年产7万吨聚丙烯装置仿真培训系统环行管状反应器建模

介绍了年产７万吨聚丙烯装置主要工艺设备－－环行管状反应器仿真培训模型的建立。     

聚丙烯环管反应器的模拟与参数在反应器内的分布

本文以实际运行的聚丙烯环管反应器为基础，分析了物料在反应器内的流动特性，建立了数学模型。通过对模型的求解，得到了固含率、物料浓度、床层温度和冷却水温度等参数在反应器内沿物料流动方向上的分布。计算结果与实际数据的拟合较好，为聚丙烯反应器的优化操作提供了依据。     

泡沫塑料熔体粘度的研究

在塑料熔体的发泡成型过程中,熔体的粘度是基本的流变性能之一,粘度影响到气泡的成核和长大,是制定发泡成型工艺和原料配方即设计发泡机头的重要依据,带有发泡剂的塑料熔体的粘度是温度、剪切速率和熔所含发泡剂种类、浓度及分布状态等的函数,对含有化学发泡 以ＣＯ２为发泡剂的泡沫塑料熔体粘度分别进行了探讨,介绍了相应的计算公式,分析了其影响因素 。     

橡胶介质中发泡剂分解特性测试方法的研究

建立了一种测试发泡剂在橡胶介质中分解特性的方法。采用的装置是由ＸＬＹ－Ⅱ型毛细管流变仪改装而成的，可记录恒压下等速升温或恒温时胶料的发泡曲线，测得发泡剂在橡胶介质中的起始分解温度、发气量和分解速度，具有实用和理论意义。     

发泡剂AC的热分解活化机理及影响因素*

采用动力学和热力学相结合的方法,用自行设计的发泡剂发气量测量装置研究了重金属盐、金属氧化物、有机酸及其盐等对发泡剂ＡＣ热分解特性的影响;用ＤＳＣ差示扫描量热仪测定了各体系的动态分解温度和热效应。结果表明,三盐基硫酸铅、二盐基亚磷酸铅、硬脂酸铅和柠檬酸对发泡剂ＡＣ都有较强的活化作用,属于加速型发泡助剂;氧化锌是发泡剂ＡＣ较理想的活化引发剂,当其用量为０１份时,活化作用较好;而硬脂酸、硬脂酸钡和柠檬酸钠的活化作用较小,属于延缓型发泡助剂     

中心气升式气-固环流反应器与自由流化床流动特性对比

对中心气升式气固环流反应器和自由床流化反应器的流动特性进行了对比. 结果表明,在同样的操作条件下,在轴向高度h=112~512 mm范围内,环流反应器导流筒区的径向不均匀指数RNI比自由床的RNI减小27%~36%;与自由床相比,环流反应器导流筒区的局部不均匀指数减小20%~59%,整体不均匀指数减小17%~43%,环流反应器的流化质量较高;环流反应器导流筒区和自由床内均存在气体返混现象,导流筒区各采样点示踪气体的浓度和轴向扩散系数Da,g比自由床均有所降低,在表观气速0.2~0.4 m/s范围内,导流筒区Peclet准数的绝对值比自由床增大12%~58%,说明导流筒区气体返混程度小于自由床,气-固两相流向上的宏观流动可有效抑制气体的轴向返混.     

ADC发泡剂干燥工艺的改进

阐述我国目前ＡＤＣ发泡剂干燥工艺的过程,剖析当前生产技术中存在的问题,并提出改进措施。     

加氢反应器配管设计重点

通过对加氢装置中加氢反应器的平面布置、反应器构架及平台的设置、反应器管嘴的开口方位、反应器的管道布置及支架设置方式等方面进行了详细的阐述,总结了加氢装置反应器配管设计的重点。     

HFC-134a反应器的设计

大直径不带法兰的立式列管固定床HFC-134a反应器材料和加热方式的选择,以及各主要部件结构的设计特点。     

塑料网套专用LDPE树脂结构与性能的研究

分析了发泡工艺过程及其对原料的要求,对发泡网套用低密度聚乙烯(LDPE)2420H的结构性能、流变性能进行了分析研究,并与进口产品进行了对比。结果表明:2420H的重均分子量较小,分子量分布较窄,支化度低于对比样,使得2420H的熔体强度较低,熔体黏度较小,导致制品回弹性损失过快,需适当提高2420H的支化度以增加熔体强度。     

Subtitution of Pentane by a Mineral Clay as a Blowing Agent for Phenolic Foam

The main drawback of using pentane as a blowing agent for rigid phenolic foam is its flammability. It presents a real risk of explosion and therefore requires specific conditions for handling and storage. In this article its replacement by a mineral clay composed mainly of calcium carbonate as the major component in addition to some other metal oxides, was investigated in terms of performance requirements. The proposed formulations contained instead of pentane different proportions of the clay and a mixture of toluene sulphonic acid and sulfuric acid. It was found that, except for a slight increase in the thermal conductivity, all other properties such as foam density, water absorption, permeability to water vapor, compression resistance, and flexural resistance were within the plant specifications. To complete the study, it is recommended to investigate possible adverse long-term effects in terms of chemical resistance and foam morphology.     

环管反应器中聚丙烯颗粒内部的质量与热量传递模型

针对环管反应器中Ziegler-Natta催化剂催化的聚丙烯颗粒增长过程,采用多层模型建立了聚丙烯颗粒内部的质量与热量传递预测模型.通过模型模拟得到聚丙烯颗粒内部的丙烯单体浓度梯度和温度梯度.此外,通过模型分析了聚丙烯颗粒的增长规律.结果表明,环管反应器中的聚丙烯颗粒内部的单体浓度梯度明显,该浓度梯度值随扩散系数的增大而减小,随催化剂初始粒径减小而减小;相比于浓度梯度而言,聚丙烯颗粒内部的温度梯度并不明显,温度值随聚合进行而增加,温度梯度则随催化剂初始粒径的增加而增加;不同大小的催化剂颗粒增长得到的聚丙烯颗粒的增长倍数不同.     

