Mass transfer intensification by means of resonance oscillations in a pulsation apparatus with a central tube with and without nozzles

Abstract

An experimental study of resonance and non-resonance oscillations in a pulsating apparatus with a central tube was performed. Pulsating apparatus in two configurations was thoroughly investigated in the following way: (i) pulsating resonance apparatus with central tube, without nozzles and (ii) pulsating resonance apparatus with central tube, an additional tube, and nozzles. The following parameters were investigated as criteria for the onset of resonance: the liquid surface oscillations amplitude, the gas pressure oscillations amplitude in a gas-filled elastic element, the solid particles dissolution rate. A comparative analysis showed that the resonance frequencies, determined by the maximum amplitude of the liquid surface oscillations, by the gas pressure fluctuations and the dissolution rate of solid particles, are in good agreement with each other and with the theoretical value. The pressure pulsations were found as an easy and reliable for resonance identification. The dissolution rate of KOH particles increases up to 4–6 times at resonance frequency. At the same energy dissipation rate possesses approximately 10 times larger values of the liquid-solid mass transfer coefficient compared to the stirred tanks. With a decrease in the volume of a gas-filled elastic element, the amplitude of the oscillations at resonance increases, which is consistent with theory.