Caracterização mecânica da noz pecã e projeto do decorticador

Abstract

Nowadays it has been noticed that there are some difficulties in processing industries due especially to the use of common nut peelers. This is owed to the lack of efficient equipment since the nut is an anisotropic fruit with high mechanical resistance. The development of a suitable system to peel the fruit requires knowledge and application of mechanical characteristics of the fruit. In this context, the study aims to investigate some of these features, such as Poisson’s coefficient and nut bending resistance. Thickness profile Young’s modulus and fragility of the endocarp have also been investigated. From the data obtained in these investigations, a nut peeler in model scale was developed, as well as a detailed design whose principle of operation is by radial compression associated with cored shear. The methodology of this project is outlined in four stages: first, the identification of equipment needed; second mechanical tests of fruits and peeler conceptions; third, the detailed design is performed in order to characterize the conceptions; and finally, the analysis and selection whose function is to qualify the project’s remaining stages. Results are expressed by design memorial description. The fruit compression test showed difference in mechanical resistance between the fruits in nature and dry for different breaking speeds. The compression test showed 316,87 MPa for Young’s modulus, and kernels have presented 11,07 MPa and 0,36 for the Young’s modulus and Poisson’s coefficient respectively. The nut peeler scale model showed an efficiency of 53,81% for whole nuts, summing between whole almonds and half 81,61% of performance. The effect of drying and cutting the ends of fruits has not been tested in the model.