Twin Screw Conveyor for EPDM Rubber

General Description

Customer needed a solution for conveying EPDM (ethylene-propylene-diene monomer) rubber particles. KWS worked closely with Lion Copolymer to design a unique conveyor for the application. EPDM rubber is fed into the conveyor by a perforated dryer belt that travels across the top of the twin screw conveyor. Excess EPDM falls through the perforations where they get picked up by the twin screw conveyor and discharged into a collection bin. EPDM rubber is used in a wide variety of outdoor and automotive applications due to the resistance to oxygen, ozone, heat and weathering.

Design Parameters

KWS Advantages

Engineers from Lion Copolymer and KWS worked together to design a twin screw conveyor to convey EPDM from the perforated belt dryer. A twin screw design was required due to the size of the belt dryer discharge. Product arching and bridging had been an issue when conveying EPDM. The twin screw design provided by KWS eliminated the arching and bridging issue by providing a wide inlet opening with vertical wall transitions. KWS Engineers modeled the system and worked around some existing space constraints.

Special Features

The twin screw conveyor is powered by one drive unit with spur gears driving both screws. The driven screw utilizes a special bearing configuration on the drive end due to the limited space in bulkhead assembly. The non-drive end has staggered pillow block bearings so they don’t interfere with each other because the shaft centers are so close. The trough is completely open so the excess EPDM coming from the dryer belt can fall down the entire length of the conveyor. One reverse flight over the discharge of the conveyor conveys any excess EPDM that gets past the discharge back into the discharge.