Design And Experimental Analysis Of Electric Double Atomization Thermal Smoke Machine

At present,the conventional spraying method of manual sprayer is mainly used in facility agriculture of our country,followed by more advanced modern plant protection operation methods,such as smoke,normal temperature smoker,hot smog machine and so on.But the conventional spray method has great labor intensity and dosage of liquid,smoke method is easy to cause drug damage,at the same time,there is hidden danger of fire,and the dosage of smoke fumigant is not easy to master.The effective spray distance of normal temperature smoker is short,the atomization effect is poor and the volume is huge,it is inconvenient to move in the room,the noise of hot smoker is bigger when working,and it is easy to cause oil pollution and tail gas pollution.Therefore,the above-mentioned method is not suitable for plant protection of facility agriculture in our country.So develop a defense It is of great significance to improve the control effect of diseases and insect pests,reduce the use of pesticides and reduce the residues of pesticides in crops by means of a facility with uniform spraying and no pollution.The main research contents of this paper include the design and manufacture of the test device,the study of the secondary atomization mechanism,the simulation of the velocity under different conditions,and the test and analysis of the atomization performance of the test device.The research on the mechanism of secondary atomization mainly includes the principle of secondary atomization,the influencing factors,the relationship between characteristic crushing mode and dimensionless number,and the related parameters and standards for evaluating the atomization quality of droplets.The simulation includes the simulation of velocity under different pressures and different media and the analysis of the results.The composition of the test device mainly includes power supply,heating chamber,heating pipe,high temperature steam solenoid valve,nozzle,temperature resistant pressure gauge and safety valve.The liquid atomization prescription studied in this paper The zero use of fuel is realized by using gas-liquid integrated heating evaporation vaporization mode.The primary atomization is realized by heating evaporation vaporization in the heating chamber,and the secondary atomization is realized by air flow impact according to the pressure generated by the heating chamber,and the droplet diameter is reduced.The blade attachment rate of droplets is improved,and the high speed gas produced by conventional pulse jet engine is replaced by the pressure generated by heating chamber,which can not only achieve the atomization effect of the existing thermal smoke machine,but also eliminate the oil pollution and tail gas produced by fuel.Filled in the domestic and foreign blank.The device takes electricity as the only power source,which is more environmentally friendly,less noise and low cost,so it is more suitable for facility agriculture at present.Plant protection requirements.According to the simulation results,the velocity of the medium increases with the increase of pressure under different pressures,and the amplitude of velocity attenuation is basically the same under different pressures.According to the same pressure condition,the velocity of air,water vapor and water varies greatly,which is mainly affected by its viscosity,density and other factors.The velocity of the central air flow at the outlet of the nozzle of the conventional pulse smoke machine(where the liquid is in contact with the pulse air flow)is about 50 m / s,and the pressure is about 0.8 MPA,which is in good agreement with the velocity cloud picture of the above water.Therefore,the nozzle outlet speed is higher than that of the conventional pulse smoke machine under the same conditions,and the working distance can be obtained by using the water vapor mode.You can reach farther.According to the designed test,the atomization performance of the test device was tested in laboratory.The effects of the parameters such as the opening pressure,the initial water quantity and the nozzle aperture on the atomization effect were analyzed.The experimental results show that:(1)the influence of each factor on VMD,NMD,DR and water consumption is in order of nozzle diameter,initial water volume,opening pressure,and the influence of each factor on injection distance is nozzle aperture and opening pressure in turn.Initial water volume;(2)the experimental indexes increased with the increase of nozzle diameter,and the effect was significant;(3)VMD,NMD first decreased and then increased with the increase of initial water volume,D R decreases with the increase of the initial water quantity,and the injection distance and water consumption increase with the increase of the initial water quantity.(4)with the increase of the opening pressure,VMD,NMD and DR firstly increase and thendecrease,and the injection distance and water consumption first increase with the increase of the opening pressure,then tend to dynamic stability;(5)Comprehensive analysis shows that the opening pressure is the best for 0.4 MPa,the initial water quantity for 1100 ml is the best,and the nozzle diameter is the best for 2.5 mm;(6)in this paper,the influence of each factor on the test result is analyzed only through the test device,and a preliminary reference scheme is given to the design of the prototype,and then the smog machine needs to be brought in.The whole machine is designed and manufactured,and field tests are carried out.