Fluid dispensing system and method for concrete mixer

摘要

System and method for dispensing liquids into concrete mixer drums, particularly suitable for use on concrete mix trucks, involve use of liquid admixtures nozzle that is separate from water conduit and water nozzle, the admixtures nozzle being aimed and focused to spray through drum opening with dispersion pattern substantially within air/concrete interface defined by minimal volume concrete contained within the drum; and the water conduit or nozzle having a dispersion pattern preferably whereby wash water hits a portion of the inner drum wall and a portion of the air/concrete interface defined by a maximum amount of concrete contained within the drum. In preferred embodiments, a check valve assembly is used to connect separate admixture and water lines, so that both admixture and water nozzles can be used simultaneously during purging operation.

主权项

1. An apparatus for injecting liquids into a rotatable concrete mixer drum, comprising:
a concrete mixer drum which is rotatably mounted to permit rotation about a rotation axis inclined at an orientation of 5-40 degrees relative to level ground and which has an oblong drum body with a inner circumferential wall connecting opposed first and second ends for defining a cavity within which to contain a fluid concrete; one of said two opposed ends of said oblong drum body having an opening to permit loading and unloading of concrete, and the other end being conformed to contain a nominal maximum concrete capacity such that a fluid concrete contained in the drum in the amount of 10%-30% of said nominal maximum concrete capacity presents an air/concrete interface having a first exposed surface area, designated herein as “ESA1,” and such that a fluid concrete contained in the drum in the amount of 70%-100% of said nominal maximum concrete capacity presents an air/concrete interface having exposed surface area, designated herein as “ESA2,” whereby ESA2 is greater than ESA1; a first conduit connected to a water source for introducing water into said mixer drum through said opening, said first conduit being aimed and mounted with respect to said drum opening, whereby 0%-100% of the water introduced through said first conduit into the drum would hit the air-concrete interface within ESA2; and a nozzle connected to a liquid chemical admixture source for introducing liquid chemical admixture into said drum through said opening, said nozzle being aimed and mounted with respect to said drum opening and having a nozzle aperture which is focused, whereby 75%-100% of the chemical admixture sprayed through said liquid chemical admixture nozzle into the drum would hit the air-concrete interface within ESA1.