薄鋼板の無酸化加熱の生起条件と最適温度の予測
1990 年 76 巻 3 号 p. 345-351
詳細
1990 年 76 巻 3 号 p. 345-351
The Direct Reductive Heating (DRH) was great practical advantage in continuous heating of thin steel plates compared with the conventional indirect heating conducted under nitrogen environment.DRH has been so far employed experimentally with some success at the level of know-hows.However, its theoretical background has not been given as to what aerothermochemical conditions necessary for reduction at a steel surface to be realized.An computational approach for the 2-D flame held in the boundary layer of a steel surface shows some evidence of DRH judging from the concentration profiles of chemical species.In fact, the ratio of CO2 /CO the most crucial measure for the reduction goes down to less than 0.1 on the surface just behind the flame foot, for a narrow wall temperature range around 900°C.It is concluded thereby that a fuel-rich hydrocarbon-air mixture can generate a reductive region behind the flame front where the oxygen is depleted if the cooling effect due to the wall is favorable for formation of more CO rather than CO2.
