Water wheel in Portugal

[Griffen]

Another Newbie asking questions ..

I've bought a wreck of an olive oil mill in Portugal.


It is besides a river that flows all year round.The machinery is powered by a small,narrow 10 ft high overshot waterwheel (buckets approx 12 ins wide).The wheel drives the kollergang & is required to dead start the two large granite mill stones trundling around.

The leat is narrow & approx half a mile long.We estimate the head to be between 18 & 21 ft. & the flow rate in the summer of about 17l per second.



Above a picture of the weir close by the Mill. The leat starts at a much smaller weir half mile upstream.
I realise that the wheel is not going to whiz round so will need to be geared.What is the maximum multiplier ? Is it 7 ? At the moment we are wondering if it is worth even using the wheel as the leat needs so much work.

Sorry I can't post anymore pics at the moment ..the internet speed is limping.

[Billy]

Sweet,

A quick look at  6 metre head and 17l/second flow gives around 500w for a medium head turbine.  That would be continuous mind, so not to be sniffed at.  The cost of a medium head turbine is around 3 - 5k plus the fitting and pipework.  Once done it shouldn't need much else as opposed to the ongoing maintenance/refurbishment of the leat, wheel and whatever contraption you can invent to put on the other side of the wheel to generate your sparks.  There are folk on the forum who have practical experience with this and the story is ongoing.  Here is the link to one sight, I hope anyway.  Guy's story is also available on this forum and details his travail.

http://www.dewdneyhydro.co.uk/

Good luck, a brill project.

billy
 

[guydewdney]

hello.....

the nice thing about water wheels is that you can throw dead sheep through them - try that with a turbine.....

Theres no limit to the multiplier - just how many times you do it - My system has a 1:10 speed up chain drive (a bit more than the recommended 7 or so) and is fine. It then does a 1:3.5 with pulleys.

 I personally would advise to use either a PMA (try looking at ginlong - they make a super low speed one) or a three phase motor driven with an inverter drive in 'regen' mode. Small inverters are very cheap on fleabay etc.

power 24/7 is nice to have - what are the regulations about grid connect in portugal? Do you want to be on or off grid?


Lastly - im sure I can come over and advise.... lol

[noah]

Considering the picture (albeit of larger weir) I`m surprised at the figure of 17 l/s. Looks like more should be available. One problem with wheel is windage losses due to high gearing ratio needed. At that sort of flow you would need very efficient gearing , preferably planetary gearbox to give ratio of 100:1 +. One good thing is that at this low power the gearbox does not have to be outrageously robust -look at the size of mine here

http://s990.photobucket.com/albums/af26/brianfaux/Waterwheel/

But even with a low power wheel, a 20 foot diameter still means a lot of torque and a substantial driveshaft.

[Griffen]

Many thanks for the positive answers & encouragement.  I calculated perhaps optimistically the wheel would have generated about 8 -10HP in its heyday.  We have a piece of machinery that takes a 5HP 3 phase motor to start a .25 ton dead weight spinning so to shift two millstones its got to be more than that.

The wall of the mill leat is broken in  places as it wends it way along the top of numerous allotments. Each allotment owner is allowed to use the water from it for so many hours (?) every other day for irrigation. The Mill ,of course,was only used in the autumn to process the local olives when no irrigation was required. Now most of these strips are uncultivated as the village is dying.

An initial thought is to pipe the supply to the wheel separately & hopefully not upset the locals too much.We are going to have another go at measuring the flow when we next go out. Last time we both succeeded in falling in the river on different attempts. Of course I was avoiding getting bitten by the world's largest dragon fly at the time.

We measured the flow at the first weir where the leat starts. Walking down the valley we noticed quite a few little springs feeding in through the river bank so I guess that is maybe a reason for increased flow at the 2nd weir by the Mill.

Guy,although we are very close to a mains supply,in many ways we would prefer to go off grid. That may mean a second turbine such as a powerspout or a genny.  Our  consumption at present is about 14kw per 24 hours with some business use.

PT does not do grid tie for micro hydro easily or quickly & we are not prepared to wait for 4 to 5 years.The regulations seem to change from one year to another so we could end up with an enormous amount of expense & a negative outcome.

The Mill will have to be rebuilt anyway so we shall have an opportunity to get in very good insulation & lots of sun facing windows as well as power friendly lighting & appliances.

