Spray Simulation And Mist Recycling Optimization Of The Painting Robot

High-pressure airless spraying is the main painting method which is widely used in the hull plate painting by the shipyard.Because of the worker’s spraying technology,the spraying process may have the problem of producing more painting mist and low efficient which can be addressed significantly by using painting robot.The research on the painting robot is mainly focused on the principle of wall attachment,loading mode and trajectory planning at home and abroad.Meanwhile,there are few researches on the technology of high pressure spray atomization and paint mist protection.Aiming at this problem,the high pressure spray atomization and paint mist protection is researched in this thesis,the main work of this thesis is summarized as following:(1)The paper summarizes the development of the painting robots,and analyses their merits and demerits.Then based on the walking mechanism,function module and the painting method,design the new concept painting robots,which make the painting robots come to the real application.(2)Building the inner cavity model of the nozzle which has a equivalent diameter of 0.43 mm,and analyze the flow characteristics of the paint with different inlet pressure,then compare the simulation results with experiment results.According to the calculation model,determine the relation between spray pressure and the mass flow in the nozzle with a 0.48 and 0.38 mm equivalent diameter,providing computation basis for the atomization and the paint mist recycling.(3)The research studies the influence of the critical Weber number on the atomization effect with the DPM and atomization model in the Fluent.Simulation results show that the critical Weber number can be used to characterize the atomization difficulty,and the spray effect is influenced by the equivalent diameter of the nozzle.The higher the critical Reynolds number,the more difficult the atomization is.With the increase of critical Weber number,the Sauter Mean Diameter increases,and the air phase has a lower influence on the droplet velocity.(4)The paper studies the atomization effect under different atomization pressure and deposition rate under different spraying parameters.With the pressure increases,it can be found that the atomization effect is better,and the impact energy of the droplet decreases significantly,meanwhile the droplet which locate in the edge of the rectangle spraying area has a lower energy.The overall deposition rate rises when the spray pressure increases,and the distribution law of the paint is similar to the droplet impact energy.(5)The paper preliminary design the mist recovery cover and studies the kinetic characteristic of the paint mist in it,which discover that the mist has higher kinetic energy on the vertical direction.By lengthen the cover’s half long axis length on the vertical length and the number of the inhale surfaces,the efficiency of the cover increases significantly.The final project has a 83.4% recovery efficiency of the mist,which meets the needs of the practice.By studying the spray simulation,the paper further elucidate the influence law of the spray parameters on the atomization and deposition of the paint,study the motion characteristics of the mist and provide the guidance on the recycle cover design.