Method and arrangement for monitoring a burner

Abstract

A method and apparatus for monitoring combustion of a fuel with an oxidant in an industrial furnace. The fuel and oxidant are supplied to a burner head, and a burner outlet flame is monitored by an ultraviolet light detector. At least one fuel channel and at least two oxidant channels are provided and open at an outer surface of the burner head that faces the interior of the furnace. The fuel channel and a first oxidant channel are located at a predetermined first distance from each other, and the fuel channel and the second oxidant channel are located closer to each other at a second distance. The detector is positioned at the fuel channel or at the second oxidant channel. A fraction of the total amount of oxidant supplied is supplied to the second oxidant channel, and oxidant is supplied to the second oxidant channel during the entire combustion process.

1 . A method for combustion of a fuel with an oxidant in an industrial furnace, in which the fuel and the oxidant are supplied to a burner head and where the flame is monitored by means of a detector for ultraviolet light, said method comprising the steps of: providing at least one fuel supply channel and at least two oxidant supply channels that open at an outlet surface of the burner head that faces into the furnace; positioning the fuel supply channel relative to a first oxidant supply channel at a first distance from each other; positioning the fuel supply channel and the second oxidant supply channel relative to each other at a second distance from each other that is smaller than the first distance; arranging the detector at one of the fuel supply channel and the second oxidant supply channel at a burner inlet region; furnishing a fraction of a total supply of oxidant to the second oxidant supply channel; and maintaining oxidant supply to the second oxidant supply channel during an entire combustion process.  
   
   
       2 . A method in accordance with  claim 1 , including the step of supplying between 4 and 40% of the total supply of oxidant to the second oxidant supply channel.  
   
   
       3 . A method in accordance with  claim 1 , including the step of supplying between 5 and 15% of the total supply of oxidant to the second oxidant supply channel.  
   
   
       4 . A method in accordance with  claim 1 , including the step of positioning the second oxidant supply channel coaxially with the fuel supply channel.  
   
   
       5 . A method in accordance with  claim 1 , including the step of spacing the second oxidant supply channel and the fuel supply channel from each other and in parallel relationship.  
   
   
       6 . A burner for the combustion of a fuel with an oxidant in an industrial furnace, in which the burner is arranged to supply fuel and oxidant to the burner head of the burner, and wherein a detector for ultraviolet light is present to monitor a flame issuing from the burner head, said burner comprising: at least one fuel supply channel and at least two oxidant supply channels that open at an outlet surface of the burner head that faces into the furnace; wherein the fuel supply channel and a first oxidant supply channel are positioned at a first distance from each other; wherein the fuel supply channel and a second oxidant supply channel are positioned from each other at a second distance from each other that is smaller than the first distance; wherein the detector is positioned at one of the fuel supply channel and the second oxidant channel at a burner inlet region; and wherein a fraction of a total amount of oxidant supplied to the burner head is supplied to the second oxidant supply channel.  
   
   
       7 . A burner in accordance with  claim 6 , wherein the burner supplies between 4 and 40% of the oxidant to the second oxidant supply channel.  
   
   
       8 . A burner in accordance with  claim 6 , wherein the burner supplies between 5 and 15% of the oxidant to the second oxidant supply channel.  
   
   
       9 . A burner in accordance with  claim 6 , wherein the second oxidant supply channel and the fuel supply channel are coaxial.  
   
   
       10 . A burner in accordance with  claim 6 , wherein the second oxidant supply channel and the fuel supply channel are spaced from each other and in parallel relationship.