Floor cleaning machine

A floor cleaning machine comprising:

• a base,
• a cleaning element arrangement, held and driven on an underside of the base, the cleaning element arrangement being configured for engagement with a floor surface, wherein the cleaning element arrangement has at least one driven cleaning element, to which engagement elements for engagement with a floor surface to be cleaned are attached, wherein sections of the engagement elements which are provided for engagement with the floor surface extend in an engagement element plane,
• an operating bar, attached to the base, for guiding and actuating the floor cleaning machine,
• a suction foot, attached to the base or to the operating bar, the suction foot being configured for sucking up cleaning liquid from the floor surface,
• a dirty water tank, attached to the base or to the operating bar, for receiving cleaning liquid taken up by the suction foot,
• a suction turbine, which is attached to the base and has a suction turbine housing, which has an inlet opening and an outlet opening, wherein the suction turbine is configured to generate a suction air flow from the suction foot into the dirty water tank during operation, wherein the suction turbine is constructed in such a way that the suction air flow runs through the inlet opening towards the outlet opening, and
• a separation container that adjoins the suction turbine housing, the suction container having an interior, which communicates with the inlet opening, an inlet, which communicates with the interior, and a bottom wall section facing the interior,
• wherein, when viewed along a vertical axis running perpendicularly to the engagement element plane, the bottom wall section is arranged closer to the engagement element plane than the inlet opening, and
• wherein a drainage opening leads out of the bottom wall section into the environment, which opening is provided with a valve, which is configured in such a way that it is closed when the suction turbine is in operation and open when the suction turbine is out of operation.