液化气胺处理装置塔设备改造

上海石化股份有限公司芳烃厂,为处理加氢裂化装置中含硫燃料气和含硫液化气,建了胺处理单元,用DEA溶剂脱除燃料气和液化气中H_2S。共设置三台塔器,包括吸收塔、萃取塔和溶剂解吸塔,原设计使用瓷鲍尔环和瓷拉西环填料塔。 运行中液化气质量有波动,特别当原料发生变化时,塔设备适应能力小,影响产品质量。在萃取塔中液化气夹带溶剂量大,同时瓷环易碎,影响塔设备效率,且管道和泵引起阻塞,增加检修次数,既影响平稳生产又增加溶剂损耗。 为提高塔的分离效率,稳定液化气质量,减少单耗和能耗。对塔设备进行改造,用环矩鞍填料和QH-l扁环填料更新原有瓷鲍尔环和拉西环。最终在1991年5月完成改造,经几年运转效果良好。达到预期目标。     

带缺陷液化气球罐安全运行分析

某炼化企业于上世纪70年代建造的2台液化气球罐,投用3个月就发生开裂泄漏,经修复带缺陷运行,在服役30年后,因应力腐蚀开裂报废。本文结合硫化氢应力腐蚀开裂的机理和影响因素,对这两台液化气球罐的运行条件进行了深入分析,给出了液化气球罐运行安全控制建议。     

16MnR(HIC)抗氢钢的评定试验与首次压力容器焊接

中石油重点工程的土库曼斯坦阿姆河右岸天然气处理厂配套的压力容器均由四川油建容器厂制造,其中脱硫脱碳装置的核心设备是四台胺液吸收塔。该设备规格P6.49 MPa,DN 3000×29622,工作介质为高含量S2H、CO2及MDEA溶液,有强烈的硫化氢应力腐蚀开裂倾向,主体材料壁厚72mm和80 mm的16MnR(R-HIC),熔炼分析:w(S)≤0.003%,w(P)≤0.015%,w(Mn)=1.20%～1.35%,且受压元件和对接焊缝应具备抗HIC和SSC性能。四川油建容器厂首次焊接16MnR(R-HIC)压力容器,选择了满足抗氢钢焊接的焊接材料,按照JB4708标准做了六个焊接工艺评定,抗HIC、SSC性能试验合格,满足产品要求和完成制造,至今设备已安全运行三年。     

316L不锈钢在普光净化厂含氯胺液中的应力腐蚀开裂

普光气田净化厂胺液(MDEA溶液)系统大量采用了316L不锈钢材料,设计之初预计集输流程会分离所有氯离子,但实际使用过程中,发现胺液中的氯离子含量逐渐升高,最高达到8 000μg/g。为评估普光气田胺液系统中316L不锈钢的使用安全性,通过模拟工况应力腐蚀试验研究了316L不锈钢在含氯胺液中的应力腐蚀开裂行为。结果表明:胺液具有很好的保护性能,316L钢在高含硫含氯胺液环境中具有很好的韧性,未发生应力腐蚀开裂。研究认为,胺液中的特殊环境,使得具有毒化功能的硫离子被络合,从而避免了发生硫化物应力腐蚀开裂的可能性。而胺液的碱性环境,也使得发生氯化物应力腐蚀开裂的门槛值显著上升。     

环链的机械镀锌

在机械镀的滚筒中,环链与料液能产生合理的流态运动,使筒内处理的环链中每个链节的滑动和转动保证了与冲击介质之间的碰撞,获得合格的机械镀锌层。经两年的生产运行证明采用机械镀锌是环链表面防护处理的一种经济可靠的方法。     

冷芯盒的固化设备——气体发生器

酚醛/氨基甲酸乙脂冷芯盒法用叔胺类材料做催化剂。用于生产的有二甲基乙基胺(DMEA),三乙胺(TEA),三甲胺(TMA)三种。输送胺到芯盒里的动力是气体,被称为载体,它也是固化过程中不可缺少的材料。实际上,干燥的压缩空气、氮气和二氧化碳都可做为载体使用。气体发生器的作用就是把液胺喷射到载体中,并使其雾化,生成胺与载体的混合气,迫使其沿管道进入芯盒里,使树脂砂固化。气体     

压铸铝合金熔炼过程中除渣及精炼除气的分析

压铸铝合金熔炼是压铸生产过程中的一个重要工序,熔炼工艺控制不严,会造成Al液含渣量及含气量增多,并且会使化学成分产生变化,导致铸件产生针孔、氧化夹渣、缩松和化学成分不合格,影响铸件品质。通过对熔炼过程中熔炼前的新旧料配比,熔炼温度,Al液除渣净化、精炼除气等关键工序进行试验研究,确定合理的工艺范围,从而提供优质Al液,最终获得合格铸件。     

铜合金真空差压铸造设备的研制

自主开发了铜合金真空差压铸造设备,对设备主体、升液管结构、中隔板与升液管之间的密封等进行了优化设计,使其满足真空差压铸造铜合金的工况条件,并通过此设备成功制备出合格的金属型端盖铸件以及熔模叶轮铸件.     

