玉米亲本种子精选分级生产线文丘里混种装置设计与试验

Design and Testing of Venturi Seed Mixing Device for Maize Parent Seed Selection and Grading Production Line

摘要:

针对玉米亲本种子精选分级过程中出现的种子滞留问题，设计了一种文丘里混种装置。通过分析总体结构及工作原理，计算了文丘里混种装置内部流场参数，并对种子进行了动力学分析，明确了进种段角度、收编段角度、混种段长度、进种口位置、混种段直径等结构参数是影响种子流运动状态的主要因素。采用 CFD-DEM 合仿真方法，分别开展了单因素和多因素试验，结果表明：因素对出口种子的速度和质量影响显著性由大到小依次为进种段角度、混种段直径、进种口位置，通过 Box-Behnken 响应面优化，建立了回归模型，得到最优参数组合为：进种段角度 50°、进种口位置 21mm、混种段直径 46mm, 在该组合下出口种子质量流量为 156.42g/s、种子平均速度为 5.92m/s。通过高速摄影试验方法对仿真结果进行验证，结果表明：出口种子平均速度为 6.16m/s, 相对误差为 4.09%; 种子质量流量为 164.43g/s, 相对误差为 5.12%。

Abstract:

Aiming to address the seed retention problem encountered in the precision grading process of maize parental seeds, a Venturi seed-mixing device was designed. Based on an analysis of the overall structure and working principle, the internal flow-field parameters of the Venturi mixer were calculated, and the particle dynamics of seeds were investigated. The results indicated that key structural parameters, namely the seed-inlet section angle, converging-section angle, mixing-section length, seed-inlet position, and mixing-section diameter, were the primary factors affecting seed flow behavior. Using a coupled CFD - DEM simulation approach, single-factor and multi-factor experiments were performed. The results showed that the significance of factors affecting the outlet seed velocity and mass flow rate decreased in the following order: seed-inlet section angle, mixing-section diameter, and seed-inlet position. Based on Box - Behnken response surface optimization, a regression model was established and the optimal parameter combination was obtained: seed-inlet section angle of 50°, seed-inlet position of 21 mm, and mixing-section diameter of 46 mm. Under this combination, the simulated outlet seed mass flow rate and mean seed velocity were 156.42 g/s and 5.92 m/s, respectively. High-speed imaging experiments were further conducted to validate the simulation results. The measured mean outlet seed velocity was 6.16 m/s with a relative error of 4.09%, and the measured seed mass flow rate was 164.43 g/s with a relative error of 5.12%.