Cupola furnace

is a foundry shaft furnace for the melting of cast iron. The metal charge (raw iron, scrap and recycled materials) is melted with the addition of slag-forming additives, limestone and coke as energy transmitters. The combustion air (known as wind) is compressed by a blower, and blown into the furnace shaft through nozzles. These are categorised into cold wind or hot wind cupola fur- naces, depending on whether the combustion air is cold or heated.