چكيده به لاتين
In this study, the effect of three parameters of mixing velocity, dispersed phase velocity and continuous phase, interphase tension on droplet size, holdup and slip velocity in four columns, oldshoe-Rushton, PRDC, Kuhni, ARDC in hydrodynamics and mass transfer based on central composite design ( CCD) are examined. The systems studied in this research include toluene-water chemical system (high interfacial tension), normal butyl acetate-water (medium interfacial tension), butanol-water (low interfacial tension) in hydrodynamics, and toluene-acetone-water system. - Water, butyl acetate - acetone - Water is in the mass transfer section. With a very accurate prediction of the system due to the correlation of coefficient values (R2) above 0.99, which is a very good value and shows the accuracy of the method used, based on the model, three correlations have been created for the studied answers. Using RSM method, the effect of operational parameters on (drop size, dispersed phase inventory, slip velocity and Kod) in four columns of RDCs was investigated, and it was observed that the two parameters of holdup and drop size strongly affect the mixing speed. Increasing the mixing speed increases the dispersed phase inventory. Because the droplet failure increases and as a result the droplet size decreases. According to the results, the oldshoe-Rushton column not only shows more scattered phase inventory at the same speeds, but also shows a greater effect of the rotor speed than other columns, which can be due to the presence of paddle blades and design Be specific to the interior of this column. As the dispersed phase flow increases due to the increase in the number of droplets in the fixed volume, the dispersed phase volume fraction increases and as a result the holdup increases for all four columns, among which the PRDC column shows a smaller increase. This increase is observed in all 4 columns, with the difference that in the three columns of Kuhni, oldshoe Rushton and ARDC, to the design of the internal auditorium, it shows the same behavior. For all four columns, the droplet size decreases as the rotor speed increases. This decrease occurs more severely for the oldshoe-Rushton and Kuhni columns. Increasing the dispersed phase velocity in the four studied columns has increased the drop diameter, which is more in the Oldshoe-Rushton column than in the other three columns. Increasing the continuous phase velocity for the four columns causes subtle changes in the droplet size, in other words the effect of this parameter on the droplet size is negligible, and it changes equally in all four columns. By increasing the agitator speed at constant and continuous phase flow rate, the sliding speed decreases, with increasing the dispersed phase flow rate and consequently increasing the number of droplets at constant stirrer speed and continuous phase constant flow rate in four columns, the sliding speed increases. With increasing continuous phase discharge, the slip velocity decreases. With increasing continuous phase discharge at constant stirrer speed and constant phase discharge, the relative velocity between the droplets and the continuous phase decreases, which reduces the slip velocity of the phases. The mass transfer coefficient in both systems increases as the rotor speed increases, the droplet size decreases as the internal circulation within the droplets decreases, and as a result, the Kod decreases as the rotor speed increases. Reducing the droplet size reduces the internal circulation inside the droplets, and as a result, the Kod decreases as the rotor speed increases. The results showed that the effect of mass transfer coefficient is generally less than the common surface and as a result the overall performance of the column increases with increasing rotor speed.
