Plant & Works Engineering
Pumping system solution
Published:  19 July, 2021

A wastewater pumping system at a large shopping centre in Bristol was causing a headache for facility managers, as it was suffering multiple breakdowns. Designed to pump wastewater from a 1000 L basement tank over a 10m head and along to the main drains, two pumps kick in once a certain level is reached, emptying the tank. However, the 20-year-old system was showing its age. The tank itself was leaking, causing the seepage of wastewater into the basement area. This required clean up, which was jeopardising the reopening of shops post-lockdown.

Paul Pearce, sales director at Rotamec, quickly found himself involved in a project to replace the system: “A contractor approached us regarding overhauling the wastewater pumping system at the shopping centre, with facility managers indicating that they would prefer the work to be completed ready for reopening after lockdown. We quickly arrived on-site to assess the system.”

After a thorough inspection, it was clear that the whole system required replacement with a more efficient and reliable solution. The ageing tank, pumps, valves, electrics and control system would all require replacing. “We offer a turnkey service,” Pearce explained. “We can source and repair equipment on short lead times, and this project entailed sourcing a new pre-cast 1000 L polyethene tank, two new pumps with motors, new non-return and gate valves as well as pipework, electrics and controls.”

Rotamec also relied on its in-house fabrications department to expedite the project. A 160 mm high steel frame was designed and constructed to raise the new tank off the floor, which allowed for easier integration of the new system into existing pipework. This simplified the layout of the pipework too. Each new pump features an open impeller, optimal for pumping wastewater, driven by a 5.5 kW motor that provides greatly improved efficiency compared to the previous units, unlocking energy cost savings. The new tank eliminated any leaks or seepage, ensuring that the basement no longer required cleaning. The project was completed within three weeks.