立式辊磨机辊隙检测装置改进

<正>1存在的问题我公司研发设计的系列辊式磨机可用于水泥熟料、原料、矿渣的最终粉磨,其工作原理是:物料经过下料溜槽进入磨机,借助于重力而落到磨盘中央。磨盘与减速机相连,以恒速旋转,磨盘将粉磨物料均匀的水平分布在磨盘的衬板上,磨辊压住物料并将其碾碎。在液压系统的作用下,磨盘、磨辊和物料之间产生了压力和摩擦力,从而对物料进行粉磨。离心力将粉碎后的物料从磨盘中部甩至磨盘的     

串联式磨盘螺杆挤出机磨盘混炼段分布混合性能的研究

采用计算流体力学软件POLYFLOW 对串联式磨盘螺杆挤出机的磨盘研磨混炼段进行三维等温流动的数值模拟,并从统计学和动力学角度,采用分离尺度和时间平均混合效率,对磨盘区域的分布混合性能进行分析,研究磨盘构型和磨盘间隙对分布混合性能的影响.结果表明,臼目形磨盘的分布混合性能较好;磨盘间隙增大在一定程度上有利于提高分布混合性能.     

熟料粉磨系统的节能

用辊磨磨熟料由于辊磨粉磨熟料比球磨节能,十年前伯力鸠斯公司开始制订一项发展规划,将辊磨的应用范围由粉磨原料扩展到粉磨水泥。通过不断的改进,最近设计的一台辊磨产量为400吨/时,传动功率为3500千瓦。磨机的主要组成部分为:电动机,它通过伞形行星式减速机传动磨盘;磨盘,安装在倾斜座垫的推力轴承上;两对辊轮;磨机外壳和带有调节导向板的静力分离器。物料通过溜槽喂入磨盘中心。当磨盘旋转时,物料从辊轮下通过。磨盘设计成双槽形的,     

主要工艺参数对串联式磨盘挤出机混合性能的影响

采用Polyflow软件模拟了聚合物熔体在串联式磨盘挤出机混炼段内的混合过程。将混合指数和分离尺度作为评价指标,借助统计学方法,分析了主要工艺参数(转速和喂料速率)对串联式磨盘挤出机混合性能的影响。研究结果表明:转速增大,串联式磨盘挤出机的分散混合性能和分布混合性能提高;喂料速率增大,串联式磨盘挤出机分散混合性能下降,但喂料速率对串联式磨盘挤出机分布混合性能影响较小。     

基于CFD对启停阶段干气密封槽型控制与演变的数值仿真分析

基于螺旋槽的结构,考虑低速下动压不足和静压较弱的现象,提出一种在普通螺旋槽的槽根部增设台阶周向贯通环槽新结构,简称阶梯形螺旋内环槽.基于密封系统和动静环的结构特点,建立了润滑气膜计算域模型,使用Gambit划分网格,随后采用Fluent软件数值模拟获得气膜压力分布和速度分布,提取开启力和泄漏量随转速和压力变化的数据进行...     

金刚石品级与分布密度对磨盘使用性能的影响

以600目金刚石微粉磨盘为对象,通过磨削加工水晶的试验,研究了金刚石品级、分布密度对磨盘使用性能和质量稳定性的影响.     

液氦铁路槽车储槽热响应数值研究

以某85m~3液氦铁路槽车储槽为研究对象,考虑液氦及氦气物性的变化,采用有限体积法进行了非稳态热响应数值研究,得到了不同时刻的储槽压力、温度及流速分布,分析了蒸发率和充装率对储槽压升、温升规律的影响。研究表明:随着模拟时间的增加,液氦出现了热分层,压力呈上部小、下部大的阶梯式分布,而气相空间压力分布较为均匀;近壁区液氦受热后,在浮升力作用下沿壁面上升至自由液面后流入液氦主流区;随着蒸发率的增加,储槽气相空间的温升及压升速率增加,而充装率对储槽的温升及压升速率影响较小。     

基于迹线的拟合曲线槽干气密封气膜流场的性能研究

对螺旋槽中间面的中间线上的流体迹线进行拟合,将该拟合曲线作为干气密封的槽型线,建立拟合曲线槽三维立体模型,运用Fluent软件对该拟合曲线槽在干气密封特定工况下(压力为0.50MPa、转速为3kr/min)的最大压力、泄漏量进行数值模拟和分析,并与螺旋槽进行比较。研究结果表明:在相同工况下拟合曲线槽的最大压力为0.60MPa,螺旋槽的最大压力为0.55MPa;拟合曲线槽的泄漏量为8.0×10-3m3/h,螺旋槽的泄漏量为9.6×10-3m3/h。拟合曲线槽和螺旋槽相比,其动压效果更好,泄漏量更小,在工程上可以考虑用拟合曲线槽代替螺旋槽实现更好的密封效果。     

螺旋槽干气密封微间隙流场的CFD数值模拟

应用Solidworks软件建立螺旋槽干气密封三维立体模型,应用Fluent前处理Gambit软件对模型划分网格,应用Fluent软件对螺旋槽干气密封特定工况下的内部微间隙三维流场进行数值模拟,得到了流场的压力分布、速度分布以及泄漏量,所得流场数据与文献中实验结果吻合较好。改变操作参数再次模拟,得到了不同参数下流场的压力分布及泄漏量,并分析了操作参数对螺旋槽干气密封的影响。     

制备石墨烯的高剪切力耐磨橡胶磨盘及其制备方法和应用

<正>一种制备石墨烯的高剪切力耐磨橡胶磨盘及其制备方法和应用,包括上磨盘、下磨盘和驱动上磨盘转动的驱动机构,上磨盘为上磨本体底部连接固定耐磨橡胶上磨盘,下磨盘为下磨本体顶部连接固定耐磨橡胶下磨盘。耐磨橡胶上磨盘为合成橡胶和/或天然橡胶制备而成,耐磨橡胶下磨盘为合     

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。