LLDPE装置反应器内静电产生原因与应对措施

针对线型低密度聚乙烯装置开车期间反应器内产生静电的现象,通过对装置工艺参数及实际操作情况进行分析,得出产生静电原因主要为:原料杂质含量高,床层再生频率低,种子床储存密封性差,输送期间产生静电,催化剂活性低生成细粉多,装置进退冷凝态操作不当,流化气速高。处理措施为:降低原料杂质含量,优化床层再生频率,优化种子床储存和输送方式,控制催化剂活性,减少细粉生成,严格控制反应器进退冷凝操作,控制反应器流化气速,减少大幅操作,较好解决了静电问题。     

脉冲气流输送磷矿粉

我们于75年6～8月份曾在浙江大学化工系试验脉冲气流输送磷矿粉料,并取得成功。今年6月底我所年产300～500吨磷酸铵悬浮肥料中间试验车间开车后,一直使用至今。从近半年的使用结果来看,效果是好的,主要好处有以下几点:1.操作稳定。只要矿粉水份含量在2％以下,不要夹入纸屑、杂草、碎石等,输送管道     

新的配料与输送方法

大约在20年前,在处理流态化粉料过程中人们发现,干的粉料甚至可以通过短的软管输送。由此得出结论,连续的流态化粉料还可以通过长距离进行灵活输送。本文叙述了SCIROCCOⅡ流态化软管的设置与操作方式。从工厂管理者的观点说明了这样一个输送系统的优点与限定因素。     

粉料风送设备的设计

在工业生产或农业生产中,经常会遇到需将粉状或粒状物料由车、船运至仓库,或由仓库送至生产车间。粉料在运输途中容易损失或逸出有害粉尘,影响环境卫生。解决此问题,一般采用粉料在管道内输送的风送设备。粉料风送设备由于粉料在密闭管道中输送,因此不会飞扬和污损。输送系用管道,途中可不受建筑物或机器的影响,在狭窄地区也可设置。其设备结构较为简单,输送途中不需操作人员,可大大节约劳动力。它既可以集中或分散输送又可以远距离输送,且输送中还     

牙膏生产粉料输送系统的技术现状及发展趋势

介绍了国内外牙膏生产工艺中粉料输送系统的技术现状，分析了国际上先进的粉料输送系统所采用的真空输送与自动称重技术的优势，提出牙膏生产粉料输送系统应用真空输送与自动称重技术是一种发展趋势，对促进我国牙膏行业生产技术水平的提高具有重要意义。     

空气链式输送机

<正>(充气FU或水平空气输送槽)专利名称:粉状物料链式空气输送机专利号:新型实用ZL2013 2011 6889.0粉料水平输送重大突破,每小时可达1200m~3一、简介空气链式输送机是一种组合式粉料输送设备,它是在传统的链式输送机壳体底部加装充气箱,利用高压空气把壳体内粉料气化而使内摩擦降低,这样壳体内的气化物料在较小的输送链条和传动能耗下,即可实现大输送量的效果,从而实现节能降耗的目的。可广泛应用于库顶、库底、码头以及粉料的长距离输送。     

最大规模煤制烯烃项目投产聚丙烯

<正>中天合创煤炭深加工示范项目35万t/a气相聚丙烯装置已经开车成功,成功产出合格粒料。据悉,中天合创35万t/a气相聚丙烯装置于2016年5月26日顺利中交。10月21日,35万t/年聚丙烯(一线)装置顺利打通聚合工段和粉料输送流程,产出的聚丙烯粉料进入中间料仓。11月12日16时催化剂进入装置内,13日3时第一反应器出料,14日下午挤压机顺利启动。在第一反应器和挤压造粒系统稳定运行一天后,于15日启动气锁系统和第二反应器,并于16日下午成功迎来第二反应器出料,开车一次     

山西龙舟输送机械有限公司

<正>空气链式输送机(充气FU或水平空气输送槽)专利名称:粉状物料链式空气输送机专利号:实用新型ZL 2013 20116889.0粉料水平输送重大突破,每小时可达1200m~3一、简介空气链式输送机是一种组合式粉料输送设备,它是在传统的链式输送机壳体底部加装充气箱,利用高压空气把壳体内粉料气化而使内摩擦降低,这样壳体内的气化物料在较小的输送链条和传动能耗下,即可实现大输送量的效果,从而实现节能降耗的目的。可广泛应用于库顶、库底、码头以及粉料的长距离输送。     

