Design And Experimental Study Of Gas-assisted Ultrasonic Atomizing Nozzle With Adjustable Spray Width

Ultrasonic atomization technology has been widely used in various fields due to its good uniformity of droplets,small average particle size,concentrated distribution,and low power consumption.In order to solve the existing problems,and further enhance the anti-interference ability of the spray and the practicability of the spray head.Under the premise of ensuring the uniformity of spraying and the stability of the fog cone,the adjustability of the spraying width within a relatively large range can be achieved as much as possible.In this paper,a method of combining mathematical modeling and finite element simulation analysis was used to design a gas-assisted ultrasonic atomization device.Based on this,an adjustable gas supply fluid channel was designed to achieve a convergent spray and scattering type spray in an ultrasonic atomizing nozzles.The main research content of this paper are as follows:First of all,the specific size parameters of the main mechanical vibration structure ultrasonic transducer and the horn of the air-assisted ultrasonic atomizing nozzle with adjustable spray width are calculated through theoretical formula derivation.Combined with the finite element analysis technology,the modal analysis method was used to perform virtual simulation analysis on the transducer with a horn,and the simulation results were compared with the theoretical design values.The modal analysis of the designed structure was performed by ANSYS software.The longitudinal vibration modes with only 0.075% error from the theoretical design were obtained.The performance requirements of the ultrasonic atomization transducer were satisfied.The correctness of the theoretical design was verified by simulation.The final dimension parameters of each part of the mechanical vibration structure are obtained.Secondly,the composition and basic working principle of the air-assisted ultrasonic atomizing nozzle are introduced.On the premise of determining the mechanical vibration structure,the flow channel of the ultrasonic atomizing nozzle is designed through a fluid simulation method.When spraying with a small width,a single variable method is used to change the various parameters of the fluid structure,and the optimal structural parameters are selected by observing and analyzing the motion of the gas inside the nozzle and the jet flow at the nozzle in the fluid simulation results.When spraying with a wide width,a turbine gear is used to increase the spray width and the feasibility of the design is directly verified by fluid simulation.Determining the overall structural parameters,materials,and making a prototype.Finally,an ultrasonic atomization spray test platform was set up to complete the spray experiment.A series of related experiments were conducted on the air-assisted ultrasonic atomizing nozzle designed to study the control factors that affect the spraying effect.The experimental results show that in the case of small width spraying,the spraying width first increases and then decreases within a certain supply pressure range,and finally becomes stable.The spraying height was changed within a certain range.As the height increased,the spraying width first increased slightly and then decreased and eventually became stable.In the same way,changing the liquid supply flow within a certain range,it was found that the change in the liquid supply flow has little effect on the spray width.When spraying with a large width,it was found that within a certain supply pressure range,the spray width increased with the increase of the air supply pressure,and eventually stabilized.When the spray height is changed within a certain range,the spray width gradually increases as the height increases,and eventually becomes stable.In the same way,changing the liquid supply flow within a certain range,it was found that the change of the flow rate of the liquid supply had little effect on the spray width,and the spray width remained basically unchanged.The small-width and wide-width spray test conducted in the atomizing nozzle fully prove that the ultrasonic spray nozzle spray width is adjustable within a certain range.Finally,the spray effect was tested.The results showed that the spray was uniform,the spray fog cone characteristics were stable,and the spraying effect was good.