Process for controlling the addition of an auxiliary fuel

Abstract

The invention relates to a process for controlling the addition of an auxiliary fuel to combustion of at least one combustible material in a combustion chamber. In addition, the invention relates to the use of the process, in which the concentration is measured in the flue gas of at least one pollutant formed by incomplete combustion. In a second step, the rate of the auxiliary fuel fed to the combustion is increased when the concentration of the at least one pollutant in the flue gas exceeds a predetermined upper limiting value, or is decreased when the concentration measured of the at least one pollutant falls below a predetermined lower limiting value. Measurement of the concentration and setting the rate of the auxiliary fuel is repeated until the measured concentration of the at least one pollutant in the flue gas is in a range between the lower and upper limiting values.

1 - 15 . (canceled) 
     
     
         16 . A process for controlling the addition of an auxiliary fuel to the combustion of at least one combustible material in a combustion chamber, comprising:
 (a) measuring the concentration in the flue gas of at least one pollutant formed by incomplete combustion,   (b) increasing the rate of the auxiliary fuel added to the combustion when the concentration in the flue gas of the at least one pollutant measured exceeds a predetermined upper limiting value or decreasing the rate of the auxiliary fuel added to the combustion when the concentration of the at least one pollutant measured falls below a predetermined lower limiting value,   (c) repeating the measuring and increasing and/or decreasing until the concentration measured in the flue gas of the at least one pollutant is in a range between the lower and upper limiting value.   
     
     
         17 . The process according to  claim 16 , wherein, in addition, the temperature of the flue gas is in a range between the lower and upper limiting values. 
     
     
         18 . The process according to  claim 17 , wherein the temperature of the combustion is set by increasing or decreasing the rate of the auxiliary fuel added to the combustion. 
     
     
         19 . The process according to  claim 16 , wherein the at least one pollutant is carbon monoxide, at least one hydrocarbon or at least one unburnt or incompletely burnt component of the at least one combustible material and/or of the auxiliary fuel or a mixture thereof. 
     
     
         20 . The process according to  claim 16 , wherein the at least one pollutant is carbon monoxide. 
     
     
         21 . The process according to  claim 16 , wherein the concentration of the at least one pollutant in the flue gas is measured downstream of the combustion chamber or downstream of an apparatus arranged in the flue gas channel. 
     
     
         22 . The process according to  claim 21 , wherein the apparatus arranged in the flue gas channel is used for cooling or purifying the flue gas. 
     
     
         23 . The process according to  claim 21 , wherein the apparatus arranged in the flue gas channel is used for steam generation. 
     
     
         24 . The process according to  claim 16 , wherein the at least one combustible material is not combusted in a self-sustaining manner. 
     
     
         25 . The process according to  claim 16 , wherein the at least one combustible material is waste, sludge comprising combustible substances, liquids comprising combustible substances, or exhaust gas comprising combustible substances. 
     
     
         26 . The process according to  claim 16 , wherein the auxiliary fuel is selected from coal, coke and liquid or gaseous hydrocarbons. 
     
     
         27 . The process according to  claim 16 , wherein the oxygen content is additionally determined in the flue gas. 
     
     
         28 . The process according to  claim 27 , wherein in the case of an excessive oxygen content in the flue gas, the rate of oxygen-comprising gas fed to the combustion is reduced and in the event of an insufficient oxygen content in the flue gas, the rate of oxygen-comprising gas fed to the combustion is increased. 
     
     
         29 . The process according to  claim 16  used in a refuse incineration plant or a plant for thermal exhaust gas purification. 
     
     
         30 . A process for controlling the addition of an auxiliary fuel to combustion of at least one combustible material in a combustion chamber, comprising:
 (a) setting a preset value for the combustion temperature, wherein the preset value is of a level such that complete combustion of the at least one combustible material proceeds,   (b) measuring the combustion temperature and increasing the rate of the auxiliary fuel added to the combustion if the measured temperature falls below the preset value of the combustion temperature and decreasing the rate of the auxiliary fuel added to the combustion if the preset value of the combustion temperature is exceeded by the measured temperature,   (c) measuring the concentration of at least one pollutant formed in the flue gas by incomplete combustion and lowering the preset value of the combustion temperature,   (d) repeating said measuring of combustion temperature and concentration until the measured concentration of the at least one pollutant formed by incomplete combustion exceeds a predetermined limiting value,   (e) increasing the preset value of the temperature and repeating said measuring of combustion temperature and concentration until the measured concentration of the at least one pollutant formed by incomplete combustion is again below the predetermined limiting value.   
     
     
         31 . The process according to  claim 30 , wherein the at least one pollutant is carbon monoxide, at least one hydrocarbon or at least one unburnt or incompletely burnt component of the at least one combustible material and/or of the auxiliary fuel or a mixture thereof. 
     
     
         32 . The process according to  claim 30 , wherein the at least one pollutant is carbon monoxide. 
     
     
         33 . The process according to  claim 30 , wherein the concentration of the at least one pollutant in the flue gas is measured downstream of the combustion chamber or downstream of an apparatus arranged in the flue gas channel. 
     
     
         34 . The process according to  claim 33 , wherein the apparatus arranged in the flue gas channel is used for cooling or purifying the flue gas. 
     
     
         35 . The process according to  claim 33 , wherein the apparatus arranged in the flue gas channel is used for steam generation. 
     
     
         36 . The process according to  claim 30 , wherein the at least one combustible material is not combusted in a self-sustaining manner. 
     
     
         37 . The process according to  claim 30 , wherein the at least one combustible material is waste, sludge comprising combustible substances, liquids comprising combustible substances, or exhaust gas comprising combustible substances. 
     
     
         38 . The process according to  claim 30 , wherein the auxiliary fuel is selected from coal, coke and liquid or gaseous hydrocarbons. 
     
     
         39 . The process according to  claim 30 , wherein the oxygen content is additionally determined in the flue gas. 
     
     
         40 . The process according to  claim 39 , wherein in the case of an excessive oxygen content in the flue gas, the rate of oxygen-comprising gas fed to the combustion is reduced and in the event of an insufficient oxygen content in the flue gas, the rate of oxygen-comprising gas fed to the combustion is increased. 
     
     
         41 . The process according to  claim 30  used in a refuse incineration plant or a plant for thermal exhaust gas purification.