加氢精制反应器的腐蚀与防护

由于加氢精制装置操作条件的特殊性,加氢精制反应器有可能出现一些如氢脆、氢腐蚀、不锈钢堆焊层的剥离等特殊的损伤现象。为避免这些破坏性损伤的产生,加氢精制反应器必须要有正确的设计与选材,并且合理使用,从而保证设备的使用安全。     

加氢精制反应器检验与分析

在加氢精制反应器全面检验中,使用超声测厚、无损检测和金相等方法,对该设备进行检验和评价。通过对检测结果的分析,得到加氢精制反应器损伤原因,为加氢精制反应器的设计、制造和检验提供参考。     

对苯二甲酸加氢精制反应器的数学模拟

分析了对苯二甲酸加氢精制固定床反应器的传质特性,在对反应器进行合理简化后,建立了对苯二甲酸加氢精制反应器的非均相一维平推流数学模型,对有关物性数据和模型参数进行了计算.利用该数学模型对工业装置对苯二甲酸加氢精制反应器进行了模拟计算,计算了各组分沿反应器床层的浓度分布.模拟结果与实验数据相吻合,说明建立的数学模型是可信的.     

加氢反应器床层压降升高的原因及处理

首先叙述了汽柴油加氢装置反应器床层压降升高的经过,通过具体分析认为原料中所含的焦粉过和二烯烃是导致床层压降上升的主要原因,其次介绍了相关应对措施及实施效果,最后总结出类似事故的处理建议。     

磷铵管式反应器流动状况的实验研究

通过对不同液速、气速、管径、安装形式、流体物性与流体之间关系的研究,提出磷铵管式反应器的流动可用Pe=20～50之间的扩散模型来描述;液速对返混的影响远大于气速;竖直安装比水平安装增大返混20％～30％;粘度变化虽使流速对Pe的影响发生逆转,但在管式反应器操作液速范围内,没有数量级的差别。     

滴流床反应器中泡沫流床层压降的实验研究

选用过氧化氢生产用蒽醌工作液体系,完成了滴流床反应器中泡沫流床层压降的实验研究. 通过测定瞬时床层压降,建立了反应器内的流型识别方法,借以研究了在泡沫流和泡沫脉冲流区的床层压降梯度与气液相流速、填料尺寸的关系,并采用Specchia和Baldi提出的经验式对发泡体系泡沫流区床层压降进行了估算. 结果表明,通过实验数据回归,可采用Specchia和Baldi经验式预测泡沫流区的床层压降,最大偏差小于5%.     

PTA加氢精制反应过程研究项目通过鉴定

20 0 4年2月,由扬子石油化工股份有限公司承担的中国石化集团公司精对苯二甲酸(PTA)入世攻关项目的子项目———“PTA加氢精制反应过程研究”通过了中国石化集团公司的技术鉴定。与会专家听取了“PTA加氢精制反应过程研究”的研究报告,一致认为,该项目研究中采用的实验手段属国内首创,反应器模型开发成果填补了我国PTA工艺研究空白。该项目研究成果对于PTA国产化工艺软件开发及现有PTA生产装置的工艺优化和技术改造具有重要价值,也为进一步研究开发PTA成套生产技术奠定了坚实基础。PTA加氢精制反应过程研究项目通过鉴定@郑宁来!通…     

蜡油加氢精制-临氢降凝单反应器工艺试验

采用加氢精制-临氢降凝单反应器工艺,以某炼油厂蜡油为原料生产润滑油基础油。结果表明,该工艺能够达到很好的降凝效果,产品370℃润滑油馏分的凝点为-10℃,收率为79.4%,工艺副产少量轻柴油、粗汽油及石油液化气,工艺主要产品为高粘度的润滑油馏分,其凝点降到-10℃以下,副产少量轻柴油、粗汽油及石油液化气。     

