Design Of Safflower Filaments Harvesting Device And Numerical Simulation Of Airflow Field In Pneumatic Conveying System

In view of the rapid development of the Xinjiang safflower planting industry, however the research actuality on safflower mechanized haevesting is still in its infancy, there are no machines put into application, the harvesting of safflower rely mainly on manual work. On the basis of the research on the material properties of safflower, using the methods of theoretical analysis and computer simulation design a safflower filaments harvesting device with the theory of pneumatic and mechanical. Using CFD technology make the numerical simulation to different structure of the pneumatic conveyor system., determine the best internal structure of the conveying system, provide a scientific basis and method for researching safflower mechanized harvesting device. This article mainly carry out the following aspects of work:1. Analysis of the safflower material properties. By combining the methods of literature, field investigation and experimental research get the data of the safflower biological characteristics (achene diameter and filaments moisture, etc.) and the mechanical characteristics (separating force between different maturity filaments and achenes, achenes and stalk, etc.), determine there important influence on safflower harvesting device, and provide a theoretical basis for the parameter design of safflower filaments harvesting device.2. The structure design and three-dimensional modeling of safflower harvesting device. Make theoretical analysis of the cutting mechanics properties and suspended mechanical characteristics to safflower filaments, determine the optimal cutting force between filaments and achenes and the suspended conveying parameters of the airflow. Using Solidworks software for3D modeling,3D assembly and interference checking, using the ADAMS software to carry on the motion simulation analysis to rotary cutting head, and study the harvesting process of the safflower harvesting device, verify the correctness of the principle.3. In order to improve the combing and collecting effect, and to achieve the purpose of improving net rate and reducing drop rate, design a cone model and a ellipsoid model of the flower entrance based on the cylindrical model, Using Fluent software make flow field numerical simulation to the three different flower entrance. Through the contrast and analysis to the three simulation results, indicate the distribution of air velocity is uneven and the pressure gradient is not obvious in the cylindrical model, the effect of filaments combing and collecting is poor. The transverse and longitudinal pressure in cone model and ellipsoid model are more pronounced, the pressure difference is grater from the inlet to the outlet, and it has great improvement to the distribution of airflow in the flower entrance.4. To improve the filaments conveying effect, and to achieve the purpose of enhancing filaments conveying efficiency and reducing the energy loss, on the basis of the cylindrical-conical flower reservoir, sets the deflector inside it, using Fluent software make flow field simulation analysis to different flower reservoirs which contains a different number of deflector. The simulation results show that the flow field inside the original flower reservoir exist independent eddy, the energy loss is bigger and the filaments conveying effect is poor. When the flower reservoir contains three to four deflector, the airflow distribution is more conducive to the filaments conveying through the guiding role of the deflector, reduces the energy loss of the conveying process.