| 摘要 |
In removing sulphur from the fume gases produced in a water-tube boiler fired by coal dust, the fumes descend in one or more vertical tube-lined combustion chambers into which powdered lime is blown through nozzles located below at least some of the burners. Before the flames turn to rise vertically through the parallel flue contg. further heating surfaces, they are intensely mixed by nozzles blowing in combustion air and/or fumes, which may also contain powdered lime. Alternatively mixing is mechanically provided, esp. by a rotary stirrer driven by a motor outside the combustion chamber, the stirrer being cooled by a low pressure fluid such as oil, in a heat exchanger, whose heat is applied to the combustion air, the feed water, or the steam produced. Forcing the flame against its normal thermal lift direction causes more uniform and prolonged passage of fumes and flame, which favours combination of CO2 with the lime. |
