Wayne; This idea of reduction is a misconception that all the people that have worked hydro knows that the case is not so.
A water column produces a pressure of 0.433 PSI per foot of water height, so, a 10 feet column produces 4.33 PSI. Another principle says that water velocity is: the square root of the product of 2 * Head(watercolumn) * Gravity and that is the ultimate velocity of water volume that has a stable water column level behind it and the water is coming out of a restricted area , principle that is quite important for power generation. Regards Nando ----- Original Message ----- From: "wayne burton" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Tuesday, October 18, 2005 4:59 PM Subject: Re: [microhydro] Re: direct drive of centrifugal pump by a turbine > Hi Nando I am impressed by the level of knowledge you > have If you have written a book on these things please > tell me where to find it . > I remember someone telling me once that to increase > water pressure flowing through a hose he reducrd the > size (diameter )of the hose for every couple of feet > .oes this sound practical to you ? > > --- HYDRO <[EMAIL PROTECTED]> wrote: > > > --------------------------------- > Wayne: > > The idea may be good, using Bamboo, BUT since you are > learning now, do not > use it, take the Bamboo problems out by using either > plastic or other > materials for your project, then later, when you KNOW > what you are supposed > to do, change the materials to your needs. > > I learnt from my father the use of Bamboo. > He taught people how to use it in the early 1930's in > remote areas of my > native country. > Taught how to carry water for long distances using > Bamboo aqueducts, how to > protect the Bamboo for long lasting, how to clean the > inside chambers to > present a clean and continuous surfaces to reduce the > roughness, increase > the pressure carrying capabilities, house hold water, > including baths and > toilets and how to make small generators for local > energy. > > Try to get your turbine already done to save time. > > Can you detail what your plans are ?. > > Regards > > Nando > > > ----- Original Message ----- > From: "wayne burton" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Monday, October 17, 2005 3:54 AM > Subject: Re: [microhydro] Re: direct drive of > centrifugal pump by a turbine > > >> Thanks a lot Nando !! >> I will be building a prototype of the system . >> I will build my own turbine I saw where someone >> mentioned actually making a turbine from bamboo . I >> beleive the effeciency will be considerably lower > than >> if I had used a commercially available product. >> I will keep you updated >> >> --- HYDRO <[EMAIL PROTECTED]> wrote: >> >>> Wayne: >>> >>> The velocity of a flowing water is determined by > the >>> head ( the difference >>> between to heights when the water is piped between >>> both points). >>> >>> The water velocity = meter/sec= squreroot( 2 * >>> Head(meter)*9.81(gravity)) >>> >>> GROSS WATTS = Volume(liter/sec) * Head(meter) * >>> 9.81(gravity) >>> >>> Then you need to multiply by the efficiencies of > the >>> turbine and the >>> generator to reach the final output power that for >>> small hydros, it looks >>> around 0.6 to 0.7 total efficiency multiplying >>> factor. >>> >>> Regards >>> >>> Nando >>> >>> >>> ----- Original Message ----- >>> From: "wayne burton" <[EMAIL PROTECTED]> >>> To: <[email protected]> >>> Sent: Sunday, October 16, 2005 3:25 PM >>> Subject: Re: [microhydro] Re: direct drive of >>> centrifugal pump by a turbine >>> >>> >>> > >>> > Hello ! >>> > Does anyone know how to increase the >>> velocity/force of >>> > flowing water without using a pump ? >>> > I need to create sufficient force to turn a >>> turbine ? >>> > I know without saying what kind of turbine it >>> might be >>> > a bit hard to give the best solution I just need > a >>> > general solution any available theory application >>> > --- Joseph Hartvigsen <[EMAIL PROTECTED]> wrote: >>> > >>> >> Nandi, >>> >> I've recently built a turbine and helped a > fellow >>> >> select a pump for >>> >> direct drive from the turbine. I haven't heard >>> yet >>> >> how it worked. In >>> >> principle there are a couple of issues to >>> consider. >>> >> First, a >>> >> centrifugal pump, unlike most generators, has a >>> >> specified direction of >>> >> rotation. With a Pelton, there is no issue as it >>> is >>> >> symmetric and can >>> >> be flipped over to change the direction of >>> rotation. >>> >> A turgo on the >>> >> other hand can also be turned over, but it >>> changes >>> >> the jet entrance >>> >> and exit faces. In the case of the turbine I > just >>> >> built for this >>> >> application this meant that the jet exit needed >>> to >>> >> be on the pump >>> >> side. Normally I would prefer the other way so >>> that >>> >> it is easier to >>> >> keep water off the pump bearings. A Pelton will >>> >> deflect water toward >>> >> the pump bearings no mater which direction of >>> >> rotation is required. >>> >> >>> >> The other factor is matching the torque vs. rpm >>> >> curves of the pump and >>> >> turbine. With a pump, the torque increases with >>> rpm. >>> >> With a turbine, >>> >> the torque is highest at 0 rpm and decreases to > 0 >>> >> torque at freewheel >>> >> rpm. Somewhere in the middle the two curves >>> >> intersect. That will be >>> >> the operating point. You need to match the >>> turbine >>> >> to the pump so that >>> >> that point of intersection is also at the peak >>> power >>> >> rpm of the >>> >> turbine. This rpm should also be a point >>> compatible >>> >> with matching the >>> >> pump's output head and flow to that required by >>> your >>> >> application. >>> >> >>> >> The torque/power vs. rpm for the turbine can be >>> >> computed with a >>> >> momentum balance. I have such a spreadsheet for >>> any >>> >> impulse turbine on >>> >> my web site. Unfortunately, it is setup only for >>> >> units of hp, ft-lb, etc. >>> >> See http://h-hydro.com/turgo_drive.html near the >>> >> bottom of the page >>> >> >>> >> Most pumps are designed to be driven by an >>> electric >>> >> motor at 3600 or >>> >> 1800 rpm (assuming 60Hz, or 3000/1500 rpm at 50 >>> Hz). >>> >> You should be >>> >> able to obtain a pump curve from the >>> manufacturer. >>> >> These pump curves >>> >> will likely be at 3600 or 1800 rpm. To scale to > a >>> >> different rpm, what >>> >> is knows as "turbomachinery affinity laws" are >>> used. >>> >> These laws help >>> >> scale a geometrically similar design to a larger >>> or >>> >> smaller size, or >>> >> scale the performance of a fixed unique device > as >>> >> head, flow, rpm, >>> >> power, etc. need to be changed. In the recent >>> case I >>> >> helped with, he >>> >> was eventually able to find a 1200 rpm pump that >>> >> matched his needs, >>> >> but it was a custom industrial pump. >>> >> >>> >> This link has some info, but you can google >>> >> "turbomachinery affinity >>> >> laws" and find dozens of referrences. >>> >> >>> > >>> >> > http://caltechbook.library.caltech.edu/22/01/chap1.htm >>> >> For the same pump run under different conditions >>> "D" >>> >> or the >>> >> characteristic diameter (usually the impeller or >>> >> runner diameter) is >>> >> fixed, and flow varies with rpm (double rpm >>> doubles >>> >> flow capacity), >>> >> Head varies with rpm^2 (double rpm = 4x head) > and >>> >> the same for torque. >>> >> Power varies as rpm^3. So if you have a pump >>> rated >>> >> at 1800 rpm and run >>> >> it at 1400 rpm, its flow is reduced to 78%, head >>> & >>> >> torque to 60% of >>> >> the 1800 rpm value, and power is reduced to 47% >>> of >>> >> the rated power. >>> >> >>> >> >>> >> Joe >>> >> >>> >> >>> >> --- In [email protected], "S.N.Group of >>> >> Companies" >>> >> <[EMAIL PROTECTED]> wrote: >>> >> > >>> >> > hi all!!!! >>> >> > >>> >> > >>> >> > has any bodythought of using turbines to drive >>> >> centrifugal pumps >>> >> > directly?? >>> >> > we are currently working on a concept wherein >>> the >>> >> turbine shft will be >>> >> > directly connected to the drive shaft of a >>> >> centrifugal pump . providing >>> >> > flow all year round . >>> >> > any help in this matter is solicited. >>> >> > >>> >> > regards, >>> >> > nandi >>> >> > >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> > >>> > >>> > >>> > >>> > __________________________________ >>> > Yahoo! Music Unlimited >>> > Access over 1 million songs. 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