无害化城市生活垃圾直接气化熔融焚烧技术的试验研究

Experimental Research on Harmless Technology of Municipal Solid Waste Incineration with Direct Gasification and Ash Melting

通过试验研究,开发出了一种新型的无害化城市生活垃圾直接气化熔融焚烧技术,其工艺流程为:将配好料的生活垃圾直接置于温度为1300～1500℃,炉内气氛为还原性的气化熔融焚烧炉中进行处理,助燃粉煤由炉子底部喷人,可燃气体产物进入二次旋风燃烧室完全燃烧后进行余热发电或供热;熔融渣和金属或从一个渣口中排出并被水急速冷却,被冷却的熔融渣和金属经分选机分选出金属和无机残渣,金属回收利用,无机残渣则作为建材;或分别从金属口和熔融渣口排出,金属回收利用,熔融渣经水淬后再生利用。该炉的基建投资和运行费用比国外研制的垃圾直接气化熔融炉要低得多,一般只需国外的65％～85％。原垃圾中99.8％以上的二恶英可被分解,烟气中二恶英的排放量≤0.01 ng-FEQ/m3,熔融渣中二恶英的排放量≤0.003 ng-TEQ/g。

A novel harmless MSW disposal, incineration technology with direct gasification and ash melting was developed, with experiment investigation. The technological process can be represented as: the pretreated MSW was put into an incinerator and incinerated in a molten bath under reduction atmosphere at a temperature range from 1 300℃to 1 500℃. In order to maintrain the stability of the combustion process, it is needed to blast combustion-supporting coal powder from the bottom of the incinerator. Combustible gases were leaded and burned completely in a secondary swirled combustion chamber, and the heat was recycled and come into utilization. In some cases, melted slag and alloy were discharged from a same slag notch, and then they were quenched and separated each other. In other cases, melted slag and alloy were discharged from two different notches, and quenched in their own quenching pool. In both the former and the later case, the alloy was recycled and the melted slag can be used as construction materials in the same way. Experimental results form an industrial-scale pilot plant show that the investments of capital construction and running cost of this incineration system are only 65 ~ 85 percent of those of the similar types incinerator developed by western countries. It is necessary to point that 99.8 percent of dioxins involved in primary MSW were decomposed, and the dioxins content in exhausted gases and melted slag were lower than 0.01 ng-TEQ/m3 and 0.003 ng-TEQ/g respectively.