Patent ID: 7320539

Claim:
A concrete batching system comprising: (1) a pre-mixing system for pre-mixing a selected portion, but less than all, of a concrete batch, said premixing system further comprising: (a) a cementitious ingredient supply system including a weigh batcher for apportioning weighed amounts of cementitious ingredients for concrete batches excluding stone and sand aggregate materials; (b) a pre-mixer agglomerator for blending said cementitious ingredients and wetting agents excluding said aggregate materials to form a concrete pre-mix fraction of a concrete batch, said agglomerator having spaced inlet and discharge openings toward opposite ends thereof and including a twin screw mixing and conveying system having intermeshing screw conveyors for both mixing and conveying said ingredients, said screw conveyors being further characterized by a variable pitch that increases from inlet to discharge; (c) a pre-feeder for metering said cementitious ingredients at a selected, controlled feed rate into said pre-mixer agglomerator; (d) a liquid supply system for supplying a selected amount of wetting agents at a selected rate for blending with said cementitious ingredients in said pre-mixer agglomerator; (e) a control system for controlling the amounts and rates in apportioning and mixing of cementitious ingredients and wetting agents in said concrete pre-mix; (2) an aggregate supply system configured to supply aggregate ingredients only directly to a final mixing vessel bypassing said pre-mixing system; and (3) a final mixing vessel for receiving premixed material from said pre-mixing system and aggregate from said aggregate supply system and conducting final mixing of ingredients.