Kinetic Process Of Droplet And Continuous Phase Acting On Liquid Film In Gas-liquid Separation

Gas-liquid separation based on the principle of inertia is designed to be a complex multiphase-flow process.The corrugated plate gas-liquid separation is a typical representative of gas-liquid separation.The collision process of droplets on the wall,as well as the interaction process between the continuous phase and the liquid film on the wall not only determines the separation efficiency of corrugated board gas-liquid separation,but also widely exists in nature and industry,such as raindrop falling,inkjet printing and so on.Therefore,studying this process plays a significant and instructive role in both improving the gas-liquid separation efficiency of corrugated board and the explanation of natural phenomena and the description of other processes in industry.(1)Based on the volume of fluid method,this paper studied the effects of We,collision incidence angle and liquid film thickness on the collision behaviors of liquid droplets and liquid film,and then obtained the characteristic conditions of absorption,breakup and splashing during the collision process.The research shows that when We goes between 0 and137 and the droplet diameter ranges from 50μm to 100μm,the incidence angle of droplet increases from 36°to 90°,the critical We reduces in the collision evolution from adsorption to breakup and increases from breakup to breakup and splashing.When the incidence angle of the droplet increases from 30° to 36°,the critical We increases during the collision evolution from adsorption to adsorption and splashing and decreases from adsorption and splashing to breakup and splashing.With the dimensionless film thickness decreasing,the critical We reduces in the collision evolution from adsorption to breakup and decreases from breakup to breakup and splashing,when the droplet vertically hits the liquid film.(2)Based on the volume of fluid method,this paper studied the effects of gas inlet velocity,gas phase physical properties and liquid film thickness on the result of the gas phase and liquid film interaction process,and then obtained the characteristic conditions of the integrated gas phase viscosity(μ)and gas flow velocity on the effect of stable peeling and rupture during the action process.The characteristic conditions of stable peeling and rupture in the process of liquid film thickness and gas flow velocity are also obtained.The research shows that when the liquid film thickness is 0.2mm,the critical velocity when the liquid film ruptures due to the action of different gas phases and the liquid film decreases with the increase of the viscosity(μ)of the gas phase(air<methane<hydrogen).Under the same conditions of the gas phase,the gas phase interacts with the liquid film.As the gas velocity increases,the rate of gas phase peeling off the liquid film first increases and then decreases.When the thickness of the liquid film approaches a certain value,the liquid film is peeled off.The rate slowed down rapidly and approached zero until the liquid film was completely peeled off the wall.When the gas phase is the same and the inlet velocity is the same,the gas phase interacts with the liquid film.As the liquid film thickness increases,the critical rate of liquid film rupture and the volume fraction of the liquid film to be stripped also increase.(3)Realizable k-ε model and DPM method are used to study the influence of corrugated plate inlet velocity,plate spacing and continuous phase physical properties on the corrugated plate gas-liquid separation efficiency,and the influence of various parameters on the separation efficiency and the average liquid film thickness on the wall is obtained.The research results show that when the corrugated plate separates the water droplets contained in the air,with the increase of the inlet flow rate,the separation efficiency of the corrugated plate first increases and then decreases,and the critical stripping speed of the air is as large as 7m/s.with the increase of the corrugated plate spacing,the separation efficiency decreases gradually.with the product of the density and viscosity of the continuous phase increases,the average thickness of the liquid film on the wall decreases,the critical stripping speed also decreases,and the separation efficiency decreases.Through the simulation research in this paper,we have obtained the influence of We,collision incident angle and liquid film thickness on the morphological evolution of the impact of the droplet and liquid film,and the gas inlet velocity,gas physical properties and liquid film thickness on the morphological evolution of the gas and liquid film.Based on the basic analysis of the mesoscopic level,we can guide the improvement of the separation efficiency of corrugated plates in the macroscopic view.The mechanism of corrugated plates separation process is studied across the scales,which provides a reference for improving the gas-liquid separation efficiency of corrugated plates.It can be extended to the inertial separation process in gas-liquid separation,and has reference significance for optimizing gas-liquid separation equipment and selecting appropriate separation conditions.