Liquid cooled lance for blowing oxygen onto a steel bath.

摘要

A liquid cooled lance is used to blow a primary supply of oxygen at the surface of a molten steel bath to form a burning spot. A central duct in the lance delivers the primary supply of oxygen to the tip (1). A secondary supply of oxygen is blown from nozzles (16) around the side of the lance to burn up CO from the burning spot and so heat the bath. Several conduits (8) run in parallel within the lance to deliver the secondary oxygen to the nozzles (16). There is preferably one conduit per nozzle. The conduits (8) may run within an annular coolant duct, and preferably comprise, at least in part, pipes (9) in the form of a winding around the lance axis. This construction has good resistance to thermal expansion stresses.