For more than 100 years we have been devastating the Salmon populations by killing the fry swimming downstream, forcing them through high speed turbines, and blocking upstream breading migration and then providing inadequate remedial methodologies such as fish ladders which are barely adequate to keep the fish species alive.
It's time we correct the problems, meet our treaty obligations and return the rivers to a healthy thriving state and this can be done remarkably well by redesigning the Kaplan turbine.
This is done with US Patent 6,741,000 which describes a full Archimedes screw with an axial field generator built onto the outer screw cylinder and allowing unobstructed fish passage. Because the screw can be enlarged to accommodate every dams pressure and flow, the water flows can be slowed to eliminate the velocity barrier which currently prevents adult salmon to swim upstream.
What changes need to be made to hydroelectric generators to allow salmon free passage of the water ways? Here is my argument:
1. Substantive, innovative design changes are required in the hydro management system to return salmon passage to a natural instinct driven path.
2. Fish ladders are inefficient partly because they draw fish away from that instinctive path resulting in an irreparable dissonance between fish instinct and ladder function.
3. A long screw with a given amount of energy produces low velocity in-line flows and a short screw produces high velocity in-line flows.
4. High velocity flows create differential mixing turbulence which can be resolved by reducing turbine exit water velocity with a long screw design.
5. Rapid decompression (at times, cavitation) is a problem of current turbine design because the time-rate change of pressure takes place over centimeters but is not a problem in properly constructed water screws where the pressure change occurs over meters, not millimeters.
6. Eliminating components that injure fish (stay vanes, wicket gates, and draft tube piers) coupled with reduced rotational speed and water velocity will reduce damage to fish.
7. Hydroelectric generator devolution is trending back toward the water screw for these reasons.
8. Others have proved horizontal generation is functional and efficient in light of Newton's laws of motion.
9. A screw design generator allows for more energy removal, eliminating the velocity barrier.
10. Water screws used to raise fish are effective and safer than helical blades.
11. Therefore, a water screw used as a generator will resolve the major problems with current dam designs and result in safe, efficient, natural catadromous fish traffic.
The current attempts to mitigate damage will continue to have marginal benefit and every higher cost until the dams are removed or the problem is solved with a solution similar to this device. What is required is substantive alterations of strategies by dam owners in the management and operation of dams.
Continued efforts to undo some of the damage created by the mechanical devices blocking anadromous fish migration are futile while continuing to killing 40% of juvenile catadromous fish migration (Columbia River system wide) I would submit that the "hundreds of millions" spent each year on mitigation will continue until either all dams are removed or a device is implemented that returns essentially riverine conditions despite the existing dam structures.
When the problem is that fish cannot migrate past the generators upstream, and many are killed passing them down stream, correcting this particular problem seems elementary.
The problem is mechanical, not biological. A mechanical solution will correct the problem, not improving breeding beds or other environmental factors (though they are marginally beneficial).
An Archimedean screw as the prime driver of a hydroelectric generator, designed specifically for each dam will do precisely that. Creating a device which removes most of the energy currently wasted by the extant Kaplan and Francis turbines, as evidenced by the energetic water destroying the riverbeds below the dams, would not only result in reduced erosion of the river bed, eliminate the velocity barrier which prevents anadromous migration of adults to their breeding grounds, but also increase the available electricity due not only to this reduction in energy from the water but also from the increased productivity of newer generator technologies.
Disruptive Technology for hydroelectric machines.
A disruptive technology or innovation is one that creates a new market or value statement that disrupts the current technological basis for the old device(s) disrupting the current marketplace.
Innovations that improve a product design in ways that the market does not expect, in this case by the resolution of a century old problem. All other incremental improvements to hydroelectric machine to accommodate the needs of anadromous fishes have met the goal of incremental improvements in fish traffic but not in energy efficiency.
This innovative technology si disruptive to the market because it allows for more dams, but also eliminated the uses of the century old turbine technologies.
A screw and the power derived from them is governed by the size of the inner and outer cylinders, the number and pitch of the blades, and the length of those blades.
With these 5 variables, any size dam can have specific screw generators designed to allow for water to travel down the screw at velocities salmon are capable of traversing.
This is the only generator ever designed which will allow for safe fish passage upstream through the generator itself.
Water Screws have been used to raise water for human use since Archimedes invented them some 2500 years ago. A modified screw generator will solve most of the issues we have with dams currently.
Article Source: http://www.abcarticledirectory.com
US Patent 6741000 "Electro-magnetic Archimedean screw motor-generator" salmongenerator.com lays out these same arguments with images. The author, former Adj. Prof. Ronald A. Newcomb, SDSU College of Sciences, can be reached at (619) 501-1800 and is currently president of Marine System Inspection LLC
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