【作者】 安春国；

【导师】 蒋旭光； 金余其；

【作者基本信息】 浙江大学 ， 热能工程， 2010， 硕士

【摘要】 医疗废物是具有感染性、毒性、放射性特征的危险性废物,诸如化学品废物、感染性废物、沾污的利器等。医疗废物焚烧处置能够有效地实现废物的无害化、减量化和资源化,是目前认为最适合的处置方法。医疗废物及其灰渣的化学组分和特性是优化焚烧炉设计、运行与控制的重要影响因素。医疗废物中存在大量的低熔点的医用玻璃瓶,这些玻璃瓶不能参与燃烧,会成为灰渣的主要组分,对灰渣的熔融特性有很大影响。医疗废物在回转窑内焚烧时,着火燃烧产生的高温会将医用玻璃熔化,熔融的玻璃可能会粘结在回转窑内壁上,导致回转窑的结渣,或者滚动粘结灰渣颗粒,形成大的熔体团,堵塞回转窑的出渣口。因而研究医用玻璃和医疗废物灰渣的熔融特性,以期能够为优化医疗废物的燃烧和防止回转窑的结渣提供帮助。从医疗废物处置中心采集了医用玻璃样品,对其进行化学组分和熔融温度的分析,并且与医疗废物灰渣、生物质灰和煤灰进行了比较。通过不同玻璃间的比较,总结了化学组分对熔融温度的影响。软化温度随着SiO2、CaO含量的增加而升高,但随B2O3、Na2O含量的增加而迅速降低。调整几种玻璃间的比例,研究了混合玻璃的熔融特性。利用煤灰结渣指数对医用玻璃的结渣倾向进行了评定。应用SiO2置换法研究了化学组分对医用玻璃熔融特性的影响,实验结果显示不同化学组分对熔融温度有不同的影响。其中Na2O对医用玻璃熔融温度的影响是最显著的,每增加1%的Na20,软化温度就会降低19.8℃,流动温度降低34.0℃。通过简化多元函数Taylor公式,得出了医用玻璃四个熔融特性温度的预测函数,验证结果表明医用玻璃熔融温度的预测值和实验值吻合较好。为了研究医疗废物灰渣对回转窑焚烧炉运行的影响,从医疗废物处置中心采集了数个灰渣样品,分析了这些灰渣样品的化学组分、显微结构、矿物物相和熔融温度等性质。用分析纯代替灰渣的化学组分,研究了几种化学组分(SiO2、Al2O3、B2O3、Fe2O3、CaO、CaSO4、Na2O和NaCl)对医疗废物灰渣熔融特性的影响。危险废物回转窑焚烧处置技术具有诸多优点,回转窑焚烧炉在处理危险废物时能够适应多种形态的物料,并且运行操作简单。因此,为了研究危险废物热解焚烧处置的特性,设计并搭建了回转窑热解焚烧试验台。该热解焚烧试验台主要由三部分组成：危险废物进料系统、焚烧系统(回转窑焚烧炉、二燃室和能量回收设备)和烟气处理系统(急冷塔和二级布袋除尘器)。更多还原

【Abstract】 Medical wastes include infectious, toxic and radioactive wastes and belong to hazardous wastes, such as chemical wastes, infectious wastes and contaminated sharps and so on. Incineration has been identified as the best disposal option for medical wastes because it is harmless and realizes a large reduction in volume as well as resources recovery. The compositions and characteristics of medical wastes and medical waste slag are important parameters for improving incinerator design, operation and control. Generally, large amounts of medical glass bottles present in medical wastes have rather low fusion temperatures and couldn’t participate in combustion. Therefore medical glass composes the principal component of medical waste slag and influences the melting characteristics of slag badly. When medical wastes are incinerated in a rotary kiln incinerator, medical glass is heated and melted. Molten glass may adhere to the inner wall, leading to slagging. In other cases, the molten glass probably tumbles and rolls, bonding to other slag particles;finally large slag agglomerates are formed, blocking the exit of rotary kiln. Therefore, the melting characteristics of medical glass and medical waste slag are important for optimizing medical waste incineration and preventing slagging of rotary kiln incinerators.The composition and fusion temperatures of medical glass, collected from a medical waste disposal center, were analyzed and compared with medical waste slag, biomass ash and coal ash. The contribution of glass components to fusion temperatures of medical glass was investigated by comparing different glass samples.Softening temperature was increased with a rise of SiO2 and CaO content, whereas it was declined sharply while B2O3 and Na2O content increased. The fusibility of blended glass was researched by adjusting the proportion of several medical glasses. Using coal ash slagging indices, the slagging propensity was assessed for medical glass.The effects of glass components on the melting characteristics of medical glass have been researched by the SiO2 replacement method. The experimental results showed that different components played quite different influences on fusion temperatures;that of Na20 was the most marked. The softening temperature and flow temperature decreased 19.8℃and 34.0℃respectively with every 1% rise of Na2O content. Predictive functions of four characteristic melting temperatures have been obtained by simplifying the multi-variant Taylor series. And predictive functions were verified by testing glass samples.The calculated results revealed that predictive values of fusion temperatures tallied well with experimental values.In order to investigate the effects of medical waste slag on incinerator operation, medical waste slag samples were collected from a medical waste disposal center to analyze their chemical components, microscope structure, mineralogy and fusion temperatures.The effects of chemical components (SiO2, Al2O3, B2O3, Fe2O3,CaO, CaSO4, Na2O and NaCl) on the melting characteristics of medical waste slag were analyzed by substituting analytical reagents for chemical components.Rotary kiln incineration has several advantages when used to dispose of hazardous wastes, for example being adapted for various feeds and simple operation. So an experimental platform of rotary kiln incinerator have been designed and established to investigate the pyrolysis and incineration disposal for hazardous wastes.This experimental platform was composed of hazardous waste feeding system, incineration system (rotary kiln incinerator,secondary combustion chamber and heat recovery equipment) and flue gas treatment system (quench tower and double bags filter).更多还原