Frequently Asked Questions - EMSCO, Inc.

Frequently Asked Questions

induction furnace use

What is an induction furnace used for?

Induction furnaces are used in foundries to melt iron, steel, copper, aluminum, and precious metals to name a few. Once melted, the metal is poured from the induction furnace into a mold. Once the metal has solidified, it is removed from the mold. This finished product is called a “casting.” The induction furnace can be used in an atmosphere or in a vacuum chamber. Induction furnaces possess a key advantage over gas furnaces due to their ability to convert solid metal to liquid with less contamination (high return).

How does an induction coil work?

Induction starts with a coil of conductive material (ex: copper). As electrical current flows through the coil, a magnetic field in and around the coil is produced. The ability of the magnetic field to do work depends on the coil design as well as the amount of current flowing through the coil. The energy from the coil is transferred to the metal inside the crucible, thereby heating the metal to a desired point.

What is a foundry?

A foundry is a factory that heats metal to a molten state using a furnace and then pours the molten metal into molds to produce metal castings. Aluminum and cast iron are examples of metals commonly processed in foundries. The types of products manufactured in foundries range from cast iron cooking vessels to highly advanced aerospace components.

What is a coreless induction furnace?

The primary component of a coreless induction furnace is its coil. The coil is fabricated from high conductivity copper tubing and housed within a steel shell. To prevent overheating, the coil is water-cooled with a cooling system, such as our own HyprCool® Hybrid Process Cooling Systems. Coreless induction furnaces offer a high level of control over the temperature and chemistry of the metal, as well as even heat distribution courtesy of the induction coil. These characteristics make coreless induction furnaces ideal for melting all grades of steels and irons, many non-ferrous alloys, and re-melting.

What is a channel induction furnace?

Channel induction furnaces are comprised of a refractory lined upper case which houses the molten metal. An induction unit assembly, called the lower case, is attached to the upper case via a throat to provide the melting or holding power. Together, these components create a transformer in which the molten metal loop forms the secondary and receives the power from the induction coil. The loop generates heat as well as a magnetic field which causes the metal to circulate in the upper case of the furnace. This circulation creates a beneficial stirring action in the molten metal. Typically channel induction furnaces are used for melting, or as a holding unit for various alloys.

What is the process of metal casting?

Metal casting is a manufacturing process performed in a foundry. Liquid metal is poured from a melting furnace into a mold and then allowed to solidify. Once the metal has solidified, it is removed from the mold. The finished piece is a casting.

What is a foundry ladle made of?

Foundry ladles are made from hot rolled steel (HRS) and then rammed or poured with refractory lining to prevent damage when the ladle is used to transport molten metal. Without the refractory lining, molten metal would rapidly melt the ladle upon contact.

What is a sand casting?

Sand casting is a metal casting process where sand is used as the mold material. The mold is made of sand and molten metal is poured from a melting furnace into the mold to make a casting. The term “sand casting” may also refer to an object produced via the sand casting process.

Is molten metal magnetic?

Metal loses its magnetism before reaching melting its temperature. The Curie temperature is the temperature at which certain materials lose their permanent magnetic properties, to be replaced by induced magnetism. Different metals have different Curie temperatures. Click here to learn more about the Curie temperature.

What is slag?

Slag is the by-product left over after a desired metal has been separated (smelted) from its raw ore. Slag is typically comprised of metal oxides and silicon dioxide, but can contain metal sulfides and elemental metals. Beyond simply being a by-product of smelting, slag can help control the temperature of the smelting process and can assist in preventing re-oxidation of the final liquid metal product before the molten metal is poured.

Is there a difference between a foundry and a forge?

Foundries heat metal scrap, turnings, and other similar alloys into a molten liquid state. This molten metal is poured into a mold to create a desired shape. Forges heat metal billets and ingots, but the metal is not heated to the point of melting. The application of thermal and mechanical energy to the metal in forging allows the shape of the metal to be manipulated while in remaining in a solid state.

What is metallurgy?

Metallurgy is the science of forming metal into desired shapes or manipulating a metal’s properties through heating or melting and alloying to achieve the desired finished metal shape and chemistry.

What is smelting?

Smelting is a process. The primary use of smelting is to extract a base metal, such as silver, iron, or copper, from its ore. Secondary smelting is the process of removing impurities from old materials and returning to the original base metal.

What is adiabatic cooling?

EMSCO defines “adiabatic” as the process of evaporation where dry air absorbs moisture, thereby dropping its temperature. This process allows us to precool the air without energy cost and cool the process fluid with a smaller, more efficient system than if we were to use the air at its warmer ambient temperature. Click here to learn more about adiabatic cooling systems.