新疆乙烯裂解炉及合金炉管

本文着重介绍国外研制的挤压合金炉管。     

使用新型炉管 实现降本增效

大庆乙烯装置为了实现降本增效,将裂解炉原有的"W"型四程炉管更换为高选择性的"对程U型"炉管,以提高乙烯收率,实现装置效益最大化。     

乙烯裂解炉炉管开裂分析

某厂乙烯裂解炉停车检修时,发现横跨段相关炉管开裂,对炉管缺陷部位进行宏观检查、成分分析、金相分析和扫描电镜断口分析,明确裂纹产生的原因,为该类设备的优化设计和稳定运行提供参考。     

乙烯裂解炉炉管失效分析

针对服役2个月的乙烯裂解炉管开裂情况,从材料成分、微观组织、断口形貌以及温差应力等方面进行分析,得出失效原因——局部超温导致材料劣化引起开裂,并提出了解决措施。     

裂解炉对流段炉管结焦的原因及其对策

ＳＲＴ－Ⅳ（ＨＳ）型裂解炉辐射段炉管和对流段原料／稀释蒸汽混后炉管的结焦,可以通过空气／稀释蒸汽的烧焦来清除,而对流段原料／稀释蒸汽混合前原料在预热管中结焦的现象时有发生,却没有较理想的解决办法。中原乙烯首次尝试把对流段热管割开,从而准确地观察到原料／稀释蒸汽混合前预热管的结焦情况。本文的目的在于描述裂解炉对流段炉管的结焦情况及处理措施,以供各乙烯生产厂参考。     

裂解炉炉管弯曲及断裂原因分析

分析计算了裂解炉炉管受力情况，指出裂解炉自身结构的相互约束力和炉管渗碳是导致炉管弯曲、断裂的主要原因，并提出了相应的措施。     

裂解炉新旧炉管焊接裂纹的产生及预防措施

对裂解炉新旧管焊接裂纹的产生原因进行了分析,并对几种修复焊接工艺进行了对比,提出了预防裂纹的措施。     

论乙烯装置裂解炉辐射段炉管整体更换

对乙烯装置裂解炉辐射段炉管的结构、换管原因、整体更换方法及施工程序等方面进行了较为全面的阐述。     

裂解炉炉管表面温度的测量

介绍了裂解炉炉管表面温度测量的基本原理及温度修正方法。分析了影响测量结果的主要因素:发射率、炉墙内壁的反射辐射和炉内的烟气。提出了炉管表面温度测量的正确方法和具体的测量步骤。     

乙烯裂解炉炉管失效形式及其原因分析研究进展

总结了乙烯裂解炉炉管的失效形式,分析了炉管失效原因。发现乙烯裂解炉炉管失效形式主要表现为弯曲失效、穿孔失效和开裂失效,其失效原因通常表现为多种因素共同作用的结果。     

High-entropy alloy: An alternative approach for high temperature microwave-infrared compatible stealth

To achieve microwave-infrared compatible stealth in high temperature conditions, high-entropy alloys (HEAs) thin films were deposited on Al₂O₃ matrix by magnetron sputtering technology. Films were annealed to investigate thermal stability at 500 °C, 600 °C and 700 °C, respectively. Results from X-ray diffract meter (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), and Fourier transform infrared spectrometer (FTIR) suggested that high-entropy alloy (HEA) film was seriously oxidized when the annealed temperature reached 700 °C for 6 h, causing a significant decrease of infrared reflectivity. Conversely, HEA films showed low infrared emissivity of 0.09 at 600 °C. Additionally, the films possessed excellent thermal stability at 500 °C for 20 h with low infrared emissivity of 0.11. Finally, a simple metamaterial design utilizing HEA films was proposed for infrared-microwave compatible stealth. With the ability of incorporating excellent thermal stability and durable high temperature stealth performance, the study shows great potential of introducing HEAs in the field of high temperature compatible stealth.     

