Rotary gas dispersion device for treating a liquid metal bath

Abstract

Rotary injector for injecting gas into a liquid metal includes a drive shaft, stirring means, means for circulating the gas and means for emitting the gas. The emitting means is entirely or partially made of at least one material capable of being wetted by the liquid metal.

1 . Rotary injector ( 1 ) for injecting gas ( 2 ) into a liquid metal ( 3 ), comprising a drive shaft ( 4 ), stirring means ( 5 ), means ( 6 ,  7 ,  11 ) for circulating said gas ( 2 ) and means ( 8 ,  9 ) for emitting the gas ( 2 ), and characterized in that the emitting means ( 8 ,  9 ) are entirely or partially made of at least one material capable of being wetted by said liquid metal ( 3 ).  
     
     
         2 . Rotary injector ( 1 ) according to  claim 1 , characterized in that said wettable material is also substantially inert to said liquid metal ( 3 ).  
     
     
         3 . Rotary injector ( 1 ) according to  claim 1  or  2 , characterized in that said material is rendered wettable by means of a coating made of a material capable of being wetted by the liquid metal.  
     
     
         4 . Rotary injector ( 1 ) according to any one of  claims 1  to  3 , characterized in that said emitting means include at least one orifice ( 8 ) for emitting said gas ( 2 ).  
     
     
         5 . Rotary injector ( 1 ) according to  claim 4 , characterized in that the diameter of said or each orifice ( 8 ) ranges preferably between 0.5 and 5 mm.  
     
     
         6 . Rotary injector ( 1 ) according to any one of  claims 1  to  5 , characterized in that said emitting means comprise a porous material capable of being wetted by said liquid metal ( 3 ) or a porous material rendered wettable by means of a coating made of a material capable of being wetted by the liquid metal.  
     
     
         7 . Rotary injector ( 1 ) according to  claim 6 , characterized in that the diameter of the open pores appearing at the surface of said porous material is less than 0.5 mm.  
     
     
         8 . Rotary injector ( 1 ) according to any one of  claims 1  to  7 , characterized in that it includes an insert ( 90 ) comprising said emitting means ( 8 ,  9 ) and made of said wettable material or a material rendered wettable by means of a coating made of a material capable of being wetted by the liquid metal.  
     
     
         9 . Rotary injector according to any one of  claims 1  to  8 , characterized in that said stirring means ( 5 ) are also entirely or partially made of at least one material capable of being wetted by said liquid metal or a material rendered wettable by means of a coating made of a material capable of being wetted by the liquid metal.  
     
     
         10 . Rotary injector ( 1 ) according to any one of  claims 1  to  9 , characterized in that said drive shaft ( 4 ) is also entirely or partially made of at least one material capable of being wetted by said liquid metal or a material rendered wettable by means of a coating made of material capable of being wetted by the liquid metal.  
     
     
         11 . Rotary injector ( 1 ) according to any one of  claims 1  to  10 , characterized in that the wettable material or materials are selected from amongst the group comprising molybdenum, tungsten, vanadium, titanium, chromium, iron, steels or their alloys, and titanium diboride, aluminium nitrides, aluminium carbides, and titanium carbides.  
     
     
         12 . Rotary dispersion device ( 30 ), characterized in that it comprises at least one rotary injector according to one of  claims 1  to  11 .  
     
     
         13 . Device for treating a liquid metal ( 40 ), characterized in that it comprises at least one rotary injector according to any one of  claims 1  to  11  or at least one rotary dispersion device according to  claim 12 .  
     
     
         14 . Ladle for degassing a liquid metal comprising at least one rotary injector according to any one of  claims 1  to  11  or at least one rotary dispersion device according to  claim 12 .  
     
     
         15 . Furnace comprising at least one rotary injector according to any one of  claims 1  to  11  or at least one rotary dispersion device according to  claim 12 .  
     
     
         16 . Trough equipped with at least one rotary injector according to any one of  claims 1  to  11  or at least one rotary dispersion device according to  claim 12 .  
     
     
         17 . Use of a rotary injector according to any one of  claims 1  to  11 , a rotary dispersion device according to  claim 12 , a treatment device according to  claim 13 , a degassing ladle according to  claim 14 , a furnace according to  claim 15  or a trough according to  claim 16  for treating a metal in the liquid state.  
     
     
         18 . Use according to  claim 17 , characterized in that said metal is selected from amongst aluminium, aluminium alloys, magnesium and magnesium alloys.  
     
     
         19 . Method for treating a metal in the liquid state, characterized in that use is made of at least one rotary injector according to any one of  claims 1  to  11 , at least one rotary dispersion device according to  claim 12 , at least one degassing device according to  claim 13 , at least one degassing ladle according to  claim 14 , at least one furnace according to  claim 15  or at least one trough according to  claim 16 .  
     
     
         20 . Treatment method according to  claim 19 , characterized in that said metal is selected from amongst aluminium, aluminium alloys, magnesium and magnesium alloys.