Abstract:

The slurry bubble column reactors with implanted vertical heat exchange pipe bundles are widely used in practice.Hydrodynamics for this reactor is very complicated and very few works were reported before.In this paper, velocity and gas hold up distributions along the radial direction of a Φ500 mm×5000 mm bubble column with and without vertical pipe bundles were measured with the Pavlov tube and conductivity probe respectively.The experimental results showed that the vertical pipes would remarkably enhance the axial velocity and the large scale liquid circulation on the one hand, while impede the radial or lateral turbulent motion of liquid and bubbles on the other hand.The effect led to steeper distributions of axial velocity and gas hold up, and enhancement of liquid and gas phase backmixing, which increased the risk of scale up for bubble column reactor with vertical pipe bundles.At a lower gas superficial velocity while sustaining turbulent bubble flow regime the “funneling effect” of the pipe bundles would become more remarkable.

Key words:

浆态鼓泡塔, 流速分布, 列管内构件

摘要：

浆态床反应器内部往往安装有密集的竖直列管换热内构件，有关列管束对流场分布的影响还少有研究。本文在Φ500 mm×5000 mm的大型冷模实验装置中测定了安装不同密度列管束时的速度分布和气含率分布。实验表明，列管的存在一方面会显著提高浆料轴向速度，促进大尺度流体循环，另一方面也抑制了液体与气泡的径向湍动，使速度和气含率的径向分布更不均匀，造成液体与气体轴向返混加剧，增大了有列管束的浆态床反应器的放大风险。在低气速湍动鼓泡条件下，列管加入造成的“烟囱效应”将更为显著。

关键词:

浆态鼓泡塔, 流速分布, 列管内构件