open-hearth furnace

from The Century Dictionary.

• noun The form of regenerative furnace of the reverberatory type used in making steel by the Martin, Siemens, and Siemens-Martin processes. See steel.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a furnace for making steel in which the steel is placed on a shallow hearth and flames of burning gas and hot air play over it