The City of Beaver Dam is located in south-central Dodge County, Wisconsin, and attracts tourists year round. The wastewater plant receives a significant food-based industrial load and is subject to the usual wet-weather flows.
After doing extensive upgrades to other parts of the plant, it was time to replace the aging headworks bar screens. The plant could trace high maintenance costs and clarifier sludge pump failures directly to the high volume of debris passing through the bar screens. The screen evaluation team rated high capture as the top priority for the new screens.
Beaver Dam’s screen evaluation process was complicated by hydraulics. Inclined screw pumps lifted the wastewater to the headworks and limited the hydraulic grade line. This meant that the new screens had to fit into the current channel footprints. There was no money in the screen budget for civil work. They could not do both.
Installing a multiangle screen
The evaluation team overwhelmingly favored the FSM FilterScreen perforated plate belt screen. However, the standard 75-degree single-angle screen that fit the channel could not handle the storm flow.
Enviro-Care proposed the FSM FilterScreen multiangle screen. The wetted section of this screen sits at a 30-degree angle which significantly increases the exposed surface area. The screen then transitions to a 75-degree transport area.
This 30-degree angle can provide up to a 100% increase in capacity relative to a 75-degree screen. With this screen configuration, Beaver Dam could reach a one-screen peak flow of 11.1 mgd with no civil work, solving the problem.
Beaver Dam purchased a second FSM multiangle FilterScreen less than a year later. To eliminate the cost of constructing a bypass channel, Enviro-Care proposed adding a hydraulic lift to the second FSM screen.
Enviro-Care / SAVECO, a member of the WAMGROUP, supplies screening and solids/grit management equipment to the North American water and wastewater market.
815-636-8306 | ecsales@enviro-care.com | www.enviro-care.com
