Cupola Furnace

A cupola furnace is a vertical, cylindrical melting furnace used in foundries to melt cast iron, Ni-resist iron and some bronzes, resembling a large smokestack, typically lined with refractory brick and fitted with swing-down doors at the bottom for removing the melted metal. Furnaces of this kind date back to ancient China, with cupola-type furnaces built during the Warring States period between 403 and 221 BC and redesigned with improved cold-blast injection during the Han dynasty; the scientist Rene-Antoine Ferchault de Reaumur developed a modern version around 1720. The cupola furnace remained the standard melting furnace for iron foundries for centuries because it can melt scrap metal continuously and cheaply using coke as fuel.