胺液吸收塔筒节纵缝焊接工艺

胺液吸收塔主材质为16MnR,是一种低合金高强度钢,其低温焊接性较差.通过采取焊前预热、控制焊接线能量和层间温度、焊后保温缓冷等工艺措施,并采用相应的检测方法,保证了胺液吸收塔的低温焊接质量.     

关于醋酸钠封孔添加剂的研究

在铝合金型材沸水封孔过程中,当SO_4~(2-)超过500mg/L后将使封孔不合格。只是简单进行再封孔处理也不合格。但是添加1％的醋酸钠,在95℃以上再封孔处理15分钟,可以使封孔合格,从而避免了从头返工。再封孔液可以使用纯水,自来水或井水,其使用寿命主要取决于SO_4~(2-)、Cl~-、F~-等强酸阴离子的浓度。醋酸钠封孔添加剂的作用机理是在氧化膜孔中造成局部碱化,使AL~(3+)水解而封孔。     

液化石油气储罐缺陷的超声波监测

在役液化石油气储罐硫化物应力腐蚀开裂、氢鼓泡和氢致开裂等缺陷可能会扩展，需要监控其扩展状况。介绍了针对这些不同类型缺陷的超声波监控方法，总结了超声波监测过程中所必须注意的要点。     

铜精炼过程液化气消耗泛函混沌优化器的设计

基于铜精炼过程中还原阶段的热工机理建立了铜精炼过程液化气消耗真实目标泛函,采用泛函分析与混沌优化算法等理论相结合对其进行融合处理,得出了能计算铜精炼过程中烟气最优升温曲线、最优升温速度曲线以及能实现全局优化的液化气消耗泛函混沌优化器。液化气消耗泛函混沌优化器应用结果表明,除了液化气耗量/t阳极铜降低了9.20%外,铜精炼炉燃烧状况也得到了较好的改善。     

液化石油气贮罐开裂分析及防范措施

某液化石油气贮罐在定期检验中,发现其焊缝内表面存在大量裂纹,通过材质、硬度、宏观、金相等方面的分析,表明,裂纹属于典型的应力腐蚀开裂。通过对应力腐蚀机理、介质环境、应力水平等方面的探讨,分析了该罐发生应力腐蚀开裂的成因,并针对开裂原因有针对性的提出了一些防范措施。     

The Effect of Temperature and Acid Gas Loading on Corrosion Behavior of API 5L X52 Carbon Steel in Amine Unit

The effect of temperature and H₂S concentration on amine corrosion of API 5L X52 carbon steel in a CO₂-saturated 25 wt.% diethanolamine solution was investigated via electrochemical techniques. It was found that increase in temperature from 25 to 80 °C resulted in severe increase in corrosion rate from 0.88 to 16.24 mpy due to increase in degradation rate of amine. Also, it was concluded that increase in H₂S concentration led to increase in corrosion rate because of formation of more heat stable amine salts. The effect of temperature on corrosion rate was more significant than acid gas loading.     

天然气集输管道积液对有机胺缓蚀性能的影响

采用室内动态循环多相流高温高压釜模拟气田集输管线的服役环境,在流速5m/s,有无积液存在条件下进行腐蚀试验、电化学试验和接触角测量,研究了积液对于有机胺缓蚀剂缓蚀性能的影响。结果表明:积液的存在使管材的腐蚀速率增大,相对降低了有机胺缓蚀剂的缓蚀率,且加大了试样发生点蚀的概率。建议合理设计各设施的位置、管线的走向和适当的监测,尽量减少管道的落差,从而减少管道中的积液的形成,同时使用具有一定抗冲刷能力的缓蚀剂。     

Study of corrosion behaviour of A106 carbon steel absorber for CO2 removal in amine promoted hot potassium carbonate solution (Benfield solution)

