双锥燃烧器燃用污泥水煤浆的燃烧特性和数值模拟

为促进城市污泥的资源化利用,解决污泥物理处置中存在的二次污染问题,以及传统污泥干化焚烧中干燥成本高的问题,提出了将污泥浆与煤粉掺混制备污泥水煤浆,利用具有强化燃烧功能的中心逆喷双锥燃烧器燃烧的技术思路。通过热重分析试验对比了煤粉、水煤浆、污泥水煤浆的燃烧特性,并利用数值模拟研究污泥水煤浆在双锥燃烧器上的燃烧特性,通过降低二次风量、提高二次风旋流强度及二次风温度等强化燃烧的措施,研究污泥水煤浆在双锥燃烧器上应用的可行性。污泥水煤浆的基础燃烧特性试验结果表明,水煤浆中水分超过35%,除影响燃料热值外,水蒸发吸热是影响污泥水煤浆燃烧过程着火和燃尽的关键因素。由于水分的存在,水煤浆起始着火温度高于煤粉11. 3℃,燃尽温度低于煤粉13. 6℃,其最大吸热速率为0. 504 k W/kg,占水煤浆最大放热速率的56. 05%,总吸热量为1. 917 MJ/kg,占燃烧放热量的9. 94%;掺烧20%污泥时,污泥水煤浆起始着火温度高于水煤浆12. 3℃,燃尽温度低59. 1℃,水蒸发吸热量为0. 546 kW/kg,比水煤浆燃烧高8. 4%,总放热量为16. 88 MJ/kg,比水煤浆燃烧低12. 5%。通过采用双DPM的离散相数值模拟模型,充分考虑污泥水煤浆燃烧时水蒸发过程的影响,对污泥水煤浆燃烧的数值模拟更接近实际结果。14 MW双锥燃烧器的污泥水煤浆燃烧模拟结果表明,直接使用现有双锥燃烧器无法实现污泥水煤浆的稳定燃烧,仅可燃烧水含量为25%左右的污泥水煤浆。污泥水煤浆中水含量由0增至35%时,平均每提高1%水含量,燃烧器出口温度下降7. 95℃,燃烧器内平均温度下降7. 69℃;水含量为35%时,燃烧器内平均温度降低269℃,燃烧器出口平均温度降低278℃。污泥水煤浆在双锥燃烧器内的燃烧,可通过降低二次风量、增加二次风旋流强度、提高二次风温度等强化燃烧措施实现。二次风旋流强度由1变为2时,燃烧器出口平均温度提高20℃,二次风量减少为理论空气量的0. 6,燃烧出口平均温度提高203℃,综合使用降低二次风量、增加旋流强度和提高二次风温的措施后,燃烧器出口平均温度提高289℃,基本接近该燃烧器燃用煤粉时的燃烧条件,双锥燃烧器基本可达到稳定燃烧污泥水煤浆的目的。     

污泥掺混制备生物质燃料技术现状与发展前景

为了减轻市政污泥对环境的污染,实现污泥的资源化利用,阐述了国内外污泥处置的现状,介绍了污泥与煤掺混制备污泥水煤浆、与煤(半焦)掺混制备成型燃料以及与植物秸秆掺混造粒制备燃料制备生物质燃料的研究现状。结果表明,污泥制备生物质燃料可以充分利用污泥中有效热值,既可以代替少量煤炭,还为污泥合理利用提供有效的技术途径。分析了污泥制备生物质燃料还存在规模小、能耗高、工艺复杂以及燃料热值低等问题,同时针对这些问题提出了应加强污泥深度改性制备高浓度燃料水煤浆、污泥与燃料秸秆造粒及污泥与煤(半焦)制备成型燃料所用高效黏结剂的开发、污泥在成型前的脱水干燥、成型燃料的防水处理以及污泥制备生物质燃料的工业化等方面的研究,以加速污泥制备生物质燃料的工业化应用。     

污泥改性制备污泥水煤浆的中试试验研究

为解决污泥与煤掺混制浆时存在配入量少、污泥水煤浆浓度过低、添加剂用量大、成本高等问题,在实验室开发了污泥复合改性剂与高效改性机相结合的新型污泥改性制备高浓度污泥水煤浆的工艺,并进行了中试制浆试验。结果表明,采用复合改性剂与高效改性机对污泥进行改性,得到的改性污泥黏度比单纯用改性剂得到的改性污泥黏度降低30%以上,这种改性方法完全可以替代流体激波工艺处理污泥。污泥添加量为15%时,污泥水煤浆浓度比不添加改性污泥的普通水煤浆低3%左右,而采用同样污泥改性工艺和优化粒度级配,污泥水煤浆的浓度与普通水煤浆浓度相当,说明采用污泥改性和优化粒度级配可以解决污泥水煤浆浓度低的问题。中试生产线制浆试验结果验证了小试结果和中试装置的可靠性。     

高效水煤浆制浆燃烧集成技术研制与应用

为促进煤炭的清洁高效利用,株洲市蓝宇热能科技研制有限公司依托子母炉层-悬浮燃烧水煤浆锅炉,集成膜分离、功率超声处理与高效机械离心分离等绿色低碳技术,构建了新型高效生物质水煤浆制浆燃烧系统。该系统由有机废液的高效预处理模块、污泥的高效预处理模块、生物质水煤浆制浆模块、生物质水煤浆燃烧模块和净化水生化处理模块5个模块组成。高效水煤浆制浆燃烧集成技术已有多项工程应用实例,结果证明:该技术能有效降低有害气体的排放,同时实现污泥、有机废液的能源、资源化利用。     

选煤技术在中国洁净煤技术中的地位

中国的洁净煤技术体系应包括煤的洁净生产和洁净利用两部分。煤的洁净生产是指煤炭的合理开采、煤炭的洗选、配煤、型煤、水煤浆、煤的气体和液化等,即煤炭在利用前所做的一切准备工作,目的是为了有效利用煤炭,减少燃煤造成的污染。煤的洁净利用是指煤炭的高效与洁净燃...     

