Patent ID: 7687020

Claim:
An apparatus for injecting particulate and/or gaseous material into a metallurgical vessel for performing a metallurgical process, the apparatus comprising: a duct through which to inject the material; inner and outer water flow passages extending through an outer annular wall of the duct, the inner and outer water flow passages being for inflow of cooling water from a rear end to a forward end of the duct and for outflow of cooling water from the forward end to the rear end of the duct; and an annular duct tip disposed at the forward end of the outer annular wall and providing a water flow connection between the inner and outer water flow passages; and wherein the inner and outer cooling water flow passages are configured such that out flowing water passing from the duct tip to the rear end of the duct must travel through a longer flow path than inflowing water passing from the rear end of the duct to the duct tip.