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循环流化床中含钒石煤料球的焙烧特性试验研究 总被引:2,自引:0,他引:2
为避免传统提钒工艺所存在的问题,采用循环流化床钙法焙烧工艺,以添加钙基原料的石煤料球为焙烧原料,在热输入功率为1 MW的循环流化床燃烧试验台上进行了含钒石煤焙烧特性试验,研究了燃烧稳定性、燃烧效率、污染物排放特性、燃烧后灰渣特性和灰渣钒浸出特性.结果表明:在以烟煤为助燃燃料的条件下,石煤料球可以在1 MW循环流化床试验台上稳定焙烧运行,且燃烧效率较高;料球中的钙基添加剂有较好的脱硫作用,但对于高硫石煤,要达到国家污染物排放标准,必须采取尾部烟气脱硫措施;焙烧产物以飞灰为主,飞灰中V2O5浸出率接近70%,表明循环流化床对石煤中的钒矿物具有良好的焙烧氧化作用. 相似文献
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燃煤电厂固体废弃物在综合利用过程中存在汞逃逸造成二次污染的风险。本文概述了汞在燃煤电厂排放产物中的分布,分析了燃煤飞灰和脱硫石膏及其工业产品在加工、存放过程中汞的二次污染问题。分析表明,温度是影响汞逃逸最主要的因素,低于200℃汞逃逸率较低,高于200℃逃逸率随温度升高大幅增加;此外,低温条件下,汞的逃逸与汞在飞灰和脱硫石膏中存在形式有关。自然环境条件下使用,富集在固废中的汞不会因自然水体冲洗中造成二次污染。利用常规污染物脱除装置进行汞排放的控制,燃煤飞灰和脱硫石膏综合利用工艺处理温度应控制在200℃以下。 相似文献
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在额定蒸发量为410t/h的循环流化床锅炉上进行以烟煤、石油焦混合物为燃料的锅炉热力性能试验,根据ASME锅炉性能规程计算了锅炉热效率,并对温度、汽水流量、气态污染物排放、灰渣含碳量等多个参数进行了测试,整理得到了一些规律性的结果。结果表明,锅炉以烟煤、石油焦为燃料,添加石灰石脱硫,采用尾部飞灰再循环,额定负荷下锅炉热效率可达92.8%;炉内密相区温度分布均匀;床温、分离器入口温度、排烟温度和排渣温度等各温度稳定;主蒸汽流量、给水流量、减温水流量等汽水流量波动小;气态污染物均可控制在较低水平。这对我国循环流化床锅炉燃用煤焦混合物的设计和运行工作有一定借鉴意义。 相似文献
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一、前言当前,我国工业锅炉的燃料主要是煤炭。煤在燃烧过程中产生的烟尘是污染大气的污染物。“烟”一般指的是烟炭(炭黑),它是不完全燃烧的产物,通常是由极微细的炭粒和飞灰组成,其粒径一般均小于微米。“尘”通常指在燃烧过程中,由烟气带出的飞灰(灰粒) 相似文献
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在发电厂焚烧烟气净化收集过程中,垃圾焚烧之后产生的残余粉状物质则是飞灰,其属于危险废物(编码为HW18)且处理难度较大,其中含有有机污染物二噁英与Cr、Cd、Hg等重金属。本文重点分析水泥窑协同处置垃圾焚烧飞灰问题,探究水泥窑协同处置垃圾焚烧飞灰的技术途径,以便更好的提升其技术应用效果,并为类似水泥窑层面的研究提供参考依据。 相似文献
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《燃烧科学与技术》2016,(1)
在6,k Wth流化床实验装置上进行了贵州烟煤的燃烧实验,采用电感耦合等离子体质谱仪(ICP-MS)研究不同添加剂/吸附剂对11种痕量元素(Be、Cr、Mn、Co、Cu、As、Mo、Cd、Sb、Ba、Pb)在燃烧产物中的富集规律.结果表明:活性炭和稻壳焦对痕量元素都有一定的吸附作用,稻壳焦可增加Be、Mn、Co、Cu、As、Mo、Cd、Sb、Ba、Pb这些元素在飞灰中的富集程度,降低了Cr在飞灰中的富集程度;活性炭对Cr、Mn、Cu、Mo、Cd、Sb、Pb的富集都有一定的促进作用.原煤中掺混Ca Cl2能提高Mn、Sb和Ba在飞灰中的富集程度,同时抑制了其他元素在飞灰中的富集;掺混NH4Cl对Co和Cu在飞灰中的富集有抑制作用,但作用很小,对其他的痕量元素在飞灰中的富集都有一定的促进作用,其中对Mo、Cd和Sb的促进最为明显. 相似文献
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The effects on enrichment characteristics of trace elements (TEs) in fly ash by adding halide salts into the coal during coal combustion were conducted on a 6 kWth circulating fluidized bed (CFB) experimental device. Results show that unburn carbon content in fly ash has little relationship with the concentration of TEs namely Hg, As, Pb, Cr and Mn. All the TEs are enriched in fly ash for the raw coal CFB combustion. Concentration of Hg and Mn increases with increasing the addition amount of CaCl2, NH4Cl and NH4Br. As, Pb and Cr enrich in fly ash more strongly when adding more CaCl2 into the coal while more addition of NH4Cl and NH4Br leads to the decrease of their enrichment compared to addition amount of 0.1 wt%. On the whole, putting halide salts into the coal results in the TEs enriched in fly ash, which benefits for TEs removal during the coal combustion. Combining this method with the chemical sequential extraction or thermal treatment of the fly ash will be a promising way to realize the TEs removal and their recovery. 相似文献
