Maintenance & Reliability
Machine Drive: Paper Machine Drive System pushes productivity to new levels
January 1, 2002 By Pulp & Paper Canada
For most papermaking industries, deciding how and when to upgrade critical machine drive system equipment can be a very difficult and time-sensitive task. Poor timing can be problematic in a very comp…
For most papermaking industries, deciding how and when to upgrade critical machine drive system equipment can be a very difficult and time-sensitive task. Poor timing can be problematic in a very competitive, capital-intense environment like paper or pulp production.
However, new technology used by NorskeCanada not only increased production at one of its mills, but also resulted in reducing downtime by a staggering 90% in the first few months.
With a head office in Vancouver and approximately 4,400 employees, the company now operates four fully-integrated mills in British Columbia. The Crofton Division paper mills produce newsprint, directory and specialty grade papers, serving the publishing and commercial printing industries. The old machine drive needed to be replaced by a new drive system to improve productivity and reduce excessive downtime.
The mill worked with Rockwell Automation Drive Systems to modernize their PM3, originally a 1982 General Electric powered machine. The machine drive system caused excessive operating downtime, resulting in unacceptable levels of production losses and very high maintenance costs. With the new drive system, NorskeCanada has increased its productivity and reduced downtime significantly. “We have reduced downtime by 90% over the last two months of operation and expect that to get even better as time goes on,” said Doug Kraft, P. Eng., E/I Project Engineer at Crofton Division.
During the six-day maintenance shutdown, the 30-section drive system change was the critical path job, and it was extremely important to complete the work as quickly as possible. The team, both supplier and client, worked together to meet budget and schedule, resulting in a smooth startup with very few problems. “I have been in the business for 25 years and I haven’t seen or heard of a complete paper machine drive installation and startup in such a short time with so few problems,” said Bill Seip, Rockwell service technician.
Conversion to Variable
Frequency Drive Technology
With the change-out of this drive system, all three paper machine drives and all three winder drives at NorskeCanada, Crofton Division, are now standardized to current, fully digital Rockwell DC drive systems. NorskeCanada’s PM3 helper drives were also converted from DC common armature supply to individual AC variable frequency (VF) drives and motors. For the first time they now have a paper machine drive system that is a mix of AC and DC technology. The new AC helper drive sections have resulted in more precise control especially around the baby dryer, which was a recommendation by the machine builder for better operation and runability.
The benefits from this application allow NorskeCanada to set independent controls on the helper drives, and can now set the load-sharing arrangements to accurately work over the full range of operation. This is particularly important to the third press and first dryer sections, as the old arrangement was very difficult to adjust and operate, resulting in much grief and downtime. Since the change-out, the section has run smoothly without the usual kick-outs. “We no longer have to worry about the drive performance. We can concentrate on running the machine,” said Walter Tarnowsky, No. 3 Paper Machine Manager.
The mill executed a plan to standardize all three paper machines and winders to a common platform.
“This standardization has helped reduce costs and improve productivity, and will continue to be a competitive edge they will benefit from for many years to come”, said Stefan McDonald, senior drive systems specialist.
New drive installation on TMP3 eliminates drive system-related downtime.
NorskeCanada’s TMP3 plug screw feeder drive system that feeds the machine critical TMP refiner line, was also old equipment that was constantly failing. Maintenance problems with this old hardware would result in occasional but very costly machine production interruptions.
During the engineering and manufacturing cycle for the PM3 paper machine drive system, the mill asked if Rockwell could provide replacement drives for the existing failing units, in time to make the scheduled shutdown. Due to the fast delivery needed to meet this date, Rockwell worked with the regional drives center in Seattle, WA, and Los Angeles, CA. These regional drive centers specialize in low engineering, fast delivery, custom drive systems, and were able to provide a cabinet mounted controller and drive with custom mounting panel and wiring arrangements (for mounting in existing cabinets) in supersonic time.
The controller and one drive were replaced during the installation/startup of the PM3 machine system, and the second unit was installed shortly after. The installation and startup went very smooth, and has eliminated drive system related downtime — supporting the mill’s objective for increased production and reduced maintenance costs.
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