3 December 2020
by Stuart Hill

The circle of life - new role for refurbished industrial shredder

Stuart Hill, at Alphadrive Engineering Services, UK, explains how a refurbished industrial shredder has improved efficiency and enhanced its own environmental credentials.

The data energy logger unit (yellow casing) inside the shredder
The data energy logger unit (yellow casing) inside the shredder © Alphadrive

Last winter, Alphadrive Engineering Services took delivery of a fire-damaged Tana Shark, a type of shredder that processes pallets, furniture and mattresses.

The shredder’s owner, who ran a recycling business, aptly sought to refurbish the shredder with the following requirements:

  • Quiet running – to allow out of hours operation
  • Efficient running – lower fuel costs with less emissions for increased margins
  • An effective condition-based monitoring and preventative maintenance system to reduce downtime and optimise throughput

Installed in the machine are two 250Kw/4 pole high-efficiency 380/400v electric motors, coupled with 98% efficiency closed loop hydraulic pumps and several analogue 0-10v transducers and sensors.

A Human-Machine Interface (HMI) touch screen, Programmable Logic Controller (PLC) and software development enabled the required performance from a hydrostatic drive, which brought together all key parts of the installation.

We wanted to produce a high torque of 500,000Nm at the rotor using minimum motor current and lower hydraulic pressure within the system. This was achieved by taking data provided by the sensors fed into the PLC with specific formulas to balance the system.

To draw out maximum performance for the machine, we designed a PLC-based system and by using the HMI and Global System for Mobile Communications (GSM) with Wi-Fi connection, the machine can remotely adjust and tweak its own performance while in operation.     

To establish energy usage, a ‘Tiny Tag’ current monitoring data logger is used. The energy logger monitors voltage current and can determine power and power factor, measuring peak and average values. Voltage is measured via a standard mains supply lead to the equipment and current by using non-invasive flexible clip on Rogowski coils. These were connected to a three-phase power feed, shown in the image above (left) with the coils in blue.

 Following testing, we have achieved a maximum average use of 320.5A with an average general level of around 200A. The noise levels under shredding conditions have also been positive with tests showing 72.9dB from a two-metre distance. 

We have managed to achieve a harmonic balanced sinewave throughout the system. This is proving to have a 50% saving on operational running costs against the diesel engine. As an R&D-based machine concept, progression will continue to develop the electric eco-drive well into the future.

Authors

Stuart Hill

Alphadrive Engineering