Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed
Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed
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DOI：
10.1016/j.powtec.2008.04.017
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发表时间：
2009-01-31
影响因子：
5.2
通讯作者：
Peglow, M.
中科院分区：
文献类型：
--
作者：
Link, J. M.;Godlieb, W.;Peglow, M.
喷动床常用于造粒生产颗粒或颗粒。该产品可广泛应用于洗涤剂、化肥、医药和食品等领域。喷动沸腾床具有许多有利的性质，如颗粒的高流动性，防止了不必要的团聚，并产生了良好的传热性能。对于每个元素，动量平衡都得到了解决。离散元模型模拟的结果与现场测量的时间平均颗粒体积分数和颗粒速度进行了比较。采用Geldart B型氧化铝颗粒对三种不同的情况进行了模拟和实验：自由鼓泡床、无液滴喷动床和有液滴存在的喷动床。结果表明，实验结果与数值计算结果在定性上是一致的，说明了离散元模型可以用来获得关于离散相之间相互作用的信息，即喷动床内的生长区。对数值结果的进一步分析表明，对于所研究的试验情况，没有发生液体穿透。(C)2008爱思唯尔B.V.保留所有权利。
Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties.A discrete element model is used describing the dynamics of the continuous gas phase and the discrete droplets and particles. For each element momentum balances are solved. The momentum transfer among each of the three phases is described in detail at the level of individual elements.The results from the discrete element model simulations are compared with local measurements of time time-averaged particle volume fractions as well as particle velocities by using a novel fibre optical probe in a fluidized bed of 400 mm I.D. Simulations and experiments were carried out for three different cases using Geldart B type aluminium oxide particles: a freely bubbling fluidized bed; a spout fluidized bed without the presence of droplets and a spout fluidized bed with the presence of droplets. It is found that the experimental and numerical results agree in a qualitative manner.It is demonstrated how the discrete element model can be used to obtain information about the interaction of the discrete phases, i.e. the growth zone in a spout fluidized bed. Additional analysis of the numerical results indicates that liquid breakthrough does not take place for the studied test case. (C) 2008 Elsevier B.V. All rights reserved.