Kracík Tomáš, Moucha Tomáš, Petříček Radim
Chemical Engineering Department, University of Chemistry and Technology, Prague, Technická 5, 166 28 Praha 6, Czech Republic.
Institute of Hydrodynamics of the Czech Academy of Sciences, Pod Pa'ankou 30/5, Prague 166 12, Czech Republic.
ACS Omega. 2020 Mar 5;5(10):5072-5077. doi: 10.1021/acsomega.9b04005. eCollection 2020 Mar 17.
Mass transfer processes are one of the most important operations in chemical, biochemical, and food industries worldwide. In the processes that are controlled by the gas-liquid mass transfer rate, the volumetric mass transfer coefficient becomes a crucial quantity. The dataset was measured with the aim to create a correlation for prediction in a non-coalescent batch under the wide range of experimental conditions. The dynamic pressure method, which was reported as physically correct in the past, was chosen to be the method for experimental determination of . Our previous work targeted the dependencies in viscous and coalescent batches resulting in correlations that are viable for the broad range of process conditions. We reported that the best-fit correlation is based on the hydrodynamic parameter circumferential velocity of impeller blades in the case of non-coalescent liquids in the vessel equipped by single or multiple impellers at a constant / ratio (diameter of the impeller to the inner diameter of the tank). Now, we focus on the influence of various impeller diameters on transport characteristics (mainly ) in a non-coalescent batch. The experiments are carried out in a multiple-impeller vessel equipped with Rushton turbines (of four diameters) and in both laboratory and pilot-plant scales. Various impeller frequencies and gas flow rates are used. We examine the suitability of the hydrodynamic description, which was reported in the past, to predict also when the / ratio changes. We show that the correlation based on the energy dissipation rate better fits the experimental data and predicts values more accurately in the case of varying / values. This correlation could be adopted in the design and scale-up of agitated devices operating with non-coalescent batches.
传质过程是全球化学、生化和食品工业中最重要的操作之一。在由气液传质速率控制的过程中，体积传质系数成为一个关键量。测量该数据集的目的是建立一个在广泛实验条件下用于非聚并间歇过程中体积传质系数预测的关联式。过去被报道在物理上正确的动态压力法被选作实验测定体积传质系数的方法。我们之前的工作针对粘性和聚并间歇过程中的体积传质系数相关性，得到了适用于广泛过程条件的关联式。我们报道，在配备单个或多个叶轮的容器中，对于非聚并液体，在恒定的叶轮直径与罐体内径之比（d/i）的情况下，最佳拟合关联式基于叶轮叶片的流体动力学参数圆周速度。现在，我们关注不同叶轮直径对非聚并间歇过程中传输特性（主要是体积传质系数）的影响。实验在配备有四种直径的Rushton涡轮的多叶轮容器中进行，涵盖实验室和中试规模。使用了不同的叶轮频率和气体流速。我们检验过去报道的流体动力学描述在d/i比变化时预测体积传质系数的适用性。我们表明，基于能量耗散率的关联式能更好地拟合实验数据，并且在d/i值变化的情况下能更准确地预测体积传质系数值。该关联式可用于设计和放大运行非聚并间歇过程的搅拌装置。
