Design And Experimental Study On Pneumatic Fertilizer Deep Applicator For Paddy Field

Rice is one of the main crops in our country.Top dressing can supplement the deficiency of nutrient elements in mud soil,base fertilizer and seed fertilizer,and is the guarantee for high and stable yield of rice.At present,the top dressing method of rice is mainly fertilizer spreading,but the fertilizer loss is serious,the utilization rate is low,and water and environmental pollution are easily resulted.It is of great significance to explore reasonable fertilization technology to ensure efficient utilization of fertilizer,ensure high and stable yield of rice and avoid fertilizer pollution.For this reason,a pneumatic top dressing device for rice was designed in this study.It explores a top dressing fertilizer application method that uses high-speed airflow as conveying power,divides water to reduce drag,and injects high-speed fertilizer particles into muddy soil.The main research contents and conclusions are as follows:1)A topdressing device that uses high-speed airflow to deliver and inject high-speed fertilizer particles into muddy soil.Because the surface of paddy field is covered with water,the fertilizer particles need to overcome the resistance of water before entering the mud,which affects the depth of mud entry and has poor mud entry effect.Therefore,a deep topdressing method of water diversion and drag reduction is adopted to solve the problem of high resistance of water in the process of fertilizer entering the mud,so as to improve the utilization rate of fertilizer.2)Overall design of the pneumatic deep top dressing device was carried out according to the agronomic requirements of top dressing for rice,.The design of key components such as fertilizer box,parallel four-bar profiling mechanism,gas pipeline,gas-fertilizer mixing joint and manifold was carried out.The structural parameters of each component were determined through theoretical calculation and empirical analysis.3)Through dynamic analysis,the conditions under which fertilizer can be smoothly discharged from the gas delivery pipe into paddy soil are studied,and the outlet velocity of the air pressure stabilizing distribution chamber is determined.Theoretical calculation shows that the inlet velocity of air flow is 32 m/s.At the same time,fertilizer can be smoothly injected into paddy soil,which further provides a theoretical basis for designing the air pressure stabilizing distribution chamber.4)Fluent numerical simulation is used to compare and analyze the uniform flow distribution performance of the direct current air chamber and the flow distribution air chamber.It is revealed that adding three-way and elbow flow distribution devices in the inside of the direct current air chamber can significantly improve the uniformity of the output air flow.On this basis,the influence of air inlet velocity on the pressure loss and distribution uniformity in the air chamber was further studied to provide theoretical basis for the optimization of pneumatic rice deep fertilizer application device.5)Taking the air flow speed,the amount of fertilizer applied and the advancing speed of the machine as the test factors,and taking the rate of fertilizer breaking and the depth of fertilizer buried as the test indexes,the performance test research of the pneumatic deep fertilizer application device for rice was carried out.The influence of the test factors on the test indexes and the better range were determined through the analysis of variance of single factor test.On this basis,the regression model of the factors with the fertilizer crushing rate and the fertilizer penetration depth was established through the ternary quadratic general rotation combination test.The response surface method was used to analyze the influence of interaction of factors on the fertilizer crushing rate and the depth of the fertilizer into the soil.the Design-Expert optimization module was used to determine the best combination of working parameters of the device during the operation,i.e.the airflow inlet speed is 56 m/s,the working tooth width of the fertilizer discharger is 39 mm,and the traction speed is 2.3 m/s.at this time,the fertilizer crushing rate is 3.88%,and the depth of the fertilizer into the soil is 24.2mm,which meets the design requirements of the pneumatic deep fertilizer application device for rice.