but one should take into account the parameters of drying process, in order to reduce the depreciation of the grain quality. The research is conducted towards a drying technology based on flue gases heat energy input. One purpose consists of solving the question if any pollutants from the flue gases affect or attempt to reach the grains, through the proposed technology. Thus one focuses on pollutants measurement resulting from the burning process of propane, at entrance and exit from the dryer. Complementary the necessary air quantity that is used in the drying process is controlled and indicated as an important parameter of the success of the process. It is also attested that the resulted combustion compounds resulted from the moisture extraction process of the grain, by using the proposed type of dryer, through convection, do not affect the food safety. The pollutants analysed are SO-2, CO, C_mH_n, O_2, NO and NO_2. The coefficient of air excess was also determined, through a computational operation, as well as the concentration of CO_2, flow, speed and the mass flow of the flue gases, for all the analysed situations. Not at least, a phytologic analysis of the grains studied is presented which indicates that finally the grains are totally not contaminated by the drying process. The humidity reduction of the grain is thus reached that is very useful for the long-term deposit of quality grains.