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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