尿素装置水解系统解吸塔计算分析

计算和霜尿素装置水解系统解吸中设计工况和实际操作工况,就排放水中氨含量超标的问题,提出了切实可行的改造方案。     

解吸塔及蒸氨塔的改造与计算

通过解吸塔和蒸氨塔的改造实例，应用模拟计算结果，讨论了它们各自的不同流程设计及特点。比较和分析了不同改造要求下的各设计方案。     

高效规整填料在尿素解吸塔的应用

尿素装置联产三聚氰胺后，解吸系统需处理的工艺冷凝较量大幅增加。为确保废水达标回收，将解吸塔结构由浮阀塔肋改为ZUPAK高效规整填料，实现了废水达标回收。     

计算塔板板效率的局部贡献法

<正>引言 塔径较大的塔板上液体流动的不均匀性对板效率的影响早已引起了人们的注意,在大型塔板上,由于气液两相的剧烈湍动,致使不同区域液体的流动各不相同,如果只采用单一形式描述塔板上液体的运动特点,未免有失普遍性。因而,本文将在分析塔板上液体运动特点的基础上,提出一种新的计算模型,力求更好地符合实际情况。1 实验现象 塔板上流体力学的测定是在前已述及的装置上进行的,用热膜风速仪直接测定了塔板上气液两相流场的分布,发现不仅塔板弓形区存在返混,而且塔板入口堰附近一段距离内,液体也存在返混,其具体长度随液流强度、气相负荷以及出口堰高度等因素而异。采用逐步回归分析方法对实验数据进行回归,得到入口堰返混段长度关联式     

解吸塔及蒸氨塔的改造与计算

我国目前尿素装置多采用水溶液全循环法生产工艺。在生产过程中会形成一定数量的含NH3 5％～8％的稀碳铵液，浓度太低不能利用，直接排放既污染环境又损失氨。国家废液排放标准中要求含NH3≤0．07％(质量百分数，下同)，随着人们对环保要求的重视，有些地方排放废水中含氨     

有机胺法脱硫系统中解吸塔再沸器选型研究及应用

介绍了有机胺法脱硫系统中再沸器的工作原理,对管壳式再沸器、板式再沸器的结构形式及优缺点进行了分析和比较,并结合相关工程实例,展示了不同形式再沸器的实际选型及应用情况。板式再沸器与管壳式再沸器相比,经济性及易于扩容的优势比较突出,更加适用于有机胺法脱硫系统。     

尿素解吸塔改造小结

0　前　言我公司老系统采用水溶液全循环尿素生产工艺 ,由于历史、技术的局限性 ,在对工艺冷凝液的处理及回收时只采用了解吸系统。经这种老式的解吸系统处理后的工艺冷凝液中仍含有 7%的氨和 1 %～ 2 %的尿素。同时 ,我公司老系统尿素装置经过技术改造后 ,生产能力由 1 1 0 kt/a提高到了 2 0 0 kt/a,而技改中只对一些关键设备进行了扩改 ,工艺冷凝液系统改动不大 ,因而出现了解吸废液排放超标 ,造成环境污染以及尿素装置氨耗偏高等情况。在目前国家环境保护标准与规范日趋完善和严格的情况下 ,改造工艺冷凝液系统已迫在眉睫。为此 ,公司于 …     

硫酸钾装置中HCl解吸塔材质的选用

分析了整体玻璃钢、钢壳衬瓷板、钢体衬橡胶板再衬石墨板3种材质的氯化氢解吸塔使用情况。实践证明，钢体衬橡胶板再衬石墨板解吸塔应用效果良好。     

新型复合保冷结构在二氧化碳解吸塔上的应用

分析砌块型、浇注型两种常用保冷施工方法的优缺点，提出一种新型复合保冷结构，并叙述了该保冷结构的施工要点。     

环流预汽提组合旋流快分系统粒级效率的三区计算模型

在大型提升管冷模实验装置上,系统地考查了带有环流预汽提的旋流快分(CVQS)系统的气相流场和粒级效率。结果表明,随着旋流快分系统喷出口气速的增加,粒径小于7 μm颗粒的粒级效率的变化较小,7～20 μm颗粒的粒级效率逐渐变小,而超过20 μm颗粒的粒级效率则逐渐增大。根据CVQS快分系统的气固分离原理和结构特点,建立了计算CVQS系统粒级效率的三区模型。计算结果表明,在颗粒粒径大于20 μm时,模型预测的粒级效率与实验值吻合较好,其最大相对偏差不超过6.1%;在颗粒粒径小于20 μm时,模型计算的粒级效率与实验值相差较大,其相对偏差在45.7%～80.3%之间变化,并且随着颗粒粒径的减小,其相对偏差逐渐增加。模型对于主要用于分离20 μm以上颗粒的CVQS系统的工程设计,具有重要参考价值。     

Gas and solids mixing in a dynamically scaled fluid coker stripper

Gas mixing and solids mixing were studied in a geometrically and dynamically scaled cold model fluid coker stripper. Tracer gas (helium) was first injected into the stripper standpipe to quantify total gas entrainment into the underflow stream. Tracer gas was then injected into the upper reactor and lower stripper separately to investigate gas mixing in the stripper. The stripping efficiency was found to depend strongly on operating conditions (solids circulation rate, stripping gas velocity) as well as on the baffle configuration in the stripper. Unsteady state measurements were also obtained in an effort to understand gas dispersion in the stripper. The results show that gas mixing is most intensive in the stripper core. To study solids mixing and residence time distribution in the stripper, solid tracer particles impregnated with salt were injected into the reactor and detected at the top of the stripper and standpipe. The results indicate that axial dispersion of solids in the presence of the baffles could be represented by axially dispersed plug flow.     