胶乳聚合釜新型内冷结构的设计

胶乳聚合釜是丁苯胶乳生产的关键设备之一,传热装置的结构形式直接影响聚合过程进而影响产品质量。本文主要介绍了在胶乳聚合釜内冷装置设计中采用的一些新型结构以及计算方法。     

冷凝水冷却器的设计及改进

首先,介绍了某核电站冷凝水冷却器的功能及其结构特点,该冷凝水冷却器属于典型的管壳式换热器,在化工行业应用广泛。其次,在对原有参考设备消化吸收的基础上,对该冷凝水冷却器的结构进行了改进。最后,对冷凝水冷却器的设计计算做了简要分析。     

Temperature Control of a Bench‐Scale Batch Polymerization Reactor for Polystyrene Production

Batch polymerization reactors commonly use optimal temperature control as the strategic operation parameter. This strategy allows for better operability and a more economic process. The main objective of the batch polymerization reactor control is to obtain acceptable product quality. Direct measurement of polymer quality is rarely achievable, which makes the online control of the reactor difficult. Temperature is the most controllable operational variable in the polymer reactor, which is seen to have a direct effect on the polymer properties. Temperature is chosen as the set point by using either the isothermal temperature or optimal temperature trajectory. Online control of the optimal temperature profile of a bench‐scale batch polymerization reactor was experimentally investigated in this study. The temperature trajectory was used as the target for controllers to follow. The time‐profile temperature was obtained with the objective of obtaining the desired conversion and number‐average chain length within the minimum time. Two advanced controls of fuzzy logic control and generic model control were applied to the polymer reactor. A comparison of the controllers reveals that both performed better than conventional controllers.     

300kt/a氨合成塔外壳的设计

对某 30 0kt/a氨合成塔外壳的设计、材料选择及部分密封件结构与焊接情况等作了说明。筒体采用多层包扎 ;多层筒体与底部球形封头之间用一锻环过渡 ;筒体端部与圆形平盖之间采用大型螺栓紧固的双锥密封结构。内筒材料为SA387Gr .1 2CL2 ,多层层板材料为SA72 4Gr.B ,底部封头材料为SA387Gr.2 2CL2。筒体及筒体与端部的堆焊材料为INCONEL 82。双锥环以柔性石墨作垫片。测试结果表明 ,该设计经济可靠。     

化学制药技术专业综合实训的设计与教学实践

高职高专院校中,专业综合实训设计与实施管理已成为教学管理的一个重要组成部分。专业综合实训质量的好坏、优劣,直接关系到人才培养质量的提高。本文针对专业综合实训缺乏整体设计、综合度不够的问题,以化学制药技术专业综合实训教学设计与运行管理为例,对综合实训项目设计改革思路进行了初步探讨,列举了高职高专化学制药技术专业综合实训项目实践教学几点改革措施和取得的成效。     

Synthesis and Assessment of a CO2‐Switchable Foaming Agent Used in Drilling Fluids for Underbalanced Drilling

In underbalanced drilling, a switchable foam fluid is essential to reduce the drilling cost. A switchable foaming agent was synthesized by carbonyl–amine condensation and characterized by Fourier transform infrared and ¹H nuclear magnetic resonance (NMR) spectroscopy. Thermogravimetric analysis and differential scanning calorimetry showed that the tolerable temperature limit of the surfactant was 128 °C. The effectiveness of CO₂/N₂ switching was confirmed by analysis of the electrical conductivity and surface tension. Utilizing the foaming agent, 3 different foam systems (unstable, stable, and hard) were designed for drilling after formula optimization. Experimentally, the self‐circulation indicated that the foaming fluids still maintained great foaming performance even after multiple cycles. The experiment also indicated that the suspension of the foam systems was 50–90 times that of water and had a significant resistance to salts (NaCl, CaCl₂). Besides, the foam systems found that the suitable foaming temperature was 40–100 °C and that the hard foam system could maintain the foaming performance up to 120 °C. In the oil resistance experiment, the foaming ability of the foam systems decreased obviously above a kerosene content of 5% (w/v), whereas a certain foaming performance still could be ensured below 10% kerosene.     

Design of a Pipe/Ring Type of Sparger for a Bubble Column Reactor

The sparger is an important accessory of bubble column reactors which governs the performance of the reactor. Specifically the sparger design becomes more important when the aspect ratio of the bubble column is low. The maldistribution and design of the sparger are of major concern and both these aspects are described in detail in the present work. Various methods for reducing maldistribution have been discussed and a simple method for its reduction is presented experimentally. Further a step‐wise design procedure for a pipe/ring type of sparger for bubble columns is presented together with a work example.     

Design of a Flexible Pilot Plant Reactor for the Steam Cracking Process

A design technique for a pilot plant reactor of single diameter is presented to scale up or down steam cracking coils of different configurations like mono‐tubular, classical, and reversed splits. Using dimensional analysis, two criteria are selected in establishing partial similarity between different scales, the mean residence time, and the axial pressure profile in the reactor, in addition to preserving the flow pattern within the turbulent region. The sensitivity and accuracy of the proposed method is compared to another conceivable alternative that focuses on the lateral gradients. The pilot reactor coil is adapted for any large‐scale reactor by the adjustment of feed flow rate and the effective length exposed to the firebox heat flux. Simulation results for naphtha cracking in a commercial split coil and also the equivalent pilot plant reactors are used for verification and validation of this method.