Burner, and combustion equipment and boiler comprising burner

Abstract

A burner including a fuel-containing fluid supply nozzle which supplies a fuel-containing fluid, from a connecting part in a fluid transfer flow passage for transferring a fuel-containing fluid including a fuel and a medium for transfer of the fuel, toward an outlet part provided on a furnace wall surface. The nozzle in its cross section perpendicular to the direction of flow of the fluid has a rectangular, elliptical, or substantially elliptical form having major and minor axis parts from a connecting part in the fluid transfer flow passage toward the outlet part provided on the furnace wall surface. Further, the area of a cross section perpendicular to the direction of flow of the fluid is gradually increased from the connecting part in the fluid transfer flow passage toward the outlet part. Air supply nozzle(s) for supplying combustion air are provided on the outer peripheral part of the nozzle.

What is claimed is: 
     
         1 . A burner, comprising:
 a fuel-containing fluid supply nozzle supplying a fuel-containing fluid, containing a solid fuel and a medium for transfer of the solid fuel, to an outlet part disposed on a wall surface of a furnace from a connecting part of a fuel-containing fluid transfer flow passage that transfers the fluid; and one or more air supply nozzles supplying combustion air and disposed at an outer peripheral part of the fuel-containing fluid supply nozzle; wherein,   from the connecting part of the fluid transfer flow passage toward the outlet part disposed on the wall surface of the furnace, a cross section of the fuel-containing fluid supply nozzle perpendicular to a flow of the fluid has a rectangular, elliptical, or substantially elliptical shape with major and minor axis parts and, from the connecting part of the fluid transfer flow passage toward the outlet part,   a size of the major axis part of the cross section perpendicular to the flow of the fluid increases gradually along a direction of the flow of the fluid from the connecting part of the fluid transfer flow passage,   a size of the minor axis part of the cross section perpendicular to the flow of the fluid is unchanged or decreases gradually along the direction of the flow of the fluid, and   a fluid distribution plate, distributing the fuel uniformly inside the fuel-containing fluid supply nozzle is disposed at an inlet part of the fuel-containing fluid supply nozzle.   
     
     
         2 . The burner according to  claim 1 , wherein
 fuel-containing fluid guide plates disposed at a plurality of different inclination angles with respect to a plane passing along a line extending a central axis in the direction of the flow of the fluid in the fuel-containing fluid supply nozzle toward the furnace and parallel to a shortest axis of the minor axis part of the nozzle.   
     
     
         3 . The burner according to  claim 1 , wherein
 the fuel-containing fluid supply nozzle has, in an interior of the outlet thereof, fuel-containing fluid direction changing guide plates forcibly changing a direction of ejection flow of the fuel-containing fluid.   
     
     
         4 . The burner according to  claim 3 , wherein
 the fuel-containing fluid direction changing guide plates are disposed in a plurality of mutually different directions with respect to planes parallel to a plane passing along a line extending the central axis of the fuel-containing fluid supply nozzle toward the furnace and passing through a longest axis of the major axis part of the nozzle.   
     
     
         5 . The burner according to  claim 3 , wherein
 the fuel-containing fluid direction changing guide plates for a portion of the fuel-containing fluid are disposed parallel to planes parallel to a plane passing along a line extending the central axis of the fuel-containing fluid supply nozzle toward the furnace and passing through a longest axis of the major axis part of the nozzle, and the fuel-containing fluid direction changing guide plates for another portion of the fuel containing fluid are disposed at an inclination angle with respect to the plane passing along the line extending the central axis of the fuel-containing fluid supply nozzle toward the furnace and parallel to the longest axis of the major axis part of the nozzle.   
     
     
         6 . The burner according to  claim 1 , wherein
 the fuel-containing fluid supply nozzle is partitioned into a plurality of flow passages by the fuel-containing fluid guide plates, and central axes of the respective flow passages are disposed at the wall surface of the furnace at a plurality of mutually different inclination angles with respect to planes parallel to a plane passing along a line extending the central axis of the fuel-containing fluid supply nozzle toward the furnace and passing through a longest axis of the major axis part of the nozzle outlet.   
     
     
         7 . The burner according to  claim 1 , wherein
 fuel-containing fluid partitioning plates, capable of plurally partitioning the outlet part of the fuel-containing fluid supply nozzle, are disposed at the outlet part.   
     
     
         8 . The burner according to  claim 1 , wherein
 a flame stabilizer with an L-shaped cross section is disposed at the outlet part of the fuel-containing fluid supply nozzle.   
     
     
         9 . The burner according to  claim 8 , wherein
 a guide plate outwardly changing an ejection direction of the combustion air in a periphery of the flame stabilizer is disposed at a front end of the L-shaped flame stabilizer.   
     
     
         10 . The burner according to  claim 1 , wherein
 a combustion air guide plate, outwardly spreading an ejection direction of the combustion air at an outer side of the one or more combustion air supply nozzles disposed at the outer peripheral part of the nozzle with respect to a fuel ejection direction, is disposed at a front end of the combustion air supply nozzles.   
     
     
         11 . The burner according to  claim 1 , wherein
 a condenser, narrowing the flow passage of the fuel-containing fluid once and then expanding the flow passage again, is disposed in an interior of the fuel-containing fluid supply nozzle.   
     
     
         12 . The burner according to  claim 1 , wherein
 a nozzle, ejecting a liquid fuel or a gas fuel that is an auxiliary fuel to a vicinity of the fluid ejected from the fuel-containing fluid supply nozzle, is disposed at a vicinity of the fuel-containing fluid supply nozzle.   
     
     
         13 . A combustion equipment wherein
 the burners according to  claim 1  are disposed in a plurality of stages in an up/down direction at each of two opposing furnace walls, and a plurality of burners disposed at each stage are disposed respectively symmetrically in wall surface regions divided in two at a central part of width in a horizontal direction of the same furnace wall.   
     
     
         14 . A combustion equipment wherein
 the burners according to  claim 1  are disposed in a plurality of stages in an up/down direction at each of two opposing furnace walls, and burners, which, among the plurality of burners disposed in each stage of the same furnace wall, are adjacent each other in a horizontal direction, are burners of the same structure.   
     
     
         15 . A boiler including: a furnace wall formed by spirally winding a set of water wall tubes inclined with respect to a horizontal direction; wherein
 openings of rectangular, elliptical, or substantially elliptical shape are disposed in the furnace wall along a longitudinal direction of the water wall tubes and the burner according to  claim 1  is mounted in each opening.   
     
     
         16 . A boiler including: a furnace wall formed by a set of water wall tubes extending in a vertical direction; wherein
 openings of rectangular, elliptical, or substantially elliptical shape are disposed in the furnace wall along a longitudinal direction of the water wall tubes and the burner according to  claim 1  is mounted in each opening.