Feed-Time Distribution in Pneumatic Feeding of Softwood Seedlings
Authors
Ulf Hallonborg
The Forestry Research Institute of Sweden, Uppsala, Sweden
Abstract
Long seedling-feed times can restrict the performance of a planting machine. In this study feed times were measured in a pneumatic feed-test rig. Test variables were seedling type, air velocity and hose diameter. Feed-time histograms were then tested against chi-square distributions. Each accepted distribution was used for calculating the proportion of seedlings that could reach a planting head in time and the proportion arriving late, with respect to the machine-cycle time. The mean feed times for those two categories were then weighted together to obtain a total feed time. Two models for describing the total feed time, one for "normal" seedlings and one for "butt-ended" seedlings were constructed, with machine-cycle time, air velocity and fullness quotient as input variables.
