超声场对毛细管内电解质扩散系数的影响  

Effect of ultrasound on diffusivities of electrolyte in a capillary

作　　者：秦炜[1] 张英[1] 戴猷元[1] 

机构地区：[1]清华大学化学工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2001年第6期41-43,共3页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目 (2 94762 45 )

摘　　要：以封闭于毛细管内的溶质扩散模拟固液分离体系中深层溶质扩散过程。采用液相色谱毛细管法测定毛细管内的二元扩散系数 ,通过分析温度、超声场 (排除热效应 )、直接超声场的影响 ,探讨了超声场对微孔深层扩散的强化作用机理。实验结果表明 ,超声场对毛细管内二元扩散系数的影响是热效应和管内流体扰动两方面共同作用的结果。在排除超声场热效应的条件下 ,随超声功率的增大 ,毛细管内的二元扩散系数随之增大 ,相对二元扩散系数与测量的流速无关 ;在无超声场作用时 ,毛细管内的相对二元扩散系数随温度升高而增大 ,呈线性关系。直接超声场的影响可采用超声场的热效应、管内流体扰动及相互作用参数叠加的方式表示。Solute diffusion inside a capillary was used to simulate the mass transfer process inside a solid for a liquid solid system. The diffusivities in the capillary were measured by the Taylor dispersion technique. The influences of temperature and ultrasound power with or without temperature control on the diffusivities were discussed. The experimental results indicated that the heating and the micro disturbances caused by the ultrasound were the two main aspects intensifying the mass transfer in the capillary. The diffusivity increased with ultrasound power with temperature control and the relative diffusivity did not vary significantly with flow velocity. The diffusivity increased linearly with temperature without the ultrasound. The diffusivity with the ultrasound could be described by combining the heating and micro disturbance effects. The correlated values agree well with the experimental data.

关 键 词：超声场 扩散系数 电解质 毛细管 固液分离体系 化工分离 

分 类 号：TQ028.5[化学工程] TQ021.9