Rotary Lobe Pumps from NETZSCH reduce maintenance and downtime for wastewater treatment plant in the USA

At a main wastewater treatment plant serving a city in the state of Delaware in the USA, plant operators turned to NETZSCH TORNADO^® T2 rotary lobe pumps with full-service-in-place (FSIP^®) design to replace existing pumps, leading to a decrease in maintenance and downtime. The wastewater treatment plant includes a high-rate activated sludge plant, three pump stations, industrial pre-treatment program, industrial leachate and sludge disposal. NETZSCH has provided the company with new pumps that have dramatically lowered maintenance and downtime in two different sludge handling applications including transporting thickened sludge and digester recirculation.

A low maintenance solution for a problematic thickened sludge line
The first NETZSCH TORNADO^® T2 pump with a FSIP^® design replaced a competitor’s pump which won’t work to the satisfaction of the customer. The plant operators also replaced a second pump from the same manufacturer but with a traditionally designed rotary lobe pump from a NETZSCH competitor. However, that rotary lobe pump was not able to handle this heavy-duty application and was finally also replaced by a TORNADO^® T2 with FSIP^® design. Since the two pumps are working 24/7 in that application.

According to plant operators, the two earlier pumps would go down every three month and the longest running pumps would last about one year. The wastewater treatment plant installed the TORNADO^® T2 06/70 pump with FSIP^® design and it has been running continuously for three years. They replaced two seals duringthat time, but with the easy access through the face cover, that was a very simple operation.

Digester circulation line now running almost maintenance free
According to one of the maintenance engineers, some of the sludge digesters have always had problems with gas bounding. He said, “Before we installed the NETZSCH pumps, we had been using recessed impeller centrifugal pumps for years.” He notes that the NETZSCH pumps have been running almost six months in the sludge circulation application without any downtime and have completely solved the air-bounding problem.

He said, “Not only that, since the pump is belt-driven, there is no oil needed to lubricate  a gear. You don’t have to worry about putting in the wrong oil or running out of oil. There is a small container that puts a small amount of oil on the seal – but that’s it. We have two NETZSCH pumps now working in this process. They are both TORNADO^® T2 pumps with FSIP design.”

He goes on to say that the plant maintenance staff regularly checks the pumps to see if the lobes need to be changed, but that they haven’t had to since the lobes don’t show significant wear. “Our guys, in terms of maintenance, they love the NETZSCH pumps,” said the maintenance engineer. “The design is very simple and it takes about 15 minutes to check them over. Even when we had to repair the seals, it was easy because, due to the design, you don’t have to pull the pumps out.”