Engineering design method for cavitational reactors: I. Sonochemical reactors

High pressures and temperatures generated during the cavitation process are now considered responsible for the observed physical and chemical transfor mations using ultrasound irradiation. Effects of various operating paramete rs reported here include the frequency, the intensity of ultrasound, and th e initial nuclei sizes on the bubble dynamics, and hence the magnitude of p ressure generated. Rigorous solutions of the Raleigh-Plesset equation requi re considerable numerical skills and the results obtained depend on various assumptions. The Rayleigh-Plesset equations was solved numerically, and th e results have been empirically correlated using easily measurable global p arameters in a sonochemical reactor. Liquid-phase compressibility effects w ere also considered. These considerations resulted in a criterion for criti cal ultrasound intensity, which if not considered properly can lead to over design or underdesign. A sound heuristic correlation, developed for the pre diction of the pressure pulse generated as a function of initial nuclei siz es, frequency, and intensity of ultrasound, is valid not only over the enti re range of operating parameters commonly used but also in the design proce dure of sonochemical reactors with great confidence.