A Supercalender was experiencing increased electronic hardware failures due to age and condition. A project was proposed to replace the electronic equipment including the drives. The Fitch Company was contacted to execute this project due to past experience on similar projects and extensive experience on finishing applications (reels, supercalenders, winders, roll wrap, cut size, and sheeters). The project had a very aggressive schedule, requiring design and construction in only a four month time period. The Fitch Company provided all field coordination, hardware specification & procurement, panel fabrication, software development, field engineering, startup and checkout for the entire project excluding the drives. A new drive system for the unwind drive, two main stack drives, and the rewind drive was provided by Rockwell Automation. The Fitch Company provided field-engineering support to creating the necessary field details for getting the drive system installed.
The Scope of this project included replacement of the following control systems:
NIPCO Roll Control System
The #2 Stack Supercalender includes zoned Nipco rolls on the top roll (queen roll) and the bottom roll (king roll) of the stack. These rolls include two counter zones and eight NIPCO zones. The shell of the NIPCO roll is positioned relative to the roll shaft based on the interaction of the counter zones and the NIPCO zones. These rolls have a floating shell design. Pressure control and position control is required for both NIPCO rolls. In addition, stack closure occurs with shell position control and the roll leveling pistons. The old system performed the majority of the control algorithm in the Siemens S5 -150. This was difficult for mill personnel to understand, or troubleshoot. The new control software developed by The Fitch Company resides in the ControlLogix processor utilizing standard PLC ladder and function block instructions in a very well documented manner.
Sensomat Control System
The existing Sensomat control system consisted of rack mounted analog control boards. Adjustments to the system were made utilizing potentiometers, jumpers, and other hardwired modifications. The new system developed by Rolf Schuh and The Fitch Company was implemented utilizing standard PLC ladder, function block instructions and Rexroth solenoid driver cards.
Roll Leveling / Loading / Stack Opening Control System
The existing Roll Leveling / Loading control system resided in rack mounted analog control boards. Adjustments to the system were made utilizing potentiometers, jumpers, and other hardwired modifications. The new system developed by The Fitch Company was also implemented utilizing the ControlLogix PLC system.
The Fitch Company was the prime engineering company for this controls upgrade project. The new control system is comprised of an Allen Bradley ControlLogix PLC, with an RSView32 HMI. The Fitch Company provided all PLC / HMI software configuration for the Supercalender excluding the drive software. All control system cabinets were built and fabricated in The Fitch Company's Rumford, Maine office. The top section of the existing operator console was replaced with new, equivalent, stainless steel panels, housing new operator devices and two HMI's. We provided complete system documentation included interconnection diagrams, schematic diagrams, block diagrams, network diagrams, and cable / wire pulling schedules. Subcontractors were used for hydraulics (Joe Qualey of Advanced Hydraulics Inc.), and for the Sensomat replacement (Rolf Schuh of Calserv). The drive software was written and provided by Rockwell Automation. Field construction for the project was done by Cianbro Corporation, Pittsfield, Maine.
The project was a complete success. The new system has essentially eliminated downtime caused by the controls. This new Supercalender Control System now provides the following: