It is One most widely and commonly used method in foundry for melting iron. It has quite a lot of advantages over other melting furnaces which has added to its importance. Before talking about its advantages let's have a look at its construction.

It is a vertical furnace with a hollow shell which may be ovel, elliptical in shape. The shell is lined with refractory material and lined with fire bricks. The arrangement lies intact vertically over the iron plate. Nowadays shell are made of various shapes like cylindrical, Along and square. This type of furnace can be suited both for small and large amount of raw materials depending on the use. When cupola is to be handled for large amount of melting of iron the foundation should be strong enough. Strong rock support from both side is provided. The bottom of cupola furnace which is made up of cast iron should must have proper thickness to avoid any casualties.


A cupola consists of vertical column lined with refractory material. The bottom part of column or shell is called hearth. It is hinged from two sides. When the furnace is hinged,it opens at the bottom most part and for removal of molten material. At the bottom front part there is a hole for molten iron to come out and just above it there is another hole for molten slag to escape out of cupola shell.

The shell of the furnace is fitted with tuyeres which supply hot air inside the shell that comes from wind box. This arrangement is made at the lower section of furnace. Now charge ( mixture of iron pieces + limestone flux + coke fuel ) is introduced into operation

 from above . The coke burns as it moves down the furnace and as such it raises the temperature of furnace. This is preheat stage for the iron to be melted.

As the iron moves down the high temperature leads to melting of iron which is collected at the bottom ( hearth ) of the furnace. The hinge allows the molten metal to be evacuated out of the furnace with the help of the laddle ( a collecting device ). At the same time new charge is introduced into the shell so that continuity is maintained


  • continuous operation
  • Economical and Less power usage
  • Can be used for both small quantity raw material and large quantity.

Next Post »