Análise da deformação em um pinhão de um secador rotativo horizontal

Abstract

Several grains are produced in Brazil and worldwide, being used as raw material in food production. For good grain quality, good beneficiation is required, which consists of several steps, one of which is drying the beans. The horizontal rotary dryer is a machinery used for grain drying, which aims to promote better product quality due to more uniform drying, leaving no odor in the product and also has low energy consumption for drying. This equipment has a set of gears, one of which is the nodular cast iron pinion, which must be able to withstand efforts, have wear resistance and good mechanical properties not to fail in operation. The main objective of this work was based on the analysis of the cause of excessive pinion deformation, component of a rotary dryer with capacity of 18000 l. For this, initially the metallography of two deformed teeth of the pinion was performed, which revealed the presence of nodular and vermicular graphite, being expected the presence of only graphite in the nodular form. The observed ferritic and perlite matrix was in accordance with the ASTM standard with GGG 40 specification. The hardness values obtained were higher than expected by the standard. In addition, a chemical analysis of the component was performed, verifying that it complies with the standard and according to the foundry, which manufactures the pinion supplied to Calli do Brasil located in Maringá-PR undergoing minor changes to acquire requested mechanical properties. The pinion deformation is due to the change of its mechanical properties, through the analyzed microstructure it was possible to observe graphite in the form of nodules and vermicular, influencing its properties.