Fusion furnace, gasification fusion furnace, and method of processing waste

Abstract

The slagging combustion furnace ( 10 ) of the present invention includes a combustion chamber ( 11, 12, 13 ) for combusting a combustible gas containing ash and melting the ash, and a slag discharge port ( 17 ) for discharging molten slag ( 20 ) produced by melting the ash. The slag discharge port ( 17 ) is formed by refractory material which is replaceable.

1 . A slagging combustion furnace comprising: 
 a combustion chamber for combusting a combustible gas containing ash and melting said ash; and    a slag discharge port for discharging molten slag produced by melting said ash;    wherein said slag discharge port is formed by refractory material which is replaceable.    
     
     
         2 . A slagging combustion furnace according to  claim 1 , wherein said slag discharge port comprises an opening formed at a central portion of a slag discharge port block, and at least one slag discharge groove extending from an outer peripheral portion of said slag discharge port block at the upstream side of a flow of combustion gas to said slag discharge port is formed in an upper surface of said slag discharge port block.  
     
     
         3 . A slagging combustion furnace according to  claim 2 , wherein said upper surface of said slag discharge port block is a slant surface which is inclined downwardly toward said slag discharge port, and an upper end of an outer wall forming said slag discharge port at the upstream side of said flow of said combustion gas is higher than an upper end of said inner wall forming said slag discharge port at the downstream side of said flow of said combustion gas.  
     
     
         4 . A slagging combustion furnace according to  claim 2 , wherein said upper surface of said slag discharge port block is a slant surface which is inclined downwardly toward an outer circumferential portion of said slag discharge port block.  
     
     
         5 . A slagging combustion furnace according to  claim 1 , wherein said slag discharge port block comprises a plurality of block pieces.  
     
     
         6 . A gasification and slagging combustion system, comprising: 
 a gasification furnace for gasifying wastes to produce a combustible gas containing ash and unburned carbon; and    a slagging combustion furnace for combusting said combustible gas containing said ash and said unburned carbon and melting said ash;    wherein said slagging combustion furnace comprises a slagging combustion furnace according to  claim 1 .    
     
     
         7 . A slagging combustion furnace comprising: 
 a combustion chamber for combusting a combustible gas containing ash and melting said ash; and    a slag discharge port for discharging molten slag produced by melting said ash;    wherein the height of an inner wall forming said slag discharge port is higher at the upstream side of a flow of combustion gas than at the downstream side of said flow of said combustion gas.    
     
     
         8 . A slagging combustion furnace according to  claim 7 , wherein an upper surface at an outer circumferential portion around said slag discharge port is a slant surface inclined upwardly toward said slag discharge port, and at least one slag discharge groove extending to said slag discharge port is formed in said slant surface at the upstream side of said flow of said combustion gas.  
     
     
         9 . A waste treatment method comprising: 
 gasifying wastes to produce a combustible gas containing ash in a fluidized-bed furnace;    combusting said combustible gas and melting said ash to form molten slag in a slagging combustion furnace, said slagging combustion furnace comprising a primary combustion chamber, a secondary combustion chamber and a tertiary combustion chamber;    trapping said molten slag on an inner wall surface of said primary combustion chamber and flowing said trapped molten slag downwardly into said secondary combustion chamber;    flowing said molten slag on said inner wall surface of said secondary combustion chamber and discharging said molten slag through a slag discharge groove formed in a slag discharge port block to a slag discharge port formed in said slag discharge port block, said slag discharge port block being disposed at a lowermost part of said secondary combustion chamber, said slag discharge groove being formed at said primary combustion chamber side;    trapping molten slag on an inner wall surface of said tertiary combustion chamber from combustion gas introduced into said tertiary combustion chamber, and then discharging said trapped molten slag through said slag discharge groove to said slag discharge port block; and    supplying said molten slag discharged from said slag discharge groove to a water quenching trough and cooling said discharged molten slag in said water quenching trough.    
     
     
         10 . A waste treatment method comprising: 
 gasifying wastes to produce a combustible gas containing ash in a fluidized-bed furnace;    combusting said combustible gas and melting said ash to form molten slag in a slagging combustion furnace, said slagging combustion furnace comprising a primary combustion chamber, a secondary combustion chamber and a tertiary combustion chamber;    trapping said molten slag on a wall surface of said primary combustion chamber and flowing said trapped molten slag downwardly into said secondary combustion chamber;    flowing said molten slag on said wall surface of said secondary combustion chamber to a slag discharge groove and discharging said molten slag through said slag discharge groove, a slag discharge port block disposed at a lowermost part of said secondary combustion chamber having said slag discharge groove at said primary combustion chamber side;    trapping molten slag on a wall surface of said tertiary combustion chamber from combustion gas introduced into said tertiary combustion chamber, and then discharging said trapped molten slag through said slag discharge groove to said slag discharge port;    cooling and solidifying said molten slag discharged from said slag discharge groove; and    drawing steam generated by said cooling and solidifying of said molten slag and combustion gas through said slag discharge port of said secondary combustion chamber to form a mixed gas, and introducing said mixed gas to said tertiary combustion chamber.    
     
