An experimental study was carried out to enhance osmotic dehydration of fruits—apples using acoustic cavitation.The variation in water losses and dry matter gain rates of materials with solute concentration, cavitati...An experimental study was carried out to enhance osmotic dehydration of fruits—apples using acoustic cavitation.The variation in water losses and dry matter gain rates of materials with solute concentration, cavitation intensity, the thickness of materials and treating time segment during osmotic dehydration was discussed,at the same time, the influence of different materials on mass transfer during osmotic dehydration using acoustic cavitation was investigated.The results showed that water losses rates of materials were remarkably increased during osmotic dehydration using acoustic cavitation, but dry matter gain rates increased very little.Meanwhile the physical mechanism of enhanced mass transfer during osmotic dehydration with acoustic cavitation was clarified on the basis of analyzing the experimental results.展开更多
In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the st...In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the steadycavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order methodwith adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure fielddownstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (correspondingto the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motionof bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamicbehaviors of bubble different from those in previous papers are displayed. In addition, the internal relationshipbetween bubble dynamics and process intensification is also discussed. The simulation results reported in thiswork reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundationfor the practical application of hydrodynamic cavitation technology.展开更多
文摘An experimental study was carried out to enhance osmotic dehydration of fruits—apples using acoustic cavitation.The variation in water losses and dry matter gain rates of materials with solute concentration, cavitation intensity, the thickness of materials and treating time segment during osmotic dehydration was discussed,at the same time, the influence of different materials on mass transfer during osmotic dehydration using acoustic cavitation was investigated.The results showed that water losses rates of materials were remarkably increased during osmotic dehydration using acoustic cavitation, but dry matter gain rates increased very little.Meanwhile the physical mechanism of enhanced mass transfer during osmotic dehydration with acoustic cavitation was clarified on the basis of analyzing the experimental results.
基金support of the National Natural Science Foundation of China (Grant No. 50806078)the National High-Tech Research and Development Program of China (863 Program, Grant No. 2006AA05Z203).
文摘In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the steadycavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order methodwith adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure fielddownstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (correspondingto the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motionof bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamicbehaviors of bubble different from those in previous papers are displayed. In addition, the internal relationshipbetween bubble dynamics and process intensification is also discussed. The simulation results reported in thiswork reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundationfor the practical application of hydrodynamic cavitation technology.
