Kuotsung Yu

A fluid-dynamic model for flow pattern on a distillation tray

Abstract A fluid–dynamic model for describing the liquid-phase flow on a sieve tray with consideration of both the resistance and the bubbling effect created by the uprising vapor phase is presented, and solved numerically by the method of control volume. For verifying the proposed model, the liquid velocity distributions on a sieve tray were measured by the hot-film anemometry. The theoretical predictions by present model are in agreement with the experimental results by the authors and from the literature.

Computational fluid-dynamics and experimental verification of two-phase two-dimensional flow on a sieve column tray

A modified two-fluid theoretical model is presented to describe the two-dimensional liquid phase flow on a sieve tray with consideration of the resistance created by uprising vapour, and solved numerically by the method of controlled volume. A sieve tray simulator is used for the experimental verification in which the local two-dimensional velocities of the liquid phase are measured by an improved technique using the hot film anemometer. The experimental results show that the liquid phase flow on a tray is substantially two-dimensional if the measurement is made more than 10 mm above from the tray floor, below which the flow is found to be three-dimensional. A comparison between the theoretical computations using the present model, the experimental results produced by the authors and those from the literature indicates that the proposed model gives a good prediction for the two-dimensional liquid phase flow on a tray under normal operation. Factors affecting the liquid phase circulating flow are discussed.

Two-dimensional flow and eddy diffusion on a sieve tray

Abstract Mean residence time distribution (RTD) profiles are measured by tracer technique on a single- and a double-pass experimental half-tray 2.0 and 2.4 m in diameter, respectively. By solving a two-dimensional diffusion model together with a specially arranged RTD measurements, the local liquid velocities and eddy diffusion coefficients in the longitudinal (main flow) and transverse (perpendicular to main flow) directions are estimated by the method of time domain least squares. Correlations on two-dimensional eddy diffusion coefficients are presented.