Patent ID: 8591746

Claim:
A screening installation comprising, provided in a flume ( 5 ) conveying a fluid flowing with a total flow QE: a screening device ( 10 ) comprising a screen which comprises at least one filter member in order to screen a fraction Q 10 of the total flow, at least one first permanently open passage in the flume having a passage cross-section adapted to allow a fraction Q 31 of the total flow to pass such that Q E =Q 10 +Q 31 , the total flow thus being divided between the screening device and said at least one first passage so long as the head loss between the upstream side and the downstream side of the screening device is less than a predetermined value, at least one second passage ( 32 ) in the flume which is operative when the head loss between the upstream side and the downstream side of the screening device is greater than a predetermined value and which has a passage cross-section adapted to allow a fraction Q 32 of the total flow to pass such that Q E =Q 10 +Q 31 +Q 32 when said head loss is greater than the predetermined value.