射流鼓泡反应器内气泡分布特性

采用气体分布盘和缩径式液体喷嘴的射流鼓泡反应器冷模实验装置,以空气-水作为模拟体系,考察了表观气速(ug)和喷嘴出口液速对气泡分布特性的影响。实验结果表明,在不同ug下,平均气含率均随着喷嘴雷诺数(Re_j)的增大而增大,平均气含率经验关联式计算值与实际值的平均相对偏差为8%。射流鼓泡反应器中心处气含率较高,边壁处气含率较低;随着Re_j的增大,气含率最高点向壁面方向移动,径向气含率分布趋于均匀。随着Re_j的增大,气泡具有不同的运动轨迹和分布状态,从类似字母"C"逐步演变为类似字母"B"和"A"。     

Structure optimization of gas-liquid combined loop reactor using a CFD-PBE coupled model

Flow characteristics, such as flow pattern, gas holdup, and bubble size distribution, in an internal loop reactor with external liquid circulation, are simulated to investigate the influence of reactor internals by using the computational fluid dynamics (CFD)-population balance equations (PBE) coupled model. Numerical results reveal that introducing a downcomer tube and a draft tube can help to improve the mass and heat transfer of the reactor through enhanced liquid circulation, increased gas holdup and reduced bubble diameter. The hydrodynamic behavior in the internal loop reactor with external liquid circulation can be managed effectively by adjusting the diameter and axial position of the draft tube.     

采用氙气的鼓泡床流体力学特性研究

Xenon was used as gas phase to investigate the hydrodynamic characteristics in a bubble column. It was found that the flow pattern is mainly in the churn-turbulent flow regime by analysing the relationship between the slip velocity and gas holdup. The influences of operating conditions on the gas holdup and Sauter mean diameter were studied. The experimental results show that the Sauter mean diameter decreases with the increase of energy dissipation rate. A new correlation was developed to predict the Sauter mean diameter with an average error less 15%.     

柴油加氢反应器泡罩开裂失效分析

通过对三联合加氢反应器分配器内泡罩开裂的失效分析,初步探明了泡罩的失效原因,可供大型泡罩的设计、制造和使用者参考.     

Structure of the bubble layer in an asphalt oxidation tower

Based on published data on the air bubble rise velocity in water and using methods of similarity theory and mathematical tools for calculating precipitation processes and surfacing of solid particles in a liquid, the structure of the bubble layer in a tower for production of oxidized asphalts was analyzed. A conclusion was drawn concerning the existence of an ascending gas ”liquid stream in the central part of the bubble towers and a descending liquid stream near the walls. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 26–27, March–April, 2006.     

Simulation of catalyst on-line replacement for Fischer-Tropsch synthesis in slurry bubble column reactor

A multi-phase dynamic model has been developed for Fischer-Tropsch synthesis in a slurry bubble column reactor operating in a heterogeneous flow regime. The catalyst particles concentration distribution, deactivation, and on-line replacement were considered in this model. The population balance equation model has been utilized to calculate the catalyst age distribution. Based on the dynamic model, the process of catalyst replacement has been investigated, and the effect of catalyst replacement on the design and operation of the reactor has been studied. A correlation between the catalyst replacement rate and the catalyst activity has been developed in this research [ A_C = ( 1 - a_￥ )e ^{- k_dt} + a_￥ ] \left[ {{A_C} = \left( {1 - {\alpha_\infty }} \right){e^{ - {k_d}t}} + {\alpha_\infty }} \right] .     

加氢反应器堆焊层铁素体含量对焊接工艺的影响

阐述了不锈钢堆焊层中铁素体的存在对焊缝的影响以及测定铁素体含量的方法,研究了化学分析和磁性2种测量方法测得的铁素体含量的差异及焊接参数对铁素体含量的影响。     

薄层固定床反应器中甲烷氧化偶联反应热效应的研究

研究了甲烷氧化偶联制乙烯强放热反应在催化剂装量为２００ｍｌ的薄层床中的起燃条件、甲烷空速、ＣＨ４／Ｏ２比、床层高度、反应时间等与床层温升和催化剂活性的关系，得出在床层高度为３０～５４ｍｍ的薄层床中，反应可平稳地进行，反应的最高温区在气体进催化剂层人口以下１５～３０ｍｍ内，床层厚度的增加对Ｃ２收率影响不大，但Ｃ２选择性下降。床层最高温度随甲烷空速升高而增加，最高温区增宽。ＣＨ４／Ｏ２比增加温度降低，Ｃ２选择性增高。用预热与加强保温的办法，该反应在薄层床反应器中可能实现自热反应。     

水冷等温列管甲醇合成塔中绝热层设置的探讨

通过对水冷等温列管甲醇合成塔中催化剂绝热层设置的优缺点进行分析,探讨设置催化剂绝热层的可行性。     

Heat transfer of a liquid-film-covered bubble

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 3, pp. 22–25, March, 1995.