气泡大小对反应器内氧传递系数的影响

在气液反应过程中,气泡的大小对结果往往起了决定性的作用。通过减小气泡的尺寸,可以促进气液传递,加快反应的进程。在气液搅拌式反应器上安装了一种特殊的气体分布器,通过搅拌产生离心场,从而诱导生成泰勒涡柱,使大量进入反应器的空气气泡保持在泰勒涡柱的内部。由于减少了气泡间的凝并作用,气泡尺寸减小,与对照组相比,反应器中最小的气泡尺寸减小了近50%,气泡的比表面积增加近80%。通过对不同通气流量和搅拌速度下气液反应器内氧传递系数的测量,与对照实验比较,使用特殊气体分布器的反应器中,氧的传递系数增加了10%~40%,证明这种气体分布器确实可以增加气液间氧的传递。

Effect of bubble size on the oxygen transfer coefficient in reactor

In gas-liquid reaction process,the size of the bubble always plays a decisive role to the result.By reducing bubble size,gas-liquid transfer can be promoted and thus the reaction process is accelerated.In this paper,a special gas distributor is equipped in a gas-liquid stirring reactor,by stirring a centrifugal field is produced and Taylor vortex column is induced into reactor.Large quantities of air bubbles that are pumped into reactor will be kept in the Taylor vortex column.By this way the coalescence effect between bubbles is reduced and the bubbles size remain small.It is found the size of the smallest bubble in the reactor reduce nearly 50% comparing to the check group.At the same time the specific area of the bubbles increase by almost 80%.After that oxygen transfer coefficient in the gas-liquid reactor is measured at different air flow rate and agitating rate.Comparing to the check test,the oxygen transfer coefficient in the reactor that use special gas distributor increase by 10%~40%.This proves that gas distributor can strengthen the oxygen transfer.