DESCRIPTION

Installed across a channel in which the water to be cleaned flows through. The screen consists of a set of rectangular screening mesh panels, carried by two endless chains. The downstream panels travel down into the water, around the bottom and up again along the upstream side. The water flows across the upstream and then the downstream panels. The debris are arrested on the upstream face.

The debris-laden panels travel up above deck level, around the top and down again. One or two spray pipes with fantail jet nozzles set on the down stream side of the panels within the screen’s head structure, back-wash the panels, remove the debris which are projected into a collection trough. They travel in a deck flume to the debris disposal system (basket, separator, etc.)

The screens are normally stopped and are washed periodically when obstructed by debris. Permanent rotation can be provided.

ADVANTAGES

• Over 100 years of experience

• Large debris-handling capacity

• Compact civil structure

• Fully automatic

• Fish-friendly option

• Reduced maintenance

• Cost effective

• No debris carry-over

• Easy access to external debris trough

• No internal debris interference

NECESSARY ANCILLARIES

• Spray-water supply circuit

• Head-loss monitoring system

• Electrical control cabinet

• Upstream bar rack (25 to 75 mm spacing (1 to 3”)

• Pit dewatering stoplogs

• Trash collecting system (basket, etc).

OPTIONAL FEATURES

• Two or three-speed operation

• Seismic qualification

• Special high travel speed design for handling heavy debris loads

• Jellyfish lifting trays

• Screening medium resistant to fiber build-up

• Screening medium preventing jellyfish adherence

• Low pressure water-life protection system

• Atex compliance

• “Scoop-a-fishTM” total fish survival system

• Wall-mounted chain guides on full carrying structure

MATERIALS

• Main structure, panels, frames, guide rails :       
  For fresh-water applications: painted carbon steel or AISI 304L stainless steel     
  For seawater applications: AISI 316L stainless steel, duplex or super-duplex stainless steel      
   

• Head-shaft, sprockets, chain links and pins, tensioning capstan screws:     
  For fresh-water applications: High-tensile steel 
  For seawater applications: Duplex or super-duplex stainless steel      
   

• Bolts, nuts, washers:        
  For fresh-water applications: A2 or A4 stainless steel  
  For seawater application: A4, duplex or super-duplex stainless steel  
   

• Small fittings, spray-water pipes:
  For fresh-water applications: AISI 304L stainless steel
  For seawater applications: AISI 316L, duplex or super-duplex stainless steel     
   

• Screening mesh frames, sprocket teeth:
  In all cases: composite materials
   

• Covers :    
  GRP or stainless steel on special request
   

• Anodes:    
  None required for fresh-water applications        
  For seawater applications: required for use with AISI 316L stainless steel and sometimes for duplex stainless steel.