Coal burning boiler apparatus

Abstract

In a coal burning boiler apparatus, temperature of the pulverized coal to be fed to the boiler can be set depending on the property of the combustion coal, so that stable ignition and combustion can be made regardless of the property of the combustion coal fed. Provided are a coal burning boiler 1 , a coal pulverizer 2 for pulverizing massive coal 6 into fine powder, a temperature sensor 18 for detecting temperature of the primary air 35 for entraining the pulverized coal to the coal burning boiler, regulators 9, 12, 13 and 14 for regulating the temperature of the primary air and a controller for controlling the primary air temperature regulators on the basis of detected result of the temperature sensor so as to make the primary air have a given temperature.

1 . A coal burning boiler apparatus characterized in that it comprises a coal burning boiler, a coal pulverizer for pulverizing massive coal into pulverized coal, a temperature sensor for detecting temperature of primary air entraining the pulverized coal to said coal burning boiler, means for regulating temperature of said primary air and a controller for controlling said regulating means on the basis of a detected result from said temperature sensor so as to make said primary air have a given temperature. 
   
   
       2 . A coal burning boiler apparatus as claimed in  claim 1 , wherein said primary air temperature regulating means comprises a primary air feed pipe passing through an air preheater heated by exhaust gas from the boiler, a primary air bypass pipe bypassing said air preheater and joining into said primary air feed pipe, a first flow rate regulating damper arranged in said primary air feed pipe and a second flow rate regulating damper arranged in said primary air bypass pipe, said first and second flow rate regulating dampers being flow-rate controlled by said controller. 
   
   
       3 . A coal burning boiler apparatus as claimed in  claim 1 , wherein said controller has data on properties of coals and data on spontaneous ignition temperatures corresponding to said properties of the coals, spontaneous ignition temperature corresponding to a property of the coal supplied being calculated on the basis of said data on the properties of the coals and said data on the spontaneous ignition temperatures, temperature of the primary air being set on the basis of a result of the calculation. 
   
   
       4 . A coal burning boiler apparatus as claimed in  claim 2 , wherein said controller has data on properties of coals and data on spontaneous ignition temperatures corresponding to said properties of the coals, spontaneous ignition temperature corresponding to a property of the coal supplied being calculated on the basis of said data on the coal properties and said data on the spontaneous ignition temperatures, temperature of the primary air being set on the basis of a result of the calculation. 
   
   
       5 . A coal burning boiler apparatus as claimed in  claim 3 , wherein said data on the properties of the coals include data of volatile portion, fuel ratio and total moisture content. 
   
   
       6 . A coal burning boiler apparatus as claimed in  claim 4 , wherein said data on the coal properties include data of volatile portion, fuel ratio and total moisture content. 
   
   
       7 . A coal burning boiler apparatus as claimed in  claim 3 , wherein said temperature of the primary air is temperature on the outlet side of said coal pulverizer and set to be lower than a corresponding ignition temperature by 20° C. 
   
   
       8 . A coal burning boiler apparatus as claimed in  claim 4 , wherein said temperature of the primary air is temperature on the outlet side of said coal pulverizer and set to be lower than a corresponding ignition temperature by 20° C. 
   
   
       9 . A coal burning boiler apparatus as claimed in  claim 1 , wherein a further temperature sensor is provided on the inlet side of said coal pulverizer to conduct monitor for prevention of the temperature of the primary air flowing into said coal pulverizer from being higher than the given temperature.