Separating waste with automation

A European waste facility required automation and control equipment to separate paper from commercial and industrial waste. A compact one-stop solution was chosen. Sourcing the technology from one company meant the installation of the various components was straightforward and enabled the control system to be replicated at two further facilities.

The Prisma Plus intelligent motor control centre containing Schneider Electric's distribution, control and automation products.
The Prisma Plus intelligent motor control centre containing Schneider Electric's distribution, control and automation products.

A new waste recycling plant in Luton, UK, commissioned automation control systems company, DB Controls, to supply automation, motor control and SCADA. DB Controls chose Schneider Electric to supply all of the automation & control equipment. By choosing this one-stop solution from Schneider Electric, DB Controls was able to offer a cost-effective Form 2 type-tested control panel.

The waste facility was designed and installed by OKLM Recycling Technology, for waste management company Cawleys. The plant represents a multi-million pound project to create a sorting facility for commercial and industrial waste; the first in the country to feature automated separation of paper from this type of waste. Operating as a sub-contractor to OKLM, DB Controls was responsible for all of the system integration.

For the control systems, the Schneider Electric M340 PLC platform was chosen, a compact solution which offers plug-and-play options with other Schneider Electric devices. The PLC has twin Ethernet ports programmed with Unity Pro IEC 61131-3 compliant software. Although small in size, this PLC controls 80 Tesys Model U direct on-line integrated motor starters, 18 ATV71 variable speed drives and four racks of Advantys fieldbus IO with Telefast 2 direct termination units. The Tesys U DOL starters can be installed in a very compact space resulting in a reduced footprint, and works in conjunction with VSDs and remote IOs which are all networked using Modbus over TCP.

This package of equipment has been built into a Prisma Plus intelligent Motor Control Centre, a BSEN 61439-2 compliant offer, based on proven Prisma Plus distribution switchboard and designed to be fully integrated with Schneider Electric distribution, control and automation products.

The recycling plant is designed using a complex arrangement of conveyors to transport waste from stage to stage, recovering different types of recyclable material at each phase. The MCC's high-technology inverter drives ensure the motors powering the conveyor system run at the correct speed, even though the loading may be continuously changing.

The separation process uses a range of technologies, including infra-red, magnetic and sorting by blowers in a large rotating drum. The plant runs continuously and requires constant monitoring to ensure the safety of workers and the protection of the machinery should abnormal items get onto the conveyor system or blockages occur. Ensuring safe and reliable plant operation is the primary function of the SCADA system.

For DB Controls there were cost and efficiency advantages in using all Schneider Electric components, as sales director David Trueman explains: “Being able to purchase all of the equipment from one source meant that integration of the various components was very straightforward, particularly with the model used by Schneider Electric for network production. By building the MCC in this way, we were able to offer a fully verified solution.

“We have an established relationship with Schneider Electric and a good knowledge of their range built over previous applications. One of the key benefits of working with them has been the ability to use Ethernet networks in control applications: Schneider Electric was one of the first manufacturers to introduce this.”

In operation, the M340 and ATV71 both have an active web page, accessed through the system software, to open up windows on the SCADA display to show device parameters and status. The system is fully accessible remotely at DB Control's engineering office.

Now fully operational at Cawleys' Luton plant, the control system has since been replicated at two further waste recycling facilities.