Seed Cleaner, Electromagnetic

a machine for separating the coarse-surfaced seeds of weeds, for example, the genera Cuscuta, Acroptilon, and Centaurea, from the smooth-surfaced seeds of crops, such as clover, medics, and flax.

The operating principle of a seed cleaner is based on the property by which the coarse surface of seeds can become coated with a special magnetic, metallic powder—a mixture of 80 percent ferrous and/or ferric oxide and 20 percent chalk—and be attracted to an electromagnetic drum. The seeds are poured into the machine, where they are mixed with the powder; if the powder does not stick readily the bulk material is moistened in advance. The seeds enter an electromagnetic drum and then a receptacle underneath. The seeds of the crop being separated are not attracted to the drum and fall into another receptacle. The amount of powder used is approximately 2 percent of the weight of the seeds. Foreign seed cleaners operate on similar principles.