乙烯裂解炉管渗碳蠕变复合损伤的剩余寿命评价方法

提出了一种乙烯裂解炉管渗碳蠕变复合损伤剩余寿命的工程评价方法,结合炉管壁厚及渗碳检测、有限元应力分析及蠕变累积损伤计算,实现了炉管剩余寿命的工程评价。用该方法对服役乙烯裂解炉管进行了寿命评价,利用金相观察确定炉管渗碳层厚度,通过有限元计算渗碳应力,应用LarsonMiller参数法计算了炉管的蠕变累积损伤及剩余寿命,得到了炉管的剩余寿命为2.7年。该方法为乙烯裂解炉管的安全服役及稳定运行提供了依据。     

裂解炉管的蠕变应力计算模型

通过对乙烯裂解炉管运行工况的分析 ,在金属扩散理论与渗碳失效机理的基础上提出了渗碳产生的应力计算方法。对HP Nb材料制成的乙烯裂解炉管在 832～ 90 2℃下的应力场进行了模拟 ,分析了炉管在温度、内压、渗碳和蠕变等交互作用下炉管管壁应力的分布情况。结果表明 ,渗碳是引起炉管失效的主要因素。     

乙烯裂解炉LMPH管失效分析

乙烯裂解炉是乙烯裂解工艺生产过程中的核心装置。乙烯裂解炉辐射段(LMPH)炉管长时间受到火焰辐射冲刷或高温烟气传热,易发生渗碳、硫化、氧化、变形等腐蚀损伤。对某石油化工企业的裂解炉装置的LMPH管失效原因进行了分析后可知,LMPH管失效是由高温和炉管渗碳两大因素的共同作用导致的,并针对其失效原因提出了相应的预防措施和建议。     

裂解炉辐射段炉管破损原因分析及对策

本文主要分析了乙烯装置裂解炉在日常操作中由于操作压力,裂解温度,炉管渗碳,炉管检修等操作过程中的控制不当导致裂解炉辐射段炉管破损的原因,并且针对各种原因提出了相应的对策。     

乙烷裂解炉管开裂原因分析

通过对材质为35Cr45Ni+NbMA的乙烷裂解炉炉管进行宏观形貌、微观形貌、扫描电镜、金相、化学成分等方面的分析,分析了炉管失效的原因,提出了相应的预防措施和建议。结果发现:炉管长期高温服役,力学性能下降,炉管内形成的厚结焦层与炉管母材的热膨胀系数之间的差别,导致在停炉过程中产生超过常温断裂强度的高水平应力,是该乙烷裂解炉炉管断裂失效的主要原因。     

裂解炉对流段二次注汽过热炉管失效原因分析

通过对发生腐蚀穿孔的BA-1104裂解炉对流段二次注汽过热炉管进行了宏观腐蚀形貌分析,对含裂纹部位进行了光学显微镜观察,断口进行扫描电镜观察以及对腐蚀产物的化学成分和金相组织分析,指出造成炉管腐蚀穿孔的决定性因素与操作温度及介质中存在的碱有关。进而提出了腐蚀控制与防范的措施,确保裂解炉的安全运行。     

乙烯裂解炉改造及效果分析

针对中国石化扬子石油化工有限公司2#乙烯装置BA-1101裂解炉投油量和运行周期达不到设计水平、热效率低等问题进行分析,采用中石化自主开发的CBL裂解炉技术对辐射段炉管进行改造,在对流段增加管排回收热量,改造后,BA-1101投油量和运行周期达到设计值,排烟温度大幅下降,热效率显著提高。     

乙烯裂解炉喷涂纳米高温节能涂料节能效果分析

为了改善乙烯裂解炉的工作性能,将纳米高温节能涂料分别喷涂在乙烯裂解炉的炉衬和炉管表面,使用正平衡法对喷涂纳米高温节能涂料前后的乙烯裂解炉的热效率进行计算,分析比较了改造前后两台乙烯裂解炉工作状态参数。试验结果表明,纳米高温节能涂料喷涂炉衬和炉管可强化炉内的辐射换热,引起炉内热平衡的重新分配,提高裂解炉热效率;纳米高温节能涂料有效降低了炉壁的热量散失,能够在一定程度上降低炉内燃气消耗量,节能效果显著。     

SiO2/S涂层与硫磷抑制剂对轻石脑油裂解结焦的影响

引言乙烯裂解炉辐射段炉管结焦是制约乙烯装置长周期运行的主要因素。裂解炉管的结焦会引起[1]:①管壁热阻增加,传热效率降低,裂解炉能耗增加;②炉管内径变小,流体压降增加,装置处理量减少;③炉管内壁渗碳,材料性能弱化;④周期性的清焦引起炉管热疲劳现象,而清焦过程中焦炭的     

乙烯裂解炉炉管渗碳微观组织研究

选用裂解炉常用炉管HP40Nb(25Cr35NiNb-MA)作为实验材料,利用低压高温真空渗碳技术,对未曾服役的炉管进行不同时段的渗碳,从而研究渗碳前后炉管金相组织的变化,并结合扫描电子显微镜(SEM)、能谱分析仪(EDS)及电子探针等技术分析析出的碳化物,最终确定渗碳对炉管材料的影响。     

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。