The newly launched W Range Large Auger progressing cavity pump from Mono NOV was installed by Wessex Water to resolve the problem of transferring thickened sludge.
Wessex Water’s Bristol Waste Water Treatment Works (WWTW) is the UK’s sixth largest works serving a population of about 800,000 from Bristol and surrounding areas. Wessex Water has installed a Biodrier system at Bristol to transform two thirds of the site’s sludge into dry, odourless fertiliser granules, as per the requirements of the EU Urban Waste Water Treatment Directive.
The W Range Large Auger pump has been installed to transfer the remaining sludge with a dry solids content of 32% to a storage bay for disposal by landfill. It is also used as an emergency standby pump in the event of failure of the Biodrier system.
Wessex Water was previously using a progressing cavity pump equipped with a bridge breaker to handle the thick sludge. However, the high solids content of the sludge had caused problems with the level sensing equipment, resulting in sludge entering the bearings and leading to pump failures, repairs and downtime.
Mono recommended its W Range Large Auger pump combined with an extended inlet hopper, which enables the pump to handle sludge with viscosities as high as 1,000,000 cP without the need for an additional bridge breaker.
The pump is also able to meet the site’s stringent low speed specifications for the transfer of sludge: a speed of 27 rpm and pressures between 12 and 16 bar.
Key features of Mono Large Auger progressing cavity pump:
- Replaceable flanged ball end pin joints minimise maintenance requirements
- Separate flanged throat section enables the auger assembly unit to be quickly removed for routine maintenance
- Available as a close coupled or bareshaft pump
- Can be supplied as a two or four stage unit, in cast iron or stainless steel
- Develops pressures up to 48 bar and handles capacities up to 215m³/h with a range of hopper sizes
- Many components interchangeable with Mono’s industrial pumps to minimise spare part requirements