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第二部份、煤中矿物质与结渣关系与炉膛结渣有关的煤灰特性是灰的熔融温度和灰渣粘度,而决定煤灰熔融特性和灰渣流动特性的是煤中矿物质的成分与组成。鉴于矿物质的组成难以很好确定,现今的研究基本上是通过灰的化学成份,主要是Si_2O、Al_2O_3,Fe_2O_3、CaO、MgO、Na_2O、K_2O对灰熔融温度和灰渣粘度的影响来进行。 相似文献
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通过直流等离子体电弧熔融技术对危废焚烧灰渣熔融固化的处理效果的实验室研究,着重研究了其添加剂用量和熔融温度对灰渣中重金属固化效果和重金属的毒性浸出特性的影响,并对飞灰、底渣和熔渣的化学组成、物相组成、重金属毒性浸出特性和微观结构等进行了深入分析。结果表明,随着添加剂用量增加,熔渣中重金属固化率提高,重金属浸出质量浓度显著降低。熔融温度从1 250℃升高到1 450℃,重金属Cr、Ni、Cu、Zn的固化率显著提高,Pb、As的固化率逐渐降低。等离子体熔融产出的熔渣重金属浸出质量浓度都远低于毒性标准限值。本试验对于灰渣等离子熔融机理进行了深入研究,试验出最佳运行工况,对灰渣等离子技术装备的工业化开发具有重要意义。 相似文献
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无害化城市生活垃圾熔融焚烧技术的研究进展 总被引:1,自引:0,他引:1
近年来,为防止全球气候变暖,社会上对环境保护的要求日益严格。尤其是要求城市生活垃圾处理最大限度地采用无害化技术,抑制二恶英的排放。能够遏制二恶英产生和排放的无害化城市生活垃圾熔融焚烧技术被提出。本技术一般分两类。一类为垃圾直接熔融焚烧技术,该技术的工艺流程为:先将城市生活垃圾在500-600℃温度下热解气化制得可燃气体,制得的气体再根据用途进一步精制,垃圾中95%以上的含氯物质经除去后所剩下的含碳灰渣在温度为1300℃以上的熔融燃烧设备中进行熔融处理,原垃圾中99.8%以上的恶英可被分解掉,无害化熔融渣可以多种用途;另一类为垃圾间接熔融焚烧技术,该技术的工艺流程为:先将垃圾在传统的焚烧炉中进行焚烧,然后将焚烧灰渣在温度为1350-1500℃的熔融燃烧设备中进行熔融处理,原垃圾中99.0%以上的二恶英可被分解掉。对近年来美国、欧洲、日本等发达国家及作者本人所研制的无害化城市生活垃圾熔融焚烧技术的工艺特点及其进展作一介绍。 相似文献
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城市生活垃圾气化熔融焚烧技术 总被引:2,自引:0,他引:2
近年来,为防止全球气候变暖,社会上对环境保护的要求日益严格。尤其是要求城市生活垃圾处理最大限度地采用无害化技术,抑制二恶英的排放。能够遏制二恶英产生和排放的无害化城市生活垃圾气化熔融焚烧技术被提出。本技术一般分两类,一类为垃圾气化 灰渣熔融焚烧技术,该技术的工艺流程为:先将城市生活垃圾在500-600℃温度下的热解气化制得可燃气体,制得的气体再根据用途进一步精制,垃圾中95%以上的含氯物质经济去所后所剩下的含碳灰渣在温度为1300℃以上的熔融燃烧设备中进行熔融处理,原垃圾中99.8%以上二恶英可被分解掉,无害化熔融渣可以多种用途;另一类为垃圾直接气化熔融焚烧技术,该技术的工艺流程为:交垃圾在温度1350-1500℃的熔融燃烧设备中进行熔融处理,原垃圾中的99.8%以上的二恶英可被分解掉。文章介绍新型城市生活垃圾气化熔融焚烧技术。 相似文献
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在分析各种回转窑特点的基础上,总结出了当前最适合处理危险废物的回转窑的形式。结合工程实际,介绍了回转窑处理危险废物系统的设计过程,并对回转窑处理危险废物工程焚烧系统中出现的常见问题进行了深入的剖析。 相似文献
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《节能技术》2016,(4)
为研究生物质成型燃料的结渣特性,本文采用生物质成型燃料链条锅炉燃烧设备,选择5种生物质成型燃料,采用工业锅炉节能监测方法和结渣率测定方法,对炉膛温度、过量空气系数及炉渣成分和灰熔融特征温度等对结渣率的影响进行了试验研究。试验结果表明,炉膛温度越高,过量空气系数越高,结渣率就越高;对大多数生物质成型燃料来说,软化温度越低,结渣率越高;当软化温度超过1 368℃时,不会发生结渣,燃用生物质成型燃料的锅炉,炉膛的出口烟温应低于1 000℃,可以减少结渣。另外,结渣也与生物质灰渣中的Si元素、碱金属元素及碱土金属元素有关,碱土金属可以抑制结渣,而碱金属和Si元素可促使结渣,从而为设计适合生物质成型燃料燃烧设备及改善燃料的燃烧性能提供依据。 相似文献
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The reserves of Zhundong (ZD) coal in China are huge. However, the high content of Na and Ca induces serious slagging and fouling problems. In this study, the ZD coal was burned in a DTF (drop tube furnace), and the ashes collected at different gas temperature with non-cooling probe were analyzed to obtain the ash particle properties and their combination mode. The results showed that Na, Ca and Fe are the main elements leading to slagging when the gas temperature is about 1000 °C during ZD coal combustion, but their mechanisms are quite different. Some sodium silicates and aluminosilicates and calcium sulfate keep molten state in the ashes collected at 1000 °C. These molten ash particles may impact and adhere on the bare tube surface, and then solidified quickly. With the growth of slag thickness, the depositing surface temperature is increased. The molten ash particles might form a layer of molten film, which could capture the other high fusion temperature particles. The Fe2O3 sphere were captured by the formed molten slag and then they blended together to form a new molten slag with lower melting temperature. 相似文献
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危险废物管理及其焚烧处理综述 总被引:4,自引:0,他引:4
从危险废物的管理入手,比较了中美在危险废物管理法律法规上的差距,并对危险废物焚烧系统做了概述,同时介绍了几种常用的危险废物的焚烧炉型和焚烧产生的污染影响的分析。 相似文献
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双回转式固体废弃物焚烧系统设计 总被引:1,自引:0,他引:1
