A cupola furnace is a type of melting furnace used primarily in foundries to melt cast iron. It is a vertical cylindrical structure that operates continuously, allowing for the efficient melting of large quantities of metal. The furnace is charged with layers of metal, coke, and limestone, which help in the melting process and remove impurities. The operation of a cupola furnace involves the combustion of coke, which generates heat to melt the metal. Air is blown into the furnace to support combustion, and the molten metal collects at the bottom, where it can be tapped off for casting. This method is widely used due to its cost-effectiveness and ability to recycle scrap metal.