US 7,320,539 B2
Concrete batching facility and method
Ronald E. Christenson, Parsons, Tenn. (US); and Robert J. Horton, Rochester, Minn. (US)
Assigned to McNeilus Truck and Manufacturing, Inc., Dodge Center, Minn. (US)
Filed on Apr. 05, 2004, as Appl. No. 10/818,394.
Prior Publication US 2005/0219941 A1, Oct. 06, 2005
Int. Cl. B28C 7/04 (2006.01); B28C 7/06 (2006.01); B28C 7/12 (2006.01)
U.S. Cl. 366—14  [366/17; 366/18; 366/20; 366/34; 366/35; 366/50; 366/66; 366/301; 366/323] 16 Claims
OG exemplary drawing
 
1. 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.