Patent ID: 8388888

Claim:
An apparatus for injecting gas into a metallurgical vessel supporting a metallurgical process, the apparatus comprising: a gas flow duct extending from a rear end to a forward end from which to discharge gas from the duct; an elongate central tubular structure extending within the duct from its rear end to its forward end with a forward end of the central tubular structure disposed adjacent the forward end of the duct; a plurality of flow directing vanes disposed about the forward end of the central tubular structure to impart swirl to a gas flow through the forward end of the duct; inflow and outflow cooling water passages within the central tubular structure for inflow of cooling water forwardly through the central tubular structure to its forward end and for outflow of cooling water from the forward end back to its rear end; and a nose portion at the forward end of the central tubular structure provided with one or more water passages for internal water cooling of the nose portion; and wherein: (a) the vanes are provided with internal vane passages for internal water cooling of those vanes, and wherein in use water flow is communicated through the vane passages from the inflow cooling water passage in the central tubular structure, back to the inflow cooling water passage and then to the one or more water passages in the nose portion of the central tubular structure such that at least some of the inflowing water passes successively through the vane passages and the one or more water passages in the nose portion and thence to the outflow cooling water passage; and (b) the vane passages are successively spaced from a root of each vane towards a tip of the respective vane, so that the vane passages each have a different length, and the vane passages are configured to provide generally equal resistance to flow and generally equal pressure drop through all of the vane passages.