Method for improving the efficiency of heat transfer in a furnace

Abstract

An additive having as components, at least two metal oxides selected from iron, manganese, cobalt, and copper oxide, may be added to a fuel to reduce the brightness of ash produced therewith. Further, the additive serves to increase the heat transfer efficiency of furnaces.

1 . A process for treating a fuel to increase heat transfer efficiency in comprising contacting the fuel or an ash resulting from fuel combustion with an additive wherein the additive functions to increase radiant heat adsorption as compared with an otherwise identical process absent the additive; and
 the additive does not include a fluxing agent.   
     
     
         2 . The process of  claim 1  wherein the additive is a pigment comprising at least 2 oxides selected from Fe, Cu, Co, and Mn oxides. 
     
     
         3 . The process of  claim 2  wherein the pigment comprises Fe, Cu and Mn oxides. 
     
     
         4 . The process of  claim 3  wherein the pigment comprises from about 15 to about 60% by weight (as metal) copper oxide; from about 20 to about 70% by weight (as metal) manganese oxide; and from about 5 to about 30% by weight (as metal) iron oxide. 
     
     
         5 . The process of  claim 4  wherein the pigment comprises from about 25 to about 45% by weight (as metal) copper oxide; from about 35 to about 60% by weight (as metal) manganese oxide; and from about 10 to about 25% by weight (as metal) iron oxide. 
     
     
         6 . The process of  claim 2  wherein the pigment comprises Fe, Cu and Co oxides. 
     
     
         7 . The process of  claim 6  wherein the pigment comprises from about 15 to about 60% by weight (as metal) copper oxide; from about 20 to about 70% by weight (as metal) cobalt oxide; and from about 5 to about 30% by weight (as metal) iron oxide. 
     
     
         8 . The process of  claim 7  wherein the pigment comprises from about 25 to about 45% by weight (as metal) copper oxide; from about 35 to about 60% by weight (as metal) cobalt oxide; and from about 10 to about 25% by weight (as metal) iron oxide. 
     
     
         9 . The process of  claim 1  wherein the additive is a pigment comprising Fe, Cu, Co, and Mn oxides. 
     
     
         10 . The process of  claim 1  wherein at least one of the metal oxides is in the form of a pellet prepared by sintering prior to being applied to the fuel or introduced into the furnace. 
     
     
         11 . The process of  claim 10  wherein two or more of the metal oxides are admixed and then sintered prior to being applied to the fuel or introduced into the furnace. 
     
     
         12 . The process of  claim 1  wherein the additive is introduced to the fuel prior to combustion. 
     
     
         13 . The process of  claim 12  wherein the additive is sprayed onto the fuel. 
     
     
         14 . The process of  claim 13  wherein the fuel is coal and the process further comprises pulverizing the coal, and the additive is sprayed onto the coal prior to pulverizing. 
     
     
         15 . The process of  claim 13  wherein the fuel is coal and the process further comprises pulverizing the coal, and the additive is sprayed onto the coal after or concurrently with pulverization. 
     
     
         16 . The process of  claim 12  wherein the additive is admixed with the fuel as a solid. 
     
     
         17 . The process of  claim 16  wherein the additive is admixed with the fuel prior to or concurrently with pulverization. 
     
     
         18 . The process of  claim 1  wherein the additive is introduced to the fuel concurrently with combustion. 
     
     
         19 . The process of  claim 19  wherein the additive is sprayed into the furnace. 
     
     
         20 . A process for treating a fuel to increase heat transfer efficiency in furnaces comprising: contacting the fuel with an additive wherein:
 the additive functions to increase radiant heat adsorption of ash;   the additive does not include a fluxing agent; and   the additive is a pigment comprising at least 2 oxides selected from Fe, Cu, Co, and Mn oxides.