管式固定床反应器柱状颗粒床层流体流动模拟与实验研究

针对管式固定床反应器内管束数量多、规模大等特点,选取单个管束作为特征结构。对装填不同直径柱状颗粒的管束,采用程序坐标定位的方法,建立柱状颗粒床层的物理模型。采用DEM与CFD联合数值仿真方法,探究反应管内径与柱状颗粒的等比表面积球当量直径之比(管径比Di/dp)对柱状颗粒床层流体流动的影响,并建立单管固定床反应器试验台,采用差压测试方法进行实验研究。结果表明,当Di/dp由5.37增至12.75时,床层空隙率和流体分布均匀性均得到改善,壁面效应的影响由床层中心减弱到管壁。基于数值模拟及实验结果对Di/dp=12.75的柱状颗粒床层进行床层压降Ergun公式常系数修正,CFD模拟计算的结果与拟合公式吻合较好。研究结果能为固定床反应器压降预测提供参考。     

泰勒反应器应用技术进展

作为基于泰勒涡流原理制得的一种新型反应器,泰勒反应器得到了日益广泛的应用,呈现出良好的发展前景。本文讨论了内圆筒转速、轴向流速、半径比及纵横比等操作参数对泰勒反应器性能的影响,综述了泰勒反应器在颗粒制备、光催化降解、生物培养等领域的应用现状,针对气体通入影响、流动特性改进、反应器放大等应用问题提出了相应解决办法,并指出寻求合理的反应器放大方法以及对反应器放大后进行稳定性和可靠性研究是该领域今后研究的重点。     

Radial pressure profiles in a cold‐flow gas‐solid vortex reactor

A unique normalized radial pressure profile characterizes the bed of a gas‐solid vortex reactor over a range of particle densities and sizes, solid capacities, and gas flow rates: 950–1240 kg/m³, 1–2 mm, 2 kg to maximum solids capacity, and 0.4–0.8 Nm³/s (corresponding to gas injection velocities of 55–110 m/s), respectively. The combined momentum conservation equations of both gas and solid phases predict this pressure profile when accounting for the corresponding measured particle velocities. The pressure profiles for a given type of particles and a given solids loading but for different gas injection velocities merge into a single curve when normalizing the pressures with the pressure value downstream of the bed. The normalized—with respect to the overall pressure drop—pressure profiles for different gas injection velocities in particle‐free flow merge in a unique profile. © 2015 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 61: 4114–4125, 2015     

Nature and characteristics of gas–liquid flow regimes in a micro-packed bed reactor

Micro-packed bed reactors (μPBRs) have the advantages of high heat and mass transfer efficiency and excellent safety, and they have been successfully applied to hydrogenation and oxidation reactions. However, the study of gas–liquid flow regimes in the μPBR, which is essential for the mass transfer modeling and reactor scale-up, is still insufficient due to the limitation of micro-scale and complexity of capillary force. In this work, the flow regimes in the two-dimensional μPBR were systematically studied by visual method utilizing a high-performance camera. Four typical flow regimes and characteristics were captured, and flow regime transition was revealed. Effects of gas and liquid superficial velocities, liquid physical properties, and particle sizes on liquid spreading areal fraction and pressure drop were investigated. Flow regime transition correlation of churn flow and pseudo-static flow in the μPBR was provided for the first time based on the summary of the current and previous published results.     

Pinched tube flow reactor: Hydrodynamics and suitability for exothermic multiphase reactions

A novel tubular flow reactor where a straight tube is modified by pinching it periodically at a fixed pitch and at different angles is presented. Pinched tubes (straight tube as well as helical coils) with different pitch and angles between successive pinching are studied. This work reports a detailed hydrodynamic study involving single and two‐phase flow. Mixing experiments showed that having an angle of 90° between successive pinchs achieves the shortest mixing length when compared to lower angles. Pressure recovery along with sequence of high and low shear zones and change of flow direction imposed better mixing. Residence time distribution studies showed that higher number of pinch sections decreases the extent of dispersion, yet it deviates from plug flow. The performance is evaluated by carrying a homogeneous and two‐phase aromatic nitration and also liquid‐liquid extraction. Pinched tube presents an economical option as a flow reactor for conducting exothermic reactions. © 2016 American Institute of Chemical Engineers AIChE J, 63: 358–365, 2017     

Hydrodynamics and flow regime transition study of trickle bed reactor at elevated temperature and pressure

