摘要
以羧甲基纤维素钠水溶液(CMC)为液相,空气为气相,研究了不同桨型组合、体系黏度、气量、桨间距、气体分布器等对搅拌过程中氧传递的影响。结果表明:在CMC体系中,下层用径向流的涡轮斜叶桨、上层用轴向流的翼型桨有利于氧传递。当单位体积功率P/V≥1.5 kW/m3时,涡轮斜叶翼型组合桨(SRT-HI)比传统的双层透平组合桨(RT-RT)的传质系数提高约10%,且高径比越大,SRT-HI优势越明显。进一步用CFX11.0进行模拟,得到了不同桨型组合下气液两相的速率、气体和氧传质系数的分布等。并在50 L发酵罐中分别采用SRT-HI与RT-RT研究了搅拌对多黏类芽孢杆菌HY96-2发酵溶氧影响的热模实验,结果表明,在P/V=1.6 kW/m3条件下采用SRT-HI发酵,过程中体系的溶氧情况明显好于采用RT-RT时的溶氧情况。
Effects of impeller combination, system＇s viscosity, gas-flux, space of impellers and gas sparger on the oxygen transfer with CIVIC as liquid phase and air as gas phase were investigated in this paper. The results indicated that slope blade Rushton turbine-hydrofoil impeller （SRT-HI） was favorable to oxygen transfer in CMC system. When the power consumption per volume （P/V） was not less than 1.5 kW/m^3, the transfer coefficient （kLa） of SRT-HI was 10M higher than that of the double Rushton turbine combined （RT-RT）, and even better with increase of the ratio of height to diameter. The distributing profile of velocity, gas and oxygen transfer coefficient in the gas-liquid two phases were obtained through CFX 11.0 simulation. The effect of SRT-HI and RT-RT to dissolved oxygen was studied through paenibacillus polymyxa HY96-2 fermentation in 50 L agitated reactor, and the results indicated that the dissolved oxygen of SRT-HI was higher than that of RT-RT when P/V was 1.6 kW/m^3.
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第3期339-345,共7页
Journal of East China University of Science and Technology
基金
国家"十一五"863项目(2006AA02Z222
2006AA10A211)
