The air channel separates lighter particles from the grain. The air flow can be adjusted for different kinds of wheat in order to get optimal performance. There are two models: one with a vibration motor and one without a vibration motor. When the product enters the air channel from a single pipe, the vibration motor evenly distributes the grains and increases the performance. When the air channel is used after a grain separator, there is no need for a vibration motor since the product arrives well distributed already. The machine does not produce negative air pressure and therefore it should be connected to the mill’s aspiration system.