Page 8 - Industrial Technology EXTRA 15th March 2021

VARIABLE SPEED DRIVES...

Key challenges when designing

recycling or shredding machines

When designing a machine for shredding and recycling applications, many challenges
need to be overcome to ensure the machine performs at a high level over many years.
Three of the most important are limiting downtime, eliminating contamination issues
and energy cost savings. Selecting the right drive technology from an experienced

supplier is critical, says Jeff Kardell of KEB Automation.
he first challenge that machine
builders face in shredding
applications is ensuring that the
Tmachine has minimal downtime.
Shredding machines are designed to process
a lot of material in a short amount of time and
so any downtime forces delays in the overall
system. If a shredder were to shut down for
maintenance, it can sometimes be offline for
days and cause large backups of material.
To ensure minimal downtime, KEB has in-
built protection parameters for its drive
controllers. If there is an issue, the protection
parameters shut down the machine before
significant damage occurs. For example,
users have the ability to program torque limits in the jam because of material blockage, an operator
drive to protect the mechanical components in the would need to shut down the machine, then
drive train, including shafts, gears and the motor. disassemble and clear the blocked material. KEB’s
Actively monitoring both the variable frequency Jam Detection VFD function is able to quickly detect
drive (VFD) and motor temperatures ensure the a jam condition and react quickly. This usually
components do not overheat and fail. means the rotor stops, reverses and clears the
material, then quickly reverses again and returns to
Jam detection normal speed. This function clears a jam condition
Jam detection is a unique function built into KEB in a matter of seconds compared to hours or days to
drives to help avoid downtime. If a shredder were to manually clear it.

March 2021 • INDUSTRIAL TECHNOLOGY EXTRA • p8