blast furnace vs furnace

blast furnace and furnace both are nouns.

Word	Noun	Adjective	Verb	Adverb
blast furnace	Yes	No	No	No
furnace	Yes	No	No	No

As nouns, furnace is a hypernym of blast furnace; that is, furnace is a word with a broader meaning than blast furnace:

blast furnace: a furnace for smelting of iron from iron oxide ores; combustion is intensified by a blast of air
furnace: an enclosed chamber in which heat is produced to heat buildings, destroy refuse, smelt or refine ores, etc.

blast furnace (noun)	furnace (noun)
a furnace for smelting of iron from iron oxide ores; combustion is intensified by a blast of air	an enclosed chamber in which heat is produced to heat buildings, destroy refuse, smelt or refine ores, etc.