Method for improving the efficiency of heat transfer in a coal fired furnace

Abstract

An additive having as components, at least three metal oxides selected from iron, manganese, cobalt, and copper oxide, may be added to coal 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 coal to increase heat transfer efficiency in coal burning furnaces comprising: contacting the coal with an additive prior to or concurrent with combustion of the coal wherein:
 the additive functions to increase radiant heat adsorption of coal ash 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 3 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 9  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; from about XX to about YY % by weight (as metal) cobalt; and from about 5 to about 30% by weight (as metal) iron oxide. 
     
     
         11 . The process of  claim 10  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; from about XX2 to about YY2% by weight (as metal) cobalt; and from about 10 to about 25% by weight (as metal) iron oxide. 
     
     
         12 . The process of  claim 1  wherein the additive is introduced to the coal prior to combustion. 
     
     
         13 . The process of  claim 12  wherein the additive is sprayed onto the coal. 
     
     
         14 . The process of  claim 13  wherein 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 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 coal as a solid. 
     
     
         17 . The process of  claim 16  wherein the additive is admixed with the coal prior to or concurrently with pulverization. 
     
     
         18 . The process of  claim 1  wherein the additive is introduced to the coal concurrently with combustion. 
     
     
         19 . The process of  claim 19  wherein the additive is sprayed into the furnace. 
     
     
         20 . A process for treating coal to increase heat transfer efficiency in coal burning furnaces comprising: contacting the coal with an additive prior to or concurrent with combustion of the coal wherein:
 the additive functions to increase radiant heat adsorption of coal ash;   the additive does not include a fluxing agent; and   the additive is a pigment comprising at least 3 oxides selected from Fe, Cu, Co, and Mn oxides.