Key Equipment: Enhanced services for ANDRITZ DD-Washers

With installations in 24 countries, the DD-Washer is clearly preferred for fiberline washing applications. To support this installed base, ANDRITZ has developed a full range of monitoring, diagnostic, and support services to reduce lifecycle costs and keep availability high.

Virtually all the DD-Washer systems ever delivered are still in operation. Many of the advances made over the five generations of washers are available as retrofits or upgrades to these installed systems.



An almost universal trend in mills today is to extend the period between planned shutdowns for maintenance. There is always a trade-off: intervals too short may subtract from maximum production; intervals too long may lead to degraded performance or even a catastrophic component failure.

Washing efficiency is a key parameter for cost-effective pulp production. If a mill has continually increased production over the years without upgrading or reevaluating operational setpoints for the washer, it is possible that the operation is no longer optimized. However, there are rather simple retrofits, such as upgrading the wash water distribution system, to keep washing efficiency high or even improve it by as much as 20%, even at the higher loadings. Efficiency can also be improved by readjusting wash water and filtrate flows between washing stages. In addition, adding a high-pressure oscillating shower to the screen plate will often eliminate losses in throughput or efficiency if plugging is an issue. A retrofit to optimize the cake height is also possible for older generation drums.


In addition to equipment upgrades, the ANDRITZ Service division has developed modern tools to monitor, enhance, and extend the life of DD-Washers. These services are available on a contract basis.

These service tools take advantage of recent advances in the Industrial Internet of Things (IIoT), including smart sensors and data analytics. Sensors can be installed in the washer system to continually measure sealing water pressure and flow, sealing air pressure and flow, the rotation speed of the drum, drum positioning, the running life of the end seal, etc. This gives insight into the condition of the end seal, which is one of the critical consumable parts of the washer. The user interface to this information is a simple DD-Washer Dashboard using traffic light indicators (red, yellow, green). The information is displayed on a handheld tablet for maintenance teams and optionally a DCS screen for operators and is available via a Metris app at anytime and anywhere.

In addition, there are new monitoring tools for early detection of drum leaks, for detecting scaling on the perforated screen plate, and for monitoring the thickness of the end seal to predict when it should be replaced.

ANDRITZ’s combination of operational, shutdown, and lifecycle services ensures safe and optimal performance of the DD-Washer – no matter when or where installed.


“Our service concept, combining mill audits, shutdown services, and effective IIoT service tools, is a powerful way to let the mills focus on production while we ensure the runnability of the DD-Washers.”

Product Manager, ANDRITZ

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  • Key Equipment:

    Enhanced services for ANDRITZ DD-Washers

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