Double disc pumps solve problems at treatment plant

Problem: In April 2010, the staff in Moline, Illinois, needed to replace a piston (plunger) pump at the North Slope Wastewater Treatment Facility. The pump, which fed a blend of wastewater and lime blowdown sludge at 8 to 10 percent solids to the belt filter press, needed to pull a small suction lift and operate against a discharge pressure of 10 to 20 psig because the press was across the plant.

Solution: After a trial run, the plant team installed 6-inch Penn Valley Pump Double Disc Pump Model 6DDSX76. The city later purchased a second pump from Penn Valley Pump to replace a piston pump for press feed. In the next three years, the city chose pumps from Penn Valley Pump for other replacements at its South Slope plant, including a 4-inch pump for waste activated sludge transfer and a 6-inch pump for primary sludge transfer.

Result: In 2014, the city took bids for a $40-million upgrade at the North Slope facility, and plant staff urged the consulting engineer to specify pumps from Penn Valley Pump. That led to the purchase of seven of the company’s 6-inch pumps. 800-311-3311; www.pennvalleypump.com

School district streamlines lift station maintenance

Problem: As safety requirements tighten, specialized maintenance and service protocols for some lift stations are becoming burdensome and costly for many small- to medium-sized operations groups, like the Klein Independent School District outside of Houston. “When a submersible goes out, it’s contractor time,” says Steve Cox, maintenance supervisor. “My technician lets them in the gate, and that’s about it.”

Solution: To become more self-sufficient and minimize costs, the district is converting its submersible pumps to above-grade Wet Well Mounted Pump Stations from Smith & Loveless. The systems include all pumps, piping, valves, and controls installed outside of the wet well, at grade, making operations and maintenance simple, safe, and low-cost. Twelve of the district’s 20 lift stations have been converted.

Result: One full-time technician now operates and maintains all the district’s lift stations, easily and safely inspecting each one regularly by opening the lightweight enclosure. The technician can access all mechanical and electrical equipment including the pump internals after removing four bolts. There have been no pump repairs or replacements by contractors over the last decade. “With the above-ground stations, we can do just about everything, no problem, with just one guy,” Cox says. “Problems are not very common. The stations run very well.” 800-898-9122; www.smithandloveless.com 

Pump lets plant become a regional solution for biosolids

Problem: The Bird Island Wastewater Treatment Plant serves the city of Buffalo, New York, and neighboring communities. The plant team wanted to accept biosolids from these communities and make the facility a regional processor.

Solution: A 60-cubic-yard push-floor bin was installed where vehicles can deliver dewatered biosolids. The hydraulic push- floor sends material into a screw feeder, followed by a Schwing Bioset KSP 12V pump. The biosolids are then pumped up to the third floor for incineration. The plant team also has the option to transfer the biosolids from the bin into the subbasement where it can be rewetted and sent to the digesters to produce methane.

Result: The plant is accepting biosolids from several neighboring communities. The pump takes material at 26 to 28 percent solids range and sends it more than 65 feet up to the incinerator. The higher solids content has enabled gas consumption to be reduced by 65 percent. 715-247-3433; www.schwingbioset.com

Peristaltic pump used to deliver lime slurry to water treatment plant

Problem: The North Regional Water Treatment Plant of Palm Bay, Florida, sought a pump to deliver a 10-percent lime slurry at 25 psig and 20 gpm. The superintendent of the facility was examining shoe designed peristaltic and single rolling design peristaltic pumps. He realized that a single roller design compresses the rubber hose only one time per 360-degree revolution, whereas the shoe design pumps compress their rubber hoses twice per every 360-degree revolution. This means that hose life in the single roller design is at least two times longer. Additionally, a single roller design generates no heat, whereas the shoe design generates significant heat, which can degrade rubber hoses, reducing hose life. The superintendent realized the operating costs would be significantly higher for the shoe design peristaltic pumps.  

Solution: Flowrox single roller pumps only require approximately 10 percent food-grade glycerin when compared to shoe design pumps. The increased hose life and decreased glycerin consumption also helps the city to select the better pump for lime slurry pumping. The superintendent specified Flowrox LPP-T 1.5-inch pumps based on the technical merits and reduced operating costs by the single rolling design.

Result: The city ordered three 1.5-inch rolling design peristaltic pumps to minimize operating costs for the city. 410-636-2250; www.flowrox.com