Air-powder interactions are of practical importance in the production of pharmaceuticals, food and high value added chemicals manufactured using powders. For examples, air-powder effects enable consistent and effective dosing of fine cohesive powders into dies on high productivity rotary presses due to the suction fill effect.

A purpose built experimental testing rig was developed and calibrated in order to develop a basic understanding of effect of air pressure on the mass flow rate of fine and cohesive powders. The powder materials were selected to enable the study of the effect of particle properties, such as size and density, and processing conditions such as differential air pressure, on the mass flow rate of powders.

The models available in the literature developed for coarse free flowing sands under differential pressure were found inadequate to describe the experimental observations and to predict the flow behaviour of fine and cohesive powders. A new powder flow model was developed using established dimensional analysis methods based on the experimental data. The proposed model includes terms that account for the effect of differential pressure and reduces to the classic Beverloo model in absence of differential pressure. The models was validated and can be used for formulation and process design for flow regimes where air-powder interactions are important.

气粉相互作用在使用粉末制造的药品，食品和高附加值化学品的生产中具有实际重要性。例如，由于抽吸填充效应，在高生产率旋转压力机上，空气粉末效应可以将细密的粘结性粉末连续有效地定量注入模具中。

为了建立对气压对细粉和粘结粉质量流量的影响的基本了解，开发并校准了专用的实验测试台。选择粉末材料是为了能够研究颗粒性质（例如尺寸和密度）以及加工条件（例如气压差）对粉末质量流量的影响。

文献中发现的在压差下自由流动的粗砂的模型不足以描述实验观察结果和预测细粉和粘性粉末的流动行为。基于实验数据，使用已建立的尺寸分析方法开发了一种新的粉末流动模型。提议的模型包括解释压差影响的术语，并在不存在压差的情况下简化为经典的Beverloo模型。该模型已经过验证，可用于空气粉末相互作用很重要的流动状态的配方和工艺设计。