Ni45Cr17Al镍基合金在焚硫炉测温装置上的应用

主要介绍了硫磺制酸中几种焚硫炉测温热电偶的材质及使用情况,分析了热电偶易发生故障的原因。通过对几种材料的应用实践,选用镍基高温变形合金材料(Ni45Cr17Al)作保护套管,很好地解决了焚硫炉测温热电偶易坏问题。该热电偶可准确测量焚硫炉温度,为装置长周期稳定运行提供了保障。     

High temperature resorcinol-based phthalonitrile polymer

Resorcinol-based phthalonitrile, 1,3-bis(3,4-dicyanophenoxy)benzene, has been synthesized in high yield by a simple nucleophilic displacement of a nitro-substituent from 4-nitrophthalonitrile in a dipolar aprotic solvent. The monomer can be thermally polymerized to a network polymer in the presence of an amine curing additive. The resin is readily processed in a controlled manner as a function of temperature and quantity of additive. Thermal analyses and rheology studies were used to characterize the high temperature thermosetting phthalonitrile polymer.     

反应烧结SiC材料的高温氧化行为研究

研究了反应烧结SiC材料在 110 0℃空气中的高温氧化行为。结果表明 :反应烧结SiC在110 0℃的氧化动力学曲线符合抛物线规律 ;材料的氧化受O2 和CO在玻璃态硅酸盐中的扩散所控制 ;材料中的杂质元素降低了SiO2 氧化膜的粘度 ,促进了O2 和CO在氧化膜中的扩散     

高温绝缘涂料及其应用举例

介绍一种能耐高温和绝缘的涂料及应用于汽车点烟器发热线圈是热丝表面绝缘处理工艺,其工艺简单,高温下绝缘效果良好,符合设计要求。     

机制盘香粘合剂研发

为配合专用盘香加工机的普及使用,研发了机制盘香粘合剂.对盘香加工设备进行了简要说明,对影响盘香性能的主要因素包括粘合剂配方、木粉和粘合剂比例、干粉和水的比例等进行了分析,得到了理想的配比和工艺参数.该粘合剂已经实现工业化生产.     

High temperature stiffening of ferroelastic LaCoO3

The cyclic ferroelastic hysteretic behavior of pure LaCoO₃ perovskite ceramic has been studied at different temperatures in four point bending. The stress-strain deformation behavior of LaCoO₃ was analyzed both in the term of the maximum stress in the cycle and in terms of the temperature used when the cyclic testing was performed. The characteristics of the stress-strain hysteresis loops, such as hysteresis loop area and irreversible strain, as well as effective Young’s modulus, were analyzed, and it was established that both the loading and the temperature history have a significant influence on the mechanical behavior of LaCoO₃. Young’s modulus values are reported to be much higher in the 700–900 °C temperature range as compared to the measurements performed in the RT-400 °C temperature range.     

裂解炉出口温度控制技术的优化

通过对大庆乙烯装置80-U型裂解炉出口温度(COT)测量方式进行优化及改进,提高了对裂解深度的控制程度,进而改善了裂解炉日常的运行状况,达到了提高乙烯产品收率的目的。     

合金结构钢常温电化学发黑工艺研究

采用电化学的方法在合金结构钢表面形成一层黑色氧化膜。探讨了温度,时间,电流密度和添加剂等因素对膜层硬度和厚度的影响。该工艺简单,所得发黑膜硬度高,耐蚀性好。     

High temperature mechanical properties of porous Si3N4 prepared via SRBSN

The high temperature strength and fracture behavior of porous Si₃N₄ ceramics prepared via reaction bonded Si₃N₄ (RBSN) and sintered reaction bonded Si₃N₄ (SRBSN) were investigated at 800–1400?°C. The weight gain after oxidation for 15?min and the microstructure of the edge and center of the fracture surface clearly show that the internal oxidation of porous SRBSN is unavoidable with porosity of ~ 50% and mean pore size of 700?nm. The oxidation of Si₃N₄ and intergranular Y₂Si₃O₃N₄ phase may responsible for the high temperature strength degradation of SRBSN. Porous Si₃N₄ ceramics prepared with addition of 1?wt% C showed low strength degradation at temperature >?1200?°C.