磨煤机分离器减速机进煤粉问题及解决方法

主要介绍DF-90辊式磨煤机分离器减速机长期进煤粉的问题,分析其原因,提出相应的解决方法,通过改造后的分离器减速机,使用效果良好,延长了运行周期,有效解决了生产瓶颈制约,大大延长了煤气化装置的运行周期,经济效益显著.     

粗甲醇分离器内件改造对生产产生的影响

甲醇装置中粗甲醇分离器是一个关键设备,其内件结构对粗甲醇气液相分离效率有着决定性的影响,进而直接影响粗甲醇产品的产量、质量,以及甲醇合成催化剂的使用寿命和其他设备的运行情况。神华包头煤化工有限责任公司对合成工段粗甲醇分离器内件进行改造后,解决了粗甲醇分离器出口气相带液、循环气压缩机超负荷、膜分离单元无法满负荷运行等诸多问题,对生产系统各单元工况产生了积极的影响,有效提高了甲醇产品的产量和质量,降低了单位产品能耗,延长了设备和甲醇合成催化剂的使用寿命及装置的平稳运行周期,取得了显著的经济效益。     

环流式旋风分离器结构改进及其在煅后焦装置的应用

中海油惠州石化有限公司400Kt/a煅后焦装置采用DⅢ型旋风分离器进行烟气除尘,存在烟气除尘率低,管路和设备积灰严重、磨损大,装置检维修频次高等问题。该公司对环流式旋风分离器结构进行了改进并将其应用于煅后焦装置烟气除尘。与DⅢ型旋风分离器相比,烟气除尘率由43.22%提高了93.12%,引风机电耗下降6.4%,旋风分离器出口管路及后序设备积灰严重、磨损大的问题得到有效解决,延长了装置运行周期,每年节省装置检维修及运行费用210万元。     

关于氯乙烯精馏自聚问题的研究

氯乙烯精馏自聚严重影响氯乙烯装置的正常生产,通过对装置、设备及工艺指标的对比分析,采取HCL净化,添加阻聚剂,调整氯乙烯pH值,调整设备及对工艺指标的控制,使精馏自聚问题得到有效控制,延长管道、设备堵塞周期。     

双相钢在合成氨空压机组段间设备上的应用

针对合成氨空压机组段间冷却器和分离器在生产过程中频繁出现故障的现象,分析了设备腐蚀的原因,采取了将腐蚀部件材质改为双相不锈钢的措施,实践表明:两台设备的成功运行解决了制约生产的瓶颈问题,不仅延长了检修周期(特别是空气压缩机组),而且可以保证装置连续生产,并为合成氨装置整体提负5％.     

碱洗塔黄油生成原因分析及抑制方法

裂解气经碱洗塔碱洗过程中会生成黄油,实际生产中如果黄油问题未得到有效控制,极易堵塞碱洗塔盘,造成塔压差增大,管道堵塞,严重时将影响装置长周期运行。针对生产中碱洗塔及废碱氧化过程中出现的各种黄油异常问题进行了分析,提出了解决的思路和办法。通过工艺调解、设备改造及应用有效助剂使黄油生成得到有效控制,以达到延长碱洗塔运行周期及环保排放的目的。     

脱硫液提盐系统调试运行分析及优化方案探讨

结合陕西黄陵煤化工有限公司生产运行情况,分析了脱硫液提盐系统调试运行期间出现的设备和工艺等问题,并提出了优化改造方案:增加前置过滤装置、管道伴热、余热回收、产品烘干、副产品转换、增加负压蒸氨系统、更换管道和设备。对脱硫液提盐系统的改造,可使脱硫液副盐含量降低,脱硫效率提升,为后续甲醇的正常生产提供保障。     

循环换热分离器运行过程分析

循环换热分离器是费托合成工艺核心设备,通过总结分析8台循环换热分离器改造前后运行数据,证明现有改造措施无法长期有效解决热侧整体压降、换热性能、重质油分离效果差的问题,费托合成装置随运行周期被迫降负荷且能耗高,对此提出将换热器与分离器独立设置的改造思路,建议换热器选用传统列管式结构,分离器选用抗堵旋风式结构。     

甲醇装置直接氧化法硫磺回收工艺的优化

分析了200 kt/a甲醇项目直接氧化法硫回收装置在运行中暴露出的问题,提出了解决方案,新增1台洗涤液沉降槽、1台循环风机进口尾气分离器、更换1台循环风机,并对硫气分离器伴热蒸汽冷凝液管线及底部排硫夹套管进行改造.投入运行后,反应后H2S的质量分数平均由1.47％降至0.6％,硫磺日产量从0.9 t提高至1.2 t,系统运行周期由15d延长至30 d,可满足处理低浓度H2S酸性气要求.     

MP2519型中速磨煤机动态旋转分离器改造与应用

对我公司MP2519中速磨煤机SLS动态旋转分离器结构及故障原因进行分析,找出动态旋转分离器油池污染及故障的解决方案,对原结构进行改造,有效的消除因动态旋转分离的磨损、故障而造成的生产事故,有效的延长磨煤机动态旋转分离器的检修周期,降低了磨煤机分离器检修费用,显著的改善了磨煤机的运行工况。     

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。