解析烯烃分离装置脱甲烷塔改造

文章通过对烯烃装置脱甲烷塔系统流程和工艺参数的分析,以兰州石化公司烯烃分离装置的脱甲烷系统为例分析烯烃分离装置脱甲烷塔改造,并对改造前后烯烃分离装置脱甲烷塔运行状况进行对比分析,指出烯烃分离装置脱甲烷塔改造存在的问题,针对问题为如何优化烯烃分离装置脱甲烷塔改造进行策略分析。     

聚合装置的侧线改造难点和要点

介绍了目前中、小聚合装置改造的几种改造思路,通过装置改造提高装置的产品品种的多样性,进一步提升装置的盈利能力和生存能力;同时分析了改造方案中涉及到的难点和要点,介于装置改造过程中不可避免的涉及到长距离物料输送问题,同时也介绍了几种长距离物料输送改造需遵循的要点.     

催化重整装置扩能改造思路探讨和工程实践

从扩能改造原因分析、工艺技术路线选择、改造原则明确、规模确定等对催化重整装置的扩能改造思路进行了探讨,并结合一套半再生重整装置的扩能改造实例对扩大装置原料来源、实施节能措施等进行了论述。有如下结论:催化重整装置扩能改造时,首先分析装置扩能改造的原因,进而根据原装置类型、产品要求、扩能幅度等选择合适的工艺技术路线,最后结合产品要求、原料性质和来源、装置现有依托等确定合理的改造规模。在原料不足时,应根据工厂可利用原料的性质和数量,尽可能扩大装置的原料来源。在扩能改造时,应尽量采用新工艺、高效设备等以使装置节能降耗。     

顺序流程乙烯装置冷区扩能改造方案探讨

乙烯装置分离冷区工艺流程复杂,技术难度高,是全装置工艺设计的关键。以某200 kt/a乙烯挖潜改造、1100 kt/a乙烯装置改造和1190 kt/a乙烯装置改造为例,着重论述了顺序分离流程冷区改造的工艺技术特点,对深冷及脱甲烷系统、制冷系统和碳二分离系统的工艺改造方案进行了说明,分析了各装置在具体改造方案上的工艺技术特点,最后总结出顺序流程深冷系统、制冷系统以及乙烯全装置扩能改造的最佳方案和改造原则。     

1.0Mt/a汽柴油加氢精制装置扩能改造设计

以山东某地方炼油厂1.0 Mt/a汽柴油加氢精制装置扩能改造至1.2 Mt/a为目标,在满足目标产品质量要求的前提下,对装置扩能改造前后原料油性质、加工比例、产品质量标准、主要工艺参数、物料平衡和热量平衡进行对比和分析,并结合装置的全流程工艺模拟计算和主要设备核算分析,找出了原装置工艺和主要设备瓶颈,并有针对性的提出了具体改造措施。同时对装置扩能改造至1.5 Mt/a的可能性做了探索性分析。     

PTA老装置溶剂脱水塔HT-701优化改造

对PTA二装置HT701塔的改造方案进行了分析和比较,提出了合适的改造方案,通过改造,HT701塔完全满足装置的需要,同时,为类似PTA装置溶剂脱水塔的改造提供了参考。     

改造离心泵实验装置,提高实训质量

文章从高职院校化工原理课程教学现状出发,分析了课程实验教学过程中存在的问题及其影响。概述了离心泵性能曲线测定实验装置改造的背景及改造目的。改造过程中着重以较小的投资进行流程改造和控制方案的重新设计。根据改造后装置所要实现的基本功能,在原有离心泵实验装置的基本结构的基础上,从硬件和软件角度具体阐述了实施装置改造的技术路线。目前,改造工作已经完成,改造装置已投入运行。     

汽柴油加氢装置节能改造及效果分析

分析汽柴油加氢联合装置能耗现状,查找节能挖潜重点,从优化换热流程和调整工艺路线两方面着手,实施汽油加氢装置重沸器凝结水系统改造和柴油改质装置稳定系统改造,改造后加氢装置能耗大幅降低,同时解决了汽油加氢装置凝结水管道水击冲刷和加氢精制装置柴油闪点难调整问题,保证装置长周期安全稳定高效运行。     

DCS和PLC控制系统升级改造分析

总结和分析了大型化工装置DCS和PLC的改造升级过程,并结合中原大化合成氨、尿素装置的经验,对改造中的注意事项和难点进行重点分析,提出解决问题的办法,并进一步反思改造的效果。     

PP装置扩能改造途径

通过对国内聚丙烯(PP)市场和生产企业现状的分析,指出现有PP装置需要并能够通过扩能改造来提高产量和竞争力;分析了装置扩能改造的各种途径;举例介绍了扩能改造技术的应用。     

Tetragonal-to-monoclinic phase transformation in CeO2-stabilized zirconia under multiaxial loading

Critical stresses for the initiation of the tetragonal-to-monoclinic phase transformation in 9Ce-TZP zirconia materials with five different grain sizes have been studied. The influence of the grain size on the critical transformation stresses has been investigated in multiaxial stress states, namely, in four-point bending, biaxial bending and torsion. It was found that phase transformation occurs as a homogeneous phase transformation with a transformation strain increasing continuously with increasing applied stress and also as an autocatalytic phase transformation with the autocatalytic formation of transformation bands normal to the maximum principal stress. An investigation of the critical transformation stresses under different multiaxial loads in the tensile regime, i.e. with positive hydrostatic stress, showed that both the homogeneous and the autocatalytic transformation do not follow the shear-dilatant criterion investigated in multiaxial compressive testing. The experiments showed that under multiaxial loading the onset of both transformation types can be predicted with the maximum principal stress transformation criterion, with the difference between the critical stresses of both transformation mechanisms strongly decreasing with grain size.     

