Rotary drum screens

Rotary drum screens BFRD / BFGD type.

Perrier Sorem gravity filters are designed to protect downstream hydraulic equipments such as river or sea water pumping stations. These filters are used to efficiently respond to the difficult operating conditions found in industry or in power stations.

When the filtering band is clogged, a pressure drop detector integrated into the filter triggers the rotation of the filter as well as the counter-current washing system. The waste is then evacuated by a washed-water collector. The pressure drops then decreases to its initial value.

Perrier Sorem gravity filters are available in 304L, 316L or duplex stainless steel and can be optionally fitted with electrical control cabinet, pressure drop detector and cathodic protection.



A gear motor with one or two speeds driving a ring gear or rollers fixed on the rim of the drum allows its rotation. During this rotation, the waste retained outside are rejected by the jets of the washing ramp towards a discharge washed-water collector.

The direction of the water flow with Perrier Sorem drum filters is from the outside to the inside.

Rotary drum screens

Technical data



Model BFRD Model BFGD
Type of filter Horizontal rotary drum Horizontal rotary drum
Filtration direction Exterior to interior Interior to exterior
Waste lift speed 0,15 m/s 0,15 m/s
Waste washing system By nozzles ramp inside the drum By nozzles ramp inside the drum
Position of the discharge chute Outside the filter Outside the filter
Sealing between the filter belt and the laying surface Sliding joints on the lock wall Sliding joints on the lock wall
Gear motor power from 1 to 3 kW from 1 to 3 kW
Filter drive mode By mesh on the clean water side By mesh
Filtration mesh (min / max) 0,5×0,5 / 10×10 mm 0,5×0,5 / 10×10 mm
Usable filtration length (min / max) 800 / 4000 mm 800 / 4000 mm
Maximum filtration flow 40000 m3/h 40000 m3/h
Drum diameter (min / max) 1800 / 4200 mm 1800 / 4200 mm
Minimum pit width 2600 mm 2600 mm
Minimum pit length 1500 mm 1500 mm
Minimum pit depth 1750 mm 1750 mm
Electrical connection on terminal block on terminal block
Construction material 304L stainless steel 304L stainless steel
Options Electrical control box, specific motor, construction materials, level detection and differential measurement, etc.
Rotary drum screens


Perrier Sorem filter drums are suitable in all cases where the water levels variations are relatively low.

The filter drum is placed upstream of the pumps of the pumping stations or on potable water treatment stations.

It is installed in the axis of the flow.

The filter gradually clogs with the accumulation of retained waste, which creates an increase in pressure drop. This is controlled by a pressure drop detector associated with the drum.

When the pressure drop reaches a preselected value, the drum gear motor is energized and starts to rotate. The wash system opens and backwashes the filter cloth. Once the pressure drop returns to its initial value (clean filter cloth), the gear motor and the washing water circuit are automatically shut down at the end of the time delay until the next washing cycle.

Rotary drum screens


The BRFD and BFGD drums filters have a similar construction but contrary rotating directions:

  • BFRD: Filtration from exterior to interior
  • BFGD: Filtration from interior to exterior
Rotary drum screens

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