化工厂废水污泥的焚烧工艺研究毕业论文
2022-06-26 23:12:05
论文总字数:24686字
摘 要
我国化学工业的迅速发展以及环境保护的严厉要求的形势下,作为危险固废物的化工废水污泥的产量日益增大,由污泥引发的环境问题日益突出。化工污泥的减量化、无害化、资源化的研究已显得尤为重要。
本文针对南京市某化工厂废水污泥进行焚烧工艺研究。对污泥的理化性质进行了分析,首先对干燥后的污泥进行了元素分析,测定污泥中C、H、O、N和S的含量,计算得到单位质量干污泥焚烧所需空气量为2 .281Nm3/kg;其次对污泥进行工业分析,包括含水率、灰分含量、挥发分含量和固定碳含量的测定,测定含水率为14.98%的干污泥的热值为1108kj/kg,在此基础上进行了流化床焚烧炉的初步设计;然后对干污泥进行了热重分析实验,得到了不同湿含量的污泥燃烧特性曲线,结果表明:干污泥随温度升高可分为三阶段,第一阶段(20~150℃)为水析出阶段,第二阶段(150~450℃)为污泥中挥发份和固定碳的燃烧阶段,第三阶段(450~800℃)为污泥的部分有机物和无机物的高温分解阶段;最后进行了不同加料速率、进风量下的焚烧工艺研究,结果表明:绝热焚烧状况下,干污泥加料速率为8kg/h、进风量为22 Nm3/h时炉温可达到最高为770℃,并且在该工况下,电辅助加热,提高焚烧温度,研究了不同焚烧温度下的尾气组成和炉渣中重金属含量,得出结论:当焚烧温度为820℃时,尾气中CO为263ppm,NO为54ppm,NOx为58ppm,NO2为4ppm,O2为13.86ppm,SO2为9ppm,达到国家标准。
关键词:废水污泥 焚烧 流化床 工艺
ABSTRACT
With the rapid development of chemical engineering industry and the strict requirement of environment protection, the pollution problems caused by wastewater sludge are increasingly striking with the huge production of sludge. It’s extremely important to decrease sludge production, make sludge harmless and change sludge into resources.
A serious of sludge incineration experiments have been taken place on the wastewater sludge of chemical plant in Nanjing. Dried sludge physicochemical properties have been analyzed, including elemental analysis, content of C、H、O and S in sludge have been measured. It is calculated that unit mass sludge burning completely needs air 2.281Nm3/kg. Experiments including rate of water content, ash content, volatile content and fixed carbon content were tested. It shows that dried sludge which contain water 14.98% burning give out calorific value 1108kj/kg, then try to design fluidized bed incineration on this basis; then carried out thermogravimetric analysis experiments, characteristic curves of different moisture content were drawn. The results showed that: dried sludge pyrolysis can be divided into three stages: the first stage (20~150 ℃) was evaporation temperature range, the second stage (150~450℃) was main combustion temperature range, and the final stage(450~800℃)was decomposition temperature range; in the end experiments were taken place under different conditions including different feed rate and amount of air. The experimental results showed that under the thermal isolation condition, the optimum feed rate was 8kg/h and air amount was 22 Nm3/h, the incineration temperature can reach as high as 770 ℃. On the basis of the optimum condition,electric heating was added to rise the incineration temperature, flue gas and heavy mental content were analyzed at different incineration temperatures, and the best temperature was 820 ℃, in the flue gases every component content was CO 263ppm, NO 54ppm, NOx 58ppm, NO2 4ppm, O2 13.86ppm and SO2 9ppm, emissions could meet national standards.
Keywords: wastewater sludge incineration fluidized bed technology
目 录
摘 要 I
ABSTRACT II
第一章 文献综述 1
1.1 研究背景 1
1.2 污泥分类 1
1.3 污泥处理方法 2
1.4 污泥焚烧工艺及处理研究现状 3
1.4.1 污泥焚烧工艺 3
1.4.2 污泥焚烧设备 4
1.4.3 污泥焚烧处理研究现状 5
1.5 本文的研究内容及意义 8
第二章 污泥的理化特性 9
2.1 污泥的元素分析 9
2.2 污泥的工业分析 10
2.2.1 污泥含水率 10
2.2.2 灰分含量 12
2.2.3 挥发分含量 12
2.2.4 固定碳含量 13
2.3 污泥热值 13
2.4 重金属浸出量的测定 14
2.5 污泥热分析实验(TG、DTG) 15
第三章 流化床焚烧炉设计 19
3.1 流化床焚烧炉主体设计 19
3.2 流化床焚烧炉零部件的设计和作用 21
3.2.1 喂料速率的标定 21
3.2.2 临界流化速度测定 22
3.2.3 布风板阻力特性研究 25
第四章 污泥焚烧实验 28
4.1 流化床焚烧炉试验台 28
4.2 流化床焚烧实验 29
4.2.1 最佳进料量 29
4.2.2 最佳物料空气比 31
4.3 排放特性 32
4.3.1 尾气的检测与分析 32
4.3.2 重金属的检测与分析 34
第五章 结论与展望 36
5.1 结论 36
5.2 展望 36
参考文献 37
致 谢 40
第一章 文献综述
1.1 研究背景
随着我国经济地位的快速崛起,全国工业化水平不断提高,全国化工厂的规模在质和量上都取得了跨越式的发展。这也对化工污泥处理提出了更高的要求。
污泥是在化工生成过程中产生的一种介于液体和固体之间的浓稠物质、主要呈现浆态特征,它通常呈絮状结构,含水率比较高,很难通过普通沉降实现彻底的固液分离。污泥中含有病原菌、重金属物质、难降解有机物和化工产物等有毒有害物,且还含有大量的C、N、K、Ca等物质以及一些微量元素。它包含许多微生物菌胶团以及由它们所吸附的各种物质[1]。由于这些污染物的存在,化工污泥如果不能妥善处理将会影响环境安全和人体的健康[2-4]。因此,有必要合理解决污泥污泥问题,防止因处置不恰当造成二次污染的产生。
1.2 污泥分类
污泥一般来自于市政给排水处理系统和工业废水处理系统。市政污泥是给水、雨水、生活污水等收集处理过程所产生的污泥,可以分为以下几种:
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