Construction of mathematical model of dissolution process of solids under action of ultrasound

Mel’nick, Viktorij; Ruzhinska, Ludmila; Forostyanko, Vitalij

doi:10.15587/2312-8372.2017.93629

Cited by 2 publications

(2 citation statements)

References 7 publications

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“…До таких переваг слід віднести формований дистанційно потужний глобальний рушійний висхідний потік, який інтенсивно обмиває придонні шари та циліндричну поверхню біореактора. За потреби всередині біореактора можна встановлювати деякі, канонічної форми, засоби для розвитку тієї чи іншої інтенсивності турбулентності, а також, навпаки, зон помірної енергетичної активності [8].…”

Section: вступunclassified

Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

Mel’nick

Fesenko

2017

Research Bulletin of the National Technical University of Ukraine "Kyiv Politechnic Institute"

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Background. The main problems that arise when using equipment for cultivation are to ensure the heat and mass transfer processes in devices, presence of turbulent and stagnant zones, high-energy consumption, low heat transfer coefficients when working with viscous fluids. Objective. The aim of the paper is the experimental determination of the remote control heat transfer advantages in production line bioreactors using ultrasonic beam compared to contact methods. Methods. An experimental study of the heat and mass transfer process in a bioreactor on the stand with UZP-6-1 immersion unit of the ultrasonic radiator with radiation frequency 42 kHz is carried out. Results. Sound waves emitted into a liquid form a concentration zone of passable sound energy in the confocal vessel form of a cylindrical surface and force the liquid to move along the inner surface of the glass along the ascending cylindrical spiral, forming a motive flow throughout the volume, causing peripheral layers of liquid and bottom layers to move in a horizontal and vertical planes, without leaving stagnant zones. The closer to the coincidence angle c  is the directed ultrasonic beam the greater is the effectiveness of the driving flow. Conclusions. The use of sound waves allows obtaining a high-quality product in technological lines based on bioreactors with minimal risk for the technological process. Radiation parameters and working volume physic-mechanical properties change allow fully using the properties of resonant manifestations of the sound wave influence on the working liquid with minimal costs.

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Section: вступunclassified

Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

Mel’nick

Fesenko

2017

Research Bulletin of the National Technical University of Ukraine "Kyiv Politechnic Institute"

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“…11) If the cavitation is activated in the vicinity of the solid surface, the mass transfer is promoted by micro-jet when the cavitation bubble collapses. 12,13) Therefore, dissolution rate is promoted by thinning or destroying the concentration boundary layer formed on the surface of the solid. [14][15][16] In general, a Langevin-type ultrasound transducer is used to irradiate ultrasound into a liquid, but the performance of the ultrasound transducer deteriorates in a high temperature system.…”

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confidence: 99%

Model Experiment for Acceleration of Lime Dissolution into Slag under Ultrasound Irradiation Conditions

Okumura

2017

ISIJ International

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In the metal manufacturing process, it is considered that ultrasound technology can be applied in the promotion of solid dissolution such as lime dissolution to molten slag and solid metal addition to molten alloy. Generally, in the high-temperature reaction process, mass transfer has a large effect on the rate of reaction in isothermal conditions. In order to facilitate mass transfer, it is necessary to strengthen the agitation of the bath. However, it is impossible to avoid the erosion of the stirrer and container. Enhancement of stirring promotes mass transfer. This corresponds to thinning of the boundary layer thickness in the boundary layer theory. To further accelerate mass transfer, a new method of thinning the boundary layer of the solid surface without using mechanical stirring is needed.In this study, the effect of ultrasound on the dissolution phenomena of solid in liquid was investigated by using a sucrose-water system. Applying ultrasound to a liquid induces ultrasonic radiation pressure, acoustic streaming and various nonlinear phenomena of cavitation. Especially, when the cavitation bubble collapses, a micro jet is generated and a strong flow occurs locally. It was thought that this micro jet collided with the solid sample and the surface became uneven. If the cavitation phenomena occur at the solid surface, it is possible to disturb the boundary layer and increase the mass transfer rate by thinning the boundary layer. It was found that the cavitation in the vicinity of the solid surface at the low ultrasound frequency caused a disturbance of the boundary layer of the solid surface and promoted dissolution rate of the solid.

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Construction of mathematical model of dissolution process of solids under action of ultrasound

Cited by 2 publications

References 7 publications

Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

Model Experiment for Acceleration of Lime Dissolution into Slag under Ultrasound Irradiation Conditions

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