Análise e restauração de um forno elétrico de pequeno porte do laboratório de tratamento térmico do Centro de Tecnologia Da UFPB

Abstract

The present study aims to restore an electric furnace used for laboratory heat treatments, including the fabrication of its electric heating elements and the replacement of damaged components. The recovery of this equipment represents an improvement in the resources of the Heat Treatment Laboratory at UFPB, providing an additional learning tool for Mechanical Engineering students. The project was based on a furnace that had been out of use for several years. After identifying the defective components, calculations were carried out, and the heating elements were manufactured alongside a search for replacement parts in the electronics sector. The heating elements were made from a ferritic iron-chromium-aluminum alloy (FeCrAl alloy), due to its high electrical resistivity and oxidation resistance. The furnace operates using an analog controller and an automatic temperature control system aided by a thermocouple. Additionally, a detailed study of the operation of electric resistances was required, as well as the selection of the damaged components, including their models, specifications, and properties suitable for purchase. After manufacturing the resistances and replacing the faulty components, they were installed according to previously prepared diagrams. The furnace was then activated, and temperature tests and control system calibrations were performed to verify whether the measured values matched those obtained through calculations. Finally, it was checked whether the furnace chamber temperature met the specified values, if the electric current in the heating elements matched the designed value, whether the external temperature of the furnace complied with safety standards, and whether the heating rate was acceptable