Spray Characteristics And Experimental Study On Household Low-pressure Nozzle Based On The Principle Of Effervescent Atomization

Nozzle is one of the important parts of the household atomizer.It's structure and size has a great effects on the spray atomization.The main problem of the ordinary intermittent piston sprayer is that it's produced spray droplets size is too large.Effervescent atomization is a new method of liquid atomization,which can obtains significant improvements in performance in terms of smaller drop sizes and lower injection pressures,What's more important is that the amount of atomizing gas required is considerably less than what is employed in all other twin-fluid atomization techniques.The research of applying effervescent atomization principle on ordinary intermittent piston spray has not been found.The major work in this paper is to study the application characteristics of the effervescent atomization technology in the household low-pressure spray and mainly use the method of computer numerical simulation and experimental study.The main work and achievements are followed:1.Combined with atomization characteristics of household intermittent spray,The author designed a new effervescent atomization nozzle by referencing to the previous research results on the low-pressure effervescent atomization characteristics.2.Simulating the impact of the gas injection location in the mixing chamber on the gas-liquid mixing fluid conditions based on the structure of the nozzle with the simulation software FLUENT,then the impact of orifice aspect ratio on the droplets speed was also simulated.Found that the spray stability gets better when the vertical distance between the bubble generator and the axis of the mixing chamber is 1.5mm and when the orifice aspect ratio L/D =3,the speed is the largest and the penetration distance is the longest.3.Experimental study is the primary means of effervescent atomization study.Combined with the atomization characteristics of household intermittent piston spray,the author independently designed and built effervescent atomization characteristic measurement and control experimental platform.Then,the effect of the mixing chamber structure on the stability of the effervescent atomizers is studied by using high-speed camera apparatus.As a result,when the axial distance between the bubble generator end elliptic center and the mixing chamber is 1.5 mm,the nozzle stability is best.With Particle Image Velocimetry,the effects of orifice aspect ratio on the jet speed and the penetration distance is studied.When the orifice aspect ratio L/D =3,the speed is the largest and the penetration distance is the longest.The experimental results verify the well-prediction of the simulation results.What is also found by the experiment is that spray angle decreases with increasing aspect ratio.Consequently,in the working condition with the same velocity of the exit orifice,the author observed the spray effect of single-phase jet and effervescent atomization,and concluded that the effect of effervescent atomization is better than that of single-phase.In this paper,the author used the self-designed low-pressure spray nozzle and the effervescent atomization measure and control experimental platform,through the simulation and experimental study,the effervescent atomization technology is verified that it can improves the atomization effects of the household low-pressure spray and could be applied in the household low-pressure sprayer field.