Water conservation, efficient chemical usage, and environmental responsibility are at the core of modern industrial processes. Anssum’s “Brown Stock Washing Optimisation” project in South Africa encapsulates these values, showcasing a masterclass in control engineering and process optimisation.

Project Overview

  • Categories: Water, Chemicals, Environment
  • Location: South Africa
  • Project: Brown Stock Washing Optimisation
  • Status: Completed


The process of brown stock washing plays a pivotal role in the pulp and paper industry. However, inconsistencies in the operation can lead to inefficiencies, increased water consumption, and reduced production rates. The challenge was to ensure stable operation while optimising water and chemical consumption.

The Challenge

  • Achieve better control of consistency into the belt washer.
  • Enhance the operation stability of the belt washer.
  • Optimise the vacuum boxes in the belt washer for improved washing efficiency and vacuum profile.

Anssum's Ingenious Solution

Anssum, with its expertise in control engineering, proposed a dual-phase solution:

  • Feed Forward Control Scheme: Anssum introduced a new feed-forward control scheme that ensured better consistency control into the belt washer by appropriately loading the units. This approach allowed for real-time adjustments, leading to consistent operations and reduced inefficiencies.
  • Operational Stabilisation and Vacuum Control: After ensuring the stability of the belt washer’s operation, the focus shifted to refining the control of the vacuum boxes. This optimisation aimed to enhance washing efficiency and restore the vacuum profile, ensuring optimal water and chemical usage.

Remarkable Outcomes

  • Consistency Control: The initiative led to a massive reduction in the Mean Absolute Error (MAE) of consistency by 73.78%.
  • Operational Stability: The stable operation of the belt washer resulted in a significant production rate increase of 40%.
  • Optimised Vacuum Profile: The vacuum profile of the belt washer was successfully restored, leading to more efficient operations.
  • Water Conservation: One of the standout achievements was the reduction in water consumption per Bone Dry Tonne (Bdt) by 32.14%, showcasing Anssum’s commitment to environmental sustainability.


The Brown Stock Washing Optimisation project underscores Anssum’s dedication to blending technical prowess with environmental consciousness. By achieving operational excellence and reducing resource consumption, Anssum continues to set industry standards, demonstrating the transformative power of intelligent process optimisation.

With its unwavering commitment to conserving water, optimising chemical usage, and protecting the environment, Anssum is not just engineering solutions; it’s crafting a sustainable future.