水煤浆制备技术的发展现状及其新进展的研究

我国是能源消费大国,煤炭作为我国的基本消耗能源,这种能源消费结构无论是在现在还是未来,在很长时间内都无法被改变。水煤浆是一种新型的煤的利用途径,和传统的煤炭利用相比,同为原料,以水煤浆为原料的生产是洁净的绿色生产。本文先从我国水煤浆及其技术现状进行介绍,再对水煤浆的制备技术的工艺流程,使用的设备和添加剂、水煤浆的应有和使用情况进行阐述,并对水煤浆的未来发展前景进行分析和介绍。     

水煤浆性能的影响因素及技术进展

水煤浆技术是我国洁净煤技术发展中的重要分支,对提高我国煤炭资源的利用效率、减少煤炭利用过程中产生的污染、实现煤炭的高价值利用具有重要意义,是我国能源长效稳定发展的必然选择,符合国家政策导向和环保要求。随着水煤浆尤其是气化浆用量的扩大和节能环保要求的提高,化工厂对水煤浆质量的要求越来越高。但目前国内气化水煤浆普遍存在浓度偏低、流变性差、气化效果不理想等问题,降低了水煤浆气化炉效率,不利于企业降本增效和稳定生产。笔者基于水煤浆性能的评定指标,介绍了水煤浆性能指标的测定方法,并简要说明了水煤浆的浓度、黏度、稳定性、流态及流变性对实际生产的意义;重点介绍了煤质、添加剂、级配方式以及颗粒形态等因素对水煤浆性能的影响,为改善水煤浆性能指明了方向,强调了粒度级配对水煤浆浓度、流态及流动度改善的重要意义;总结了近年来水煤浆制浆领域的研究进展,包括对成浆用煤的复配、新型水煤浆添加剂的研发以及"以破代磨"新型制浆工艺的介绍,并对水煤浆技术的发展趋势进行了展望,包括新制浆工艺的开发和核心设备的研制、高效经济低阶煤水煤浆添加剂的研制、化工污泥和气化细渣等废弃物的处理以及水煤浆颗粒间作用规律和颗粒形态研究等。     

欢迎订阅《煤炭加工与综合利用》杂志

<正>《煤炭加工与综合利用》杂志是中国煤炭加工利用协会主办的国内外公开发行刊物。主要报道内容:煤炭洗(筛)选加工,洁净有效利用,煤炭成型,焦化、气化、液化等煤化工,煤质检验及管理,煤炭燃烧及炉具,低热值燃料发电,煤矸石及灰渣的综合利用,煤系有用矿物资源的合理开发利用,水煤浆等新型煤基燃料,煤矿及煤炭利用中的环境保护及节能技术,生产经营管理经验等。欢迎刊登广告、宣传产品或企业形象。本刊统一刊号:CN 11-2627/TD,ISSN 1005-8397;双月刊,正文64页,标准大16开。每期定价15元,全年6期90元(含普刷邮费,如需挂号另加20元)。本刊自办发行,请订户从中国煤炭加工利用协会官方网站     

活性污泥掺混水煤浆的成浆性能实验研究

将活性污泥(干基)以不同的比例与煤粉掺混,制备污泥水煤浆,研究污泥掺混量、添加剂用量、温度以及剪切速率对污泥水煤浆成浆特性的影响,并对掺混活性污泥煤浆进行流变特性和黏温特性分析研究。结果表明:污泥掺混量增加时,污泥水煤浆的最大成浆浓度有下降趋势,添加剂用量可提高污泥掺混水煤浆的整体性能;浆体温度在20℃~60℃时,水煤浆表观黏度降低,整体煤浆性能提升;掺混污泥水煤浆呈假塑性流体特征,污泥掺混量增大,浆体的假塑性特征变化并不明显;污泥添加量1%以下时,活性污泥加入对原煤黏温特性无影响。     

《煤炭加工与综合利用》杂志征订启事

<正>中国煤炭加工利用协会主办1983年创刊权威性强覆盖面广发行量大读者众多国内外公开发行统一刊号:CN 11-2627/TD,ISSN 1005—8397主要报道内容:煤炭洗(筛)选加工,煤炭转化(煤制油、煤制气、煤焦化等),煤炭提质及利用,煤质检验及管理,煤炭成型及燃烧,低热值燃料发电,煤矸石及灰渣综合利用,煤系矿物资源的开发利用,水煤浆等新型煤基燃料,煤矿生态文明建设、节能降耗、环境保护及先进生产经营管理经验等。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。