| 摘要 |
PROBLEM TO BE SOLVED: To form a flat flame temperature distribution for complete combustion in a short furnace as in an long furnace and allow regenerative burner technique to be applicable to the short furnace. SOLUTION: Combustion air of more than a theoretical amount of air is jetted into a furnace so that a jet flow cross section having a larger specific surface area is formed comparing with the case where the combustion air of the same flow rate is supplied from a perfect circle throat. Meanwhile, fuel is jetted toward this air jet flow to allow the fuel to mix with the air jet flow with considerable turbulence before the fuel loses speed energy. Specifically, an air throat 13 and a fuel nozzle 11 are disposed so that a ratio de/Dpcd of an equivalent diameter de of an opening 13a of the air throat 13 to a distance 1/2 Dpcd from the center of the air throat 13 to the center of the fuel nozzle 11, falls within a range of 0.1 to 0.5, and that a ratio La/de of the equivalent diameter de of the air throat 13 to a distance La from an intersecting point between a fuel jet flow axis and a plane on a central axis, in the longitudinal direction, of the air throat 13 to the exit surface of the air throat 13, falls within the range of 2.0 to 10.0. More preferably, the air throat 13 may have the opening 13a of a flat rectangular shape. |
