Furnaces for Casting Processes

Study Notes

Direct fuel-fired furnaces are small open-hearth furnaces that use natural gas fuel burners to heat the charge, and are generally used for nonferrous metals such as copper-base alloys and aluminum.
Crucible furnaces, also known as indirect fuel-fired furnaces, melt metal without direct contact with the burning fuel mixture, and are used for nonferrous metals such as bronze, brass, and alloys of zinc and aluminum.
Electric-arc furnaces melt the charge by generating heat from an electric arc, and are used primarily for melting steel due to their high power consumption and high melting capacity.

Crucible furnaces come in three types: lift-out, stationary, and tilting.
The container (crucible) is made of refractory material or high-temperature steel alloy.

Electric-arc furnaces can be designed for high melting capacity, but require high power consumption.
They are primarily used for melting steel.

Induction furnaces use an alternating current passing through a coil to develop a magnetic field in the metal, causing rapid heating and melting.
The electromagnetic force field also causes mixing action in the liquid metal.
Since the metal does not contact the heating elements, the environment can be closely controlled, resulting in high-quality and pure molten metals.

Cupola furnaces are the oldest type of furnace used in foundries, and are used for melting iron and ferro-alloys.
Advantages of cupola furnaces include simplicity in operation, high productivity, continuous production, and economical use.

A cupola furnace has a steel shell lined with refractory blocks, bricks, and fire clay.
The furnace has a round cross-section, and features a spark arrester, charging door, air injection by tuyeres, drop bottom, tapping hole, and slag hole.

The operation of a cupola furnace involves closing the drop bottom, charging the coke bed and wooden parts, firing, and repeating the layering process.
The furnace is cooled, and the lining is rebuilt after each operation.

The zones of a cupola furnace include the well zone, combustion zone, reducing zone, melting zone, preheating zone, and stack zone.
Each zone has a specific temperature range and function in the melting process.

A cupola charge consists of metal charge, coke, limestone, and air.
The charge is calculated using the material balance technique, considering factors such as carbon equivalent, manganese loss, silicon loss, phosphorus, and sulfur gain.

Direct fuel-fired furnaces are small open-hearth furnaces that use natural gas fuel burners to heat the charge, and are generally used for nonferrous metals such as copper-base alloys and aluminum.
Crucible furnaces, also known as indirect fuel-fired furnaces, melt metal without direct contact with the burning fuel mixture, and are used for nonferrous metals such as bronze, brass, and alloys of zinc and aluminum.
Electric-arc furnaces melt the charge by generating heat from an electric arc, and are used primarily for melting steel due to their high power consumption and high melting capacity.

Crucible furnaces come in three types: lift-out, stationary, and tilting.
The container (crucible) is made of refractory material or high-temperature steel alloy.

Electric-arc furnaces can be designed for high melting capacity, but require high power consumption.
They are primarily used for melting steel.

Induction furnaces use an alternating current passing through a coil to develop a magnetic field in the metal, causing rapid heating and melting.
The electromagnetic force field also causes mixing action in the liquid metal.
Since the metal does not contact the heating elements, the environment can be closely controlled, resulting in high-quality and pure molten metals.

Cupola furnaces are the oldest type of furnace used in foundries, and are used for melting iron and ferro-alloys.
Advantages of cupola furnaces include simplicity in operation, high productivity, continuous production, and economical use.

A cupola furnace has a steel shell lined with refractory blocks, bricks, and fire clay.
The furnace has a round cross-section, and features a spark arrester, charging door, air injection by tuyeres, drop bottom, tapping hole, and slag hole.

The operation of a cupola furnace involves closing the drop bottom, charging the coke bed and wooden parts, firing, and repeating the layering process.
The furnace is cooled, and the lining is rebuilt after each operation.

The zones of a cupola furnace include the well zone, combustion zone, reducing zone, melting zone, preheating zone, and stack zone.
Each zone has a specific temperature range and function in the melting process.

A cupola charge consists of metal charge, coke, limestone, and air.
The charge is calculated using the material balance technique, considering factors such as carbon equivalent, manganese loss, silicon loss, phosphorus, and sulfur gain.