Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method and apparatus for facilitating migration of fish past dams and other barriers in waterways










Image Number 3 for United States Patent #6273639.

Method and apparatus for fish migration past dams and other water barriers. A preferred embodiment 100 comprises a conduit 101 passing from downstream side 22 of water barrier 10 to upstream side 21 of the barrier, flow-controlling valves 102 and 105 disposed in series within conduit 101, and actuators 103 for opening valves 102 and 105 in the presence of fish. Fish 30 are attracted by flow 130 passing through conduit 101 at controlled rates by means of flow-through devices in valves 102 and 105. On entering forechamber 104 and swimming upstream the fish pass actuators 103, which cause first valve 102 to open. As first valve 102 opens, water flow through conduit 101 remains controlled and substantially uniformly turbulent under action of second valve 105. With valve 102 open fish 30 may swim to mid-span section 140 of the conduit. When no further fish are present in forechamber 104 or passing actuators 103, or enough fish are present in section 140, the first valve closes. With valve 102 closed and fish passing actuators 103 in the direction of valve 105 in mid-span section 140, valve 105 opens. As valve 105 opens flow 130 through the conduit is controlled by now closed valve 102. Upon opening of valve 105 fish 31 are free to swim past valve 105 and exit conduit 101 through sally port 141, and to swim away from barrier 10 into upstream side 21 of waterway 20. Expanded sections 180 of conduit 101 are provided as rest stations for long transits against strong currents.








 
 
  Recently Added Patents
Light-sensing apparatus having a conductive light-shielding film on a light-incident surface of a switch transistor and method of driving the same
Flash memory apparatus with programming voltage control generators
Determining a route advertisement in a reactive routing environment
Packet-loss handling for downlink multi-user multiple-input and multiple-output wireless network
Micro controller, driving method thereof and display device using the same
Task management in a workforce environment using an acoustic map constructed from aggregated audio
Information processing apparatus, information processing system, and method of controlling information processing apparatus
  Randomly Featured Patents
Analogs of benzoquinone-containing ansamycins and methods of use thereof
Process and composition for deinking dry toner electrostatic printed wastepaper
Railroad trackwork intersections
Undergarment device for treating hip displacement and dislocation
Friction brake apparatus and slack adjusting means therefor
FSK signal detector for detecting FSK signal through digital processing
Interior coating of gas well tubing
Watch information content distribution processing system, information distribution apparatus, information distribution system, hand held terminal device, information recording medium, and info
Concentrated parity technique for handling double failures and enabling storage of more than one parity block per stripe on a storage device of a storage array
Container lock and method for locking of container door