Research On The Spray Deposition Distribution Law Of The Vertical Spray Bar For Melons And Vegetables Grown On Hanging Vines In The Facility And The Design Of The Machine

Due to the closed space,insufficient light,high temperature and high humidity in the facility greenhouse,coupled with the low number of natural enemies in the greenhouse,and the low resistance of crops to diseases,the incidence of diseases and insect pests of facility-grown crops is higher than that of open-field crops.Therefore,the task of prevention and control of plant diseases and insect pests of facilitygrown crops is more severe and difficult,and the demand for prevention and control technology and equipment is higher.At present,the chemical control of crop diseases and insect pests in the facility mainly uses plant protection machinery to spray the stems and leaves.The main part of plant protection machinery is the crop canopy.The canopy structure of crops in different growth periods is not completely the same.There are certain differences in the leaf area,leaf area index,plant height,plant spacing and other parameters of the canopy.However,the existing pesticide application methods do not target the crop canopy.Characteristic for differentiated application.Aiming at the problems existing in the current facility plant protection application,this paper conducted the following research.1)Taking the existing commonly used knapsack electric sprayer and knapsack air-assisted sprayer as the research object,the typical planting crops of watermelon,pepper and other facilities are used as the target in the vegetable greenhouse in the Suzui Modern Agricultural Industrial Park,Huaian District,Huai’an City,Jiangsu Province The crops were sprayed and tested,and the spray deposition rules of the existing machinery on the crop canopy were explored,especially the fog drop density on the upper,middle and lower layers of the crop canopy and the front and back sides of each leaf was discussed.The factors affecting the distribution of deposits,as well as the advantages and disadvantages of existing pesticide application equipment,provide a theoretical basis for the design and development of new facility plant protection equipment.2)According to the planting method of hanging vine melon,the vertical spray bar spray mechanism was designed,and different structural parameters(nozzle type,installation angle,nozzle spacing)and working parameters(pressure,flow,height)were carried out using CFD simulation technology.According to the research of the deposition distribution law under the following research results,the optimal parameters of the vertical spray bar spray mechanism are determined.3)The vertical mist distribution tester and laser particle size analyzer are used to verify the deposition distribution law of the vertical spray bar spray mechanism.The research results show that the spray pressure has an influence on the mist volume of the vertical spray bar spray device,and it has an even distribution.No significant impact on performance;when the spray distance is 0.5 m,the uniformity of the mist distribution is the best;when the spray pressure increases,the droplet size of the vertical spray bar at different spray heights decreases,but the droplet size generally appears with the spray height Wavy changes.4)With the vertical spray bar spray device as the core,combined with the space structure of the facility greenhouse and the requirements of the combination of agricultural machinery and agronomy,the crawler vertical spray bar sprayer was designed and developed.Relevant design,calculation and selection of the key components of the crawler vertical boom sprayer are carried out.Use Pro/Engineer to design a digital prototype of a crawler vertical sprayer suitable for hanging vines and vegetables in facilities,use CAXA CAD electronic drawing board 2019(x64)to draw engineering drawings and conduct trial production of the prototype.The crawler vertical spray bar sprayer can realize the remote-control spraying of the separation of the human and the pesticide,and can carry out the differential spraying according to the spraying needs of the crops,reduce the spraying amount of the liquid,and improve the uniformity of the droplet distribution in the canopy.The effective utilization rate of pesticides;it can guarantee the safety of operators,which is of great significance for reducing pesticide application and alleviating land nonpoint source pollution.5)Taking the knapsack sprayer and the knapsack air assisted sprayer as CK comparison,the spray deposition test of the crawler vertical sprayer sprayer was carried out in the sunlight greenhouse of the Shouguang Vegetable Research and Development Center of the Chinese Academy of Agricultural Sciences,Shouguang City,Shandong Province.The results show that the average droplet density of the whole crop on the melon crop by the crawler vertical sprayer is 111.33/cm2,and the droplet density on the front of the leaf is slightly higher than that on the back;the coefficient of variation of the droplet density between different sampling points is 11.52% The coefficient of variation of droplet density at the same sampling site ranges from 13.46% to 38.83%,which proves that the crawler vertical boom sprayer has a better distribution uniformity,which is better than backpack sprayers and air blower sprayers,and can meet the requirements of greenhouse cranes.The inter-row application of vine melon is required to achieve the goal of combining agricultural machinery and agronomy.