提升管中烟丝运动速度的定量检测及其运动特性分析

Quantitative detection of cut tobacco velocity in upright pipe and analysis of its motion characteristics

为定量检测提升管中烟丝运动速度,研究提升管中烟丝运动特性,针对烟丝的弹性丝状特征,提出了一种基于图像配准算法检测烟丝在提升管中速度的方法,即利用高速摄像机连续采集提升管中烟丝群图片,利用不变中心矩算法对图片中的烟丝运动状态进行配准,并计算相同颗粒的像素位移,通过相机标定技术将其转化为实际的位移,最后根据位移和图像时间间隔来确定物料速度。结果表明:①同等条件下,当气速在12.5 m/s至17.5 m/s范围内等差增加时,烟丝速度的增长幅度会小于气速的增加幅度,而烟丝结构会随加工时间增加而迅速衰变;②当气速为15 m/s时,烟丝提升过程是一个由加速到匀速的过程,加速度逐渐变小,直至为0;③同等条件下,对于特征尺寸在3.29 mm至3.67 mm范围内的烟丝,不同长度的烟丝在管道两侧的边壁附近存在速度差,且烟丝尺寸越短,速度越慢;在同一水平截面上也存在速度差,烟丝尺寸越短,平均速度越慢。

In order to quantitatively measure the velocity and study the motion characteristics of cut tobacco in an upright pipe,a detection method based on image registration algorithm was proposed according to the flexible filamentary particle characteristics of cut tobacco.Firstly,the pictures of cut tobacco group in the upright pipe were collected by a high-speed camera continuously.Secondly,the movement of cut tobacco in the pictures was registered via invariant center moment algorithm,and the pixel displacement of a single particle was calculated and transformed into its real displacement through camera calibration technology.Finally,cut tobacco velocity was determined according to its displacement and image time interval.The results showed that:1)Under the same conditions,when the air velocity increased within the range of 12.5 m/s to 17.5 m/s,the increase of tobacco velocity was less than that of the air velocity,and the structure of the tobacco decayed rapidly with the proceeding of process.2)When the air velocity was 15 m/s,the elevation process of cut tobacco was a process from acceleration to uniform velocity,and the acceleration gradually decreased to 0.3)Under the same condition,for the cut tobacco with the characteristic size ranging from 3.29 mm to 3.67 mm,there was a velocity difference between different sizes of cut tobacco near two sides of the pipe,and the shorter the cut tobacco size was,the slower the velocity would be;there was also a velocity difference on the same horizontal section,the shorter the cut tobacco size was,the slower the average velocity would be.