In order to prevent the washwater nozzles from blocking and disrupting the screenings separation process, a Bollfilter automatic filtration system has been installed in the Beckton Screen House. The system which comprises of two Boll 6.19 automatic self-cleaning filters and CCD pumps is mounted on one skid for ease of installation. The 6.19 filters, which operate under low pressure conditions, are fitted to the washwater inlet feed prior to the pumps, with the added benefit of protecting these from possible particulate damage. A small amount of the pressurised washwater is fed back into the filters for efficient cleaning without the need for separate backflush pumps, creating a low energy, space efficient filter/pump solution.
Kevin Woolley, Laing O’Rourke’s construction manager said: “We have found Boll filters to be very good. We installed a similar installation at the Thames Water’s Deephams STW, following problems with two previous filter systems. The Boll filters have worked well ever since.”