Study On Coating Removal Efficiency Of Gas Liquid Two-phase High-Pressure Jet

In recent years,High pressure water jet technology has developed rapidly and has been widely used in many fields.As a non-traditional processing technology,water jet processing technology has gradually shown its unique advantages in the field of industrial manufacturing.In this paper,a gas-liquid two-phase high-pressure jet technology is proposed for the recycling of waste parts in the market.Based on the theoretical analysis,the design,simulation and experimental research of the liquid-liquid mixing device are carried out.Finally,a high-pressure gas-liquid mixing jet generator with convenient disassembly and adjustable parameters is designed and manufactured.In order to verify its flow characteristics and mixing effect,a variety of numerical experimental models are established in this paper,which are meshed by ICEM CFD and based on ANSYS the velocity and pressure distribution of gas-liquid two-phase flow field were simulated and analyzed by fluent.The mixing effect under different initial velocity and pressure and the distribution law of internal and external flow field of jet impinging on target surface under different initial pressure,velocity and target distance were obtained.The results show that when the pressure of high-pressure water medium increases,the volume fraction of gas in the gas-water mixed jet gradually decreases in the range of 20%-30%;when the pressure of mixed jet increases,the effective cleaning area gradually increases,and the increasing rate of cleaning area becomes slower and slower with the increase of jet pressure;based on the acoustic emission technology,the acoustic signal of gas-water jet impacting the target is obtained,and the acoustic characteristics are compared and analyzed The results of signal spectrum and power spectrum show that with the increase of air intake,the distribution range of main frequency is not affected from 10 KHz to 100 KHz,but the amplitude first increases and then decreases,and the power spectral density is slightly different.The cleaning efficiency of the two-phase jet is obtained through experiments with the change of the inlet flow parameters.The material removal width is related to the geometry of the jet(or jet state),and the removal width is directly affected by the inlet air volume,moving speed,target distance and other parameters.influences.The removal width of the paint coating increases with the increase of the system pressure,mainly because the impact pressure in the core area of the jet beam increases with the increase of the jet system pressure;with the increase of the nozzle movement speed,the jet beam is at a certain target.The impact residence time of the area is relatively reduced,the jet beam shape changes,and the paint removal width is relatively narrow;as the target distance increases,the jet beam diameter of the gas-liquid twophase jet gradually increases along the jet direction.Therefore,the radius of the jet impact area is also increased accordingly.Experimental studies have shown that the effective removal area radius(ie removal width)of the coating increases first and then decreases with the increase of the target distance;with the increase of air intake,the removal width also presents the rule of first increase and then decrease.The material removal rate is negatively related to the traverse speed,and positively related to the removal width,which is consistent with the simulation results.Finally,this paper establishes a regression prediction model,which can predict the results under different adjustable parameters and help select the appropriate parameters.It can be obtained that when the moving speed is 150mm/min,the optimal solution is that the air intake volume is 12.628L/min,the target distance is 125.986 mm,and the cleaning area can reach 56.77mm2.Under the same conditions,the efficiency is improved by 34.81 compared with 42.11mm2 without air intake.%;The air intake volume is 11.445L/min,the target surface distance is 83.786 mm,and the material removal rate is the maximum 215.900mm2/min.Compared with pure water jet,it is increased by 56.432%.