Desenvolvimento de um módulo de câmara gravitacional para separação mecânica das impurezas presentes no trigo recém colhido

Abstract

Brazil is a major wheat provider worldwide. In 2019 the production estimative for the country was 5.473 million de tons, 0.9% higher than 2018, according to Conab (National Supply Company). The development of the agriculture in Paraná state is largely dependent on family farming, since among the 350.000 farmers estimated in the area, 80% practice this type of farming. With that in mind, this study had the objective of developing a pre – cleaning system for wheat, focused on the necessities of those family farmers, capable of providing maximum ranges of 1% in mass of impurities in the delivery of the product to the wheat processing companies. The project of the equipment included five steps: i) the simulation of the operational conditions, in Visual Basic, in order to estimate the dimensions of it (which was based on particle fluid dynamics equations and project equations for the gravitational settling chambers); ii) the building and testing of an experimental model; iii) the optimization of operational conditions for the experimental model by using Doehlert’s matrix and the desirability function; iv) the building and testing of prototype in pilot scale, and; v) the optimization of operational conditions for the prototype by using Doehlert’s matrix and the desirability function. The testing proved the efficiency of the separation process proposed, for both, experimental model and prototype, once the maximum impurities’ percentages observed among the grains at the end of the separation were 0.28 and 0.29 %, respectively. Based on the experimental design it was found that, for the experimental model, the operational variables which minimized the percentages of impurities among grains as well as the percentage of losses due to blowing out of grains from the equipment, were a feed of 340 g and an opening in the feeding door, which controlled the grain flow, of 18,258 mm. Moreover, it was also found that, for the prototype, the operational variables which minimized the percentages of impurities among grains, the percentage of losses due to blowing out of grains from the equipment, and the accumulation of the grains in the equipment, consisted on a feed of 500 g, an opening in the feeding valve of 59.06°, and an air blowing velocity of 13,132 m s-1. Therefore, the proposed equipment is suitable to the rising demand for more affordable farming technology, thus, having potential for future commercialization.