Method for optimizing the burnout of exhaust gases of an incinerator

Abstract

A method for optimizing the burnout of exhaust gases of an incinerator includes introducing a solid material via an inlet into a combustion chamber defining a primary combustion space, combusting the solid material in the primary combustion space, in the form of a combustion bed conveyed over a combustion grate, with admission of primary air, discharging the combusted solid material from the primary combustion space via an outlet arranged opposite the inlet in the conveying direction, combusting the primary combustion gases released during the combustion of the solid material, with admission of secondary air, in a secondary combustion chamber defining a secondary combustion space and arranged downstream of the combustion chamber in the flow direction of the combustion gases, and homogenizing the exhaust gases containing the primary combustion gases in a mixing zone by means of a fluid introduced via a nozzle before entry into the secondary combustion space.

1 . A method for optimizing the burnout of exhaust gases of an incinerator, said method comprising:
 introducing a solid material to be combusted via an inlet into a combustion chamber defining a primary combustion space;   combusting the solid material in the primary combustion space, in the form of a combustion bed conveyed over a combustion grate, arc combusted with admission of primary air;   discharging the combusted solid material from the primary combustion space via an outlet arranged opposite the inlet in a conveying direction;   combusting primary combustion gases released during the combustion of the solid material, with admission of secondary air, in a secondary combustion chamber defining a secondary combustion space and arranged downstream of the combustion chamber in the flow direction of the combustion gases; and   homogenizing the exhaust gases containing the primary combustion gases in a mixing zone by means of a fluid introduced via a nozzle before entry into the secondary combustion space,   wherein the mixing zone adjoins the combustion bed at least approximately directly in the flow direction of the exhaust gases, the exit speed of the fluid from the nozzle is about 40 to about 120 m/s, and   wherein the nozzle is oriented at an angle from about −10° to about +10° relative to the inclination of the combustion grate.   
     
     
         2 . The method as claimed in  claim 1 , wherein the distance between the mixing zone and the combustion bed is at most 1.5 meters. 
     
     
         3 . The method as claimed in  claim 1 , wherein the mixing zone extends at most up to a distance of 2 meters measured from the combustion bed. 
     
     
         4 . The method as claimed in  claim 1 , wherein the exit speed of the fluid from the nozzle is about 90 m/s. 
     
     
         5 . The method as claimed in  claim 1 , wherein the nozzle is oriented at an angle from about −5° to about +5° relative to the inclination of the combustion grate. 
     
     
         6 . The method as claimed in  claim 1 , wherein the fluid comprises a flue gas returned from a subsequent zone downstream of the combustion chamber. 
     
     
         7 . The method as claimed in  claim 6 , wherein the quantity of introduced flue gas is about 5% to about 35%, of the admitted quantity of primary air. 
     
     
         8 . The method as claimed in  claim 1 , wherein the fluid is injected via a nozzle arranged in an inlet-side region of the combustion chamber. 
     
     
         9 . The method as claimed in  claim 1 , wherein the nozzle has an outer pipe and an inner pipe running in the axial direction of the outer pipe and surrounded thereby, the inner pipe being intended to carry the flue gas and the outer pipe being intended to carry air. 
     
     
         10 . The method as claimed in  claim 1 , wherein the fluid is introduced via at least two nozzles. 
     
     
         11 . A combustion chamber for carrying out the method as claimed in  claim 1 , said combustion chamber comprising:
 a peripheral wall enclosing the primary combustion space;   the inlet for introducing the solid material to be combusted into the primary combustion space;   a combustion grate for combusting the solid material,   the outlet arranged opposite the inlet in the conveying direction of the solid material for discharge of the combusted solid material from the primary combustion space; and   the nozzle for homogenizing the exhaust gases containing the primary combustion gases released during the combustion process,
 wherein the nozzle is arranged in a range of at most 3 meters above the combustion grate, and 
 wherein the nozzle is oriented at an angle of about −10° to about +10° relative to the inclination of the combustion grate. 
   
     
     
         12 . The combustion chamber as claimed in  claim 11 , wherein the nozzle is arranged in the peripheral wall of the combustion chamber. 
     
     
         13 . The combustion chamber as claimed in  claim 11 , wherein the nozzle is arranged in the region of the inlet. 
     
     
         14 . The combustion chamber as claimed in  claim 11 , wherein the nozzle is oriented at an angle from about −5° to about +5° relative to the inclination of the combustion grate. 
     
     
         15 . A waste incinerator, comprising a combustion chamber as claimed in  claim 11 . 
     
     
         16 . The method as claimed in  claim 2 , wherein the distance between the mixing zone and the combustion bed is at most 0.8 meters. 
     
     
         17 . The method as claimed in  claim 7 , wherein the quantity of introduced flue gas is approximately 20% of the admitted quantity of primary air. 
     
     
         18 . The method as claimed in  claim 10 , wherein the fluid is introduced via at least six nozzles. 
     
     
         19 . The combustion chamber as claimed in  claim 11 , wherein the nozzle is arranged in a range of about 0.5 meters to about 3 meters above the combustion grate. 
     
     
         20 . The combustion chamber as claimed in  claim 19 , wherein the nozzle is arranged in a range of about 0.5 meters to about 2 meters above the combustion grate.