顺流多层浅流化床反应器

鼓泡流化床一般可分为分布板区,鼓泡区和稀相区三个部分。工业实践及模型计算均已表明,在快反应和高扬析率的条件下,分布板区和稀相区对化学反应的作用均较鼓泡区大。由此不难设想,一个仅由分布板区和稀相区两部分组成的流化床反应器,必将是一个高效反应器。而且,因为这两个区域中都没有气泡,不存在气泡的合并和长大带来的一系列问题,     

稀相流态化

流态化技术中最常见的为鼓泡浓相流态化床。气体按几倍、几十倍、有时(特别对细颗粒物料)几百倍的临界流态化速度送入颗粒床层,一部分流经颗粒之问的空隙从床顶逸出,另一部(往往是大部分)在浓相床     

锥形移动床溢流管的研究及其流体动力学分析

在理论分析和实验的基础上,研究成功一种新型的气动式固体粒状物料的输送排加装置,称“锥形移动床溢流管”。它具有结构简单、操作连续稳定、窜气量小、料封能力强、输送量大且能自动适应输送量的变化等优点。可应用于粒状物料的输送和循环系统,如多层流态化床的溢     

锥斗溢流管的移动床上输(摘要)

本文在前人工作及文献调查的基础上,对锥斗溢流管的移动床上输进行了实验探索及理论研究。本文首先在锥斗溢流管中实现了移动床向上输送,并通过实验找出了实现稳定的移动床上输的锥斗的锥角和高度,以及与之相配合的气控点位置。此外,还研究了固体下料率、锥斗溢流管各部压力降、窜气量及气控气量等相互之间的关     

快速流态化的流动

在外径100mm,高8m的有机玻璃的装置上,对FCC催化剂、三氧化二铝粉料、铁精矿和细粒黄铁矿烧渣进行了快速流态化的流动实验。基于分布在稀薄连续相中颗粒密集体的不断形成和解体的现象,提出了快速流态化的分相流动的物理模型,并用一个一阶微分方程加以描述。其解为 In((ε-ε_a)/(ε-ε))=-(z-z_i)/Z_o 四个模型参数,即ε_a、ε、Z_o、和z_i由实验确定。     

迎接化学工程的新发展

化学工程发展成为一门推论性的科学技术,起初主要是根据设备,将不同工艺中性质相同的物理过程归纳为若干类同的单元操作。就那些具有化学变化的过程而言,则主要是按照不同的反应种类,而形成各类单元过程。为了说明各类化学反应的速率因素,     

PNEUMATICALLY CONTROLLED MULTI-STAGE FLUIDIZED BED AND ITS APPLICATION IN SOLVENT RECOVERY FROM A PLANT WASTE GAS

The downcomer is the key component of a multi-stage fluidized bed.A pneumatically controlleddowncomer has been devised,consisting of a fully fluidized dipleg followed by a conical spout for upwarddischarge in dense phase.Such a design has been found to insure against bridging of solids in descent andagainst spouting of solids from a lower layer caused by gas by-passing.In experimental investigations,flow characteristics are measured including the pressure drops of thedifferent fluidized beds and of the downcomers for various gas and solids flow rates as well as the solidsresidence time distribution,operating either with a multiplicity of gas sources for the various downcomersor with only two gas sources.In a particular design,a multi-stage ftuidized bed with dual gas supply,inwhich one half is incorporated centrally in the other,has been tested on pilot scale for recovering solventfrom low concentration ethylene dichloride streams of a plant waste gas.Main test results obtained wereas follows:adsorption rate>97%concentration of waste gas<25 mg/m~3active carbon loss<0.1%This kind of conical downcomer in which the solids arc either transported from a high- to a low-pressure region,or from a low- to a high-pressure region,is also used to control the solids discharge ofcyclone diplcgs or the feeding and discharging in other solids circulation systems.     

钒钛铁矿综合利用——流态化还原法

化工冶金研究所于1973年接受了"流态化焙烧还原钒钛铁矿"的任务,要求结合当地资源,用天然气还原铁精矿,用水力发电熔化焙砂,再从熔渣中提取钒和钛.我们对流态化还原的若干方面开展了试验研究,包括铁精矿还原反应数据的获得和有关分析,以及可供应用的两种流态化反应器的工程研究.第一种是气控式多层流态化床,第二种是快速流态化反应器.此外,对于流态化还原中的失流以及熔砂的渣～铁分离和从熔渣中提取钒钛,也进行了试验研究.本文是五年来58篇有关研究工作报告的归纳和摘要,一切报告文献目录从略.     

气控式多层流化床及其在净化排放气中的应用

溢流管是多层流化床的关键构件。本文设计的由下料料腿和锥斗组成的气控式锥形溢流管,由于物料在料腿中处于流态化状态,在锥斗中以气固顺流浓相向上输送,因此,这种溢流管可以防止物料在料腿中的架桥和喷料。 试验中测定了多气源和双气源两种气控式多层床的流动特性,包括各床层和溢流管压降以及固体停留时间分布。在回收低浓度二氯乙烷的中间工厂试验中,采用了具有同心圆的双气源多层流化床,获得以下主要结果: 吸附率>97%,排放气浓度<25mg/m~3,活性炭损失<0.1%。 这种能使固体物料由高压区输至低压区,或从低压区输至高压区的气控锥形溢流管结构,亦可用于旋风器料腿的返尘以及在循环系统中固体物料的连续加、排装置。     

PARTICLE MIXING AND SEGREGATION IN A MOVING FLUIDIZED BED IN GRAVITY AND MAGNETIC FIELD

Mixing/Segregation of an iron-and-sand mixture was investigated in a 38 mm diameter moving fluidizedbed with feed into the middle of the bed and exit from both the top and the bottom.The distribution ofvolumetric concentration of iron beads,measured by means of a specially designed sampler,was used to expressthe degree of segregation of the particle mixture in the bed.The segregation index N,defined as the ratio betweenS and Z.X_v,decreases with increase in superficial gas velocity and solids flow rate,for any given solidsdensity ratio and particle size ratio.When a magnetic field was employed,particle segregation was noted toincrease with magnetic field strength.