X-ray Diffraction Study of the t-to-m Phase Transformation in 12-mol%-Ceria-Doped Zirconia at Low Temperatures

The t -to- m phase transformation in a 12-mol%-ceria-doped zirconia at subzero temperatures was studied in situ by XRD with a cryogenic sample stage. It was found that the t -to- m transformation continuously proceeded to 30 vol% as the temperature decreased to 125 K, when a burstlike transformation suddenly occurred with a transformation to 75 vol%. A preferred orientation of the ( 1 11)_m plane parallel to the surface during the preburst transformation and XRD line broadening of both m and t phases after the burst were observed. The preburst transformation, which has not been revealed by previous dilatometry studies, is explained as surface martensitic transformation. This surface transformation occurs at higher temperatures than the burstlike transformation due to less matrix constraint and the higher probability of nucleation.     

CL-20晶型转变行为及转晶机理研究进展

从六硝基六氮杂异伍兹烷(CL-20,HNIW)的晶型特征、转晶方式、转晶影响因素、转晶机理等4个方面总结了其晶型转变的国内外研究进展。指出影响CL-20转晶的因素主要有溶剂、温度等;转晶的方向主要由各种晶型之间的吉布斯自由能决定;转晶机理主要通过Ostwald规则和溶液介导相变(SMPT)两个方面进行解释。指出今后转晶研究发展的重点是转晶的热动力学和抑制技术。附参考文献45篇。     

Metastability of the Martensitic Transformation in a 12 mol% Ceria-Zirconia Alloy: I, Deformation and Fracture Observations

A single-phase tetragonal zirconia polycrystal containing 12 mol% cerium dioxide was found to readily undergo the tetragonal-to-monoclinic phase transformation on deformation, fracture, or cooling below 150 K. Deformation tests, primarily indentation studies, indicated that an extensive transformation zone developed about the impression. The transformation zone increased in dimension as the temperature approached the martensitic start temperature for the tetragonal-to-monoclinic transformation. Associated with flexure tests at room temperature "Luders"-like transformation bands propagated entirely across the tensile surface perpendicular to the applied stress. Transmission electron microscopy and X-ray diffraction were used to monitor the extent and form of the transformation. The reverse transformation was also examined using X-ray diffraction while heating and compared with in situ transmission electron microscopy observations.     

Cr-Ni奥氏体不锈耐热钢中碳化物、σ相变热力学和转变动力学探讨

从相变热力学和转变动力学出发 ,研究了Cr Ni奥氏体不锈耐热钢中碳化物和σ相的析出过程、相变机制及转变速率 ,提供了一种新的研究高温脆性的方法     

Ce-TZP/Al2O3层状复合材料的相变与韧化研究

Ｃｅ－ＴＺＰ（氧化铈稳定四方氧化锆多晶）材料由于剧烈的自催化相变易于产生低应力屈屈服,并在裂纹尖端形成狭长形相变区从而使相变增韧的效果得不到充分的发挥。本工作从改变Ｃｅ－ＴＺＰ材料的微观结构以改变其相变屈服和相变增韧行为的目的出发,在Ｃｅ－ＴＺＰ中引入了层、生状Ａｌ２Ｏ３制成Ｃｅ－ＴＺＰ／Ａｌ２Ｏ３复合材料。研究了ＣｅＴＺＰ直通切口梁试样在三点弯曲试验条件下的自催化相变特征和力学行为,以及Ａｌ２Ｏ     

Effect of Yttrium and Erbium Ions on Epitaxial Phase Transformations in Alumina

The effect of low concentrations of Y, Er, and Cr solutes on the amorphous-to-γ transformation and on the γ-to-α transformation in aluminum oxide has been studied in situ by time-resolved reflectivity. The activation energies of the two transformations with these dopants are the same as in undoped alumina, being 4.1 ± 0.1 and 5.2 ± eV, respectively. Although not affecting the activation energies, Y, Er, and Cr do affect the transformation kinetics. Y and Cr ions decrease the γ-to-α transformation velocity and, over the limited range studied, do so in proportion to their concentration. Concentrations of Er as low as ∼6 ppm retard the γ-to-α transformation and concentrations of 32 ppm essentially stop the transformation occurring within the times and temperatures accessible within the present experiment, thereby preventing quantification of the effect of Er on the α-phase transformation. Erbium also retards the amorphous-to-γ transformation relative to undoped alumina whereas yttrium and chromium accelerate it.     

水泥窑协同处置生活垃圾项目预处理生产线的技术改造评估

本文通过对湖北省某水泥窑协同处置生活垃圾项目技术改造前后的预处理产物进行取样分析，对技术改造效果进行了评估，分析了技术改造前后对水泥窑系统的影响，证明了技术改造后预处理生产线分选效率有效提高，显著改善了预处理后可燃物与不可燃物的品质，技术改造效果显著。     

氯化苯生产的清洁工艺改造

介绍了氯化苯生产过程中"三废"的回收利用改造情况,总结了废水、废气、废渣回收改造的过程、特点和效益,经过改造实现了氯苯生产过程的清洁化和废物的资源化。     

Crack Resistance and Fatigue of Transforming Ceramics: II, CeO2-Stabilized Tetragonal ZrO2

Crack resistance characteristics and fatigue properties have been investigated in Ce-TZP ceramics with different grain sizes. The relatively low critical transformation stress allows the development of larger transformation zones (≦200 μm), leading to flaw-tolerant behavior. However, autocatalytic transformation processes are found to be bound to grain sizes beyond a critical value; transformation is then very limited in finer microstructures. Fatigue as a specific cyclic effect is more pronounced in microstructures with larger grains. Thus, damaging processes in the course of extensive t–m transformation are suspected to be intensified during cyclic loading.