使用不同催化剂转产过程中淤浆法HDPE脱气仓结块原因分析

在英力士淤浆环管工艺高密度聚乙烯(HDPE)装置上,由采用钛系催化剂生产PE100级管材专用HDPE转换成用铬系催化剂生产的过程中,使用钛系催化剂的停车期间以及使用铬系催化剂的开车期间,粉料输送至低压闪蒸脱气仓都会产生块状的聚乙烯,严重影响装置的正常运行;通过对块状聚乙烯进行密度与凝胶渗透色谱分析,发现结块的聚乙烯主要为低相对分子质量、低密度的聚乙烯粉料黏结物。停车期间,将第一反应器氢气进料量降低50%,提前终止1-己烯进料,从而完全消除结块的形成。     

涂料厂粉料气力输送技术探讨

介绍了涂料的组成,比较了常用的粉料输送技术,探讨了采用气力输送技术输送涂料厂的粉料。结果表明:气力输送技术输送大流量粉料具有输送效率高、投资和运行费用低、无粉尘污染的优点。经除尘设备处理后废气中粉尘浓度小于8 mg/m3,达到了《工作场所有害因素职业接触限值第1部分:化学有害因素》(GBZ 2.1-2019)的排放浓度要求。     

Modeling of Drying in Moving Bed

The aim of this work is to study the simultaneous heat and mass transfer between air and soybean seeds in moving bed dryers with parallel flow (concurrent and countercurrent), by means of an experimental and simulation work, verifying the validity of classical assumptions. The numerical solution of a one-dimensional boundary value problem was obtained by means of a computational code based on axial integration through DASSL code. Deviations from flat air velocity profile were taken into account considering empirical and mechanistic equations found in the literature that describes air profile as function of radius. The experimental data of air humidity, temperature, and seed moisture content and temperature at the dryer outlet were compared to the simulated values.     

Modeling of Drying in Moving Bed

The aim of this work is to study the simultaneous heat and mass transfer between air and soybean seeds in moving bed dryers with parallel flow (concurrent and countercurrent), by means of an experimental and simulation work, verifying the validity of classical assumptions. The numerical solution of a one-dimensional boundary value problem was obtained by means of a computational code based on axial integration through DASSL code. Deviations from flat air velocity profile were taken into account considering empirical and mechanistic equations found in the literature that describes air profile as function of radius. The experimental data of air humidity, temperature, and seed moisture content and temperature at the dryer outlet were compared to the simulated values.     

液固流化床内床层塌落动态过程的数值模拟

在理论分析液固流化床内床层塌落过程的基础上,对水和玻璃球体系的床层动态塌落行为进行了多相流数值模拟,详细考察了液体速度突然减小后床层表面和分隔界面随时间的变化规律,模拟结果与经典模型预测值相吻合,表明多相流计算流体动力学模拟可以很好地预测液固流化床的床层动态塌落行为。     

The Effect of Bed Temperature on Mass Transfer between the Bubble and Emulsion Phases in a Fluidized Bed

The rate of interphase mass transfer between the bubble and emulsion phases of a bubbling fluidized bed is of primary importance in all models for fluidized bed reactors. Many experimental studies have been reported, however, all these investigations have been carried out in fluidized beds operated at room temperature. In this work, the effect of the bed temperature on the interphase mass transfer is reported. Single bubbles containing argon – used as a tracer – were injected into an incipiently fluidized bed maintained at the required temperature. The change in argon concentration in the bubble was measured using a suction probe connected to a mass spectrometer. The effects of bed particle type and size, bubble size, and bed temperature on the mass transfer coefficient were examined experimentally. The interphase mass transfer coefficient was found to decrease with the increase in bed temperature and bubble size, and increase slightly with increase in particle size. Experimental data obtained in this study were compared with some frequently used correlations for estimation of the mass transfer coefficient.     