The CO₂ absorber is one of the largest pressure vessels in ammonia plants, which are suffering from severe corrosion problems worldwide. The aim of the present study is to examine the corrosion behaviour of A106 carbon steel absorber for CO₂ removal in amine promoted hot potassium carbonate solution (Benfield solution). This study simulates CO₂ removal unit in ammonia production process at Abu Qir Fertilizers and Chemical Industries Company (Alexandria, Egypt) and many other plants all over the world. A typical Benfield solution contains hot potassium carbonate K₂CO₃, potassium bicarbonate KHCO₃, diethanol amine (DEA) as a promoter and potassium metavanadate KVO₃ as corrosion inhibitor. The rate of galvanic corrosion of carbon steel absorber/stainless steel pall packings couple in Benfield solution was measured without adding the corrosion inhibitor KVO₃ in order to measure the influence of corrosive solution. The corrosion rate was measured by weight loss technique in relation to different operating parameters such as solution velocity, solution temperature, %K₂CO₃, CO₂ loading, %DEA and the effect of the presence of solution contaminants. In general, increasing solution velocity, solution temperature, %K₂CO₃, CO₂ loading and the presence of solution contaminations increase the corrosion rate. However, the increase in %DEA in solution decreases the corrosion rate. The strong dependence of corrosion rate on both solution and gas velocities indicates the diffusion controlled nature of the corrosion process. In addition, estimation of activation energy revealed a value of 4·8 kcal mol^?1. Surface morphology study depicted the presence of a porous solid film of corrosion products on carbon steel surface. It has been found that the liquid phase diffusion of bicarbonate to the steel solution interface is the rate determining step.     

Corrosion experience with carbon steel in spray absorption FGD plant

Carbon steel is the traditional material for boiler flue gas ducts and stacks. The introduction of flue gas desulphurisation systems in existing power plant units requires major changes in the flue gas system from boilers to the flue stack. In the semidry spray absorption plant at Studstrupværk power plant carbon steel has been used. This concept was chosen to utilize part of the existing carbon steel ducting and avoid the use of expensive high alloyed materials and coating systems. During the first year of operation emission of fine flakes of rust from the ducting and the stack become a major problem. To overcome this, corrosion testings were performed in laboratory and in the plant. The corrosion problems were found to be related to an atmospheric corrosion with hygroscopic chloride containing deposits. The aim of the tests was to establish the critical humidity for corrosion of carbon steel in FGD plant products and deposits. The examinations cover products and deposits from different operational conditions and parts of the Studstrupværk power plant. The laboratory tests were followed by corrosion probe tests in the plant and full scale operation tests with the plant. The results of this programme showed that carbon steel can be used and corrosion can be kept at a very low level by controlling the humidity of the flue gas below 40% RH with fresh water as process water and down to 30% RH with salt water as process water. In practice this has to be controlled by the temperature difference between the flue gas and the adiabatic saturation temperature of the flue gas. Effective insulation of the ducting has been found to be of outmost importance as the humidity should be measured relative to the surface temperature. Experience from the plant shows that the most severe corrosion is found in cold spots.     

Failure analysis of liquefied chlorine condenser

There was a serious blast of liquefied chlorine condenser last year in southwestern China and a few people were killed during the blast. To look for the reason of the explosion, the failed condenser was sampled and investigated through Industrial Computed Tomography (ICT), Scanning Electron Microscopy (SEM) and electrochemical methods. The tube sheet was made of 16MnR, and the tube was made of 10^# seamless steel, while the welding material was J507 welding rod. ICT results showed corrosion in the inner of the tube sheet. Based on the SEM results, it was shown that there was obvious erosion near the inlet of chlorine gas and corrosion at the joint area of tube sheet, tube and welding material was much more serious than that of the other parts. Moreover, the electrochemical tests indicated that the corrosion potential of the tube sheet in 6wt.% FeCl₃ solution was a little more negative than that of the other two parts while in 29.9wt.% CaCl₂ solution the potential of the welding material was more negative than that of the tube. It could be inferred that there existed electrochemical corrosion. At the beginning, local corrosion of tube sheet, tube and welding material of condenser as well as the erosion of the tube interior surface took place. Then the corrosion was speeded up and led to the final failure of the condenser in a very short period after the condenser contacted the mixture of chlorine gas and the CaCl₂ solution contained ammonia, which reacted with chlorine gas to form the explosive NCl₃.     

400m^3液化石油气球形储罐的焊后热处理

介绍了采用内部燃烧法对400 m3液化石油气球形储罐进行焊后整体热处理的过程和操作要领,以及最终达到的热处理效果。     

天然气在吸热式气氛制备上的应用及流量模型的建立

液化气价格的上涨以及其储存站的消防安全隐患,使得天然气替代液化气作为热处理原料气已成为热处理行业发展的趋势.本文针对天然气在吸热式气氛制备上的应用,从工艺原理上进行了理论分析,同时建立吸热式气氛发生装置原料气入口流量模型,为天然气改造工程中管道的选择提供理论依据.