The invention relates to a stirrer for external stirring desulphurization of molten iron before converter
steelmaking, aiming at solving the existing deficiencies at present that slags among mixing blades are numerous, large intensity of vortex at the bottom of the
metal opposing side of the mixing blades is disadvantageous to the discharging of the involved desulphurization slags. The invention comprises the following measures: the stirrer for desulphurization of molten iron is composed of a
metal core 2, a V-shaped
rivet firmware 3, a
refractory liner 4, a
metal chip 6, a V-shaped
rivet firmware 7, a double V-shaped
rivet firmware 8, a
refractory liner 9 and an
air cooling tube 10; the metal core 2, the V-shaped rivet firmware 3 and the
refractory liner 4 constitute a rotation axis 1; the metal
chip 6, the V-shaped rivet firmware 7, the double V-shaped rivet firmware 8, the refractory liner 9 and the
air cooling tube 10 constitute mixing blades 5; three mixing blades 5 above the rotation axis 1 are evenly distributed; the front
rake angle alpha of the inclined plane from bottom to top of the metal facing water surfaces 11 of the mixing blades 5 is 4.1-30 degrees, the front
rake angle beta of the inclined plane from bottom to top of the metal opposing surfaces 12 is 0.1-30 degrees, the
camber angle gamma of the inclined plane from bottom to top of the outside surface 13 is 4.1-15 degrees. In the invention, slags among the mixing blades are small, the dynamic condition for stirring desulphurization is excellent, the service life is long and the structure is simple.