A COUNTER-ROTATING TWIN-SCREW EXTRUDER FOR WASTE RUBBER RECYCLING

摘要

The invention relates to a counter-rotating twin-screw extruder for waste rubber recycling comprising a twin barrel (1) mounted in between two flange supports (11) with the help of two flanges (12), a pair of screws (3A, 3B), one left hand (3B) and the other right hand (3A), closely meshed together are fitted inside said twin barrel (1) having a very small clearance with said barrel, characterized in that each screw (3A, 3B) is divided into two zones with two different clearences, the first zone with 1 mm clearance occupying the first 40 % of the screw (3A, 3B) length and called feeding and conveying zone (17) and the second zone with varying clearance (1 to 0.5 mm) occupying 60 % length of the said screws (3A, 3B) is called compaction and pumping zone (18) for de-cross linking of rubber and expel out the air from waste rubber powder through the feeding zone during start of compaction, both screws (3A, 3B) are hanging at the delivery end with conical tips, and a detachable die assembly (4) having a small orifice (19) at the centre of said die assembly (4) is fitted to the twin barrels (1) at the end of twin screws (3A, 3B), the said screws (3A, 3B) at the other end are mounted in a housing (13) and the left handed screw (3A) is connected to the drive motor through a speed reduction gear (5) chain drive assembly (6) and the said left handed screw (3A) rotates the right handed screw (3B) in the opposite direction being closely meshed together, a feed hopper assembly (2) is provided on the barrel (1) at the beginning of the feeding and conveying zone (17) for regulated feeding of waste rubber and a barrel heating (7) and cooling (8) are provided along circumference of said barrel.