Design of a wind tunnel for separating flower parts of saffron

The separation possibility of stigma from the other parts of saffron flower using its aerodynamic properties was studied and a vertical wind tunnel was designed on the basis of the obtained results. Terminal velocities of three parts of saffron flower, including petal, stigma and anther within four days after harvest were investigated. Significant difference between terminal velocity of stigma (2.4-2.8 m/s) and the other parts (1-2 m/s) of flower on the first day after harvesting, revealed that accurate separation using air stream is possible. Equal friction method was applied for design. A vertical wind tunnel applying a fan with a flow rate of 1700 m3/h and a static pressure of 0.82 cm was designed for stigma separation of saffron flower from the other parts. The duct of introduced wind tunnel was sized equal to 40.6 × 40.6 cm for main, 40.6 × 33 and 40.6 × 18 cm for lateral branches.