The invention relates to a device and a method for separating dirt particles from the working medium of a turbine (10). The turbine (10) comprises at least one rotor (11) which is arranged in a housing (17). A swirl generator (20) is provided that sets the working medium and the dirt particles in a spiral-shaped rotational movement along a principal axis (22) by means of the geometry of the swirl generator (20) and thereby separates the dirt particles from the working medium. The swirl generator (20) is designed in such a way that the working medium experiences a reversal of the speed component parallel to the principal axis (22) within the swirl generator (20).