Fluid treatment unit

Fluid treatment unit, said unit comprising:

• a. an inlet,
• b. an outlet,
• c. a conduit between the inlet and the outlet suitable for transporting fluid from the inlet to the outlet,
• d. a transparent tube arranged at least partly in the conduit, said transparent tube being suitable for arranging a UV light source in the transparent tube,
• e. a wiper arranged on said transparent tube and arranged to be displaceable along a longitudinal axis of the transparent tube to clean the transparent tube,
• f. a displacement mechanism for displacing the wiper along the transparent tube, said displacement mechanism comprising:
• i. a spindle with an external thread, said spindle being arranged such that a longitudinal axis of the spindle is parallel to the longitudinal axis of the transparent tube and such that the spindle is rotatable around the longitudinal axis of the spindle, and
• ii. a connection element connecting the spindle and the wiper, such that rotation of the spindle drives the displacement of the wiper,
• wherein the displacement mechanism further comprises:
• g. a driving element arranged at one end of the spindle, and
• h. a rotatable ring having an axis of rotation, an outside surface and an inside surface, said rotatable ring comprising driving means arranged on the inside surface of the rotatable ring, said driving means cooperating with said driving element, such that rotation of the rotatable ring causes rotation of the driving element which causes rotation of the spindle which causes displacement of the wiper.