How the Farmers Screen Works
The Farmers Screen™ uses hydraulics to remove debris and protect fish. It has no moving parts and does not require power to operate.
Water moves over the horizontal screen material at a relatively high velocity and moves through the screen material at a very low velocity. This velocity combination carries fish and debris over the screen and back to the source with no clogging. The resulting screened water is carried to irrigators via pressurized pipe or canal.
A Inlet Flume
Attached to the upstream end of the screen, the Inlet Flume creates optimal hydraulic conditions by allowing water entering the Farmers Screen™ to achieve a uniform, steady state flow.
B Horizontal Screen
A perforated, stainless steel flat plate lies parallel to the water surface. Low downward velocity pushes water through the horizontal screen material.
Cross Section View
C Sweeping Velocity
Water sweeps over the screen surface at a velocity at least 20 times greater than the velocity of the water passing downward through the screen. This allows fish and debris to be swept over the horizontal screen material and returned to the stream while screened water can be collected and carried to irrigators via pressurized pipe.
D Taper Wall
Maintains constant velocities and uniform depth of water over the screen surface as water progresses through the structure. The taper wall decreases the cross sectional area of the flume as water is delivered through the screen.
E Weir Wall
A short, solid steel panel that runs parallel to the taper wall, the weir wall maintains a uniform depth of water over the screen and thus uniform flow through the screen.