摘要
采用Brookfield黏度仪测量了质量分数为0.5%,1.0%,1.5%的羧甲基纤维素钠(CMC)水溶液在298.15 K的流变特性。在直径为0.48 m的平底搅拌槽中,对搅拌槽内不同的3层组合桨的气液二相的分散特性进行了实验研究,考察了非牛顿流体浓度、桨型组合、通气量和搅拌转速对通气功率、相对功率和气含率的影响规律。结果表明:CMC水溶液为假塑性流体,幂律方程能很好地关联其流变特性。在相同操作条件下,随着浓度的增加气含率减小,功率消耗增加;在相同的功率输入时,下压桨型组合的气含率更高。相对功率(PG/P)、气含率关联式等研究结果对非牛顿流体的气液搅拌器设计和操作具有一定参考价值。
The rheological properties of carboxymethylcellulose （CMC） solutions with three mass fractions（0.5%, 1.0% and 1.5% ）were investigated under 298.15 K. In a multi-impeller stirred tank with 0.48 m diameter, the influences of impeller, operation conditions, viscosity or non-Newtonian characteristics on gas holdup and power consumption were studied. The results show that CMC solutions behave like pesudoplastic fluid and the relationship between its viscosity and shear rate can be described by the power-law model. Under the same operation conditions, the gas holdup drops and power consumption increases with the increasing of the concentration of CMC. At the same power input, the impeller combinations with down-pumping produce higher gas holdup and lower power consumption than that of others. The results from the correlations of gas holdup and relative power consumption are valuable to the industrial application of the gas-liquid stirred reactors.
出处
《化学工程》
CAS
CSCD
北大核心
2015年第7期44-48,共5页
Chemical Engineering(China)
关键词
气液分散
气含率
通气功率
假塑性流体
搅拌槽
gas dispersion
gas holdup
gasing power
pseudoplastic fluid
stirred tank
