Apparatus for purifying water

An apparatus for purifying water comprising a fitting for installation in a water line, said fitting having substantially parallel sections defining a primary water flow path having openings for receiving inlet and outlet water lines, said fitting also having a laterally extending section defining a secondary water flow path, a Venturi tube mounted in said fitting in said primary water flow path, said Venturi tube defining a Venturi having a converging section, a throat and a diverging section, said converging section and said diverging section adapted to face upstream and downstream, respectively, relative to said primary water flow path, said Venturi tube defining an opening communicating with said throat and said secondary water flow path, a tank removably connected to and extending below said laterally extending section of said fitting to define a sump, a container housed within said tank and secured at one end to said opening in said Venturi tube and having its other end extending above the bottom of said tank, said container adapted to hold a bed of iodine crystals, distributor means positioned at the inlet and outlet of said container, said distributor means being permeable to water containing dissolved iodine and impermeable to said iodine crystals, and a metering valve having an inlet communicating with said primary water flow line at one end of said Venturi tube and having an outlet in flow communication with the inlet of said tank, said Venturi creating a pressure differential forcing a small portion of the water to flow through said metering valve, said tank and said container and be returned to said primary water flow stream at the throat of said Venturi, said container having a cross-sectional flow area which provides minimum velocity, as calculated through the freeboard area of said container, of about 7 cm/sec based on the volume flow through said container to produce a solution with a constant iodine concentration.