twyer-box

Century Dictionary and Cyclopedia

1. n. A chamber or duct from which the separate twyer-pipes are led into the walls of the furnace proper.
2. n. In the Bessemer converting vessel, the chamber below the refractory bottom from which air passes into the molded twyer-blocks and so up into and through the molten metal. Air is supplied to the box from a pipe leading down from the hollow trunnion of the converter.