In food industry, atomization is an essential process as a large range of products are manufactured by spray drying of concentrated solutions. The pressure drop inside the nozzle, and its relation with the flowrate, is of prime importance to size an efficient continuous process. This work thus aims at both studying liquid atomization using pressure nozzles with throttle inserts and proposing a ready-to-use pressure/flowrate correlation from a series of experimental data. Beside the process parameters (flowrate) and fluid parameters (viscosity, density) of prime importance, the geometrical parameters of the nozzle were also accounted for to obtain a generic correlation. Using Newtonian maltodextrin aqueous solutions with viscosity ranging from 1 to 70.10^-3 Pa s and eleven nozzle geometries, 264 experiments were performed. Through the use of a dimensionless pressure drop number (Euler number), all the experimental points gathered on a single Eu* vs. Re curve where conventional atomization regimes could be clearly identified. A comprehensive dimensional analysis, relying on the Vashy-Buckingham theorem, was performed. A set of dimensionless correlations, allowing to predict the pressure loss over a wide range of Reynolds number from parameters linked to the fluid, process and nozzle geometry, was then deduced from experimental data.

在食品工业中，雾化是必不可少的过程，因为通过浓缩溶液的喷雾干燥可以生产多种产品。喷嘴内部的压降及其与流量的关系对于确定有效的连续过程至关重要。因此，这项工作旨在研究使用带有节流阀插入物的压力喷嘴的液体雾化，以及从一系列实验数据中提出现成的压力/流量相关性。除了最重要的工艺参数（流量）和流体参数（粘度，密度）外，还考虑了喷嘴的几何参数以获得一般相关性。使用粘度范围为1至70.10 ^-3的牛顿麦芽糊精水溶液Pa和11个喷嘴的几何形状，进行了264个实验。通过使用无量纲的压降数（欧拉数），所有实验点都集中在一条Eu * vs. Re曲线上，可以清楚地识别出常规雾化方案。依靠Vashy-Buckingham定理进行了全面的尺寸分析。然后从实验数据中推导出一组无因次相关性，从而可以根据与流体，过程和喷嘴几何形状相关的参数来预测大范围雷诺数下的压力损失。