甲醇制烯烃流化床反应器的模拟与分析

采用流化床两相模型描述甲醇制烯烃(MTO)过程,采用拉格朗日颗粒跟踪方法模拟催化剂上的积炭与反应,考察了相间传质、催化剂停留时间及返混对MTO过程的影响。结果表明,湍动流化床相间传质速率小于催化反应速率,是MTO过程的速率控制步骤;强化传质和延长催化剂停留时间都能显著提高催化剂的积炭量,有利于提高乙烯与丙烯的选择性;而减小催化剂返混或采用多级串连操作对反应选择性的改善作用不大,采用气固多级逆流操作反而会导致选择性显著下降。     

超重力旋转床中水脱氧过程的模型化研究

超重力旋转床是一种高效的强化传质和混合的新型设备。今提出了超重力旋转床中的水脱氧过程的传质模型,分别采用欧拉方法和拉格朗日方法对超重力旋转床中的气相和液滴的运动行为进行了数值模拟;在此基础上计算了液滴的传质系数,计算结果和实验结果符合较好,平均误差为7．9％。当超重力旋转床中液体存在的主体形式更接近于液滴时,模型计算结果误差减小。进一步讨论分析了液体和气体流量、转速以及填料内径的变化对于超重力旋转床体积传质系数的影响,分析表明旋转填料对液体剧烈地剪切破碎分散作用是强化传质过程的主要原因。     

顶喷流化床中干燥过程研究

本文对用于造粒和包涂过程的顶喷流化床内的干燥过程进行了较为详细的实验和理论研究。从传质传热过程中分析可知，床层可分为三段。影响生产能力的最大允许喷淋速度受流化空气流量和入口温度影响最大。     

悬浮床与固定床渣油加氢改质技术的区别

固定床渣油加氢改质技术是比较成熟的重质油加工手段,而悬浮床渣油加氢技术是较新的重油轻质化方案.以悬浮床加氢技术为主,详细地比较了两种技术在催化剂组成和性质,反应机理,工艺过程方面的区别,指出两种工艺联合使用可以充分发挥各自的优势,扬长避短,创造更大的经济效益.     

鼓泡流化床内高灰煤气化过程的颗粒尺度特性研究

基于多相流体质点网格方法(MP-PIC)对高灰煤在三维鼓泡流化床气化过程进行了数值模拟研究。在欧拉-拉格朗日框架下将气相和固相分别视作连续介质和离散相处理。首先,将模拟得到的出口处气体组分结果与实验数据进行对比,实验数据与模拟结果具有良好的一致性。其次,研究了煤颗粒在气化炉内的温度、传热系数、速度和停留时间,从颗粒尺度揭示了鼓泡流化床气化炉内的颗粒分布特性和气固流动特征。结果表明:在气化炉入口附近煤颗粒与床层温差最大,传热系数最大;由于流化床内强非线性的气固流动,床中煤温度和传热系数的空间分布不均匀;煤颗粒和床料的瞬时速度具有稳定的波动幅度,其中垂直方向速度波动最明显,且煤颗粒的瞬时速度比床料的瞬时速度略大;由于颗粒间的剧烈碰撞,延长了煤颗粒停留时间。此外,对鼓泡流化床中煤气化过程颗粒尺度的研究,有助于深入了解固体颗粒的流动行为以及气固相相互作用特性,对鼓泡流化床反应器的设计优化具有重要意义。     

Numerical Spray Model of the Fluidized Bed Coating Process

In this study, a new model for the batch top-spray fluidized bed coating process is presented. The model is based on the one-dimensional (axial) discretization of the bed volume into different control volumes, in which the dynamic heat and mass balances for air, water vapor, droplets, core particles, and coating material were established. The coupling of the droplet phase's mass and heat transfer terms with the gas and solid phases was established by means of a droplet submodel in which droplet trajectories were individually simulated.

The model calculation method combines a Monte Carlo technique for the simulation of the particle exchange with the first-order Euler's method for solving the heat and mass balances, enabling the prediction of both the dynamic coating mass distribution and the one-dimensional (axial) thermodynamic behavior of the fluidized bed during batch operation. The simulation results were validated using experimental two-dimensional spatial air temperature and air humidity distributions, which were measured in a fluidized bed pilot reactor using a scanning probe.

Sensitivity analysis was carried out to study the effect of controllable process variables, such as fluidization air and atomization air properties, as well as the properties of the spraying liquid upon the simulated dynamic temperature and humidity distributions. Also, the effects of relevant process variables on growth rate uniformity and process yield were studied. Based on these sensitivity studies it was concluded that nozzle parameters, such as air pressure and positioning with respect to the bed, are as important as the fluidization air properties (humidity, temperature, and flow rate) for the coating growth rate uniformity and process yield.