共查询到20条相似文献,搜索用时 390 毫秒
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ZY—HDSK03-WMD型中包水口快换机构广泛应用于冶金行业连铸系统,其传统的控制方式是采用继电器逻辑原理控制,由于利用继电器控制系统比较复杂,难于操作。随着技术的进步,这类控制系统已显示出越来越多的弊端,近年来PLC在工业自动控制领域应用愈来愈广,它在控制性能、安装周期和硬件成本等方面所表现出的综合优势,是其它继电器逻辑产品难以比拟的,如果用PLC控制技术对这些继电器逻辑系统实施改造,则具有普遍的技术及经济意义。因此本次设计是将其改造成为利用PLC控制,这样既可以使中间包水口快换系统更完善,提高了生产的安全性,也减少了控制系统的故障,提高了生产效率。 相似文献
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采用在水平连铸过程中施加旋转电磁场的方法制备了薄壁BFe10-1-1白铜管坯。考察了电磁场对管坯表面质量、凝固组织和力学性能的影响。结果表明,施加电磁场后消除了表面裂纹,从而使管坯表面质量明显得到改善;在电磁搅拌力的作用下管坯凝同组织显著细化,同时降低了铸造残余应力;随着凝固组织的改善。管坯抗拉强度和延伸率较未施加磁场的管坯分别提高了5%和36%。 相似文献
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氮化物陶瓷是应用广泛的特种陶瓷,但传统的氮化物陶瓷烧结方法极为消耗能源、生产周期长、成本高。为降低成本、能耗,采用燃烧合成工艺制备氮化物陶瓷基复合材料,包括氮化钛和六方氮化硼,燃烧合成工艺利用单质元素与氮气反应合成氮化物。研究结果表明:压坏与80MPa N2反应燃烧合成TiN制件致密度约75%,压坯为添加了TiN稀释剂和适量氧化铝的钛粉,压坯孔隙率45%;燃烧合成纯BN制件致密度为68%,BN基制件致密度为78%,压坯为添加了h-BN稀释剂或SiO2添加剂的B粉压坯与80MPa N2反应合成,压坯孔隙率48%;在材料体系中,稀释剂起减小晶粒尺寸和降低燃烧温度的作用,而Al2O3和SiO3添加剂则起提高强度和相对密度的作用。 相似文献
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快速冻结装置的节能新技术 总被引:1,自引:0,他引:1
在食品冷加工中,快速冻结是一个高耗能环节,除了制冷主机、辅机、快速冻结装置风机、传送机构耗能外,另一个重要耗能因素则是除霜和重新降温过程。一般认为,该过程耗能占总耗能15%左右或更多。实际表明,采用吹风快速冻结加工食品平均单位耗能约为300kwh/t左右。而含水率较高的食品如芦笋单位能耗高达373kwh/t,按平均0.72元/度计,电费268.56元/吨。因此降低快速冻结环节的耗能,降低加工成本是今后快速冻结装置的重要研究课题。快速冻结装置的各项节能新技术可以降低能耗30%,是一项可以给用户带来丰厚经济效益和应用前景十分可观的项目,同时对提高国产快速冻结装置的整体技术水平,实现技术突破具有重要意义。 相似文献
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《Composites Science and Technology》2007,67(7-8):1451-1458
The objective of this study is to analyze the fracture process of single-edge-notched (SEN) laminated composites with different lay-up configurations and different fiber composite systems based on the behavior of high amplitude acoustic emission (AE) signals. The classification of signal type according to the dominant frequency band and its magnitude via FFT, combined with the microscopic observations under reflection and transmission optical microscopy, have been also performed in order to support the effectiveness of the analysis based on the high amplitude AE signals. It has been shown that the behavior of high amplitude event rate describes well the fracture process in the SEN laminated composites with different fiber orientations; the direction of the main crack propagation in SEN laminated composites is decisively affected by the fiber orientation and is irrespective of the initial notch direction. Finally, the AE characteristics for SEN laminated composites have been summarized in association with the individual fracture process. 相似文献
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王华琛 《制冷与空调(四川)》2014,(2):191-198
简要介绍了目前世界上较成熟的LNG液化工艺技术及国内一些厂家使用的LNG工艺技术,论述了进行天然气液化技术研发的重要性,重点论述了陕西定边一期92万方/天LNG工厂三段混合制冷液化技术及应用情况,从工艺、设备、能耗、液化率、管理上比较分析,证明采用这种液化技术可靠性高、可操作性强、开停机过程容易,经济适用,有明显的优势,非常适用国内LNG发展需要,适合国情。 相似文献
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本文综述了结构差异对浸入式水口在使用过程中对防止Al2O3等夹杂物堵塞效果的影响。探讨了水口内腔孔径设计、阶梯式环状内腔、耗散型四侧孔水口结构、塞棒和永口同时吹气系统等重点结构在防止水口堵塞方面的应用以及相关机理。还介绍了保温隔热层、工作面粗糙度、结构突变等因素对减少夹杂粘附的作用。 相似文献
