浅谈回转窑筒体周长和圆度要求及测量方法*

通过对GB/T 32994—2016水泥工业用回转窑国家标准中有关筒体最大直径与最小直径差要求和测量方法的研究,分析出标准中相关技术要求和检测方法的存在问题和不足,否定了标准规定的筒体内径公差要求和相关的检测方法,并根据实际需要提出了筒体周长差要求和与筒体最大直径与最小直径差要求等效的圆度要求建议,同时介绍了相关建议要求的相应测量方法。     

回转窑筒体纵向中心线安装的新观点

1、前言 在回转窑筒体的安装中,历来都要求其纵向中心线必须是直线。如在《水泥机械设备安装工程施工及验收暂行技术规程》(建规7-62)和修订后的规程中,在冶金工业出版社出版的《回转窑》一书中,在天津水泥工业设计院编写的援巴讲义《水泥回转窑的设计》中,直到1991年发布的中华人民共和国行业标准JC333-91《水泥工业用回转窑》中都要求回转筒窑体在安装后,即在冷态时其纵向中心线满     

回转窑筒体直线度对耐火衬体的影响及应对

水泥回转窑筒体直线度是保证回转窑长期运转的一个关键。但是由于窑体长、支点多,要保持中心线准直却比较困难。造成窑体中心线不直的原因很多,如水泥回转窑在安装或调整时,托轮位置不正确,各筒体段节的接口没有对正;由于在使用中,轮带、托轮的不均匀磨损, 基础的不均匀下沉,工艺操作不当等都会造成回转窑筒体直线度不正。水泥回转窑筒体直线度偏差会造成支撑处筒体形成弯矩和交变应力,使支撑处耐火衬体受到纵向的交变应力;此外,回转窑筒体直线度偏差,会增加回转窑的运转阻力,从而增加筒体和耐火衬体的剪切力。在交变应力和剪切力的作用下,耐火衬体的稳定性受到威胁,严重时会造成耐火砖的挤碎、剪断、扭曲甚至掉砖。随着窑龄的增长,回转窑准直度对窑内耐火衬体的损坏现象日益突出。本文介绍水泥回转窑筒体直线度对耐火衬体的损坏机理和对应的措施。     

磁力半自动管道火焰切割机在回转窑改造现场的应用

水泥回转窑的现场改造,涉及到保留段原筒体的切割和坡口的开设工作,将开设好坡口的原旧筒体与新制作的筒体焊接组成新的回转窑筒体。保留段原筒体的切割和坡口开设工作,其传统和常用的做法是,手持氧气-乙炔火焰割枪切割,再用手持碳弧气刨开设坡口,为使保留段原筒体的端面和坡口达到与新筒体焊接的要求,现场还需用角磨机做很多打磨修补工作。磁力半自动管道火焰切割机在回转窑改造现场的成功应用,很好地完成了原旧筒体的切割和坡口开设工作,大大节省了人力、物力和时间,保证了保留段原筒体的端面质量。     

回转窑齿轮托轮硬度及硬度匹配合理性探讨*

通过对GB/T 32994—2016水泥工业用回转窑国家标准中有关大齿圈、小齿轮、轮带、托轮等主要零部件硬度要求的研究,分析出标准中规定的硬度区域的代表性、要求的普遍实用性、界定基准、取值等方面存在的问题。根据实际情况需要提出了实用性较强的硬度要求建议。所述回转窑主要零部件硬度要求修改建议具有合理性和适用性。     

水泥回转窑筒体检测及开裂机理探讨

水泥回转窑是水泥生产工艺的关键设备,由于回转窑长期受腐蚀介质、高温及应力作用,因此回转窑筒体经常发生开裂,导致生产事故,给企业带来巨大损失。因此,研究水泥回转窑筒体开裂机理,并提出可行的预防措施十分重要。采用壁厚测定、磁粉、超声、硬度、金相检测和物料分析等手段,分析了水泥回转窑的筒体结构,探析了筒体的薄弱部位,判断回转窑存在的潜在缺陷,推断回转窑筒体开裂机理,最终提出针对性的预防与改善措施。     

φ5.8m×97m回转窑轴线测量方法

φ5.8m×97m回转窑是江苏巨龙水泥集团有限公司水泥生产线的关键设备之一,回转窑轴线位置偏差过大将会影响工艺操作,导致轴瓦发烧.因此获得回转窑运行过程中的筒体轴线动态位置及变化情况,对调整回转窑工艺规程及托轮摆放位置、改善筒体受力状况、预防托轮轴瓦发烧具有重要意义.     

介绍一种检测简体圆度的装置

筒体是水泥工业用管磨机和回转窑的主体。我厂生产的简体从直径φ1.83～4米,长度十几米至几十米,重量十几吨至几十吨不等。国家建筑材料工业局颁布的《JC334-83》和《JC333-83》标准中,规定了筒体圆度不大于直径的0.75/1000。过去我厂检验筒体圆度,均采用多点测量法,由于很难保证测量点在同一截面处和测量点少.不能真正反映筒体截面形状等原因,     

回转窑筒体的设计经验和教训

0前言水泥回转窑筒体的设计包括窑支承点的选择、配置,筒体结构的设计和材质的选择以及制造工艺的确定。在设计回转窑筒体时,应保证筒体最小的径向变形和弯曲变形,并充分考虑材质和温度对许用弯曲应力的影响,以保证回转窑筒体的制造质量。本文结合实例,对回转窑筒体设计中的一些基本问题进行归纳总结,以期为水泥回转窑设计人员提供一些借鉴。1窑筒体支承点的选择1．l筒体出料端悬臂长一般来说,窑筒体出料端悬臂长度与窑冷却带长度有关。在设计回转窑筒体时,第一档支承点应尽量远离烧成带最高温度点。对于湿法长窑、干法中空窑和SP…     

回转窑筒体温度变化对其中心线直线度的影响分析

回转窑在热态下运转时，其筒体中心线保持为一条直线十分重要，关系到回转窑稳定运转周期的长短、生产的安全、设备的故障和事故率、窑衬寿命的长短、企业的经济效益等。引入回转窑筒体中心线动态检测技术，对回转窑筒体中心线及时进行检测，以保证回转窑长周期的正常运行。在检测过程中，根据计算获得的各档筒体中心升高值数据，采用了直角三角形相似法，可既快捷又准确地计算出筒体中心线直线度的误差，为回转窑正确调整提供依据。     

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。