超声场强化渗透脱水传质机理模型研究  

Mass Transfer Mechanism and Mathematical Model for Ultrasonic-enhanced Osmotic Dehydration

作　　者：马空军[1] 贾殿赠[1] 包文忠[2] 赵文新[2] 靳冬民 孙文磊[1] 

机构地区：[1]新疆大学化学化工学院,新疆乌鲁木齐830046 [2]新疆天山水泥股份有限公司,新疆乌鲁木齐830006

出　　处：《食品科学》2011年第13期94-101,共8页Food Science

基　　金：新疆自治区高校科研计划重点项目(XJEDU2007I06);新疆天山水泥股份有限公司博士后科研基金项目(65739)

摘　　要：研究超声场强化芋头渗透脱水,探讨芋头失水速率和干物质增加率随溶液质量浓度、温度、超声功率、材料厚度以及超声场下处理时间段的变化规律。分析超声空化泡在相间的传质过程,由此建立超声空化气泡强化相间传质数学模型Km≈DABπtm～(1/2)RδAfφ(BI-Cf2)(A为经验常数(10-8～10-15m2);B、C为超声波作用液体的有关常数,数量值分别在1014、106左右;f为声波频率/s-1;DAB为扩散系数/(m2/s);tm为时间/s;R为半径/m;δ为边界层厚度/m;φ为半径为R的气泡数占生成空化气泡总数百分比;I为声强/(W/cm2)),与实验结果相吻合,能较好地描述超声空化泡在液体中的传质行为。该关系式为超声波强化传质过程提供了理论依据。Variations in water loss and dry matter gain with respect to solution concentration, temperature, ultrasonic power, material thickness and ultrasonic time were investigated. Meanwhile, the interphase mass transfer of ultrasonic cavitation bubbles was analyzed. As a result, a mathematical model that describes the interphase mass transfer of ultrasonic cavitation bubbles was obtained as follows： Km≈DABπtm～（1/2）RδAfφ（BI-Cf2）, where A was empirical constant （10^-8 -- 10^-15 m2）, B and C relevant liquid constants with an approximate value of 10^4 and 10^6, respectively, f sound frequency（s-I）, DAB diffusion coefficient （m2/s）, Im time （s）, R radius（m）, δboundary layer thickness （m）, φratio of number of bubbles with a radius of R to total bubbles, and I ultrasonic intensity（W/cm2）. The predicted values from the model were consistent with the experimental values, indicating that the model could accurately describe the interphase mass transfer of ultrasonic cavitation bubbles.

关 键 词：渗透脱水 质量传递 超声空化 机理模型 

分 类 号：TS201.1[轻工技术与工程—食品科学]