Pneumatic Lifting of Pine Seeds from a Horizontal Surface

Abstract

Information was obtained to aid the development of a pneumatic pine seed harvester. Methods from related research were used to determine the characteristics of slash pine seeds: Mass 0.63 g Frontal area 26.0 mm² Terminal velocity 7.9 m/s Coefficient of drag 0.63 The minimum air stream velocity for conveying the seeds horizontally was calculated as being 5.5 meters per second. A mathematical model was developed to simulate the movement of a seed in air. The model was applied to the movement of a seed through the transition from horizontal to upward movement during lifting. The results of the simulation showed that the seed's elevation in the air stream when entering the transition region is more important to lifting than the air velocity in the transition region and that the air flow leaving the transition region should be kept as near horizontal as possible.