Relationships Between Physical Characteristics of Tobacco Leaves and Technological Parameters of Threshing and Pneumatic Separation

To shorten the time needed for setting the threshing system, the relationships between the physical characteristics of tobacco leaves and the technological parameters of threshing and pneumatic separation were investigated with stepwise regression, partial correlation, path analysis and cluster analysis. The results showed that: 1)The stepwise regression equation for the physical characteristics and the technological parameters reached a significant level. 2)The rotational speed of the first stage threshing drum should be elevated with the increase of leaf temperature leaving the second stage ordering cylinder; the rotational speed of the fourth stage threshing drum should be lowered, while that of the third one should be elevated with the increase of moisture content in leaves; the rotational speed of the first stage threshing drum should be elevated, while that of the fourth one should be lowered with the increase of leaf thickness; the rotational speed of the second stage threshing drum should be elevated with the increase of leaf width; however, leaf length had nothing to do with the drum's speed. 3)Air velocity in all the pneumatic separators should be set higher with the increase of moisture content in leaves leaving the second stage ordering cylinder; the first stage pneumatic separator downstream the second stage thresher should be set at higher air velocity with the increase of leaf thickness. 4)On the basis of physical indexes obtained from stepwise regression and combining with the rotational speed of threshing drum and the air velocity in pneumatic separator, fifteen of nineteen samples were divided into four categories, the leaves in the same category were processed with similar technical parameters; while the other four samples were processed by different parameters.