| 摘要 |
The thermal treatment is effected in that hot gases are passed through the charge bed. Hot gases are passed downwardly through the charge bed in heat treating zone, oxygen-containing cooling gases are passed upwardly through the charge bed in a cooling zone, and the cooling gases which have been heated are conducted under a continuous gas hood from the cooling zone into the heat treating zone. In order to reduce the energy consumption and to lower the operating costs and the structural expenditure, the cooling gases which have been heated up are caused to flow at such a high velocity under the continuous gas hood over the upper course of the travelling grate that any vertical uplift will exert virtually no influence so that parallel layers of flowing gas at different temperatures are formed under the gas hood, fuel is supplied to individual layers of flowing gas, and individual layers of flowing gas are heated to different higher temperatures and are subsequently passed in the heat-treating zone downwardly through the charge bed. |
