Pump Resilience For Low Flow / High Solids Intake
Project Overview
Rural small works wastewater treatment site needed a solution for low flow pumping
A low-flow, high-solids pumping solution is installed at this small WwTW. The LSM pump with intelligent flow control delivered operational enhancements, including fewer, safer interventions, greater resilience, and more effective flow management.
Challenge
Like many small sewage works, this WwTW (PE of <250) has very low intake flows – down to 12 l/min.
This flow range makes conventional centrifugal sewage pumps unsuitable. Such pumps are not designed to handle small flows; either the pump must be oversized to allow solids passage (resulting in frequent on-off cycling and operation off the performance/power curve), or a smaller pump is used, leading to frequent blockages.
Solids can be broken up with a macerator to fit through a smaller pump, but this brings its own problems.
This unmanned site required a low-intervention, resilient pump capable of continuous operation, handling low flows, and passing typical inlet solids.
Solution
Atlantic Pumps proposed an LSM peristaltic pump, capable of passing rag and sized to suit solids up to 50mm. A demand-responsive float switch provides a steady, variable flow rate while minimising wear from frequent on/off cycles.
Although the large passage size means less risk of blockage, if one is detected, the control panel reverses the pump for a few seconds to clear it.
Instead of being submerged in the intake tank, this pump is dry-sited at ground level.
Results
The LSM’s wide rollers, gentle rotation, and internal lubrication system result in lower energy consumption, reduced wear and less maintenance. These pumps are available from Atlantic Pumps in a wide range of sizes, for hire and sale. This water company is saving a significant amount of revenue and time on pump and part replacements, blockages, and downtime. Flow-control is optimised, aiding treatment efficiency from low flow to FFT.
This pumping arrangement brings multiple benefits over alternatives:
- Flow varies based on supply level – less on/off cycling.
- Smoother inflow aids downstream treatment.
- Low energy use. Pump draws only the power needed.
- Easy access for inspection and maintenance.
- No need for confined space working or pump lifting for inspection and maintenance.
- Sited in a non-ATEX zone.
- Self-priming (strong suction lift).
- Self-clearing of blockages.
- The pump system is inherently safe from cavitation or dry-run damage.
- Passes grit, rag, and solids.
- Valve-free back-flow protection.
