Paper production: The intelligent paper mill
Every product ordered online reaches its ﬁnal destination in a cardboard box, which today can be produced entirely from recycled paper. Paper manufacturer Cascades Inc. quickly saw a market opportunity and in 2011 began constructing a brand new paper mill in Niagara Falls, New York. Subsidiary Greenpac Mill LLC would not only manufacture innovative, lightweight packaging board, but also only use recycled paper (old boxes) in the process. Completed in 2013, the mill represents a technological milestone in American paper manufacturing. The technology also creates the optimal basis for further growth. 135 people have already found work here – in an area where previously many companies had to lay off employees or close down their ofﬁces. Every day, around 100 trucks and several railcars arrive at the mill to deliver waste paper. This is then turned into a very thin but high-strength corrugated cardboard that is shipped out in the form of rolls. Approximately 1,500 tons of linerboard are produced a day, the equiva lent of some 540,000 tons a year.
Collaboration by three partners
Cascades decided to place the entire mill technology in the hands of just three specialists – for pulping operation, for the paper machine, and for the overall electrical and electronic equipment. That Siemens would be responsible for the latter was no coincidence: the company already had experience with Siemens and the speciﬁc industry solutions offered in its Sipaper line. Siemens supplied the entire power supply, including inverter substation for the paper mill and the wastewater treatment plant located next door at the sister Cascades medium mill.
Efﬁciency across the board
Siemens used variable speed-controlled drives for a large number of pumps. These drives ensure that the pumps consistently provide the exact rate of ﬂow required by the process and, at low pumping capacity, also consume less power. Other features include dry-running turbo blowers, which deliver 50% more energy savings than conventional vacuum pumps.
The plastic that accumulates during waste paper treatment as well as other waste ﬁber stock or ﬁlling agents are transported to an external power plant, where they are thermally recycled. In return, the steam produced is used for the drying process in paper production. Most of the process water is also recycled, with the biogas generated during treatment suitable for use as a fuel for generating steam.
Without automation and process control technology, everything would stop.Murray Hewitt, Mill plant manager, Greenpac
Automation with no ifs or buts
Greenpac Mill is the paper mill that has the highest degree of automation in all of North America. Siemens installed the complete automation system, from the drives to the controllers and the process control system. “Siemens is really the brains of the mill,” says Murray Hewitt, general manager of Greenpac, referring to over 700 drives and around 1,000 ﬁeld devices such as belt positioners, ﬂowmeters, temperature, or pressure sensors. 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. “Without automation and process control technology, everything would stop. There's nothing you can do in this process manually – it's that automated,” says Hewitt, adding: “We have the ability to access information 24/7 not only through the PCS 7 system, but certainly also from our laptops and even from our smartphones.” Robert Harroun, account manager at Siemens, says the Greenpac Mill is “truly a smart digital factory facility,” and adds: “The only way to accomplish that is to have a Sipaper PCS 7 total automation solution.”
Picture credits: Greenpac, Curtis Schick, Synaptic Digital
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