大豆蛋白液喷涂粒子速度场的PIV初探

目的选择蔬菜复合纸覆膜成型过程中的最优喷涂条件。方法利用PIV(粒子图像测速)技术测量不同喷涂参数下大豆蛋白液喷涂雾化粒子的速度场分布,并通过数据分析软件Tecplot处理分析喷涂参数对大豆蛋白液喷涂雾化粒子速度场的影响,最终得出喷雾速度场中心轴上和某一截面上速度的变化规律。结果当喷涂气压一定时,喷涂粒子速度随着喷涂液压的增大呈增大趋势,但不是很明显。当喷涂液压不变时,喷涂粒子速度随着喷涂气压的增大呈先减小后增大的趋势。在喷雾场喷嘴中轴线方向上雾化粒子速度从喷口喷出后先急剧增大,随着距喷嘴越来越远逐渐呈现波动变化的趋势,最后趋于稳定。在距离喷嘴300 mm的截面处,粒子速度以轴心处最大,向外沿径向逐渐减小,大体呈对称趋势。结论用PIV技术对大豆蛋白液喷涂粒子速度场进行研究,可为后期蔬菜复合纸覆膜成型提供一个有力的试验数据参考。

Preliminary Study on Spraying Particle Velocity Field of Soybean Protein Solution by PIV

The work aims to select the best spraying condition in the process of forming vegetable compound paper by laminating. PIV (particle image velocimetry) technology was applied to measure the velocity field distribution of soybean protein solution''s sprayed atomized particles under different spraying parameters. The effects of spraying parameters on the velocity field distribution of soybean protein solution''s sprayed atomized particles were processed and analyzed with the data analysis software Tecplot. Finally, the change law of velocity on the central axis of spray velocity field and some section was obtained. When it reached certain spraying pressure, the sprayed particle velocity increased with the increase in the spraying hydraulic pressure, but it was not quite obvious. When the spraying hydraulic pressure remained unchanged, the sprayed particle velocity decreased and then increased with the increase in the spraying pressure. In the axial direction of the spray field nozzle, the atomized particle velocity increased rapidly after it was ejected from the nozzle, and then gradually presented a tendency of fluctuation with the increasingly farther distance from the nozzle, and finally, it tended to be stable. In the cross section 300 mm away from the nozzle, the particle velocity was the largest in the axis, and it decreased outwards gradually along the radial direction. The particle velocity was symmetrical to the center generally. The study on the sprayed particle velocity field of soybean protein solution with PIV technology is conducted and it can provide a powerful reference for the test data of forming vegetable compound paper by laminating in the later periods.