可吸入颗粒粒径声学夹带法测量的实验研究  

Experimental Study of the Measurement of Inhalable Particle Diameter by the Use of an Acoustic Entrainment Method

作　　者：姚刚[1] 赵兵[1] 杨林军[1] 沈湘林[1] 

机构地区：[1]东南大学洁净煤燃烧教育部重点实验室,江苏南京210096

出　　处：《热能动力工程》2006年第3期267-269,共3页Journal of Engineering for Thermal Energy and Power

基　　金：国家重点基础研究发展计划基金资助项目(2002CB211600)

摘　　要：1μm左右的单颗粒粒径测量目前仍然是一技术难题。文中提出了一种新的利用声波夹带测量微米级和亚微米级单颗粒粒径的方法。该法充分利用了单个颗粒在驻波声场压力节点位置水平振动和重力自由沉降二维力场的动力学特性,经分析推导出细颗粒粒径和驻波声场中颗粒振动之间的关系。实验测量结合了先进的显微高速摄像技术,成功地拍摄到单个微米级颗粒的运动轨迹,经过对图像的分析,获得所需的参数,经求解直接得到单颗粒的粒径和滑移系数,避免了计算过程中的滑移经验假设。实验和计算结果表明:本实验平台可进行微米级和亚微米级单颗粒粒径的测量以及动力学特性的观测和记录;声波夹带法具有可靠的理论基础,作为一种新的微米级单颗粒粒径测量法是可行的。To date,the measurement of a single particle with a diameter of about 1 μm is still a technically intractable problem.A new approach is proposed for the measurement of micron grade and sub-micron grade single particle size by the use of acoustic wave entrainment.This approach makes full use of the dynamic characteristics of the two-dimensional force field composed of the horizontal vibration and gravity-free sedimentation of a single particle at the pressure node location in a standing-wave acoustic field.Through an analysis the relationship between a fine particle size and the particle vibration in the standing-wave acoustic field has been derived.By combining experimental measurements with an advanced microscopic high-speed photography technique,the movement trajectory of a single micron-grade particle has been successfully photographed.Through an analysis of the pictures the required parameters were obtained.By way of seeking a solution the diameter and slippage factor of a single particle were obtained,avoiding a slippage assumption based on experience in the calculation process.The experimental and calculation results show that the present experimental platform can be used to measure micron and sub-micron grade single particle size as well as to observe and record dynamic characteristics.The acoustic entrainment method,being supported by a reliable theoretical basis,can serve as a new and feasible method for the measurement of micron-grade single particle size.

关 键 词：微米 声波夹带 显微拍摄 粒径测量 

分 类 号：X513[环境科学与工程—环境工程]