The unique Rotorflush Filterpump, a submersible pump with a self cleaning intake screen, is used for extracting water from raw sewage and final effluent to provide washwater for inlet screens.

The unique Rotorflush Filterpump, a submersible pump with a self cleaning intake screen, is used for extracting water from raw sewage and final effluent to provide washwater for inlet screens at sewage works across the UK. The self cleaning intake filter on the Rotorflush Filterpump enables it to be used in sewage and final effluent without danger of the pump or upstream valves and nozzles becoming blocked. With outputs up to 2 litres/sec at 4 bar it's ideal for providing washwater for inlet screens.

The pump enables cost savings both in installation and running costs.

Being a multi stage submersible there is no need for weather or frost protection, it is self priming and only requires a minimum water level of 300mm to operate.

It can be installed into channels after the inlet screen, very close to where the washwater is required.

Running costs are reduced in two ways, the first and perhaps biggest saving is the re-use of sewage water, because the cost of using potable water for sewage screens is considerable and a wasteful use of this increasingly precious resource.

The second is the reduction in losses from having long pipe runs in conventional systems, which cause pipe friction losses and hence increased electricity consumption of the pressure sets.

There are 8 models to choose from both single and 3 phase with outputs from 80-120 litres/min and pressures from 2.5 bar to 8.4 bar.

The single phase versions are available with integral float switches.

The standard screen apertures on the self cleaning intake strainer are 315 micron which is more than enough filtration to prevent most nozzles and solenoid valves from blockage.

However where finer filtration is required screens can be specified with apertures down to 50 microns.

The self cleaning filter mechanism, which is the key feature of the Rotorflush Filterpump is extremely simple.

An additional impeller inside the filter continuously backwashes the filter screen, removing any debris that might be sucked onto the screen every half a second.

Without this feature the high pressure multistage pump would be blocked in a few hours when used in sewage.

The pump is finding many other uses, for example the provision of a filtered supply of water to online analysers, irrigation of effluent from dairy and pig farms, and supply of water to membrane systems.