| High pressure gas micro-pore jet impingement technology has been widely used in engineering fields such as micro cutting, digging, jet spray dust, grouting technology, etc. Although vertical intensive mixer shows good mixing efficiency for packing powder, mixing blades are easily worn by impact of packing powder and the friction force. In order to improve broken decomposition of the packing powder and increase service life of blades, the high pressure gas micro jet impingement technology are applied in mixing of packing power. Numerical simulation and experimental study were used in the systematical research of parameters which effected the impact of high pressure gas jet micro-pore impingement in this paper. It provides theoretical support and technical guidance for the realization of high pressure micro jet impingement in the field of powder pellets stacked application.Based on the fluid dynamics of jet impingement theory, field characteristics, especially flow field of the jet and the rule of axis velocity distribution similarity of single strand, multi-strand and rotation pore pressure gas micro-pro jet impingement flow are analyzed. Characteristics of jet impingement process under different conditions are grasped. Speed and the flow relationship of the circular cross-section jet body segments and the initial segment are deduced to provide guidance for engineering calculations.Jet impact parameter test is conducted to get related properties of accumulate power. Porosity, compressibility, outside friction coefficient, internal friction angle and shear strength are obtained through the test too. The test result can provide accurate input parameters for numerical simulation as well as relevant basis for jet impingement broken decomposition test.Experiment about jet impingement morphology and spray distance were conducted to identify optimal standoff distance for different type of nozzle under different jet pressure. Test result can provide ideas and solutions for numerical simulation and experimental study.A three-dimensional simulation model of nine nozzles is established using Eulerian gas-solid multiphase flow model. Realizable κ-ε turbulence model was selected to simulate the high pressure gas micro-pore jet impingement process of powder. The effect of the jet pressure, the impact time, the packing powder particle size, nozzle type, spray distance and other parameters on the jet impingement is analyzed. Finally better working parameters are obtained.Experiment about the parameters of the jet impingement accumulation powder broken decomposition is done. The broken decomposition effect of packing dowder accumulation under the different parameters(jet pressure, impact time, nozzle spacing, nozzle type, etc) is studied. The causes of different orifice depth, cutting width, volume broken dispersion are analyzed. Optimal jet effect parameters were gained according to the test. The results of the test proved the reliability of the numerical simulation. |
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