乙氧基化反应喷嘴雾化和反应性能

摘要

外循环喷雾式反应器是目前国际最先进的乙氧基化反应器之一,其中乙氧基化反应喷嘴是核心设备,且对生产效率和产品质量起到决定性影响.建立了喷嘴的雾化性能试验台,它由喷雾系统、激光测量系统、高速摄像系统和流量分布测试系统4部分组成.对喷嘴的流量系数、流量分布、索特尔平均粒径、粒径分布和反应性能进行了试验研究,分别得到了它们随压降的变化关系;计算得到了粒径分布的概率密度函数,并与5种经验分布进行对比,发现Log-hyperbolic分布适用于乙氧基化反应喷嘴;分析讨论了喷嘴的周向不均匀度,以及径向流量分布可归纳为单峰、双峰和三峰3种形态.在上海某石化公司的乙氧基化反应器中测试喷嘴的反应性能,结果表明:索特尔平均粒径影响环氧乙烷的加成数和反应速率;粒径分布的宽度影响产品相对分子质量的分布宽度.%External Loop Spray Reactors(ELSR) is one of the most advanced ethoxylation reactors in the world.The ethoxylation reaction nozzles are the core equipments,which have great effect on the production efficiency and product quality.A test platform was established,which was divided into four parts of spray system,laser measurement system,photographic system and flow distribution test system.Discharge coefficient,flow distribution,Sauter mean droplets size,particle size distribution and reaction performance have been studied experimentally.The correlations of the characteristics mentioned above versus pressure drop were gained respectively.And the experimental Probability Density Function (PDF) of the droplets size was gained and compared with five empirical distributions.The Log-hyperbolic distribution has a most agreement with the measured PDF.The circumferential nonuniformity has been discussed.The radial flow distributions of all measured nozzles can be classified as a unimodal,bimodal and trimodal distribution.At the same time,reaction performance of the special nozzles was measured in the industrial ELSR ethoxylation reactor.It is indicated that Sauter mean diameter affects the number of EO and reaction speed.The width of droplets size distribution affects the width of the molecular weight distributions.