上海交通大学硕士学位论文城市污泥干化、焚烧特性及粘融排渣技术研究姓名：施善彬申请学位级别：硕士专业：热能工程指导教师：章明川20090201上海交通大学工学硕士学位论文 摘 要 第 I 页 城市污泥干化、焚烧特性及粘融排渣技术研究 摘 要 随着城市污水处理的普及、处理率的提高和处理程度的深化， 污水厂的污泥产生量将有较大的增长。据估算，2004 年我国的污泥（干重）产量已经超过 300 万吨， 由此引起的二次污染问题已不容忽视。 我国现有的污泥处理技术相对落后， 绝大部分是弃置或填埋，能满足较高环保标准的污泥干化焚烧技术还未见工业性应用实例。 我国目前能满足大型污水厂要求的污泥干化焚烧装置只能依靠进口， 由于投资和运行费用太高，不具备推广条件。 因此， 迫切需要开发适合我国国情的具有自主知识产权的污泥干化焚烧技术。 本文主要采用试验的方法研究上海及周边城市三家污水处理厂的污水污泥干化、焚烧及焚烧排放特性，提出了内循环流化床焚烧炉灰粘融排渣技术运用于焚烧污泥及生活垃圾的设想， 并在试验台上进行了可行性试验研究。得出了如下结论： 本文首先利用热天平对城市污水污泥的干化特性进行了系统的基础研究，得出了南通、天山、闵行三种污泥在低温干化下水分蒸发和挥发分的析出两个失重过程， 并分析了升温速率及污泥含水率对污泥干化过程的影响： 升温速率并不明显改变不同含水率污泥的失重变化趋势，但是对水分的蒸发有一定的影响， 较高的升温速率水分析出的终止温度较高， 并且含水率越高差别越明显；根据 TG- DTG 曲线采用 Coats- Redfern 法求解污泥干化反应动力学参数；并利用热显微镜和扫描电镜（SEM）分别观察污泥干化过程的表观形态和污泥干化后的残余物的表面微观结构变化。 上海交通大学工学硕士学位论文 摘 要 第 II 页 其次利用热天平研究了污泥在空气气氛下焚烧失重过程， 相比污泥干化试验而言，焚烧增加了固定碳燃烧阶段。研究结果表明：水分对能量利用的影响较大， 采取干化预处理，在能量消耗和处理成本方面均有明显的优越性； 同一含水率污泥在不同升温速率下最终产物份额基本一致， 较高的升温速率水分析出的终止温度较高。根据干燥污泥的 TG- DTG 曲线求得燃烧反应动力学参数。此外，热显微镜试验表明污泥的燃点远低于煤，但是污泥灰分熔点却很高，与煤的灰分熔点非常接近。 在带有温控单元的小型流化床装置对污泥进行焚烧实验。 研究焚烧天山污泥过程中污泥水分、氧浓度对 SO2和 NOX排放规律的影响，研究表明：氧浓度对于 SO2的生成十分重要。 在缺氧情况下不仅污泥燃烧温度滞后， 而且 SO2和 NOX的析出浓度下降明显。 并考察了焚烧底灰中 As、 Cd、Cr、Cu、Pb、Zn、Hg 和 Ni 等 8 种重金属含量随焚烧温度的变化规律，以初步了解三种污泥焚烧过程中重金属元素的迁移特性。 以上这些基础研究为污泥干化、焚烧设备的设计和运行提供了理论依据。 为了开发合适的污泥焚烧装置并考虑对污泥焚烧灰渣做进一步的减容及无害化处理， 结合内循环流化床垃圾焚烧技术探索灰粘融排渣技术在污泥焚烧中的利用。 热态试验效果明显且符合初期设想，但若此技术应用于污水处理工程实践，需对其装置及运行作一定的完善和优化，并直接以污泥为燃料进行可行性试验研究。 关键词：城市污水污泥，热天平，干化，焚烧，焚烧排放，内循环流化床，灰粘融排渣上海交通大学工学硕士学位论文 ABSTRACT 第 III 页 Experimental Study on Drying and Incineration Characteristics of Municipal Sewage Sludge and Ash- agglomerate Discharging Technology ABSTRACT With the development of sewage sludge treatment, the quantity of sludge is growing quickly. It is estimated that the annual production of dehydrated sewage sludge was more than three million tons in China. The second pollutions caused by sewage sludge cannot be ignored. Now the technologies used in sewage sludge treatment in China are relatively backward, most of which are disposed or buried directly. Few sewage industrial sludge drying and incineration technologies are used in China, most of which are imported from other countries. Due to the huge investment and operation fee, it is urgent to develop the suitable sewage sludge drying and incineration technologies for domestic utilization. The dissertation studies the drying, incineration, and emission characteristics on three kinds of sewage sludge collected from different sewage sludge treatment plants around Shanghai. And the ash- agglomerate discharging technology combined with internally circulating fluidized bed has been suggested to burn the sludge and municipal solid waste. The results are as follows: Firstly, the drying characteristics of municipal sewage sludge were studied using a thermogravimetry analyzer. Thermogravimetric analysis demonstrated that the drying process of sewage sludge could be divided into two stages: water evaporation and volatile matter decomposition. The effects of heating rate and moisture of sludge were examined. Although the heating rate does not change the trends of drying for sludge with various moistures, it affects the water evaporation. The higher the heating rate, the bigger the ending temperature of evaporation is. The parameters of sludge drying kinetics 上海交通大学工学硕士学位论文 ABSTRACT 第 IV 页 were calculated on TG- DTG curves using the Coats- Redfern method. And the shape changing process was observed by thermal microscope. Furthermore the micro traits of dried sludge surface were observed by the SEM, and the impact to the combustion traits was analyzed. Secondly, the incineration characteristics of municipal sewage sludge were studied again by athermogravimetry analysis. Compared to the drying experiments, tar combustion was added during the incineration process. The results showed that the moisture of sludge affected greatly the utilization of thermal energy. The pre- dried technology for the sludge had a great advantage of saving energy and cost. The sludge with the same content of moisture would behave the same on the production of the incineration under the same heating rate. The parameters of sludge combustion kinetics were calculated on TG- DTG curves using the Coats- Redfern method. And besides, the thermal microscope results displayed that the melting point of sludge ash was close to the melting point of coal. In order to further understand the combustion mechanism of sewage sludge, experiments of sewage sludge incineration were carried out on a lab scale combustor combined with the temperature controlling devices. The effects of moisture of sludge and oxygen content on emission characteristics of SO2 and NOX were studied. The results showed that the oxygen content was