浆料气力提升系统压降特征研究

Research on Pressure Drop Characteristics of Slurry Airlift System

在构建浆料气力提升系统动量模型与效率模型过程中发现,管内压降模型及其变化特征对上述模型精度影响极为重要。鉴于此,以进气口为分界面,基于能量守恒并结合相含率方程分别建立液-固两相压降和气-液-固三相压降模型。计算结果表明,在两相段及三相段内,压降随管径增加均表现出先急速下降,之后趋于恒定的特征,且两相段内压降鲜受气体表观流速影响,而三相段内压降却随其增加表现出显著下降趋势。此外,无论是在两相段还是三相段内,压降实测结果与计算值吻合较好,特别是在较高浸入率和低气体表观流速工况下,两者吻合程度更佳。

In the modeling of the momentum and the efficiency of the slurry airlift system,the pressure distribution in the mixture flow is of great importance to the accuracy of the model.Taking the intake surface as the interface,a liquid-solid two-phase model and a gas-liquid-solid three-phase model are established based on the law of energy conservation and the phase hold-up rate equation.The calculated results illustrated that in the two-phase and the three-phase sections,the pressure drop decreases dramatically with the increase of the pipe diameter at first.Within the some characteristic pipe diameter,the pressure drop tends to be constant.In the two-phase section,the pressure drop has been found to be insensitive to the velocity of the gas flow.In the three-phase section,however,the pressure drop varies significantly with the velocity of the gas flow.In addition,experimental results coincide nicely with the calculated results in both the two-phase section and the three-phase section,especially under the condition of large submergence ratio and the low gas flow rate.