The hydrodynamics in a trickle bed reactor (TBR) in non-ambient conditions are studied for air-water and air-acetone (pure organic liquid of low surface tension) systems. A flow map experiments for air-water and air-acetone systems are performed in a pilot plant reactor of 0.05 m i.d. and 1.25 m height. It has been demonstrated from the experimental results that the pressure drop tends to increase with increasing superficial gas and liquid velocity and reactor pressure, while it tends to decrease with increasing bed temperature. The results also show that the dynamic liquid holdup increases with increasing liquid velocity and decreases with increasing superficial gas velocity, reactor pressure and bed temperature. The dynamic liquid holdup and pressure drop values are obviously higher than those measured for air-water system at the same fluid fluxes, reactor pressure and bed temperature due to the surface tension effects. For higher reactor pressure and temperature, the trickle to pulse transition boundary shifts towered higher superficial velocities of both gas and liquid.     

Flow regimes and pressure drop of a composite tridimensional rotational flow sieve tray under concurrent gas-liquid flow

A composite tridimensional rotational flow sieve tray (CTRST) is proposed. The flow patterns of CTRST were visually categorized, combined with the standard deviation of the pressure difference. In the TRST area of the internal packing-type tray, the membrane-drip column and foam-embolic flow is present, while bubbly and milk froth-ribbon flow is present in the packing area of the external packing-type tray. The effect of the tray structure parameters on the pressure drop under co-current flow was investigated. The dry and wet pressure drop is within 160 and 900 Pa, respectively. Under the same structural parameters, the pressure drop of the internal packing-type tray was higher than that of the external packing-type tray. The flow characteristics of the standard tray under the countercurrent flow were compared. The CTRST was found to be more suitable for co-current flow. A prediction model pressure drop under co-current was established with an error of 15.5%.     

圆盘反应器的流动模型

剖析了圆盘反应器的流型及其影响因素,指出圆盘反应器的虚拟级数N应为盘数;讨论了反应器中熔体流动过程中存在多次的动量、能量的传递;由于反应器结构上存在死角和短路,其F(t),E(t)并非理想状态。对反应器气相流动作了简述。     

油水混合物在水平管中的二相流动特性研究

对内径40mm的钢管和有机玻璃管内油水二相水平流动时的流型、摩擦压降特性进行了详细的实验研究,结果表明:油包水向水包油的转变发生在含水体积分数约0. 4时。随含水体积分数的增大,油水二相流的摩擦压降先是急剧减小,其后在含水体积分数大于0. 4时压降变化趋于平缓。油水二相流的摩擦压降受含水体积分数、管壁润湿特性、管壁粗糙度以及混合物流速的影响,当二相流体处于水包油状态时,钢管内的摩擦压降比有机玻璃管内的大;而当处于油包水时,有机玻璃管内的摩擦压降则比钢管内的摩擦压降大。     

分段组合式厌氧生物反应器流态特性

厌氧生物反应器高效性与稳定性取决于其流态特性的优良,采用示踪剂脉冲刺激响应技术研究了自主研发的分段组合式厌氧生物反应器的流态,以期揭示其高效机理,便于工程化开发与应用。试验结果表明:常负荷下该反应器的流态趋于平推流;以轴向扩散模型表征,不产气与产气工况下的Peclet数分别为7.94和5.66;以多釜串联模型表征,不产气与产气工况下的串联釜数分别为4.55与3.44。高负荷与超高负荷下该反应器的流态趋于全混流,以轴向扩散模型表征,不产气与产气工况下的Peclet数分别为4.02、2.57和3.93、3.77;以多釜串联模型表征,不产气与产气工况下的串联釜数分别为2.66、2.00与2.62、2.51。反应器总死区的平均值为33.58%,其中水力死区的平均值为13.58%。建立了水力死区V_h(%)与容积水力负荷L(m³·m^-3·d^-1)和容积产气速率G(m³·m^-3·d^-1)之间的关联式。值得注意的是,在分段组合式厌氧反应器中,容积产气速率对水力死区的影响小于容积水力负荷。