【摘要】 建立了薄膜蒸发器的计算模型,采用大型计算流体力学(CFD)分析软件CFX4.4模拟了薄膜蒸发器内水及粘性料液的流动过程,得到了各种速度分布.结果表明,刮板转速、进料量对流体流动状态影响显著.提高刮板转速,可明显促进液膜和圈形波内流体的物质交换.在任一转速下,各料液均存在同一最佳进料量,此时其圈形波截面内平均速度达到最大值.对纯物质水,最佳进料量对应的流动边界层厚度与膜厚之比最小.粘性料液和水的轴向速度分布存在差异,且在液膜厚度内未形成明显的流动边界层.更多还原

【Abstract】 The calculation model of thin film evaporator (TFE) was developed, the flow of water and viscous fluid was simulated using CFX 4.4 software and the velocity distribution was obtained. The results show that the rotor speed and feeding rate have great effects on the fluid flow of TFE. The material exchange between the fillet and film can be promoted by increasing the rotor speed. There is one common optimum feeding rate under different rotor speeds for different fluids. At this feeding rate, the mean velocity in the fillet section reaches the maximum value. For water, the ratio of flow boundary layer thickness to film thickness is the minimum under the optimum feeding rate. Difference exists for the axial velocity distribution between viscous fluid and water, and no obvious flow boundary layer forms for viscous fluid.更多还原