Reducing wastewater pump clogging in demanding African duties

Describe the solids before choosing the pump

‘Wastewater’ is not a complete duty description. Rags, wipes, fibrous material, grit, stringy solids and unscreened sewage place different demands on the impeller and volute. Record what actually reaches the wet well, how often blockage occurs and whether the solids profile changes during storms or production cycles.

The selection brief should include the required flow and head, liquid temperature and chemistry, expected solids, minimum passage, wet-well arrangement and access for lifting and service.

Check the station around the pump

Repeated blockage may be aggravated by poor inlet geometry, sediment build-up, unsuitable start and stop levels or operation too far from the intended duty point. Review the wet well, pipe velocities, non-return valves and control logic alongside the pump itself.

For critical stations, compare alternatives using whole-life cost: energy, call-outs, cleaning, seal and wear-part replacement, lifting time, downtime and the consequence of overflow. A lower purchase price can be overtaken quickly by frequent interventions.

• Review the actual solids and minimum free passage.
• Confirm wet-well condition and inlet behaviour.
• Check starts per hour, run time and level-control settings.
• Include safe lifting access and isolation in the maintenance plan.

Use operating evidence to refine the solution

Local industry reporting on pump development for African wastewater conditions highlights clogging, solids carry-over, seal work and abrasive wear as practical design concerns. Xylem’s lifecycle-cost guidance likewise treats clogging probability and maintenance as part of system economics.

Liquidflow can review a problem station using duty data, fault history, site photographs and the existing installation arrangement before recommending a repair, hydraulic change or replacement range.