提出将回转窑技术与高温空气燃烧技术相结合,形成一种兼有稳定燃烧和控制二英、呋喃等污染物排放双重功能的新型固体废弃物焚烧方式。给出了回转窑焚烧系统的结构简图,介绍了其工作原理。分析了高温空气燃烧技术的高效低污染特性。针对中小规模医院的自备焚烧炉,设计了双回转式焚烧系统,并进行了热力计算。 相似文献
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《能源学会志》2020,93(6):2264-2270
The contents of chlorine and sodium in Xinjiang Shaerhu (SEH) coal are extremely high, leading to severe slagging. In this paper, the slag was sampled from a circulating fluidized bed (CFB) boiler purely burning SEH coal, to analyze the slagging mechanism based on the characterization of morphology and composition. The results show a three-layer structure for the slag sampled from the buried heat-exchanger in the dense-phase zone of the CFB boiler. The inner layer close to the heat-exchanger is NaCl, which enhances the adhesion of ash particles, while the middle layer and the outer layer are mainly composed of Ca2Al2SiO7 and other Si–Al materials. In comparison, the slag sampled from the refractory wall shows a molten state without a layered structure and mainly composed of NaCl, NaAlSiO4, Ca2Al2SiO7, and CaSiO3. The effect of mixing bed material, on the ash melting and release of chlorine and sodium was further conducted, which indicates that the mixing of bed material has no significant effect on the release of chlorine(Cl) and sodium(Na) but highly affects the melting temperature and compositions. The ash fusion temperature reaches the lowest with a 50% mixing ratio of bed material, which is 120 °C lower than that of SEH coal ash. This study can provide better guidance for controlling severe slagging, from the combustion of high Na and Cl coal in industrial furnaces. 相似文献
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Yunyun Li Wei Gao Yuying Zhang Qihui Yan Siqi Zhang 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2019,41(7):790-801
Steel slag is alkaline in aqueous solution, and this is a typical feature for solid wastes that contain large amounts of basic oxides. Therefore, this parameter is used for solid waste hazard assessments. Special attention needs to be paid to the chemical parameters of steel slag to improve its comprehensive utilization, disposal, and storage. The corrosiveness of converter slag samples from different steel plants was evaluated according to the method stipulated by the Chinese national standard GB5085.1–007 to identify whether they would be classified as alkaline hazardous waste. The results showed that steel slag leaching solution had a certain corrosivity, and the pH value of the leaching solution increased with a decrease in the particle size of the steel slag and a decrease in temperature. However, the pH value of the short-term and long-term deposited slag leaching solution was not more than the standard limit value, and hence was not a hazardous waste. It was also found that the pH value (12.66 and 12.60) of the leachate of the grounded products of some of the steel slag was close to the pH of saturated Ca(OH)2 at 16°C. The measured pH value entered the pH range for a hazardous waste because it was obtained from the grinding of slag powder products. It was not in the original state of steel slag commonly produced by the steel slag industry. Therefore, it cannot be said that this pH directly indicated that the steel slag produced by these steel plants is hazardous waste. This study provides an analytical method that can be used as a basis for the safe storage and comprehensive utilization of steel slag. 相似文献
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本文通过数值模拟的方法分析了掺烧印尼煤时炉膛内的燃烧特性和结渣特性,研究了印尼煤在不同掺混比例下对炉膛结渣的影响,试验结果表明:掺烧一定量的印尼煤有利于改善炉膛内的结渣特性,印尼煤灰熔点较低,与高热值基础煤掺混时容易产生结渣,掺烧比例不宜过大,基础煤与印尼3进行混配的最优推荐比例为5∶1。 相似文献