Method and a system for distribution of fluidisable materials

Abstract

The present invention relates to a method and a system for distribution of fluidisable materials from a reservoir ( 1 ) of materials to one or more material receiving units. In accordance with the invention the distribution system has at least two hydraulic levels between the reservoir and the material receiving units. The system further includes a novel fluidising element with good dynamic response properties. The system may preferably be used for distribution of alumina and/or fluoride to feeding equipment in electrolysis cells with a reduced consume of fluidising gas.

1 . A method for distribution of fluidisable materials comprising a reservoir ( 1 ) for the material to be distributed, fluidisable conveying means ( 9 ,  26 ,  27 ,  47 ) distributing the material to one or more material receiving units ( 34 ,  35 ), characterised in that 
 the material is distributed from the reservoir to the material receiving units through at least two hydraulic levels defined by one or more inlet locks ( 4 ,  23 ,  41 )    
     
     
         2 . A method in accordance with  claim 1 , characterised in that 
 the fluidisable conveying means ( 9 ,  26 ,  27 ,  47 ) are activated by pressurised fluidising gas in a non-continuous manner.    
     
     
         3 . A method in accordance with  claim 1 , characterised in that 
 the fluidisable material is distributed to one or more electrolysis cells (E) for the production of aluminium.    
     
     
         4 . A method in accordance with  claim 1 , characterised in that 
 the fluidisable conveying means ( 9 ,  26 ,  27 ,) is activated and controlled by means of a pre-programmed computer in a manner where the fluidising elements are activated in a progressive manner.    
     
     
         5 . A system for distribution of fluidisable materials comprising a reservoir ( 1 ) for the material to be distributed, fluidisable conveying means ( 9 ,  26 ,  27 ,  47 ) for the distribution of the materials to one or more material receiving units ( 350 ), characterised in that 
 the conveying means ( 9 ,  26 ,  27 ,  47 ) comprises at least one material lock ( 4 ,  23 ,  41 ) thus defining at least two hydraulic levels in the conveying means.    
     
     
         6 . A system in accordance with  claim 5 , characterised in that 
 the fluidisable conveying means ( 9 ,  26 ,  27 ,  47 ) comprises a plurality of branches for the distribution of fluidisable materials to a plurality of material receiving units ( 350 - 355 ) thus defining a plurality of distribution paths between the reservoir ( 1 ) and each individual material receiving units where each path is fluidised by pressurised gas in a non-continuous manner.    
     
     
         7 . A system in accordance with  claim 5 , characterised in that 
 the material lock ( 4 ,  23 ,  41 ) comprises a downwardly directed inlet ( 3 ,  28 ,  39 ), a partly fluidisable bottom and an outlet ( 8 ,  24 ,  46 ) communicating with a fluidisable conveyer ( 9 ,  26 ,  47 ).    
     
     
         8 . A system in accordance with  claim 5 , characterised in that 
 the fluidisable conveying means ( 9 ,  26 ,  27 ,  47 ) comprises at least one fluidising element constituted by a base plate ( 204 ), an inlet ( 205 ) for pressurised gas and a gas permeable element ( 206 ) attached to said base plate thus forming a plenum chamber between the base plate and the gas permeable element.    
     
     
         9 . A system in accordance with  claim 5 , characterised in that 
 the fluidisable material is alumina or fluoride distributed to one or more electrolysis cells.    
     
     
         10 . A system in accordance with  claim 5 , characterised in that 
 the material receiving units ( 350 ) are one or more feeding devices arranged in electrolysis cells (E).