Method and apparatus for sulfur trioxide flue gas conditioning

Abstract

A method and apparatus for sulfur trioxide conditioning of flue gas, to assist in the removal of flyash from flue gas exhaust streams containing such flyash. More particularly, such a method and apparatus, which introduces an improvement in the transportation of dry sulfur and the melting and storage of resultant melted sulfur. The melted sulfur is subsequently burned and thereafter catalytically converted to sulfur trioxide for injection into a flue gas for such aforesaid assistance in the removal of flyash therefrom.

1 . In a sulfur trioxide conditioning apparatus wherein heated air flows from an inlet to an outlet, and from such outlet into a flue for conditioning of flue gases containing flyash by injecting a controlled amount of sulfur trioxide gaseous mixture to vary the electrical resistivity of such flyash, such heated air flow, as it flows from such inlet to such outlet, passes first through a burner means for burning elemental sulfur to produce an air and sulfur dioxide mixture and thereafter through a conversion means to produce a mixture containing air and sulfur trioxide for use in the conditioning of such flue gases, the improvement comprising: 
 an on-site storage assembly for the storage of solid sulfur;    first conveying means for conveying such solid sulfur to a second on-site storage assembly;    said second on-site storage assembly including a melter means incorporated therein to melt such solid sulfur conveyed thereto to molten sulfur and also being adapted to store such molten sulfur therein at a temperature above the freezing point thereof; and    second conveying means being operative to selectively convey variable amounts of such molten sulfur from said second on-site storage assembly to said sulfur burner, in response to signals indicative of sulfur trioxide conditioning demand.    
     
     
         2 . A sulfur trioxide conditioning apparatus as specified in  claim 1  wherein said first conveying means is selectively operable to transfer a predetermined batch of solid sulfur to said second on-site storage assembly.  
     
     
         3 . A sulfur trioxide conditioning apparatus as specified in  claim 2 , wherein such first conveying means is selectively operable is response to a transfer demand signal indicative of the volume of sulfur contained within said second storage assembly.  
     
     
         4 . A sulfur trioxide conditioning apparatus as specified in  claim 2  wherein the predetermined batch of solid sulfur is at least a one days supply of sulfur required for such sulfur trioxide conditioning.  
     
     
         5 . In a method for producing an air and sulfur trioxide conditioning mixture by burning elemental sulfur in heated air to produce an air and sulfur dioxide flow, passing such flow through a catalytic converter to produce such a conditioning mixture for downstream use, the improvement comprising: 
 storing solid sulfur at a location upstream of such burning;    receiving a signal indicative of the requirements for solid sulfur and, in response thererto, transporting such stored solid sulfur from storage;    melting such transported solid sulfur to form molten sulfur;    storing such molten sulfur; and    selectively transporting such molten sulfur for such aforesaid burning and catalytic conversion.    
     
     
         6 . A method as specified in  claim 5  including the additional step of: 
 injecting such conditioning mixture into a flue gas stream containing flyash, for the conditioning of such flue gases to assist in the removal of such flyash therefrom, by electrostatic precipitation.  
 
     
     
         7 . A method of conditioning as specified in  claim 5  wherein such solid sulfur is transferred from storage on a predetermined batch basis.  
     
     
         8 . A sulfur trioxide conditioning apparatus as specified in  claim 7  wherein the predetermined batch of solid sulfur transferred is at least a one days supply of sulfur required to assist in such flyash removal.