Drives boost output at Manchester paper mill

Manchester, UK - Romiley Board Mill has increased output at its Manchester paper mill by 10% with the help of three new machinery drives. The drives, from ABB, control three electrically driven machine sections and synchronise these with the rest of the machine, which is driven by a line shaft, without the assistance of an external PLC.

Romiley Board Mill is an independent paper mill that manufactures paperboard from recycled fibre. The board is mainly used in packaging. The company saw an opportunity to increase output by adding a new dryer section to its existing paper machine. To avoid costly mechanical modifications to the line shaft, the new section needed to be electrically driven. The new configuration of the machine also required independent speed control of the existing calender and reel-up sections with sectional drives.

The ABB machinery drive was identified as the most suitable AC drive for this application, according to Ernie Domville, technical manager of Romiley Board. All functions for sectional speed control and communications are contained within the drive, which meant that a controlling PLC was not required, he said

The first drive receives feedback from an encoder on the line shaft and the set point is then cascaded from one drive to the next. Each drive controls a 3kW ABB process performance, high-efficiency AC motor.

In a conventional set-up, a PLC would feed out to all sections, each one driven by a DC drive. But with the control capabilities of the new machinery drive, no central control function was needed. In addition, AC motors could be used.

“All programming can be done inside the drive, so no PLC is needed,” said Nigel Vivian, a director of systems integrator Drives and Automation, which was responsible for programming, installing and commissioning the drives, as well as supplying the motors and panels.  “This simplifies the system and reduces cost. No separate software is required. The operator controls the sections from an interface linked to each drive.”

“The functionality of the ABB machinery drive can easily be modified or extended using standard, built-in function blocks,” added Vivian. “The programme resides in a separate memory unit. This enables easy maintenance and repair – just changing over the memory unit transfers the programme to a new drive. Local engineering staff can achieve this very simply.”

The new dryer comprises eight steam heated cast iron cylinders supplied by Parsons Reiss. The project has now been operational for over six months.