Shredding straining apparatus

An apparatus for refining, mixing, straining, separating and extruding vulcanized rubber from scrap tires comprising a rotor positioned within a barrel bore, and a barrel extending through successive zones:

• a hopper;
• a forcing zone including multiple helical rotor grooves including sharp leading edges to chop and shear the rubber to reduce piece size;
• a rotor to barrel to rotor to barrel to rotor transfer zone for progressively reducing the particle size of the rubber;
• multiple rotor barrier zones provided with barriers which cross extrusion grooves in the multiple rotor barrier zones, each barrier being relatively wide so that only fine and fluent material is passed between the relatively wide barriers and the barrel bore wherein the relatively wide barriers include multiple ridges preceded by a groove formed by a series of ramps wherein the clearance between successive ridges and the bore of the barrel is progressively more restrictive in a downstream direction and wherein each ridge is preceded by the barrier groove to provide space for detained material that is too large to pass between the corresponding ridge and the barrel bore;
• and
• a tapered barrel barrier zone including a tapered barrel and comprising a rotor to barrel transfer for directing all material to barrel grooves, with barrel spacers for adjusting the longitudinal position of the tapered barrel to adjust the clearance between the rotor and the tapered barrel in the tapered barrier zone, wherein the tapered barrel includes receiving and sending barrel grooves, the receiving grooves having a downstream end with zero capacity and
• openings for discharging oversize material at the downstream end of the receiving grooves.