| Fifty percent of each log is processed into lumber, 45% into wood chips and the remaining 5% bark waste is used to fuel the boilers that produce steam at the nearby Donohue paper mill. The wood
chips are trucked to the same Donohue plant for processing into pulp and paper. The Outardes sawmill contains 3 facilities: - Outardes 1 - which processes random length (10 -16 feet), 16-foot length, and tree length logs with diameters of more than 12 inches into dimension lumber.
- Outardes 2 - which processes 10-foot length and tree length logs with diameters of 12 inches or less into studs.
- The planing mill - which finishes the lumber produced by Outardes 1 and 2 and ships them to customers.
At the Outardes 2 facility, two Tanguay cranes offload the
trees into 2 unscramblers. The trees then pass through 4 debarkers operating at 300 feet per minute (and totalling 1,200 HP). A slashing deck - running at the speed of 35 trees per minute - cuts the debarked trees into 10-foot lengths. These 10-foot logs are combined with random length logs from Outardes 1, and conveyed via 5 transversal conveyors/unscramblers and 2 belt conveyors (running at 600 feet per minute) to 2 sawing pattern optimization scanners. The scanners generate a three
dimensional profile of each log, sorting it by diameter and curve into one of 6 bins. The sorted logs are then squared off by (2) canters running at 600 feet per minute. A linear infeed table located between the two canters positions the logs prior to squaring to optimize sawing. The cants are cut into lumber by a gangsaw edger with 4 saws running at 500 feet per minute (and totalling 3,600 HP), then trimmed to length, resorted and stacked for shipment to the planing facility. The rejected
logs are processed into wood chips, which are trucked to the nearby Donohue pulp and paper mill for processing.
The 3 Outardes sawmills are linked together by an Ethernet network. Each facility is controlled by 5 Schneider Electric TSX PLCs, which communicate to a central control station via a 10 M Bit control network. Each PLC displays detailed machine diagnostics on various HMIs. A single PLC controls (16) Telemecanique Altivar 66 variable speed drives, which allow fast adjustment of
conveyor speeds to allow continuous processing of small and large diameter logs (which require slower conveyor speeds to avoid logjams). The PLCs and drives are housed in (10) Telemecanique TMD Motor Control Centres. Controlling a total of 3,000 I/O points, the 5 PLCs communicate to the drives and field devices via highly distributed remote I/O modules.
Field devices include:
Schneider Electric Telemecanique Integral starters (housed in the TMD MCCs), pushbuttons, proximity sensors
and limit switches. “We installed Schneider Electric networks, software, PLCs, Motor Control Centres, drives and field devices because of their ability to be networked together”, says Mr. Robert Légaré,General Superintendent of Outardes 2.
“Schneider Electrics high speed networks allow us to access and control operations of all three facilities from any location.” Troubleshooting is facilitated by the Schneider Electric programming software, which, according to Mr. Dany Dumont, Electrical Technician, “gives us detailed, real-time diagnostics in a user-friendly format.” Installing Schneider Electric networks has also facilitated equipment upgrades, because they can be done without having to change existing networks and
wiring. “Because we can keep our existing network intact, upgrades are cost-effective and minimize downtime”, observes Mr. Légaré. The Donohue Outardes sawmills have the ability to continuously run logs of significantly varying diameters. The optimization scanners relay the log diameters to the PLC, which relays the required conveyor speed adjustment to the Altivar 66 variable speed drives. The Altivar 66 drives
ability to make real-time adjustments to the conveyor speed has significantly reduced cycle time and improved productivity, states Mr. Dumont. In addition to reducing downtime, Schneider Electrics Telemecanique control system has improved productivity and operator safety. Our sawmills are continuously being upgraded to maximize productivity, quality and safety. Schneider Electric is a key partner in helping us to
achieve these initiatives, concludes Mr. Légaré. |
