医疗垃圾焚烧炉回转窑转速与灰渣二恶英排放的关系

Correlation Between Rotary Speed of a Medical Wastes Incinerator Rotary Kiln and Dioxin Emission in Sediments

通过某回转窑-流化床医疗垃圾焚烧炉的燃烧实验,采集了不同回转窑转速条件下的飞灰和底渣样品,测定了其中的二恶英含量,并研究了回转窑转速与灰渣二恶英排放的关联特性.研究发现,随回转窑转速增加,灰渣的二恶英毒性排放总量增加;当转速为0.82,r/min时,飞灰中二恶英总量和毒性当量排放分别为41.05 ng/g和7.58,ng(I-TEQ)/g;流化床底渣样品中的二恶英含量比飞灰小很多.研究还发现,随着焚烧炉尾部烟气中NOx和H2O含量的增加,飞灰中二恶英总量呈现减少的趋势;随着烟气中O2浓度的增加,飞灰中二恶英总量也随之增加.因此,通过关联性较好的常规气体成分(污染物)浓度的检测,可以在一定程度上预测燃烧工况的好坏及飞灰中二恶英排放的程度.

Combustion experiments were conducted in a rotary kiln-fluidized bed medical waste incinerator, sediment samples of fly ash and slag at different rotary speeds were collected and detected for dioxin concentrations, and then correlation between rotary speed and dioxin emission was studied. It was observed that the emission of I-TEQ dioxin increased with the increasing rotary speed. Total and I-TEQ concentration of dioxin were 41.05 ng/g and 7.58 ng （I-TEQ）/g, respectively, in the fly ash when rotary speed was adjusted to 0.82 r/min. There was much less dioxin in the slag than in the fly ash. It was also found that with the increasing contents of NOx and H20, the concentration of PCDD/Fs decreased; at the same time, the concentration of PCDD/Fs increased with the increasing of O2 and CO contents. Consequently, incineration condition and pollution condition of PCDD/Fs to some extent by detecting common flue gases which are well correlated to PCDD/Fs.