title: Energy characterisation of ultrasonic systems for industrial processes.
abstract: Obtaining accurate power characteristics of ultrasonic treatment systems is an important step towards their industrial scalability. Calorimetric measurements are most commonly used for quantifying the dissipated ultrasonic power. However, accuracy of these measurements is affected by various heat losses, especially when working at high power densities. In this work, electrical power measurements were conducted at all locations in the piezoelectric ultrasonic system equipped with ½″ and ¾″ probes. A set of heat transfer calculations were developed to estimate the convection heat losses from the reaction solution. Chemical dosimeters represented by the oxidation of potassium iodide, Fricke solution and 4-nitrophenol were used to chemically correlate the effect of various electrical amplitudes and treatment regimes. This allowed estimation of sonochemical-efficiency (SE) and energy conversion (XUS) of the ultrasonic system. Results of this study showed overall conversion efficiencies of 60-70%. This correlated well with the chemical dosimeter yield curves of both organic and inorganic aqueous solutions. All dosimeters showed bubble shielding and coalescence effects at higher ultrasonic power levels, less pronounced for the ½″ probe case. SE and XUS values in the range of 10(-10) mol/J and 10(-3) J/J respectively confirmed that conversion of ultrasonic power to chemical yield declined with amplitude.
authors.affiliation: School of Civil Engineering and Surveying, Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, 4350 QLD, Australia. Electronic address: RaedAhmed.mahmood@usq.edu.au.
authors.forename: Raed A
authors.initials: RA
authors.lastname: Al-Juboori
authors.affiliation: School of Mechanical and Electrical Engineering, Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, 4350 QLD, Australia.
authors.forename: Talal
authors.initials: T
authors.lastname: Yusaf
authors.affiliation: School of Mechanical and Electrical Engineering, Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, 4350 QLD, Australia.
authors.forename: Leslie
authors.initials: L
authors.lastname: Bowtell
authors.affiliation: School of Civil Engineering and Surveying, Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, 4350 QLD, Australia.
authors.forename: Vasantha
authors.initials: V
authors.lastname: Aravinthan
mesh_terms: D002138:Calibration; D002151:Calorimetry / Q000379:methods*; D018481:Convection; D011211:Electric Power Supplies; D007455:Iodine / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D009596:Nitrophenols / Q000737:chemistry / Q000528:radiation effects; D010084:Oxidation-Reduction; D013814:Thermal Conductivity; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods*
chemical_list: D009596:Nitrophenols; D007455:Iodine; D007501:Iron; C024836:4-nitrophenol
keywords: Calorimetric techniques; Convective heat loss; Heat transfer; High power ultrasound; Sonochemistry