危险废物回转式流化冷渣多段焚烧系统焚烧特性研究

危险废物的处理和处置是摆在我国各级市政府面前的紧迫任务。然而我国已经运行的危险废物焚烧装置普遍存在回转窑挂壁结渣、热灼减率偏高和污染排放超标等问题,作者通过将回转窑和流化床特点相结合的方法提出了一种新型危险废物回转式流化冷渣多段焚烧处置装置。该装置采用回转窑(一燃室)、二燃室和流化床结合的热解-流化焚烧工艺,特别是采用控制窑头温度避免了回转窑挂壁结渣;采用流化冷渣装置延长未燃烬渣的焚烧时间,解决了热灼减率偏高问题;水冷式烟气急冷装置可以将烟气温度从1 100℃降到200℃,防止了二恶英的尾部低温再生成。该系统运行稳定可靠,可以处理医疗垃圾和大多数的固态和液态危险废物,实现了烟气污染物尤其是二恶英排放达到国家标准的目标。同时对该系统运行时窑头温度分布、二燃室炉膛出口氧量变化、回转窑和炉膛升温特性、燃烧室外壁温度分布等几方面运行数据都进行了详细的介绍,为危险废物焚烧炉的运行提供了宝贵的经验数据。

Incineration characteristics of multi-incineration system of rotary fluidizing and ash-cooling for hazardous wastes

The treatment and disposal of hazardous wastes are currently the urgent task of many cites in our country. Now there are many problems such as slagging in rotary kiln inside wall, high loss-on-ignition and high pollution emission existing in most of conventional hazardous waste incinerators. A muhi-incineration system of rotary fluidizing and ash-cooling for hazardous waste was developed by the combination of rotary kiln and fluidized bed. The incineration system includes primary chamber (rotary kiln), fluidized bed and secondary chamber.The problem of slagging in rotary kiln inside wall can be solved by the controlling of temperature at the rotary kiln inlet, the residence time of the incombustible slag can be prolonged by using the fluidizing and the ash-cooling device, so the problem of high value of the loss-on-ignition can be solved. The flue gas temperature can be lowered directly from 1100℃ to 200 ℃ by the flue gas quenching facility, thus the low-temperature regeneration of dioxin are prevented. Medical waste and majority of solid and liquid hazardous wastes can be disposed by the stable system. The levels of flue gas pollutants emitted from the stack especially dioxin meet national emission limits set by the Chinese EPA. The operation data of temperature distribution at the rotary kiln inlet, oxygen content at the outlet of secondary chamber with time, temperature changing with time of rotary kiln and furnace temperature distribution at the outlet of chamber are described, valuable experience data for the operation of hazardous waste incinerator can be referred for commercial incineration plants.