Study On Mechanism And Performance Based On Different Solids Media For Air-lifting

Air-lifting system has the advantages of low cost,simple structure,little pollution,safety and reliability,etc.It can realize the traditional transportation system can not be applied to the situation,Such as drilling hydraulic mining in mine with complex hydro-geological condition of mine,deep sea mining and river dredging in deep waters and so on.In particular,the air-lifting system is used in drilling hydraulic mining,deep sea mining and river dredging.Moreover,it has great significance for reducing the contradiction between economic development and mineral resources supply,improving the river environment.At present,the research on the mechanism and performance of air-lifting under solid granular medium of different is not perfect,so the application of air-lifting system is limited.Therefore,this paper takes the air-lifting system under solid granular medium of different as the research object,the variation characteristics of air-lifting mechanism and performance with operation parameters are emphatically discussed by combining theoretical and experimental studies.In this paper,the critical lifting model under solid granular medium of different based on Newton's second law is established,and the critical lifting conditions of solid granular medium in air-lifting system are analyzed.Then,the lifting efficiency model including solid particle rate and liquid phase rate based on the conservation law of energy is established.Ceramic particles and river sand particles are used as the lifting medium of the air-lifting system respectively,and the change law of the performance of the air-lifting with the operating parameters is obtained.At the same time,the flow field structure of gas-liquid solid three-phase flow under two lifting media was captured by high-speed camera.Based on this,the flow mechanism in the riser was obtained based on image processing technology,the results show that:Under two kinds of solid granular medium,the lifting rate of solid particle and liquid phase increase with the increase of submergence rate.However,the lifting rate of solid particle and liquid phase increase first and then decrease with the increase of the volumetric flow rate of air.The air-lifting efficiency of two kinds of solid granular medium increases with the increase of submergence rate,and it shows a similar inverse relation with the increase of the volumetric flow rate of air.When the volumetric flow rate of air is low,the lifting rate of the river sand particles is higher than that of the ceramic particles.In addition,the calculation results of the critical lifting model and the lifting efficiency model are in good agreement with the experimental results.There are four kinds of flow patterns under two kinds of solid granular medium,namely granular vortex flow,granular wave flow,dense bubble flow and granular-annular flow.The dense bubble flow not only has the minimum difference in flow pattern characteristics under the same flow pattern,but also has lifting rate of two kind of solid particles reaching the maximum under this flow pattern.The slight change between the same flow patterns will cause great difference in the axial and radial velocities of the two kinds of solid particles.The main contents of this study are close to the engineering practice,and the research results have important engineering application value.