A cyclone separator for phase separation of a fluid stream has a rotationally symmetrical housing with a hollow chamber. Feed lines feed the fluid stream into the housing substantially tangentially. At least one discharge line conducts the separated gaseous fraction. In order to ensure uniform and homogeneous flow distribution of the steam to be heated as it enters the heating phase, the hollow chamber, when viewed in the radial direction from the mid-axis, has an outflow chamber with a circular cross section and, in radial sequence, a heating chamber, an intermediate chamber, a dryer chamber and an inflow chamber. The inflow chamber is outwardly delimited by the housing. The heating chamber contains heating elements for heating the gaseous fraction. At least one fine separator and at least one associated condensate-collecting trough are arranged in the dryer chamber. The condensate-collecting trough is connected to a condensate discharge pipe in the intermediate chamber for conducting the condensate forming in the fine separator out of the hollow chamber.