Aerodynamic properties of wild mustard (Sinapis arvensis L.) seed for separation from canola.

BACKGROUND: Wild mustard seed is similar in size and shape to canola seed and can be separated by pneumatic means if the aerodynamic properties of these two materials are well known. The objective of this study was evaluation of the aerodynamic properties of canola and wild mustard seeds as a function of moisture content from 5% to 20% (w.b). RESULTS: The results showed that the terminal velocity of canola seeds increased, following a polynomial relationship from 5.401 to 6.566 m s(-1), as the moisture content increased from 5% to 20%. Over this same moisture content range the terminal velocity of wild mustard seeds varied from 4.276 to 5.433 m s(-1). The drag coefficient of canola and wild mustard seeds decreased linearly from 1.062 to 0.646 and from 1.432 to 0.928, respectively, as moisture content increased from 5% to 20%. Analysis of variance showed that there was a significant difference between the terminal velocity and drag coefficient of canola and wild mustard seed at a 1% probability level. CONCLUSION: The results suggest that aerodynamic separation of wild mustard seed from canola is possible. Moisture content had a significant effect on the terminal velocity and drag coefficient of seeds.