| Aiming at the problems of slow and uneven nozzle ejection speed and energy loss due to excessive inlet pressure in the reject system of cotton foreign fibre sorter, the research group proposed a foreign fibre sorter nozzle design based on a biaxially symmetric expansion contraction structure. Firstly, by the designed biaxially symmetric model, the flow velocity can be uniformly distributed and the airflow can be uniformly concentrated at the nozzle outlet. Secondly, by using the first expansion and then contraction structure of the nozzle, the airflow can be effectively expanded and make it reach a high speed. Lastly, by numerical analysis method, the simulation results of the nozzle structure of the foreign fibre sorter were obtained. The simulation results show that the optimized inlet pressure is 0.17 MPa and the four outlet velocities are 407.1, 404.6, 402.9 and 403.3 m/s respectively. Compared with the design model, optimized model inlet pressure was reduced by 0.01 MPa, and the flow velocities of the four outlets were increased by 659, 645, 643 and 629 m/s respectively. Compared with the original model, the inlet pressure of the optimized model was reduced by 003 MPa and the four outlet flow velocities were increased by 702, 645, 643 and 666 m/s respectively. It has been proven that the overall performance of the nozzle of the foreign fiber sorting machine, which is based on a biaxial symmetric expansion contraction structure, has been effectively improved. And the optimized nozzle structure has the best performance. |
