The spiral separator pictured here is a seed cleaning device that has no moving parts but permits separation of seeds that differ in their ability to roll down an inclined spiral. Round seeds can be easily separated from flat, irregular, or broken seeds since they role much faster. When seed mixtures are fed into the spiral, the round seeds move at much faster speeds and are thrown by centrifugal force off the top spiral into a second spiral below, where they are discharged separately. This type of device is commonly used to separate cabbage, broccoli, and other round seeds from the family Brassicaceae from other seeds that are not round.