     
         11 . A waste treatment method comprising: 
 gasifying wastes to produce a combustible gas containing ash in a fluidized-bed furnace;    combusting said combustible gas and melting said ash to form molten slag in a slagging combustion furnace, said slagging combustion furnace comprising a primary combustion chamber, a secondary combustion chamber and a tertiary combustion chamber;    trapping said molten slag on a wall surface of said primary combustion chamber and flowing said trapped molten slag downwardly into said secondary combustion chamber;    flowing said molten slag on said wall surface of said secondary combustion chamber to a slag discharge groove and discharging said molten slag through said slag discharge groove, a slag discharge port block disposed at a lowermost part of said secondary combustion chamber having said slag discharge groove at said primary combustion chamber side;    trapping molten slag on a wall surface of said tertiary combustion chamber from combustion gas introduced into said tertiary combustion chamber, and then flowing said molten slag on said wall surface of said tertiary combustion chamber to said slag discharge port block and discharging said molten slag through said slag discharge groove;    cooling said molten slag discharged through said slag discharge groove in a slag discharge chute; and    detecting a pressure differential between an interior of said secondary combustion chamber and an interior of said slag discharge chute;    wherein when said pressure differential exceeds a set value, a secondary combustion chamber burner provided at said secondary combustion chamber is operated to heat a portion around said slag discharge port.    
     
     
         12 . A waste treatment apparatus comprising: 
 a fluidized-bed furnace for gasifying wastes to produce a combustible gas containing ash;    a slagging combustion furnace for combusting said combustible gas and melting said ash to form molten slag, said slagging combustion furnace comprising a primary combustion chamber, a secondary combustion chamber, a tertiary combustion chamber, and a slag discharge port block at a lowermost part of said secondary chamber and having a slag discharge groove at said primary combustion chamber side; wherein said molten slag is trapped on a wall surface of said primary combustion chamber and said trapped molten slag flows downwardly into said secondary combustion chamber, said molten slag flows on said wall surface of said secondary combustion chamber to said slag discharge groove and is discharged from said slag discharge groove, molten slag is trapped on a wall surface of said tertiary combustion chamber from combustion gas introduced into said tertiary combustion chamber, and then said trapped molten slag flows downwardly to said slag discharge port block and is discharged from said slag discharge groove;    a slag discharge chute disposed below said slag discharge port block for cooling said molten slag discharged from said slag discharge groove; and    a pressure instrument for detecting a pressure differential between an interior of said secondary combustion chamber and an interior of said slag discharge chute; wherein when said pressure differential between the interior of said secondary combustion chamber and the interior of said slag discharge chute exceeds a set value, a secondary combustion chamber burner provided at said secondary combustion chamber is operated to heat a portion around said slag discharge port.    
     
     
         13 . A slagging combustion furnace according to  claim 2 , wherein said slag discharge port block comprises a plurality of block pieces.  
     
     
         14 . A slagging combustion furnace according to  claim 3 , wherein said slag discharge port block comprises a plurality of block pieces.  
     
     
         15 . A slagging combustion furnace according to  claim 4 , wherein said slag discharge port block comprises a plurality of block pieces.  
     
     
         16 . A gasification and slagging combustion system, comprising: 
 a gasification furnace for gasifying wastes to produce a combustible gas containing ash and unburned carbon; and    a slagging combustion furnace for combusting said combustible gas containing said ash and said unburned carbon and melting said ash;    wherein said slagging combustion furnace comprises a slagging combustion furnace according to  claim 2 .    
     
     
         17 . A gasification and slagging combustion system, comprising: 
 a gasification furnace for gasifying wastes to produce a combustible gas containing ash and unburned carbon; and    a slagging combustion furnace for combusting said combustible gas containing said ash and said unburned carbon and melting said ash;    wherein said slagging combustion furnace comprises a slagging combustion furnace according to  claim 3 .    
     
     
         18 . A gasification and slagging combustion system, comprising: 
 a gasification furnace for gasifying wastes to produce a combustible gas containing ash and unburned carbon; and    a slagging combustion furnace for combusting said combustible gas containing said ash and said unburned carbon and melting said ash;    wherein said slagging combustion furnace comprises a slagging combustion furnace according to  claim 4 .    
     
     
         19 . A gasification and slagging combustion system, comprising: 
 a gasification furnace for gasifying wastes to produce a combustible gas containing ash and unburned carbon; and    a slagging combustion furnace for combusting said combustible gas containing said ash and said unburned carbon and melting said ash;    wherein said slagging combustion furnace comprises a slagging combustion furnace according to  claim 5.