Experimental research regarding magnetic separation of seeds after their surface conditions using two moistening liquids

Abstract

One of the most dangerous and destructive parasitic weed seed is dodder, and due its impact it is registered in the list of crops risk factors and it also affects directly the animal health. At national level, the damage that it generates in agricultural crop production reaches 50-100 % and worldwide it is causing crop losses of 14-15 %. For this reason the forage plant production is determined by the seed purity the in sowing process, at national and international regulations it is required to be 100 % free of dodder seeds, because a single dodder seed can compromise the whole culture. Complete separation of dodder seeds from the basic culture seed mass is a complex and very difficult process, due to its shape, dimensions and its aerodynamic properties, which often are very similar. An effective separation is the magnetic separation method - a process with high complexity that does not affect the basic seed material properties, in which magnetic drums and fine iron powder are used. Due to the fact that dodder seeds have rough external surface on which wrinkles and fine threads can rise, which are filled with iron powder and gain ferromagnetic properties. The magnetic drums retain the dodder seeds or modify their trajectory, drawing them to the rational drum. The basic culture seeds continue their movement to a separation zone due to their smooth outer surface. In this paper, the experimental research will be presented in view of obtaining a seed material "free" of dodder, pursuing the influence of the drum speed on the seed behavior in the process of separation, improving the degree of adhesion of iron powder to the roughened surface of dodder seeds by using two wetting liquids and reducing the number of passes of seeds through the separator.