Greenpac Mill: Maximizing recycling through automation
Just about every product you order online arrives in a cardboard box. Making those millions of boxes from recycled paper isn’t just a good idea—it’s a major opportunity.
Paper manufacturer Cascades Inc. knew that when, in 2011, it decided to build its Greenpac Mill in Niagara Falls, N.Y. Completed in 2013, Greenpac uses only recycled paper (old boxes) for its manufacturing process to produce approximately 540,000 tons of linerboard annually.
How is that possible? By operating with the highest degree of automation of any paper mill in North America.
Siemens created Greenpac’s entire automation system, from the drives to the controllers and the process-control system.
“Siemens is really the brains of the mill,” said Murray Hewitt, general manager of Greenpac, referring to the more than 700 drives and around 1,000 field devices such as belt positioners, flowmeters, and temperature or pressure sensors that are part of the automation system.
Each of these components has a separate function block in SIPAPER PCS 7, and is part of a seamlessly networked PCS 7 process-control system.
“We have the ability to access information 24/7 not only through the PCS 7 system, but also from our laptops and even from our smartphones,” Hewitt said. There's nothing you can do in this process manually – it's that automated.”
Variable speed-controlled drives operate many of the mill’s pumps. These drives ensure exact, consistent rate of flow while enabling less power consumption at lower pumping capacity. Greenpac’s dry-running turbo blowers deliver 50-percent more energy savings than conventional vacuum pumps. Siemens automation also supports the recycling of most of the process water, with the bio-gas generated during recycling treatment being suitable as a fuel for steam-generation within the mill.
“Without automation and process control technology,” Hewitt said, “everything would stop.”