旋流塔板上的两相流场

在直径300mm塔内,用激光多普勒测速仪对旋流塔板上的流场进行了实验研究,探明其主要特征,进一步证实了过去对不同用途板型的设计思想.采用两方程k-ε湍流模型,应用有限差分法,对塔板上的气流场进行了数值模拟,计算结果与实验值符合良好.

TWO-PHASE FLOW FIELDS ON ROTATING STREAM TRAY

The flow fields of gas and simulating droplet are investigated with the DANTEC 55X laser doppler anemometer on 300mm rotating stream tray (RST). The clarified flow features include: (1)Axisymmetrical flow. (2)The tangential velocity ut distribution is composed of an inner forced vortex and an outer quasi-free vortex. (3) The upflow (axial velocity uz >0) is mainly in the annular cross-sectional area greater than 1 / 2 radius, and a downflow occurs in the area over the liquid receiving-distributing disk. (4)In the main two-phase contacting area, ut and uz are found to be well correlated as equations 1 and 2 respectively. (5)The radial velocity is about one-tenth of ut or uz. The respective purposes of the internally and externally-oriented trays in design can be established from the two-phase flow feadtures. Using a two-equation k-ε. model and a finite-difference procedure, a numerical model for calculating the turbulence flow on RST is also given in this paper. The computed velocities and pressures are compared with the experimental data, and satisfactory agreement is obtained.