Solving a Wastewater Bottleneck in Molded Pulp Production
As demand for molded pulp products continues to grow, manufacturers are under increasing pressure to expand production while staying within strict wastewater discharge limits.
In this interview, Aaron Hickman, technical manager at Kadant Solutions, discusses how one molded pulp producer overcame a critical wastewater solids bottleneck that was restricting output. He explains how the RotoFlex™ resource recovery strainer helped remove fibers and suspended solids, enabling increased production, improved compliance, and long‑term operational flexibility.
J: What challenge was this particular molded pulp manufacturer facing?
A: The manufacturer’s production was limited by its wastewater discharge permit. While the local municipality had capacity to accept more water, it had no capacity for additional suspended solids. Fiber, pulp, and debris in the wastewater were creating a bottleneck which prevented the facility from increasing production.
J: Why was wastewater solids removal so important in this case?
A: Demand for this manufacturer’s products had exploded! They had invested in the equipment and material to produce more, but producing more also meant generating more wastewater. Without a way to remove fibers and pulp from the wastewater stream, production increases were not feasible under the existing permit conditions.
J: What was the recommended solution?
A: We recommended and installed a RotoFlex resource recovery strainer. The system was designed to continuously remove fibers, pulp, and other suspended solids from the wastewater stream, allowing filtered water to be discharged directly to the municipality while recovered solids were sent for further processing and disposal.
J: How does the RotoFlex resource recovery strainer support wastewater compliance?
A: The RotoFlex resource recovery strainer separates solids from wastewater before discharge. By removing fibers and pulp debris, the system addresses the municipality’s solids limitations while allowing the facility to maintain wastewater flow. This directly resolved the discharge‑related production constraint.
J: What were the results after installation?
A: The RotoFlex resource recovery strainer eliminated the wastewater bottleneck that had been limiting production. In its current configuration, the system produces 350 gallons per minute of filtered water suitable for discharge, capable of over 500,000 gallons per day! At this rate, the filtration system outpaces wastewater generation and does not need to operate continuously.
J: How does this impact future production growth?
A: As production increases, the facility will be able to increase wastewater discharge to more than one million gallons per day without adding additional equipment. This gives the manufacturer flexibility to grow while staying within its existing discharge framework.
J: Were there operational benefits beyond capacity?
A: Yes. The facility noted that the RotoFlex resource recovery strainer is simple to operate, requires minimal maintenance, and allows for quick screen changes. These features have led the facility to consider using the system for additional applications.
J: What are some of the key takeaways from this project?
A: This case demonstrates how effective resource recovery can remove hidden constraints on production. With the RotoFlex resource recovery strainer, the manufacturer achieved excellent water and fiber recovery, handled high wastewater volumes, avoided additional infrastructure, and realized a proven return on investment.
