In modern pulp and paper production, efficiency, reliability, and ease of maintenance are key factors in selecting equipment for process optimization.
One such critical piece of equipment is the hydrocyclone cleaner—a device that uses centrifugal forces to separate contaminants from pulp slurries. Although this technology has been present in systems for decades, improvements and innovations continue to redefine performance expectations across the board.
The Xcel NT™, Kadant Black Clawson’s newest forward cleaner, stands out with several industry-leading features: simplified and modular maintenance, integrated reject dilution, optimized flow paths that prevent pressure loss, and the capability to operate at high consistency with high efficiency. Together these innovations are not just incremental—they offer a transformative impact on mill operations by reducing downtime, improving yield, and maintaining high-quality output with minimal energy consumption.
High Consistency Operation with High Efficiency
Perhaps the most game-changing capability of this cleaner is its ability to operate at high feed consistencies—up to 2.2% or higher—without sacrificing separation efficiency. This is a major advancement, as conventional cleaners often require dilution to operate effectively, which increases water usage and process complexity.
Through a combination of carefully balanced cone geometry and vortex stability, the unit maintains tight separation thresholds even at elevated consistencies, removing contaminants like sand, plastic, bark, and shives with minimal fiber loss. This allows mills to simplify upstream dilution processes, reduce water consumption, and increase the overall system capacity without major capital investments.
Lower stages in an Xcel NT™ system utilize an innovative design where the hydrocyclones are installed inverted, with the reject tip pointing up! Although this looks odd at first, the forces at work inside the cone are hundreds of times greater than the force of gravity, so the orientation doesn’t impact separation, but it does have a huge impact on maintenance.
Unfortunately, equipment plugs occasionally. As much as equipment design tries to minimize this, it is a fact of life in a paper mill. With the inverted design of the Xcel NT™ reject stages, unplugging is simplified; sometimes to the point of being automatic. Once a plugged hydrocyclone is isolated and there is no pressure driving flow to the reject tip, plugs of sand or other grit often submit to gravity, falling and breaking apart in the hydrocyclone to be processed when the hydrocyclone is brought back on-line. In more stubborn scenarios, the inverted design does make disassembly and reassembly easier since the components naturally stack together.
Primary Stage
Recovery Stage
Simplified and Modular Maintenance
One of the most compelling features of the new hydrocyclone cleaner is its maintenance-friendly design. Traditional cleaners often require significant disassembly or specialized tools for routine maintenance or part replacement. This translates into prolonged downtimes and increased labor requirements, which are two major costs in a continuous production environment.
In contrast, this advanced cleaner system is engineered with modular components that can be quickly removed and replaced without disturbing surrounding units. Whether it’s replacing wear components like cones or hoses, or reconfiguring cleaner banks for different flow rates, the modular design makes the process fast, intuitive, and cost-effective.
All hydrocyclone components are interchangeable across units, further streamlining inventory requirements and simplifying training for maintenance staff. This includes any positions or stages, including between the traditional Primary Stage and the inverted Recovery Stage configurations. This results in fewer interruptions to production and lowers the total cost of ownership over the life of the equipment.
Optimized Flow Paths to Prevent Pressure Loss
Separation efficiency in hydrocyclone operation is greatly impacted by available pressure of the feed stock. Since there are no mechanical components like a rotor to drive separation, all of the energy comes from the stock itself. This is why differential pressure measurements are so important in cleaner operation, as it is a measure of energy used. Cleaner bank designs often experience excessive pressure losses due to abrupt changes in diameter or direction and suboptimal internal geometry. These hidden loses reduce the energy available for good separation efficiency.
The Xcel NT™ addresses that challenge with precision-engineered flow patterns. Every aspect of the internal geometry—from inlet transition zones to vortex finders and underflow orifices—has been computer-modeled and flow-optimized to maintain stable flow and minimize turbulence. The result is a significant reduction in pressure loss across the unit, which allows for more energy to work for its intended purpose, to clean stock.
Header to cone transition modeling to minimize pressure losses.
Conclusion
In an industry where operational reliability and energy efficiency are critical metrics, the Xcel NT™ hydrocyclone cleaner delivers on all fronts. Its modular design simplifies maintenance and improves uptime, while its optimized flow path minimizes energy use while preserving throughput. Most importantly, it enables mills to operate at higher consistencies while maintaining high efficiency, unlocking new levels of efficiency and sustainability.
For managers and engineers looking to future-proof their cleaning systems while lowering total operating costs, this hydrocyclone cleaner is more than an upgrade—it’s a redefinition of what’s possible in stock preparation.
About the Author
Steven Johnson
Product Manager - Screening
Kadant Black Clawson, LLC
