Ultrasonic Technology for Desiccant Regeneration

The chapters in this volume explore ultrasound-assisted regeneration of silica gel, ultrasound-assisted regeneration for a new honeycomb desiccant material, ultrasound-atomizing regeneration for liquid desiccants, ultrasonic transducers, and much more.

The chapters in this volume explore ultrasound-assisted regeneration of silica gel, ultrasound-assisted regeneration for a new honeycomb desiccant material, ultrasound-atomizing regeneration for liquid desiccants, ultrasonic transducers, and much more.

About the Authors ixPreface xiAcknowledgements xiiiNomenclature xv1 Introduction 11.1 Background 11.2 Literature Reviews 21.2.1 Desiccant Materials 21.2.2 Types of Desiccant Dryer 41.2.3 Regeneration Methods 101.3 The Proposed Method 191.3.1 Basic Knowledge about Ultrasound 191.3.2 Sound Generation 221.3.3 Fundamental Theory for Ultrasound-Assisted Regeneration 241.4 Summary 26References 262 Ultrasound-Assisted Regeneration of Silica Gel 332.1 Theoretical Analysis 332.2 Experimental Study 382.2.1 Experimental Setup 382.2.2 Procedure for Experiments 392.2.3 Methods 402.2.4 Results and Discussions 422.3 Empirical Models for Ultrasound-Assisted Regeneration 512.3.1 Model Overviews 512.3.2 Model Analysis 522.4 Theoretic Model for Ultrasound-Assisted Regeneration 592.4.1 Physical Model 622.4.2 Mathematical Model for Ultrasonic Wave Propagation 622.4.3 Mathematical Model for Heat and Mass Transfer in Silica Gel Bed 672.4.4 Model Validation 752.4.5 Error Analysis for Experimental Data 852.5 Parametric Study on Silica Gel Regeneration Assisted by Ultrasound 892.5.1 Acoustic Pressure and Oscillation Velocity in the Packed Bed 892.5.2 Thermal Characteristics of the Bed during Ultrasound-Assisted Regeneration 912.5.3 Enhancement of Regeneration Assisted by Ultrasound 1062.5.4 Comparisons between the Transverse- and Radial-Flow Beds 1102.6 Quantitative Contribution of Ultrasonic Effects to Silica Gel Regeneration 1102.6.1 Theoretical Analysis 1102.6.2 Method 1132.6.3 Results and Discussions 1142.7 Energy-Saving Features of Silica Gel Regeneration Assisted by Ultrasound 1192.7.1 Specific Energy Consumption 1192.7.2 Results and Discussions 1202.7.3 Brief Summary 1252.8 Effects of Ultrasound-Assisted Regeneration on Desiccant System Performance 1262.8.1 Study Objective and Method 1262.8.2 Results and Discussions 1272.8.3 Brief Summary 139References 1393 Ultrasound-Assisted Regeneration for a New Honeycomb Desiccant Material 1413.1 Brief Introduction 1413.2 Experimental Study 1423.2.1 Experimental System 1423.2.2 Raw Material and Experimental Conditions 1423.2.3 Analysis Parameters 1443.2.4 Experimental Results 1453.2.5 Energy Attenuation and Absorptivity of Ultrasound in the Material 1543.3 Theoretical Model for Honeycomb-Type Desiccant Regeneration 1593.3.1 Basic Assumptions 1593.3.2 Governing Equations 1593.3.3 Determination of Key Parameters 1603.3.4 Model Validation 1613.4 Model Simulations and Analysis 1633.4.1 Parametric Study 1633.4.2 Quantitative Contributions of Ultrasonic Effects to the Regeneration of Honeycomb-Type Desiccant 1723.5 Summary 176References 1764 Ultrasound-Atomizing Regeneration for Liquid Desiccants 1774.1 Overview 1774.1.1 Principles and Features of the Liquid-Desiccant Dehumidification 1774.1.2 Thermo-Physical Properties of Liquid Desiccant Materials 1784.1.3 Research Status of Solution Regenerators 1824.2 Theoretical Analysis 1834.2.1 Mass Transfer Coefficients for the Droplets 1834.2.2 Atomized Size of Droplet by Ultrasonic Atomizing 1924.2.3 Droplet Distribution Characteristics and Measurement Techniques 1944.2.4 Vapor Pressure of Liquid Desiccant Mixture 1964.3 Theoretical Modeling for the Ultrasound-Atomizing Regenerator 2014.3.1 Assumptions 2014.3.2 Basic Equations 2014.3.3 Determination of Key Parameters 2024.3.4 Model Validation 2034.3.5 Parametric Study 2084.4 Performance Analysis of Liquid-Desiccant Dehumidification System with Ultrasound-Atomizing Regeneration 2214.4.1 The Ultrasound-Atomizing Regenerator versus the Packed One 2214.4.2 Performance of Liquid Desiccant System with Different Regenerators 226References 2335 Ultrasonic Transducers 2355.1 Longitudinal Vibration of Sandwich Piezoelectric Ultrasonic Transducer 2355.1.1 Overview 2355.1.2 Theoretical Analysis 2405.1.3 State Equations of Sandwich Piezoelectric Electromechanical Transducer 2485.1.4 Design Case 2565.2 Radial Vibration Ultrasonic Transducer 2585.2.1 Overview 2585.2.2 Theoretical Analysis and Design of a Binary Radial Transducer 2595.2.3 Radial Vibration Sandwich Piezoelectric Transducer 2675.2.4 Summary 2755.3 Ultrasonic Atomization Transducer 2755.3.1 Basic Principle of Ultrasonic Atomization 2755.3.2 Basic Structure of Ultrasonic Atomizers 2755.3.3 Research Status and Applications 277References 2816 Desiccant System with Ultrasonic-Assisted Regeneration 2836.1 For Solid-Desiccant System 2836.1.1 Based on the Longitudinal Vibration Ultrasonic Transducer 2836.1.2 Based on the Radial Vibration Ultrasonic Transducer 2846.2 For Liquid-Desiccant System 2876.3 Future Work 2896.3.1 Development of Ultrasonic Transducer 2896.3.2 Development of Desiccant Materials Adaptive to Ultrasound-Assisted Regeneration 2906.3.3 Development of Demister 2906.3.4 Environmental Impact 290References 292A Basic Equations for Properties of Common Liquid Desiccants 293A.1 Lithium Chloride (LiCl) 293A.2 Calcium Chloride (CaCl2) 297A.3 Lithium Bromide (LiBr) 299A.4 Vapor Pressure (Pa) 302A.5 Specific Thermal Capacity (J/(kgs C)) 303A.6 Density (kg/m3) 303A.7 Dynamic Viscosity (Pa s) 303References 306Index 307