单帧单曝光图像法对粉雾剂粉末模型分散效果的研究

利用单帧单曝光图像法(SFSEI),从相互垂直的2个方向分别对不同流量的气流分散作用下的粉雾剂粉末模型的分散粒径(及粒径分布)和颗粒速度(及速度分布)进行测量;将结果与激光衍射法、数值模拟法进行比较;分析了SFSEI法在粉雾剂分散效果测量中的适用性。研究结果表明:实验中颗粒统计数量在750以上时,所得平均粒径和平均速度结果无明显差异;对于实验条件和流道结构,竖直方向拍摄比水平方向拍摄得到的结果更接近激光衍射法和数值模拟的结果;同时,颗粒速度的测量会受粒径大小的影响。使用SFSEI方法时应尽可能减少离焦颗粒比例以提高测量精度,在气体流量较低的情况下更易于实现较高的测量准确性。

Analysis on the Dispersion Effect of a Powder Model for Dry Powder Inhalers by the Single Frame and Single Exposure Image Method

At different gas flow velocities and from two perpendicular directions, the particle size distribution and particle velocity distribution of a powder model for dry powder inhalers were investigated using the single frame and single exposure image method (SFSEI). The results were compared with those by the laser diffraction and numerical simulation methods. The applicability of SFSEI in the measurement of dry powder dispersion was analyzed. It is indicated that the measuring results are not sensitive to the particle quantity when it is no less than 750; the data obtained from vertical images are closer to the ones from the laser diffraction and the simulation results; the particle velocity measurement may be affected by the particle size. Based on this, it is shown that when applying the SFSEI method, the quantity of particles which are out of focus should be as less as possible to raise the measurement accuracy. Moreover, it is easier to achieve accurate results at lower gas flow.