Patent ID: 7125003

Claim:
A reagent injector for treating a liquid, comprising: A. an integral, solid housing having an exterior wall and a liquid inlet end and a liquid outlet end, a first conduit for liquid extending through a solid interior of said housing from its inlet end to its outlet end, a second conduit for liquid that has been injected with reagent extending through the solid interior of said housing from its inlet end to its outlet end, said first and second conduits being separated from each other in said solid housing so as to provide separated liquid flow channels through the interior of said housing with the liquid flowing in the same general direction through the separated channels, said first conduit having a first liquid inlet port at said inlet end of said housing and a discharge port for liquid without said reagent at said outlet end of said housing, a first valve seat in said first conduit between said first liquid inlet port and said discharge port for liquid without said reagent, said second conduit having a second liquid inlet port at said inlet end of said housing and a discharge port for liquid injected with reagent at said outlet end of said housing, said second conduit having a constricted portion between said second liquid inlet port and said discharge port for liquid injected with reagent that defines a venturi thereinside, an aperture through said exterior wall of said housing located at said constricted portion for entry of said reagent drawn in by said venturi that is entrained into the liquid passing through said second conduit, and there being a locator recess in said outlet end of said of said housing; B. a removable first valve closure assembly comprising a first valve closure member sized to mate with said first valve seat and a first spring urging said first valve closure member toward said first valve seat in a direction opposite to the flow direction of liquid in said first conduit, a removable first valve positioner containing said first valve closure member and said first spring that locates said first spring and said first valve closure member in said first conduit; C. a removable flow control end cap having a plurality of outlet conduits to which liquid flowing out of said liquid discharge port for liquid injected with reagent and said discharge port for liquid without said reagent are directed, an abutment extending into one of said outlet conduits, and an end cap locator protruding beyond said end cap at a predetermined location, said end cap locator being inserted into said locator recess in said outlet end of said housing so as to align said liquid discharge port for liquid injected with reagent and said liquid discharge port for liquid without said reagent with predetermined outlet conduits in said end cap and to place said abutment into contact with said first valve positioner to hold said first valve positioner in said first conduit against the flow of liquid in said first conduit; and D. means for removably attaching said flow control end cap to said outlet end of said housing.