Two-stage Oxygen Delignification System, Zelstoff Celgar Limited

Allnorth provided multiple services to upgrade an existing single-stage oxygen delignification system to a 1,664 ton-per-day, twin-tower, double-stage oxygen delignification system. Allnorth evaluated process and equipment options and benefits, specified equipment, completed budget capital cost estimates and performed detail and field engineering. We determined the optimal equipment placement and routing of piping by combining laser point-cloud scanning of the existing plant with 3D design and by conducting model reviews with the client via remote online “webinar-style” meetings. By using this time-saving and cost-effective process, the detail engineering for this challenging, space-constrained retrofit was completed in only 14 weeks. Allnorth also provided field engineering support for the client during an aggressive 3-month construction/commissioning period involving carefully sequenced pre-shutdown, shutdown and post-shutdown work.

Allnorth’s responsibilities for this project included:

  • Evaluation of process/equipment options and benefits
  • Equipment specification
  • Completion of budget capital cost estimates
  • High-level project scheduling
  • Multi-discipline detail and field engineering
  • Project management
  • 3D design and modeling


About this pulp and paper project

The Zellstoff Celgar kraft pulp mill is situated near Castlegar, British Columbia, approximately 600 kilometres east of Vancouver.

Services in this project

3D Scanning

Allnorth provides 3D laser scanning services using our in-house 3D laser scanner, Leica ScanStation™ C10. Our technical staff produce 3D solid models, volume and area calculations, topographic detail surveys, and quantity surveys.

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Mechanical Engineering

Allnorth provides comprehensive mechanical and piping engineering services to industrial projects. Our in-house  multidisciplinary expertise allows Allnorth to offer integrated service packages for clients in multiple sectors.

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Process Engineering

Allnorth provides integrated process engineering service packages for industrial projects. We recognize that downtime is expensive for our clients, so our teams specialize in retrofitting new systems into existing operations with minimal disruption.

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Project and Construction Management

At Allnorth, we believe that communication and teamwork, from start to finish, are key to the successful execution of any project. We work closely with our clients to plan and manage projects from initial concept through to delivery.

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