A coating apparatus having a rotatable drum with at least one moveable separating element arranged on an end side, and granular bodies can be transferred into the drum and/or out of the drum by a movement that leads to release. A separating element can be moved from a closed position into an open position by rotation about an axis of rotation. In the closed position, a subregion lies with its underside against an inner wall of the drum or has a small gap there. In the open position, the subregion on the underside is spaced apart from the inner wall of the drum and there is an opening there through which granular bodies can pass. On the end sides of the drum there are stop elements with which a drum of at least one further module is connectable in order to form a coating apparatus and/or a closure element.