压力容器设备法兰优化设计

针对压力容器设备法兰设计,基于优化设计基本原则,结合实例,对优化设计过程进行深入分析,提出可行的优化方法,为压力容器设备法兰设计实践提供借鉴。     

基于有限元法的法兰工程设计软件开发

为实现非标设备法兰的分析设计和优化设计,建立了整体法兰参数化有限元分析模型,根据Taylor-Waters法兰应力分析和压力容器分析设计中应力分类准则,给出了基于有限元法的法兰强度与刚度计算方法和校核判据,采用ANSYS参数化设计语言和VB编程工具,开发了基于有限元法的法兰工程设计软件CFFEA。应用该软件对某工程中的非标设备法兰进行了优化设计,优化结果符合ASMEⅧ-2-4.16的规定。     

齿啮式快开门压力容器协同智能优化设计研究

应用CAE软件Proe、Ansys和协同优化软件Isight,构建了基于Isight的协同优化设计平台,研究建立了压力容器计算机协同集成智能优化自动化设计技术和方法,提出了基于分析设计思想的应力分类设计准则,并应用这一平台基于分析设计的思想成功完成了对DN1 200mm×12mm齿啮式蒸压罐法兰的优化设计。研究结果表明,在保证应力分析设计的强度条件下,通过计算机协同集成智能优化,该法兰的总质量可减轻128.74kg,材料节省幅度达21.53%。     

基于FMEA的在用螺栓法兰接头可靠性维护方法研究

在用螺栓法兰接头泄漏一直是困扰石化装置安全稳定运行的问题,造成螺栓法兰接头泄漏的因素较多且相互作用,当前方法无法满足维护需求。本文基于故障模式及影响分析(FMEA)方法,研究制定了在用螺栓法兰接头可靠性维护方法,给出了在用螺栓法兰接头常见潜在的损伤模式。通过某蒸汽管道法兰接头的FMEA分析工作,详解了该方法的应用过程。通过实施基于FMEA的可靠性维护方法,依据螺栓法兰接头的损伤模式制定针对性的检维修措施,可以提高维护可靠度并合理配置维护资源。     

中心开孔法兰盖结构参数优化分析

高周疲劳工况下,以法兰盖横截面积S、密封面最大变形量Δy、应力强度最大值σ_max为优化目标,采用ANSYS Workbench中的响应曲面模块,对中心开孔法兰盖模型结构参数变化对优化目标的影响规律进行了探索。结果表明：增大锥颈大端半径N或者减小锥颈角θ可以作为增加法兰厚度δ的补充方法,显著提高法兰盖刚度和疲劳特性,同时实现轻量化设计,使得法兰盖的安全性与经济性得到兼顾。     

波齿复合垫片金属骨架结构参数的可靠性分析

在管内压力为4 MPa的情况下,结合波齿复合垫片标准与凹凸面对焊管法兰标准,应用ANSYS软件对波齿复合垫片金属骨架结构进行可靠性分析,了解影响其性能的关键性因素。其分析结果表明,金属骨架的可靠度为98.046 71%,说明其质量可靠性高,结构比较安全。另外,由可靠性分析中极限函数的灵敏度分析可以了解到适当的增加齿尖宽度和波齿深度有利于提高垫片金属骨架的密封性能。     

压力容器设计中法兰的优化设计

本文阐述了压力容器设计中法兰设计的原理,介绍了法兰设计的优化过程和方法,通过工程实例说明了法兰强度尺寸对法兰三项应力的影响,并对法兰设计的刚度校核方法进行了分析。     

应用浮头法兰计算公式时须注意的问题

对ＧＢ１５０、ＧＢ１５１浮头法兰计算公式进行了分析。提出了应用浮头法兰计算公式时须注意的问题：当由预紧力矩起决定性作用时，按操作力矩、预紧力矩分别计算，取两者中较大值作为法兰的计算厚度：按预紧力矩计算时，Ｌ＝０，法兰厚度计算公式为δｆ＝√Ｊ。     

压力容器法兰的合理设计原理与方法

《钢制石油化工压力容器设计规定》中所采用的法兰设计方法为Waters法,由于该设计法影响因素较多,且随意性较大,不同的设计结果就其法兰重量来说可以相差数倍。法兰的优化设计结果表明:法兰的合理设计具有明显的经济效益。     

外压容器的稳定性模糊可靠性优化设计

考虑到设计参数的随机性和设计边界的模糊性,在外压容器的稳定性设计中应用模糊可靠性优化设计理论,建立了模糊可靠性优化设计的数学模型,给出了优化方法和应用实例。优化后,圆筒有效壁厚减少14%,封头有效壁厚减少14%,加强圈有效横截面积减少46.7%,重量减轻16%左右。     

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。