ELECTROMAGNETIC PROCESSING OF MATERIALS

Second cycle degree in MATERIALS ENGINEERING

Campus: PADOVA

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