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自动化控制系统作为整套空分设备的重要组成部分,空分设备流程不同,其控制特点也不同。简介煤化工型空分设备的流程控制特点,分析空压机、增压机、汽轮机三大机组的控制技术、高压氧气阀门的应用技术、高压液氧泵和相关阀门的控制技术以及机组相互关联控制技术。 相似文献
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目的研究胶囊印字机的自动控制系统及人机界面的印字方案,从而实现胶囊自动印字控制系统的设计,完成胶囊印字和检测的全自动工业过程。方法从胶囊印字这一工业过程控制对象出发,基于PLC和触摸屏技术,制定胶囊印字机胶囊印字控制系统的总体方案设计,对胶囊印字这一工业过程进行控制,并且计数显示结果。结果该控制系统简单易操作、可靠稳定性好,极大地提高了生产效率和产品合格率,通过测试最大生产效率可高达70 000粒/小时,合格率高达99.95%以上。结论设计出的胶囊印字系统可以实现胶囊上料、印字、废品检测和剔除、计数、出料的工业过程控制。经触摸屏操作可手动、自动控制工业过程,具有产量数、装箱数、合格数、废品数的计数限值设定和清零、报警等功能。 相似文献
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林德公司一套 5 0 0 0 0± 1 2 0 0 0m3/h空分装置 ,2 0 0 2年 5月在奥地利林茨钢厂投运。介绍了此快速变负荷空分装置的产品参数、工艺流程、单体设备以及灌入液氧或液氮、快速变负荷1 2 0 0 0m3/h的运行情况 相似文献
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Shuffle-exchange networks (SENs) have been widely considered as practical interconnection systems due to their size of its switching elements (SEs) and uncomplicated configuration. SEN is a network among a large class of topologically equivalent multistage interconnection networks (MINs) that includes omega, indirect binary n-cube, baseline, and generalized cube. In this paper, SEN with additional stages that provide more redundant paths are analyzed. A common network topology with a 2×2 basic building block in a SEN and its variants in terms of extra-stages is investigated. As an illustration, three types of SENs are compared: SEN, SEN with an additional stage (SEN+), and SEN with two additional stages (SEN+2). Finally, three measures of reliability: terminal, broadcast, and network reliability for the three SEN systems are analyzed. 相似文献
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AbstractIn this article, the prediction models of the creep crack initiation for the specimen geometry was quantified by six different types of cracked specimens [including C-ring in tension CS(T), compact tension C(T), single notch tension SEN(T), single notch bend SEN(B), middle tension M(T), and double edge notch bend tension DEN(T)]. Load-independence constraint parameter Q* was introduced to quantify the in-plane constraint. The specimen order of Q* and the creep damage accumulation rate of the different specimen geometries from high to low was C(T), CS(T), SEN(B), SEN(T), DEN(T), and M(T), which generally represented the distinctions of in-plane constraint level in these specimens. For a specific load level, C(T) and CS(T) specimens showed the highest crack damage accumulation rate or the shortest creep crack initiation time, whereas the lowest rates or the longest CCI time existed in M(T). Moreover, the relationship between the CCI times and specimen thickness and crack depths was obtained, and a series of empirical equations were fitted. Finally, the power law relation between the CCI times and constraint parameter Q* was extrapolated. 相似文献