Bessemer converter
Noun
Meaning
a refractory-lined furnace used to convert pig iron into steel by the Bessemer process
Source: WordNetHypernyms
Examples
A Bessemer converter could treat a "heat" (batch of hot metal) of 5 to 30 tons at a time.
Sidney Gilchrist Thomas's invention consisted of using dolomite or sometimes limestone linings for the Bessemer converter rather than clay, and it became known as the 'basic' Bessemer rather than the 'acid' Bessemer process.