Numerical Simulation And Experimental Study On Lifting Process Of An Airlift Pump

The airlift pump relies on compressed air to lift liquid,liquid-solid mixture and other materials.It has many advantages such as simple structure,low cost,easy installation,easy clogging,safety and environmental protection,etc.Compared with other types of pumps,it can be used in deep waters.It is mainly used in mud removal work in salvage engineering,artificial ocean upwelling in fishery,mining deep sea manganese nodules,and transporting toxic or corrosive liquids in chemical industry.It is of great significance to various industries.At present,the research on the lifting mechanism and lifting performance of the airlift pump is still not perfect,and the problem of lifting efficiency has always been the focus.This paper combines numerical simulation with experimental research,the numerical simulation of the two-phase flow in the airlift pump is carried out firstly.The influence on the flow field is analyzed from the perspective of bubble behavior.Secondly,the experiment of two-phase flow in airlift pump was carried out and compared with the numerical simulation results.Finally,an experiment was carried out to raise the three-phase flow in airlift pump,and the influence of the design parameters on the lifting performance of the airlift pump was studied.In this paper,the physical model of the airlift pump is simplified,the numerical model is established,the grid is divided and verified.The standard k-ε turbulence model is selected for the flow state of the fluid in the tube.When selecting the multiphase flow model,consider the observation of the motion state and deformation of the bubble,the VOF model is selected.The boundary conditions and control parameters are determined.The numerical simulation results show that the single bubble rising deformation process is generally circular,mushroom,fusiform.When the number of bubbles increases,the bubbles affect each other and the bubble shape changes irregularly.In the process of continuous bubble rising,the acceleration of the bubble generated later is larger than the front bubble,so that the upper and lower bubbles are easy to fuse.Increasing the distance between the air-holes,the left and right bubbles are not easy to fuse.Increasing the number of holes and reducing the hole distance can increase the liquid velocity at the outlet of the airlift pump.The experimental results of the two-phase flow in the airlift pump are consistent with the numerical simulation results.In this paper,the three-phase flow in the airlift pump is also studied experimentally.The influence of various parameters on the lifting performance of the airlift pump is analyzed.The results show that the mass of the solid particles in the airlift pump gradually increases with the increase of the volumetric flow rate of air.After the maximum value,it tends to be gentle.When the volumetric flow rate of air is large,the mass of the solid particles is increasing with the increase of the volumetric flow rate of air,but the efficiency of the airlift pump is decreasing.Increasing the diameter of the pipe will delay the initial intake of the solid particles in the airlift pump.In the case of a large value of volumetric flow rate of air,increasing the pipe diameter can increase the mass of solid particles.The value of volumetric flow rate of air which makes pump has the highest efficiency changes when pipe diameter is different.To reduce the distance of the holes to a certain extent,the mass of solid particles lifted by the air lift pump can be increased,and the efficiency of the air lift pump can be increased.When the distance of the holes changes,the value of the volumetric flow rate of air that maximizes the efficiency also changes.In engineering application,in the case of a definite air volume flow value,a reasonable selection of the pipe diameter and the air hole distance can help to improve the efficiency of the air lift pump.The research content of this paper has important significance for the optimization design of airlift pump,and the research results obtained have important engineering application value.