Low porosity-high density radial burst refractory plug with constant flow

摘要

Apparatus including a nozzle or refractory pipe lance for the secondary refinement of a bath of molten metal by the injection of a gas under pressure, having one or more low porosity-high density refractory plugs which contain apertures of constant diameter, at least those about the perimeter of the plugs having an arcuate shape. For the manufacture of a pipe lance, the low porosity-high density refractory plugs are attached to a central tube. The low porosity-high density of the refractory plugs provides a corrosion resistance to any change in the diameter of the gas nozzles and thereby produces a controlled high velocity radial burst gas stream. Generating the radial burst of small bubbles and maintaning the gas velocity of a high constant rate reduces erosion of the refractory material around the tope of the apparatus and extends the lifetime of the pipe lance or nozzle. As progessive refractory wear proceeds during the useful life of the pipe lance, the gas flow rate will remain constant within a closed system.