Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Chongqing, 400030, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400030, China.
Chemosphere. 2021 Jun;272:129932. doi: 10.1016/j.chemosphere.2021.129932. Epub 2021 Feb 10.
The method of quenching was adopted to reduce the emission of PCDD/Fs from a pilot scrap preheated EAF. Because quenching can effectively inhibit the de novo synthesis of dioxins. Meanwhile the temperatures at the inlet and outlet of the quenching part of EAF off-gas were measured to investigate the quenching effect. The results show that the temperatures of the off-gas are quenched from about 1300 °C to about 250 °C in the whole tap-to-tap cycle of EAF, which attains the expected cooling effect. The dioxin Toxic Equivalent Quantity (TEQ) concentrations and congener distributions of off-gas and three kinds of sampling ash were analyzed. The results indicate that the TEQ concentration of PCDD/Fs is 0.13 ng-I-TEQ/Nm at the outlet of the chimney A (D4), which is far below the dioxin emission limit for EAFs (0.5 ng-I-TEQ/Nm) in China. At the same time the fingerprint suggests that the quenching effectively restrains the de novo synthesis, and dioxins de novo synthesize in the following flue and bag filter to some extent.
采用淬火方法降低了预预热电弧炉（EAF）中废弃物流中 PCDD/Fs 的排放。因为淬火可以有效地抑制二恶英的从头合成。同时，测量了 EAF 废气淬火部分的进出口温度，以研究淬火效果。结果表明，在 EAF 的整个出钢-出钢周期中，废气温度从约 1300°C 冷却到约 250°C，达到了预期的冷却效果。分析了废气和三种采样灰分的二恶英毒性当量浓度（TEQ）和同系物分布。结果表明，烟囱 A（D4）出口处的 PCDD/Fs 的 TEQ 浓度为 0.13ng-I-TEQ/Nm，远低于中国 EAF 的二恶英排放限值（0.5ng-I-TEQ/Nm）。同时，指纹表明淬火有效地抑制了从头合成，并且在随后的烟道和袋式过滤器中，二恶英在一定程度上从头合成。
