Process and blowing lance for blowing gases into metallurgical vessels

摘要

The invention relates to a method and an oxygen lance for processing molten metal baths in vacuum treatment tanks, more particularly steel in RH tanks, having a central pipe and a jacket pipe coaxially arranged thereon that can be cooled with a cooling medium. The central pipe and the jacket pipe are attached to supply lines which are connected to an oxygen, a combustible gas and an inert gas station and to a solid matter feeding device. The cooled jacket pipe (26) is separated from the central pipe (22) throughout its entire length. The free ring surface (AR) between both pipes (22, 26) complies with AR = 0.8 to 1.2 x AZ and AZ = free cross-section area of the central pipe. The mouth of the central pipe is Laval-shaped. The mouth of the nozzle (24) of the central pipe (22) is arranged inside the jacket tube (26) at a distance (a), wherein a = 0.5 to 0.8 x d and d = free diameter of the central pipe.