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Sand-removal system


BEAUDREY sand-removal systems are used in conjunction with a long settling basin where the sand carried by the incoming water deposits on the bottom.

The BEAUDREY sand-removal system sucks the sand from the bottom of the basin and returns it for disposal in a deck flume. Plants with very sandy water intakes use such systems.



The BEAUDREY sand-collecting gantry is installed across the settling tank channel. It runs on Rails secured at deck level to the channel’s side walls. It travels forwards and backwards along the sand-settling channel. Travel is either continuous or periodical depending on the plant’s specific needs.

A pump is installed on the pipe carried by the gantry, it travels along the bottom and removes the sand which travels up to the gantry level and is discharged in a deck flume for disposal. The pump can be either an electrical submerged sand pump or an air-lift bubble device depending on the relative levels of the pit bottom, the low waters and the deck.



  • The BEAUDREY sand-removal gantry removes large quantities of sand that would otherwise settle in the low-velocity zones of the plant or damage pumps and exchanger tubes by abrasion.

  • Simple, easy maintenance.

  • Fully automatic.



  • Widths up to 10 m are standard. Larger machines are available on special request.

  • Settling basin length, depth and width: BEAUDREY can help you optimize the design.



  • Gantry: painted carbon steel

  • Rails: carbon steel

  • Pump: cast iron (for fresh-water applications) or duplex stainless steel (for seawater applications)

  • Pipework: steel (for fresh-water applications) or GRP (for seawater applications)


Passive screen system

Equipiment produced in cooperation with ANDRITZ.


The Intake Passive Screen system is a water-life friendly intake screening system design to prevent debris from entering the downstream circuits. The system is permanently installed submerged outside the pumping station and requires no maintenance. It is automatic and self-cleaning using a large air-bubble blast type backwash which carries the debris up and away, beyond the attraction zone of the intake.


It is specially intended for small and medium-sized intakes.


The system comprises a number of cylindrical wedge-wire screening strainers arranged singly or in pairs ("T" layout) installed in the water body, well below the lowest surface level and at a sufficient distance above the bottom. The strainers are connected to the intake pipe which supplies the pump pits. An air backwash, perforated distribution pipe is installed inside the strainers at the lower level. It is connected to a compressed air tank fed by a general compressed air circuit or by a dedicated compressor. The backwash is actuated by opening a quick-release air valve. As the air is injected in a matter of seconds, it builds into an internal bubble that expands brutally thereby backwashing and lifting all debris upwards out of the suction zone of the strainer towards the surface.


The Intake Passive Screen system works if the screening strainers are located in a water current. It should not be installed in the dead-end of a canal or bay.


Like all apparently simple systems, Intake Passive Screen only works because it is designed and laid out to comply with very stringent sizing parameters and technical rules. The wedge-wire or Nocling strainers are mandatory in spite of their cost as other screening media such as wire mesh or perforated plate gradually block due to residual debris build-up and then require long outages to carry out costly maintenance.


The back-washing system must be sized to meet the required frequency of the back-washing which, in turn, depends on the maximum quantity of debris the water might contain at any given moment in time. A good knowledge of the environment of the plant is highly desirable.


An air-venting pit is needed between the intake pipeline and the pump suction to prevent bubbles from feeding into the pump suction 



  • No moving part in the water.

  • Fish-friendly, (low velocity, no entrapment)

  • Well-proven

  • Low investment cost

  • Big savings in pumping station civil engineering


  • On request, the immersed strainers can be mounted on sliding supports to allow periodical lifting out of the water for inspection or seasonal removal.



  • Air compressor

  • Air tank

  • Compressed-air pipework

  • Switchgear control cabinet

  • Differential head-loss measuring system



  • For fresh-water applications: AISI 304L stainless steel

  • For seawater applications: AISI 316L, duplex and super duplex stainless steel, copper nickel

  • Whenever the water tends to induce marine growth (seaweed, shells, etc), the system can be built from fouling-proof cupro-nickel.

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