ELECTROMAGNETIC PROCESSING OF MATERIALS

Second cycle degree in MATERIALS ENGINEERING

Language: English

Teaching period: First Semester

Lecturer: FABRIZIO DUGHIERO

Number of ECTS credits allocated: 6

Syllabus
 Prerequisites: None Examination methods: Oral examination. The examination can be splitted into two parts Course unit contents: ARC FURNACES Introduction. Types of arc furnaces. Main electrical systems of an arc furnace, in particular the furnace transformer, the secondary high current circuit. Operating characteristics. Materials used in a furnace. RESISTORS FURNACES (Indirect) Notes about the types of ovens resistors Dimensioning criteria of the walls of the oven chamber. Industrial applications. Special applications. DIRECT HEAT RESISTANCE Introduction DC current Heating Electrical parameters Thermal transient in a cylindrical body heated by constant specific power density and with no superficial losses Variations of the characteristics of the material during the heating AC current Heating Distributions of current density and power Thermal transient in a cylindrical body with variable specific power and in the absence of heat losses towards the environment Thermal efficiency and intensity of the magnetic field H0 Heating of steel bars Influence of the electrical parameters of the installation in the heating of the steel bars Compensation circuit and load balancing Heating tubes and pipes INDUCTION HEATING Introduction Distributions of induced currents and powers within a cylindrical body by a longitudinal magnetic field Induced power in a cylinder and the equivalent impedance of the inductor-load system Specific power per unit surface Total flux and impedance Ze0 Half-plane equations Hollow cylinder heated from the inside Internal resistance and reactance of the induction coil Electrical efficiency of the inductor-load system Quality Factor and power factor Transient thermal in a cylindrical body Variations of the characteristics of the material Methods for calculation of the 'short' inductors Analytical methods Numerical Methods Industrial applications of induction heating Surface hardening medium and high frequency Heating for hot working of metals Melting Furnaces Crucible induction furnaces Induction furnaces to channel HIGH FREQUENCY DIELECTRIC HEATING AND MICROWAVE HEATING introduction Characteristics of dielectric materials Choice of frequency Microwave heating Industrial applications