Challenge

Wapakoneta, best known as the home of the astronaut Neil Armstrong, the first man on the moon, is located along I-75 in western Ohio. The city's waste water treatment plant was originally built in 1936 and has been upgraded over the years to meet changing demands.

The setup originally included a raw sewage lifting station designed for three screw pumps, however, two enclosed tube-type screw pumps with internal flights were installed, leaving space for one additional pump.

In 1992, a third screw pump installation was required to meet growing capacities. On inspection, it was found that the internals of the existing tube-type pumps were heavily corroded and that the design did not allow for easy maintenance.

Solution

Rob Burns, Superintendant of the Wapakoneta plant was responsible for finding a long-term solution while keeping the existing pumps in operation for as long as possible to minimise any interruption to the influent pump station operation.

Acting on behalf of the City of Wapakoneta, consultant BBS Engineers considered different alternatives, including other tube pumps, different screw pump designs and centrifugal pumps. After a detailed study, they selected Spaans Babcock and the compact Screw Pump, as the best solution for the installation.

The compact preassembled, prealigned screw pump is easy to install, provides capital cost savings and can be easily accessed for maintenance. Provided through its-then licensee Asdor, the Spaans compact screw pump was installed next to the two existing pumps.

In 1998, after witnessing side-by-side pump operation, Wapakoneta WWTP decided to replace the remaining two tube-type screw pumps with two Spaans Babcock preassembled compact screw pumps. In 1995 Spaans Babcock had introduced a new greased-for-life lower ECO bearing which was incorporated into the new pumps installed in 2002.

Outcome

Rob Burns and his team were pleased with the project implementation and the new compact screw pumps.

Superintendant Burns commented: “Spaans Babcock solved a major problem for us. Their technical knowledge and customer service were exemplary. We were especially pleased with the ease with which the old pumps were replaced. The new Screw Pumps have a noticeably better performance and are much easier to maintain and operate.”