FILTRATION AND SEPARATION
A cost-effective sand solution
Linatex has supplied a new sand filter bed treatment plant to Bounemouth & West Hampshire Water
Maintenance of the sand filter beds at Knapp Mill is performed on a continuous cycle with some 30mm of sand skimmed off the beds every four months
A
s one of the leading performers in the ensure that 100mm of clean sand is replaced on from mild steel and is Linatex lined in all wear
UK Water industry Bournemouth & West the filter bed. This continual process is effectively areas. Fitted with extended feed box, discharge
Hampshire Water (BWHW) provides a recycling operation as new sand is only regulator and pressure flange assembly the
clean drinking water to around half a million introduced approximately every ten years. separator incorporates two pressure gauges to
people in an area from Poole to Beaulieu and As it is essential that the sand quality is measure inlet pressure and vacuum that are key
from Bournemouth to Salisbury, an area of over maintained in this operation the skimmed sand to performance of the unit to maintain
1,000 sq km. It has an excellent record for water requires scrubbing to release any impurities operational efficiency and maximise sand
quality, and supplies on average about 150 before the Linatex sand plant effectively washes recovery. The sand separator, which is mounted
million litres of drinking water every day, through and dewaters the material. in a supporting tower, incorporates three
nearly 3,000 km of water mains. discharge chutes providing approximately 2,000
With a new pumping station to be installed at Wheel loader tonnes of stockpile capacity.
its Knapp Mill site in Christchurch, the company The material, being essentially wet filter bed With the need to retain as much fine material
contacted Centristic Ltd of Newton Abbott to sand, is fed by wheel loader into a hopper which as possible, the Linatex extended separator
facilitate the re-siting of the existing Linatex sand feeds on to a 15m long inclined conveyor that ensures that the quality is achieved, proving itself
filter bed treatment plant. A review revealed that delivers the material into a 1.2m diameter x 3m to be a cost effective method of providing clean
elements of the present Linatex sand plant were long trommel (sand scrubber barrel), which is sand to a high standard. Since supplying a
too small for the feed requirements. lined with Linatex rubber and lifters. Sand and system for the BWHW Alderney water treatment
Linatex has a long history in sand plant design water discharging from this barrel is then flumed works 19 years ago, Linatex has worked with the
and has enjoyed a relationship over 25 years down a Linatex lined chute to the centre of a client consistently providing the technology and
with BWHW. As a result, it was tasked to supply a 2.1m diameter Linatex feed regulating sump with expertise in terms of sand processing plant.
25tph sand processing system, with Centristic any overflow from the sump gravitating to waste. Tony Primmer, production manager, said: “It is
acting as main contractor on the plant build. From the base of the sump a 100/100mm very pleasing to continue our long-term
Maintenance of the sand filter beds at Knapp bore Linatex lined centrifugal pump draws the relationship with Linatex. They have always
Mill is performed on a continuous cycle with slurry and feeds via 100mm bore pipework to a provided us with first-class sand washing plants
30mm being skimmed off the beds Linatex lined HK 100 extended sand separator and together with the excellent after sales back
approximately every four months. To maintain with the overflow from the separator returning to up, we look forward to working with Linatex for
effective operation the filter beds must retain a the vicinity of the feed sump for balancing the many more years to come.”■■■
minimum of 300mm of sand above the carbon, system or disposal to waste.
therefore after skimming the Knapp Mill team The Linatex HK 100 separator is constructed For further information see www.linatex.com
18 Water & Wastewater Treatment September 2009