Apparatus for injecting gas into a vessel

An apparatus for injecting gas into a vessel, comprising:

• a gas flow duct extending from a rear end to a forward end from which to discharge gas from the duct;
• an elongate body of generally cylindrical formation having domed rear and forward ends and disposed centrally within the forward end of the duct such that gas flowing through the forward end of the duct will flow over and along the elongate central body;
• a plurality of flow directing vanes disposed between the elongate central body and the duct to impart swirl to a gas flow through the forward end of the duct;
• cooling water supply and return passage means extending through the wall of the duct from its rear end part to its forward end part for supply and return of cooling water to the forward end part of the duct;
• an annular duct tip disposed at the forward end of the duct and having an internal tip cooling water passage communicating with the cooling water supply and return passage means so as to receive and return a flow of cooling water to internally cool the duct tip;
• and
• cooling water flow passages within the vanes and the elongate central body and communicating with the cooling water supply and return passage means in the forward end part of the duct for flow of water from the supply passage means inwardly through the vanes into the cooling passages of the elongate central body and from those passages outwardly through the vanes to the water return passage means of the duct.