Foundry mixer system with gas assisted resin injection

An apparatus for thoroughly and uniformly mixing foundry sand and catalyst-curable resinous binder therefor and quickly discharging with minimum residence time and comprising a multiple paddle mixer rotor enclosed within a housing, power means for continuously operating the rotor, material inlet means adjacent one end of the housing and mix discharge means at the other, and material storage containers for each of the materials to be mixed, said apparatus characterized by:

• (A) said mixer housing comprising an elongated horizontal cylindrical tube closed at both ends;
• (B) first positive feed means for introducing sand from the storage container therefor to a sand inlet at one end of the housing, and power means for operating said first feed means on demand;
• (C) separate positive feed means for simultaneously introducing liquid binder components from the storage container therefor to said housing downstream from said sand inlet, said separate feed means comprising:
• (1) power pump means for transporting said binder components in at least one flow line from the storage container therefor to said mixer housing,
• (2) at least one injection nozzle disposed on said housing downstream from said sand inlet and connected to said binder component flow line,
• (3) valve means in said binder component flow line,
• (4) a gas line in communication with said nozzle and adapted for connection to a source of gas under pressure, and
• (5) means for actuating said valve on demand to direct flow of binder components to said nozzle and into the flow of gas to said nozzle;
• (D) controls for actuation of said feed means mounted adjacent the discharge end of the mixer housing;
• (E) said mixer rotor comprising a shaft journaled for rapid rotation on a central horizontal axis within said housing, with a plurality of variable pitch paddles disposed to extend radially from said shaft and rotate with their tips in close proximity to the housing wall to mininize accumulation of sand-resin mixture on the housing walls,
• whereby said sand is dispersed and said binder is dispersed and injected therein and the sand and binder are quickly and uniformly mixed in the housing and quickly discharged therefrom with a residence time within the housing of from about 1 to 5 seconds.