Patent ID: 7516909

Claim:
An apparatus for mixing an additive into a flowing fluid to form a settable mixture, comprising: a main fluid passageway having an inlet for receiving a supply of the flowing fluid and an outlet for dispensing the fluid; a control valve defining a portion of said main fluid passageway and configured for selectively controlling the flow of fluid in said passageway; an additive injector disposed in said passageway between said inlet and said outlet, said injector having an emitter disposed at an approximate midpoint of said passageway and oriented toward said outlet for adding the additive to the flowing fluid; a purge input for receiving at least one fluid distinct from the flowing fluid and the additive and configured for purging said passageway of the settable mixture; a static mixer disposed in said passageway between said injector and said outlet for enhancing the uniform mixing of the additive and the fluid; connection points between said inlet, said valve and said static mixer being configured for the prevention of at least one of the collection and premature setting of the mixture in said passageway.