摘要
针对现有污染土壤热脱附修复存在效率低、成本高的问题,文章提出了一种热脱附与机械研磨联合作用的改进型污染土壤修复系统。该系统设计了具有独特螺旋结构的双层滚筒作为热脱附器,采用钢质载热球作为辅助载热体和土壤破碎研磨工具,并在滚筒内层与土壤混合,外层为热烟气通道,使土壤受到内外双层介质热作用,从而强化污染物的脱附过程。同时,热烟气与物料在滚筒内逆流,提高了能量利用率且防止了脱附气二次冷凝。此外,系统采用低温、高温两段式热脱附工艺,充分利用余热的同时增加了系统运行的灵活性。对六六六污染土壤的中试试验结果表明,系统运行的最佳球土质量比值为1.5,相较无载热球的热脱附情况,采用本系统天然气消耗量可减少30%,综合运行成本减少15%以上,验证了系统的节能性。
In order to solve the low-efficiency and high-cost problems of contaminated soil remediation by present thermal desorption systems,this paper proposed an improved contaminated soil remediation system combined thermal desorption and mechanical grinding.A double-layer drum with a unique spiral structure was designed as the container of thermal desorption in this system.The heated iron ball was adopted as the subsidiary heat carrier and soil crushing and grinding tool.The balls were mixed with the soil in the inner layer of the drum.And the hot flue gas flowed in the outer layer.The soil was heated by the medias in double layers,thus strengthening pollutant desorption.Meanwhile,the counter flow of hot flue gas and materials in the drum improved the energy utilization efficiency and prevented the secondary condensation of the desorption gas.In addition,the system used two-stage thermal desorption process with full use of the waste heat.And the flexibility of the system operation was increased as well.Pilot tests on Hexachlorocyclohexane(HCH) contaminated soil showed that the optimum mass ratio value of heated balls to soil was 1.5.Compared with the thermal desorption without heated balls,the consumption of natural gas in the improved system was reduced by 30% and the comprehensive cost was reduced by 15%,proofing its energy-saving characteristies.
作者
张磊
崔勇
王坚
宁禹航
陈刚
ZHANG Lei;CUI Yong;WANG Jian;NING Yuhang;CHEN Gang(Shenyang Academy of Environmental Sciences,Shenyang 110167,China;Liaoning Key Laboratory of Urban Ecology,Shenyang 110167,China)
出处
《环境保护科学》
CAS
2019年第6期119-123,共5页
Environmental Protection Science
基金
沈阳市“双百工程”重大科技成果转化项目(Z17-8-006)
关键词
污染土壤修复
热脱附
机械研磨
载热球
中试系统
Contaminated Soil Remediation
Thermal Desorption
Mechanical Grinding
Heated Ball
Pilot Scale System
