基于ANSYS的压力容器管口载荷施加方式的研究

利用ANSYS软件对三种管口载荷施加方式进行了研究,通过建立某管口的局部结构模型,对比了三种管口载荷施加方式下的管口局部应力结果,研究了不同管口载荷施加方式的基本原理,并确定了最优的管口载荷施加方式。结果表明：三种管口载荷施加方式下的管口局部应力结果几乎相同,且三种管口载荷施加方式的基本原理均为MPC法,而Workbench中的Remote Force管口载荷施加方式最为简便合理。     

容器设备管口校核方法

容器设备作为油气储藏和处理设备中的重要组成部分,其管口的安全至关重要。本文介绍了利用CAESARⅡ软件模拟容器设备管口方式、校核方法及边界条件的影响,对比不同模型的计算结果,说明了容器设备初始位移和管口柔性对管道应力和管口受力的影响,并提出降低管口受力的措施,优化管道布置。     

应力分析在极端管口载荷调整及优化过程的作用

对于非标设备,在缺少相关标准规范约束的前提下,制造商有时会选择最有利于自身的制造方案,导致极端管口载荷的情况出现。对此应首先要求制造商调整管口载荷,尽量避免极端管口载荷情况的出现。当极端载荷无法避免时,对于处于极端载荷值的管口,通过应力分析对与管口相连的管道进行优化可以有效降低管口的载荷值。采用CAESAR Ⅱ指导与管口相连的管道的优化,通过对比不同的管道布置方案,并结合CAESAR Ⅱ的计算结果分析,最终得到满足管口载荷的管道布置方案:采用在管口附近设置Π型弯,并在Π型弯之后设置固定架,可以有效避免固定架之后的管道产生的力及力矩传递到管口上;同时由于在管口及固定架之间设置了Π型弯,大大增加了这部分管道的柔性,使得管口最终能够满足极端载荷值的要求。     

板式塔管口方位设计技巧

板式塔管口方位的确定是配管设计的难点。从人孔、操作平台、仪表、分析管口以及内件管口与人孔的匹配等方面论述了板式塔管口方位的设计要点和配管技巧。     

四溢流板式塔的管口方位研究

多溢流板式塔的管口方位设计是管道设计中的一个难点。根据四溢流板式塔的结构特点,通过分析内部塔盘结构对管口方位的影响,提出了管口方位的设计要点和配管技巧。并结合工程实例,在满足工艺、管道布置、检修操作及安全疏散等要求的基础上,对四溢流板式塔的管口方位进行设计探讨。     

一种双径弹簧式传热管内插件管口固定装置

介绍了一种双径弹簧式传热管内插件管口固定装置专利技术,该技术克服了其它同类装置占用管口面积大、对流体介质阻力大、只能在一端管口安装并且容易脱落的缺陷,可广泛应用在各种立式和卧式管壳式换热器上。     

浅谈管道应力分析中管口刚度的算法

通过对管道应力分析中管口刚度各种计算方法的介绍和分析,结合设备管口刚度计算的工程实例,总结如何科学合理的计算管口刚度。     

搪玻璃设备管口设计介绍

对搪玻璃设备设计中管口的形式、位置、尺寸和结构设计作了较详细的介绍,并结合实际经验提出了搪玻璃设备管口设计的基本原则。     

CAESARⅡ在压力容器管口应力分析中的应用

论述了压力容器管口应力分析的基本理论,介绍了云图曲线法与WRC107两种常用的管口应力校核方法;以某闭式排放罐为例,将容器本体及支墩建入模型,用WRC107有限元分析方法进行校核,并对相应边界条件的选择进行了论述;分析总结了降低容器管口应力的常用方法,最终推荐一种较为合理的容器管口连接管道的布置方式。     

设备管口载荷计算的准确模拟

设备与设备外部的管道相互作用,会对设备管口产生一个作用力,运行时设备管口的受力不能超过设备的允许值,因此设备管口受力值的准确计算很重要.化工设备有多种形式,但按设备内部管道可分为三种典型形式:直管、U型管和环管.文章以某项目的三种典型设备为例,应用CAESAR Ⅱ应力计算软件中的“虚拟刚体”对设备进行模拟,并在此模型上,增加设备管口的约束条件.完成后的模型将设备与管道连成了一个整体,能直接计算设备滑动端的位移,也能在计算中考虑设备管口的约束条件.通过对设备热胀位移的计算验证了模型的准确性,计算结果体现了设备与管道的相互作用,并能同时计算多个工况的受力值,因此能提供更准确的设备管口载荷.     

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。