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燃煤电站锅炉飞灰含碳量偏高的原因分析与解决措施 总被引:4,自引:0,他引:4
在燃煤电站锅炉中 ,当煤粉不能进行完全燃烧时 ,将造成飞灰含碳量的升高。从煤粉细度、煤种特性、燃烧器的结构特性、热风温度、炉内空气动力场和锅炉负荷等方面分析了对飞灰含碳量变化的影响机理 ,指出了飞灰含碳量升高所造成的影响 ,并提出了维持锅炉稳定燃烧 ,降低飞灰含碳量 ,提高锅炉效率的有效措施。 相似文献
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Distribution of mineral matter in pulverized coal 总被引:1,自引:0,他引:1
Mineral transformations, and therefore fly ash evolution, during pulverized coal combustion, depend on the amount, composition and spatial distribution of the inorganic matter within individual pulverized coal particles. Thus, it is necessary to have information on the mineral composition of individual particles, as well as that of the raw pulverized coal. A model is proposed based on the assumption that mineral inclusions of size and composition determined using a CCSEM are distributed randomly in the coal. From this distribution it is possible to generate distributions of mineral content for any particle size and density fraction of coal. The model has been checked by comparing computed results with data on the compositional variations of narrowly and density classified fractions of an Upper Freeport bituminous coal. The results of individual coal particle compositions are used to generate information on the variability of the composition of the fly ash generated during combustion. 相似文献
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A review on the utilization of fly ash 总被引:5,自引:0,他引:5
Fly ash, generated during the combustion of coal for energy production, is an industrial by-product which is recognized as an environmental pollutant. Because of the environmental problems presented by the fly ash, considerable research has been undertaken on the subject worldwide. In this paper, the utilization of fly ash in construction, as a low-cost adsorbent for the removal of organic compounds, flue gas and metals, light weight aggregate, mine back fill, road sub-base, and zeolite synthesis is discussed. A considerable amount of research has been conducted using fly ash for adsorption of NOx, SOx, organic compounds, and mercury in air, dyes and other organic compounds in waters. It is found that fly ash is a promising adsorbent for the removal of various pollutants. The adsorption capacity of fly ash may be increased after chemical and physical activation. It was also found that fly ash has good potential for use in the construction industry. The conversion of fly ash into zeolites has many applications such as ion exchange, molecular sieves, and adsorbents. Converting fly ash into zeolites not only alleviates the disposal problem but also converts a waste material into a marketable commodity. Investigations also revealed that the unburned carbon component in fly ash plays an important role in its adsorption capacity. Future research in these areas is also discussed. 相似文献