Scale-up Design of Ultrasound Horn for Advanced Oxidation Process Using COMSOL Simulation

Transcription

1 Department of Civil, Environmental, and Geodetic Engineering Scale-up Design of Ultrasound Horn for Advanced Oxidation Process Using COMSOL Simulation Zongsu Wei October 10th, 2013 Boston, MA

2 OUTLINE 1. Background 2. Objectives 3. Simulation 4. Results 5. Future Work

3 Ultrasound (>20kHz) Emulsifying, Synthesis, Imaging, Damage Detection, cleaning Cavitation T: ~ 5000 K H 2 O H + OH (Suslick, 1989) Organic pollutants polycyclic aromatic hydrocarbon Inorganic pollutants arsenic Disinfection reduce chemical addition (Moussatov et al., 2003) Desorption enhanced oil recovery

4 Typical ultrasonic horn Localized cavitation Low energy efficiency 8-29% a Scaling-up is very difficult a Contamine et al.,1994; Kimura et al., 1996; Weavers et al., 2000; Bhirud et al., 2004; Pee, 2008; Thangavadivel et al., 2009.

5 Objectives Improved horn configuration Enhanced cavitation COMSOL Tool Piezoelectric material model Linear elastic material model Pressure acoustics model Transducer Horn a typical horn; b designed horn (a) (b)

6 Design Verification Pressure Cavitation Removal Typical horn Designed horn

7 Experimental Characterization Hydrophone Measurements a device that can record underwater sound by receiving pressure signals Reson TC4013 Hydrophone TDS 5000 Tektronix oscilloscope Distribution and Location Sonochemiluminescence (SCL) Luminol + OH Product + hν

8 Experimental Results Energy efficiency increased to 31.5%

9 Summary More energy-emitting surfaces Multiple reactive zones Higher energy efficiency Large Scale COMSOL Comparable results A reliable design tool

10 Large-Scale Evaluation 2D and 3D acoustic pressure distribution in the water tank

11 Future Work Large-volume reactor Flow cell reactor Array of designed horns Sediment treatment

12 Acknowledgement The COMSOL Conference Dr. Linda Weavers, Dr. John Lenhart, Dr. Ruiyang Xiao, Dr. Meiqiang Cai, Dr. Chin-Min Cheng, Matthew Noerpel, and Mengling Stuckman

13 Questions?

14 Governing Equations Piezoelectric material model for transducer Linear elastic material model for irradiator Pressure acoustics model for water

15 Physical Characterization Hydrophone Ultrasonic reactor volts pressure

16 Physical Characterization Sonochemiluminescence (SCL) Luminol + OH Product + hν Typical horn

17 Energy P ac = (dt/dt) C p M Ultrasonic horn Freq. (khz) Electrical power input (W) Reaction volume (ml) Emitting area (cm 2 ) Acoustic power (W) Power intensity (W cm -2 ) Power density (W L -1 ) Energy efficiency (%) Designed Typical (Branson) a Typical (Fisher Scientific) b a Weavers et al., 2000 b Pee, 2008 c Contamine et al.,1994; Kimura et al., 1996; Weavers et al., 2000; Bhirud et al., 2004; Pee, 2008; Thangavadivel et al., % c

18 Cavitation (a) TA + OH HTA HTA formation, Mmin k nor = k th (PD dh /PD th ) a (b) Acoustic power, W 315 k nor normalized rate (μm min -1 ) k th rate constant for typical horn (μm min -1 ) PD dh power density for designed horn (W) PD th power density for typical horn (W) HTA formation, Mmin Initial water temperature, C a initial temperature for experiment a is 20ºC; b electrical power input is 500 W Ultrasonic horn HTA formation rate (μm min -1 ) Designed 0.36 Typical (Sonics & Materials) b 0.08 Typical (Fisher Scientific) c 0.18 a Weavers et al., 2000 b Price and Lenz, 1993 c He, 2006

19 k, min -1 Naphthalene Degradation 60 Concentration, M Time, min Naphthalene + OH Products designed horn typical horn k nor = k th (PD dh /PD th ) a a Weavers et al., Concentration, M 50

20 Large-Scale Application Water tank setup Power Supplier (Branson BCA 900) Z = 0 Oscilloscope (Tektronix TDS 5000) Diagram of experimental setup for hydrophone measurements in plexiglas box (the depth tangential to horn tip is defines z = 0; 1 Branson 902R Model transducer; 2 serial stepped ultrasonic horn; 3 Reson T4013 hydrophone; 4 water; 5 plexiglas box)

21 Large-Scale Evaluation Transducer (PZT-5H) piezoelectric material model Horn irradiator (stainless steel) linear elastic material model Tank (water) pressure acoustics model

22 Y, cm Large-Scale Application Hydrophone reading, V X, cm Y, cm X, cm D (left) and contour (right) mapping of hydrophone measurements in plexiglas tank (X Y plane at z = 0 cm)

23 Y, cm Large-Scale Application Hydrophone reading, V X, cm Y, cm X, cm D (left) and contour (right) mapping of hydrophone measurements in plexiglas tank (X Y plane at z = +4 cm)

24 Y, cm Large-Scale Application Hydrophone reading, V X, cm Y, cm X, cm D (left) and contour (right) mapping of hydrophone measurements in plexiglas tank (X Y plane at z = 4 cm)

25 Chemical Structure Naphthalene Ethylenediaminetetraacetic Acid (EDTA)

26 Schematic diagram of longitudinal vibration of single step horn and its equivalent circuits F F 1 F (a) S 1 S 2 2 F F 1 F 1 (sσ) x (sσ) x+dx F 2 x A i i i i 12 i 22 A i (cos kl ) jcsi(sin kl ) i i j(sin kli ) csi (cos kli ) u 2 u 1 x x+dx A A A i i i i i i 1 i i1 A2 A1 i 1 i j(sin kl8 ) j(sin kl1 ) (cos kl8 ) (cos kl1 ) A csi csi jcsi(sin kl8 ) (cos kl8 ) jcsi(sin kl1 ) (cos kl1 ) (b) u 1 u F 1 F

27 Diagram of experimental set-up (1) 38 l 1 45 (2) I l l (3) (4) (5) l l 5 15 II (6) l (7) l l x (8) (a) (b)