Rotating Fluid Flow And Mass Transfer In The Bed Of The Experimental Study And Numerical Simulation

A rotating packed bed ( also called Higee ), used to intensify mass transfer and chemical reaction , is a new and high-performance equipment which was developed in the early eighties and has bright prospect in industries. In this dissertation, the fluid flow and mass transfer inside rotating packed beds were further investigated through experiments and computer simulating calculation on the basis of studies done by previous researchers in our center.Firstly, stroboscope, a new experimental method, was adopted to observe how liquid flows inside the rotating packed bed. The main principle of this technique is to control sensitization time of photographic plate by light impulse instead of shutter. With a very short light impulse time ( the shortest light impulse time is 8μs and this is the most advanced domestic technique ), we can ' freeze ' the liquid rotating and flowing at high speed inside Higee and obtain clear pictures. By this method, various pictures of flowing fluid in the three zones, i.e. the end effect zone, the block packing zone and the shell zone of RS dimple wire mesh packing and foam metal packing at different operating conditions were taken. From this pictures, It is known: ① on the surface of packing, liquid flows in the pattern of films; ② in the voids of packing, a lot of droplets, ligaments and films can be seen depending on operating conditions;③ in the end effect zone and the shell zone, liquid exists in droplets. Furthermore, the image analytic method measuring the diameters of droplets among RS wire mesh packing was used and they range from 0.1 to 0.3 millimeter.In water deaeration system, an experiment focusing on mass transfer of the end effect zone was done. In addition, we also carried on general mass transfer experiments on Higee packed with RS dimple wire mesh and plane wire mesh. On the basis of experiment results, an empirical correlation of the mass transfer coefficient of the end effect zone and curves of general mass transfer coefficient of these two kind wire mesh packing changing with operating conditions were given. These experiments were done in order to build and verify the Higee mass transfer model.Based on the observation of experiments, momentum equations and mass transfer equations describing the films on the surface of horizontal and vertical wire mesh were set up by rigorous derivation. These equations were solved, by a numerical method —...