Bessemer converter vs convertor

Bessemer converter and convertor both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bessemer converter	Yes	No	No	No
convertor	Yes	No	No	No

As nouns, convertor is a hypernym of Bessemer converter; that is, convertor is a word with a broader meaning than Bessemer converter:

Bessemer converter: a refractory-lined furnace used to convert pig iron into steel by the Bessemer process
convertor: a device for changing one substance or form or state into another

Other hypernyms of Bessemer converter include converter.

Bessemer converter (noun)	convertor (noun)
a refractory-lined furnace used to convert pig iron into steel by the Bessemer process	a device for changing one substance or form or state into another