| The Novel Rotating Foam Scrubber is a new gas-liquid mass transfer equipment developed on the basis of power wave technology,which can be widely used in chemical industry,metallurgy,medicine and other industries.Compared with the conventional washing equipment,it has the advantages of simple equipment structure,large gas-liquid flow elasticity,high mass transfer efficiency and high economic benefit.Using CFD technology to accurately simulate it can effectively reduce experimental work and production costs,and improve research and development efficiency.At the same time,the simulation results can also provide guidance for the structure optimization of the scrubber,which has very important engineering significance and economic value.In this paper,CFD software is used to simulate the internal flow field of the Novel Rotating Foam Scrubber.The gas-liquid multiphase mass transfer,heat transfer and evaporation models were established,and the newly designed washing tube and nozzle were calculated by Euler multiphase flow model respectively to study the influence of different structures on the flow field distribution.The theoretical calculation model is provided for the amplification and structure optimization of the Novel Rotating Foam Scrubber,and the basis for its industrial application is provided.The Realizable k-ε turbulence model and Euler multiphase flow model were used to simulate the gas-liquid multiphase flow in the Novel Rotating Foam Scrubber.Firstly,the three-dimensional physical model was established according to the geometric parameters of the equipment,and the mesh division and independence verification were carried out on the model.The number of mesh was three hundred and fifty thousand which could meet the calculation requirements.The mesh was imported into CFD software for calculation,and the error between the jet height and the experimental value was less than 10%,which verified the accuracy of the simulation model.Secondly,according to the internal distribution and flow conditions of the flow field,the washing pipe is divided into three mass transfer zones: gas-liquid collision,gas-liquid counterflow and gas-liquid sedimentation.It is found that in the gas-liquid collision mass transfer zone,the axial velocity is small and the horizontal velocity is large.Finally,the distribution of gas holdup in the simulation results of different operating parameters was analyzed,and the mass transfer effect was better when the liquid-gas ratio was 0.0101～0.0162.On the basis of multiphase flow,heat transfer(Ranz-Marshall)and evaporation(Lee)models were added to simulate the heat transfer and evaporation of gas-liquid multiphase flow in the Novel Rotating Foam Scrubber.In the experiment of cooling water by cold air,it is found that water evaporation is the main part of energy consumption.Through CFD software calculation,the comparison error between the evaporation amount of water and the experimental value is less than 10%,which verifies the reliability of the heat transfer and evaporation model.According to the phase conversion rate cloud map,it is found that there is a large conversion rate near the gas-liquid collision and gas-liquid counterflow region.Finally,different operating parameters were simulated,and the inlet water temperature was the main factor affecting the phase conversion rate,and the outlet air temperature under different operating conditions was predicted.The washing pipe and nozzle with changed structure were calculated by using multiphase flow model.After changing the shape of the washing pipe and replacing part of it with hyperbolic line,it is found that the turbulent kinetic energy in the gas-liquid collision zone is strengthened.When the hyperbolic line is at the upper end,it can increase the horizontal velocity of gas phase in the atmospheric liquid collision zone and promote the mixing between gas and liquid.Finally,the internal structure of the nozzle is changed to reduce the inlet pressure,but the atomization performance of the nozzle is reduced. |
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