Water purifier with adjustable volume in dwell passage

An apparatus for purifying water comprising:

• a vessel including a peripheral sidewall surrounding a central axis, a closed bottom wall, and an open top;
• a filter head for closing the open top of said vessel, said filter head including an in fluent passage coaxially aligned with said central axis and an effluent passage spaced radially outwardly from said in fluent passage;
• and
• a removable cartridge received within the interior cavity and removably sealed to the filter head so that the cartridge is in fluid communication with the in fluent passage and the effluent passage, the cartridge comprising:
• an imperforate tubular conduit having a hollow interior, an upper open end sealed to said in fluent passage, a lower open end positioned proximate to and spaced apart from the closed bottom wall of said vessel;
• a water treating system contained within said hollow interior comprising a material for imparting a biocide to water flowing through said conduit;
• a tubular filter coaxially surrounding said conduit and comprising a material for reducing a concentration of biocide from water, wherein said filter defines an exterior surface spaced apart from the peripheral wall of said vessel to define a first annular passage therewith and wherein said filter includes an interior surface radially spaced apart from said conduit to define a second annular passage extending axially to said effluent passage;
• a base for closing a lower end of said filter, said base including a seal for closing a lower end of said second annular passage, wherein said base includes a lower surface that is spaced apart from the bottom wall of said vessel to define a radial passage extending from the lower open end of said conduit to said first annular passage;
• a cap member for closing an upper end of said filter, wherein said cap member includes a seal for sealingly connecting an upper open end of said second annular passage to said effluent passage;
• whereby water to be treated flows into said in fluent passage in said filter head, from said in fluent passage into the upper open end of said conduit, through the interior of said conduit and through said material for imparting biocide held therein, from the interior of said conduit out of the lower open end of said conduit, from the lower open end of said conduit into said radial passage, from said radial passage into said first annular passage, from said first annular passage through said filter, from said filter into said second annular passage, from said second annular passage through the upper open end of said annular passage, and from the upper open end of said second annular passage into said effluent passage for discharge from said filter head.