Channel furnaces
Channel furnaces, which are another type of induction furnaces, are widely used in the melting industry. These furnaces, primarily utilized for melting non-ferrous metals or as holding furnaces for molten metal, share a very similar structure with crucible induction furnaces. Both types operate based on the same scientific principle in the melting process, which involves the generation of electric currents within the material being melted. In the following, we will examine some of the key components of these induction furnaces, which are manufactured by Araz Trans Tabriz Company.
Inductor
The inductor, which serves as the equivalent of the coil in channel furnaces, plays a crucial role in generating the necessary magnetic field to induce the required current for melting within the channel. This inductor, while structurally similar to the coil in crucible induction furnaces, is significantly smaller in size. It is composed of several loops made from copper profiles, typically arranged in two rows, similar to the coil used in internal core helical DC link applications. Apart from their much smaller dimensions compared to the coils in crucible induction furnaces, inductors lack many of the essential components found in coils, such as cooling rings, supports, and other auxiliary elements.
Core
In channel induction furnaces, the core functions similarly to the yoke in crucible induction furnaces, with the key difference being that the core in a channel furnace is completely continuous and unbroken. The inductors of a channel furnace are mounted on the core columns, and as current flows through the inductors, the core directs the magnetic flux generated by the inductors through the center of the channel. This enables the induction of the necessary electric current within the channel’s interior, facilitating either the melting of materials (in melting mode) or maintaining the molten state of the material (in holding mode).
Structurally and in terms of lamination arrangement, the core of a channel induction furnace bears a strong resemblance to the core of a transformer. Depending on the number of inductors and the number of molten material channels, the core of a channel furnace can be configured with two, three, or sometimes even four columns.
In terms of the type and quality of raw materials used in the construction of the channel furnace core, the same considerations applied to the yoke in crucible furnaces should be observed. For further details on this subject, it is recommended to refer to the section on the yoke of induction furnaces.
Cooling Wall
The cooling wall, sometimes referred to as the cooling shell or cooling jacket, is positioned between the inductor and the refractory lining of the channel furnace. Its primary functions are to cool and regulate the temperature around the inductor while also serving as a protective layer to shield the inductor from molten material leakage and other related issues.
The cooling wall consists of a sinusoidal path made from copper water-circulation profiles, encased in a stainless steel shell that is rolled and fixed to fit the outer diameter of the inductor.
