Although primarily thought of as a technology for dewatering in wastewater plants, Schwing Bioset’s screw press has also been successfully applied in other types of plants too. For example, here’s a quick look at the successful applications of our screw press technology on ferric and alum sludge generated by water treatment plants.
Davidson Water, Inc., located in Lexington, North Carolina, is a large membership cooperative with a plant capacity of 35 million gallons per day (MGD). Upon successful pilot trials, Davidson Water selected the Schwing Bioset machine for dewatering its full-scale operations. They are processing their full capacity at about 85% of the screw press’s rated throughput and obtaining 27-30% solids, with greater than 95% capture rate and less than 20 pounds of active polymer per ton. Operating conditions have achieved dry solids contents as high as 38%. Davidson Water’s operations are surpassing the performance demonstrated during on-site pilot trials and are exceeding their expectations.
Seneca Light & Water operates a 20 MGD Water Treatment facility. The original plant started in March of 1969 as a 4 MGD facility and has advanced to the current rating with several upgrades. The Seneca water plant uses aluminum sulfate as a coagulant to lower the turbidity of the water. After a series of processes, the waste aluminum sulfate is dewatered so that as little water as possible is hauled away with the solids. Historically, a plate and frame press had been used. Although that equipment provided a reasonably dry product, about 24% solids, the equipment was only able to run in batch processes, was labor intensive, and was not a clean process to work with.
Seneca searched to identify new dewatering techniques that could replace the aging plate and frame presses. Several pilot studies were completed, and Schwing Bioset was invited to run their screw press pilot. The pilot proved successful with a result of 27% solids, which was better than the performance of the existing plate and frame press, as well as the other screw press that had been tested. The Schwing Bioset equipment was chosen as the best value and the screw press was designed into the new dewatering building that was commissioned in 2015. The screw press is producing 30% solids on average with a high of 34%, which is even better than the pilot results. This is all being done with a polymer dose of 5 pounds of active polymer per ton, which has proven to be very cost effective thus far. Seneca Light & Water has met their goal of replacing their aged plate and frame technology with a very energy efficient screw press that allows continuous processing in a cleaner process that requires less housekeeping.
Schwing Bioset Screw Presses provide a state-of-the-art solution for water and wastewater plants, as well as mining and industrial operations, looking to improve their dewatering process. Offering the widest range of model sizes available on the market, mobile units, rental units, and pilots, our Screw Press also comes with a wide range of features designed specifically with the operator in mind. Dewatering results are similar to high-speed centrifuges with a fraction of the energy and maintenance costs and are suitable for unattended operations. The Schwing Bioset Screw Press offers next generation dewatering for those wanting a cost effective, durable, and efficient unit to reduce the volume of their solids.