旋流气升式环流反应器中含醇物系的局部与总体气含率研究

Total gas holdup and local gas holdup in riser in the helical-flow air-lift loop reactor for alcoholic aqueous solutions

在内径0.090m,高2.4m的旋流气升式环流反应器中,以空气为气相,分别以水,φ(异丙醇)=1%、5%、10%,φ(正丁醇)=1%和φ(乙醇)=1%的水溶液为液相,在表观气速为0.46~1.86cm/s,研究了在不同底部间隙、翅片数量、φ(异丙醇)、醇的类型条件下局部和总体气含率随表观气速的变化情况。结果表明:所有物系,表观气速一定,上升区局部气含率在轴向高度上基本不变,只随表观气速的增加而增加;随着φ(异丙醇)的增加,气含率随之增加。对于体积分数均为1%的乙醇、异丙醇、正丁醇水溶液的两相物系,总体气含率乙醇物系最大,正丁醇次之,异丙醇的最小。在表观气速小于0.931cm/s时,导流筒上固定的翅片数越少气含率越高,而在表观气速大于0.931cm/s时,则有相反的结果;其它条件相同时,底部间隙越小气含率越大。

Total gas holdup and local gas holdup in riser were studied on different bottom tap,the numbers of helical sheets,the volumetric concentration of isopropanol aqueous solution(1%,5%,10%),type of alcohols,with sperficial gas velocities,for the systems of the air being gas phase and water,isopropanol,n-butanol and ethanolaqueous solution being liquid phase,respectively,in the helicalflow airlift loop reactor(HALR)with 90 mm in inner diameter and 2 400 mm in height.The superficial gas velocities was in the range of 0.46~1.86 cm/s.The results showed,that the local gas holdup was changed a little along the axial height and increased only with superficial gas velocities for any systems used.The gas holdups increased with increasing of the concentration of isopropanol aqueous solution.The total gas holdups of ethanol aqueous solution was largest,one of the n-butanol was smaller and one of the isopropanol was minimum for the alcohols.The less the numbers of helical sheets was,the larger the gas holdups was,at the gas velocities was less than 0.931 cm/s.The more the numbers of helical sheets was,the larger the gas holdups was,at the gas velocities was more than 0.931 cm/s.The less the bottom tap,the larger the gas holdups at other identical conditions.