Patent ID: 8414779

Claim:
An apparatus for liquid disinfection by ultraviolet (UV) light, the apparatus comprising: a conduit to carry a flowing liquid to be disinfected, said conduit having UV-transparent walls, an inlet to receive said liquid and an outlet to discharge said liquid, wherein an external surface of said UV-transparent walls is coated with a UV reflective coating; and two or more UV sources to illuminate said liquid with UV light, wherein the UV sources are positioned serially within the conduit along a longitudinal axis of symmetry of the conduit along the liquid flow direction, and each of the UV sources is positioned substantially perpendicular to the longitudinal axis of symmetry of the conduit and to the liquid flow direction and at a different rotational angle with respect to the axis of symmetry than at least one of the at least one other UV source, wherein a light ray that is emitted from each of the UV sources is reflected by the reflective coating into the liquid more than once while advancing away from the UV source and the UV sources are positioned at a distance for each other such that a substantial portion of light rays emitted from each of the UV sources are not blocked by the other UV sources.