Hydrodynamic screws - Cee-Environmental

Hydrodynamic screwsEnergy extraction – efficient and fish-friendly

WaterinmotionHydrodynamic screwPower take-off unitTroughThe new type of energy generationIn the form of the Archimedean screw, the water extraction screw has been known since ancienttimes. What is new is the patented application, which by an inversion of the energy flow in itsoperation, turns the Archimedes’ screw trough pump into a power generator for the extractionof energy.A water power generating facility makes use of the energy difference between two different levelsof flowing water by transferring the water from natural bed of the stream at the higher level tothe bed at the lower level and effectively extracting its potential energy, which is then madeavailable at the rotor shaft for further use.

Timeandcost optimisedRitz-Atro’scompact solutionThe constructional effort required for a hydrodynamicscrew is small compared to thatrequired for a turbine. If the compact versionof a hydrodynamic screw (hydrodynamic screw+ trough + power take-off unit combined asa single unit) is used, the constructional effortcan be further reduced. The whole system isdelivered as an integrated whole. You savevaluable time, which you would otherwisespend during the careful matching up of theindividual construction components.We are happy to provide advice as to whichhydrodynamic screw is most sensible for you.Give us a call and agree upon a non-bindingon-site appointment!Examples of useReplacement for small turbine units whichrequire reconditioningReplacement for defective water-wheelsClean water outlet of sewage treatmentplantsResidual water screw for installation intoexisting channel or weirProduction of low-level hydrodynamic powerin former irrigation weirsYou can, of course, decide in favour of a conventionallydesigned hydrodynamic screw inthe aforementioned areas of application ratherthan a compact worm.The advantages at a glanceNo control system – the screw matches itself automatically to the supply frequency andthe water supplyThe efficiency is greater than with comparable waterwheels and small turbinesFlat, stable efficiency gradientRobust, long wearing, trouble freeNo cleaning, little maintenanceNo fine screens necessaryLittle underground digging required in comparison to turbinesVery friendly to fish

Why use a hydrodynamic screw?Fossil fuels can be saved by means of theenvironmentally-friendly use of this source ofenergy. In this process the hydrodynamic screwcan be ideally inserted into the environment– without having a disruptive effect.Varying water heads and varying water flowrates upstream and downstream of the screwonly marginally affect the efficiency and haveno effect on the function or operation of thehydrodynamic screw.With hydrodynamic screws, even minimumhydrodynamic potentials at powers from 1 kWcan be made use of economically.Energy losses due to a decrease in the heightof fall or flow losses are thus avoided.Due to the large jaw settings of the upstreamcoarse screens the rakings’ quantities that areincurred – and thus the waste disposal costs– are greatly reduced.Small hydrodynamic facilities hide an immensepotential for extracting natural energy fromwater power.Another positive aspect is that the water becomesenriched with oxygen, which in turn improvesthe quality of the water downstream.With hydrodynamic screws, fine screeninginstallations for protecting against floatingobjects and fishes, needed for turbines, canbe done without: The parts washed up andfish can pass through the screw unhinderedand unharmed.

The advantages for fishFishery biological assessment (extract)Ritz-Atro has commissioned a survey with anindependent expert in order to investigate thefish friendliness of its patented hydrodynamicworm. Here are some extracts:Water banking and turbine installations arenot only a major obsticle and potential hazardfor fishes travelling upstream but also forfishes travelling downstream. Water powergeneration of any type is an obstacle for thespawning migration of migratory fishes. Inmany flowing waterways this affects the Europeaneel because eels are considerably affectedby Kaplan turbines and Francis turbines. Butgrey trout, salmon or river lamprey are also atrisk. […]The length distribution for the various speciesshow that both small fishes (larger than 8 cm)and large specimens (up to 58 cm) can passthrough the hydrodynamic screw without harm.Even relatively small and weak fish such asgudgeon or the miller's thumb have been ableto pass through the hydrodynamic screw withoutinjury. […]The overall result is that the hydrodynamicscrew is very friendly to fishes and highlysuitable for fish migration. According to presentknowledge, the fishes suffer, if at all, onlyminor injury in form of damaged scales andbruising.

Electric power provided to terminals(Generator Power)11300 kW200 kW10150 kW950 kW75 kW100 kWHead H [m]8765425 kW10 kW5 kW3 kW32100 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0Water flow Q [m 3 /s]Technical detailsWater flowup to 5500 l/sEfficiency up to 90%Headup to 10 mPowerup to 300 kW

Efficiency of the hydrodynamic screwExpert report by the Kaiserslautern University of Applied Scienceto determine the efficieny10090Efficiency as a percentage807060504030201000 10 20 30 40 50 60 70 80 90 100Quantity of water as a percentageHydrodynamic screwOvershot waterwheelKaplan water turbinedoubly regulatedFrancis turbinenq = 37Francis turbinenq = 75By way of a summary the results of measurement carried out are as follows:The efficiency of the hydrodynamic worm issimilar or higher than that of other small waterpower stations of this type (turbines, waterwheels).However the high partial load efficiency, whicheven still makes it possible to efficiently usethe hydraulic energy that is available even inthe event of a low inflow volume. This is onlypossible with great difficulty in plants of similarsizes.Worm efficiency under full load: 84,25%(near design point)Maximum absolute error: ± 4,21%Average absolute error: ± 1,98%Worm efficiency under partial load: 79,13%(approx. 40% of the hydraulic design capacity)Maximum absolute error: ± 4,98%Average absolute error: ± 2,55%These values are determined at our ”Mühlen in Taufers”plant and apply for the following sizes:Nominal water quantity1420 l/sHeight of fall2,11 mDiameter of the hydrodynamic screw2 mNumber of revolutions 42,7 min -1

Hydrodynamic screws Screw pumps Propeller pumpsRitz-Atro, founded in 1969, is now one of the most significant companies inthe area of effluent treatment and environmental protection – and indeedthroughout the world. Innovative drive and pioneering spirit characterised thecompany from the very beginning.Ritz-Atro sees itself as its customer's partner. Right from the phase of theinitial planning the customer is supported by well qualified staff, who guaranteethe secure and economic realisation of the construction project.Ritz-Atro takes all conceivable measures to constantly further improve thehigh standard of quality of its products. A quality management system certifiedin accordance with DIN EN ISO 9001 is thus an important component partof the company philosophy.Ritz-Atro Pumpwerksbau GmbH Telefon + 49 (0) 911 998 12 - 0Max-Brod-Straße 2Telefax + 49 (0) 911 813 76 4690471 NürnbergeMail sales@ritz-atro.deGermanywww.ritz-atro.dewww.schleich-burckhardt.de Issue date: 03|2005