1,4-丁炔二醇汽提塔塔顶节能改造

1,4-丁炔二醇汽提塔塔顶气相为350 kPa左右的饱和蒸汽,直接进入冷凝器与循环水进行热交换,浪费了其中大量的潜热。通过在1,4-丁炔二醇汽提塔塔顶增加废热锅炉,使塔顶蒸汽中所含有的潜热得到了充分的利用,生成了二次蒸汽,节约了能源,达到经济效益、环保效益、安全效益三赢的目的。     

Transfer efficiency for airless painting systems

Spray transfer efficiency (TE) is defined as the mass fraction of sprayed paint which is deposited on the intended target, the remainder of the sprayed paint becomes undesirable overspray. The relationship between TE and gun supply pressure (or paint mass flow rate), gun-to-target distance, gun traverse speed, the angle of the spray gun relative to the target (gun-to-target angle), plus spray cone angle is reported herein for a typical fan spray system. Experimental results indicate that spray momentum rate (SMR) and droplet size dictate the TE for the various combinations of parameters considered here. The key finding is that TE correlates with SMR and spray mean drop size (Sauter mean diameter, or D₃₂) via an expression of the form TE=a+b SMR − c (SMR)²+d D₃₂, where a, b, c, and d are coefficients, determined by fitting the experimental data, and SMR is estimated via SMR=m²/ρA, where the paint mass flow rate m, the paint density is ρ, and the gun exit orifice effective tip cross sectional area is A. This expression accounts for physical phenomena that govern sprayed droplet deposition characteristics, such as entrainment, bounce-back, and drop size. Experimental results also show that, for the range of parameters studied, gun traverse speed has no effect on TE, but increasing the angle of the spray gun relative to the target (gun-to-target angle), increasing the spray cone angle, or increasing the gun-to-target distance will decrease TE.     

用于镀锡钢板的水性脱漆剂的研制

针对用于食品罐的镀锡钢板表面的白涂、金属油墨和罩光清漆样板研制一种水性脱漆剂。当苯甲醇的质量分数为35%、丙二醇碳酸酯质量分数为6%、甲酸质量分数为10%、十六烷基三甲基溴化铵(CTMAB)质量分数为2%、蒸馏水质量分数为47%时,所得脱漆剂脱漆效率最高。该脱漆剂含有一定水组分,挥发性小,不易燃烧。扫描电镜检测表明该脱漆剂对镀锡钢板的腐蚀性较小。     

搬迁项目设备搬迁费用的计算

介绍了设备搬迁费用的含义,对设备搬迁费用的计算提出了建议;并结合某搬迁项目举例计算出某个设备的搬迁费用。     

Capital costs and energy considerations of different alternative stripper configurations for post combustion CO2 capture

Capturing and storing the greenhouse gas carbon dioxide produced by power plants and chemical production plants before it is emitted to the atmosphere will play a major role in mitigation climate change. Among the different technologies, aqueous amine absorption/stripping is a promising one. In this study, five different configurations for aqueous absorption/stripping have been compared with regards to capital investment and energy consumption. The process simulations are made with the use of Unisim Design and ProTreat, while for the cost calculations, data from Turton et al. (2009) and Sinnott and Towler (2009) are used.We cannot identify one single configuration to be the optimum always for all situations, as it depends on many parameters like energy and material costs, interest rate, plant complexity, etc. With the assumption and estimated parameters in this study we find that vapor recompression configuration is the best configuration because it has the lowest total capture cost and CO₂ avoided cost. In addition, the plant complexity does not increase very much compared to the benchmark. The split-stream configuration with cooling of semi-lean amine is the second best. However, this configuration increases the investment cost and plant complexity significantly.The effect of heat integration between the compression section and the stripper is also considered. We can reduce heat requirement by heat integration, but since the inlet temperature to the compressors become higher, the compression efficiency will decrease and compression work will increase. In addition, the capital cost and the complexity of the plant will increase. Because of the higher inlet temperature the water content of produced CO₂ is higher and consequently the corrosion problems is more serious in pipes and equipment for compression and injection section.     

塔板全导流装置导流条长度计算法

提出了塔板全导流装置导流条长度的计算方法。实际应用表明 ,这种计算方法可以使下料精确可靠。     

尿素装置氨汽提塔工况的优化

分析了影响尿素装置氨汽提塔汽提效率的因素,并结合实际生产总结经验,优化操作,改善氨汽提塔工况,提高汽提效率。     

原煤可选性评定新方法——特定数量效率法

分析了现行几种煤炭可选性评定方法的适用范围及其局限性 ;提出采用特定条件下的数量效率作为煤炭可选性的评定方法。该方法可以克服现行评定标准存在的各种问题 ,适用于所有原煤在任何分选密度下的可选性评定 ,科学而简便 ,并且不会出现偏差。