The case for choppers07 December 2018

Should have had a chopper; example of clogged submersible pump

According to distributor P&M Pumps, 80% of the 366,000 sewer blockages occurring in the UK are caused by non-flushable items, of which the biggest offender is wet wipes.

The UK’s water companies have the responsibility to invest in the correct equipment to deal with the liquid waste they are paid to transport and process. This includes waste water pumps that can handle large spherical solids. In most cases, the single-channel, vortex and other designs of pumps installed do the job. However, disposable wipes are not large spherical solids, at least not until they’ve been given the conditions and opportunity to form them.

Over time wipes laminate with fats and greases, bonding them on to the surfaces of lift stations and large-diameter sewers resulting in restricted flows, backing up and eventually blocking the system.

P&M Pumps has successfully replaced failing submersible pumps with Vaughan Chopper Pumps, which it distributes.

For example, at Anglian Water’s pumping station in Cambourne, two Vaughan 30kW, 1460rpm SE6W chopper pumps were specified to handle flows up to 400m3/hr at heads of 17.8. A retrofit used all of the existing installation hardware.

Stray solids that may be trapped within the mechanical seal chamber are shredded and removed by the impeller pump-out vanes turning against the upper cutter. In addition, solids are then chopped by the cupped and sharpened impeller blades turning across the cutter bar, creating a smooth slicing effect, enabling the conditioned slurry to be pumped upstream. Finally, a centred nut with a tooth cuts stringy materials that tend to wrap at the pump inlet. Where non-fibrous hard solids are present, there is the option for a (removable) disintegrator tool that agitates and breaks up large solids to prevent suction blockage.

William Dalrymple

Related Companies
P&M Pumps

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.