I'm having problems posting images so will have another go in a separate post.


 

[Griffen]

 The kollergang & gearing to wheel shaft



Horizontal yellow line shows path of Mill leat as it approaches the Mill. The Wheel is hidden at the side of the Mill.



The old bridge downstream from the Mill showing the river during the summer months.

[billi]

Hi Griffen


Please  do yourself the favor  to  get the realistic flow and head figures  right

as well think of ideas about the land you have   and the stream  , beside the Mill

The more you tell us the more you will get ideas


Billi

[biff]

wow griffin,
          you have a really nice place and i wish you luck in your renewable venture. there are water wheel boffins on here who will be able to keep you right.by all accounts ,you have masses of work ahead of you so a steady head and correct figures are essential.
                                                          happy christmas,  biff

[RobNute]

Hi there, looks like a great project. Here is our story , if I was in your position I would try to utilse your waterwheel for battery charging and be off grid. I don't think anyone on this forum has done that yet so we need you to do it for our sake! Its probably better to use a turbine but the wheel will be more satisfying and everyone will love it. Good luck and best wishes, Rob.

http://www.navitron.org.uk/forum/index.php/topic,12399.0.html

[Griffen]

Hi Biff,
How's the wind at the moment ? Blowing, gusting & raining here in Mayo all day.

 Billi ,
Our guessimate is based on altimeter readings from a climber's watch and I agree with you 100% about getting accurate measurements. I'd love suggestions on how to do this when the terrain is almost impossible to penetrate because of thick undergrowth & trees leading to a lack of sight lines. It is only the last 50 yards that is on our own land so we can't go hacking down other people's vegetation.The only solution I can see is to stand in the river itself & work  ??  

I have checked with the river authority & there are no measurements of flow for our river whatsoever.We do know that PT rivers are prone to sudden floods with all sorts of boulders being carried along. There is a depth measurement on the bridge by the mill saying 10 years ago the river reached a depth of 14 ft as opposed to its usual  1 foot in the summer months. We do know it flows all year round which is not often the case with minor rivers in PT. However I don't think the arches of the bridge are kept clear on a regular basis so some of that depth might have been caused by blockages.

When it comes to accurately measuring flow .. again questions.
1. If the leat starts at the smaller top weir just to confirm that that is where we should measure the flow? (I am sure this is a newbie question.)
2.How important is it to take readings at different times of the year for doing the calculations?
Does it matter if only the lower summer measurement is used & a theoretical value is given for  a maximum volume that could be carried by the leat?


Rob,
 Many thanks for the link to your earlier post. Your father wasn't a paper mill engineer in a previous life by any chance? I know of a couple of elderly papermachines whose speed is controlled by lorry gearboxes! Great video but I don't think I'll show it to the other half just yet as it might induce a case of cold feet  & a fervant desire for a Powerspout. One of our concerns is protecting an mini hydro installation or elements of from being nicked when we are not there. This has happened in the last year with a PowerPal installation 30 miles away.

[knighty]

the wheel looks to be in pretty good order.... would it take much to get it running ? or do you have any idea of it's design speed ?

that would be the easiest way to work out the flow ?

tho I guess if it was only used part of the year, then it would be designed for the flow at that time of year only ?


if you intend to charge batteries... it should be pretty easy to use a big 48v alternator as a generator
(they're a bit like car alternators but bigger made for powering things like those big American motor homes)

giving you an advantage an you'll have a very wide rpm range to work with, something like 1000 to 8000 rpm
(once it's geared up from the wheel)

if you use one which can generate more power than your wheel could possible produce then it would also prevent any problems with overspeed etc...

but you would need some decent dump loads, and a decent dump load system to take all the extra power if your batteries were full)
(like some electrical heaters etc..)

[RobNute]

Hello again, just been thinking about your wheel, in one of your posts you say -  "I calculated perhaps optimistically the wheel would have generated about 8 -10HP in its heyday.  We have a piece of machinery that takes a 5HP 3 phase motor to start a .25 ton dead weight spinning so to shift two millstones its got to be more than that." I think that this is very optimistic from a 10 ft x 1 ft wheel, one thing to consider with a waterwheel is that it can actually be more powerfull at startup than it is when its running. I know that sounds daft but what happens is that you have a stationary wheel directly geared to your mill gear and you open up the leat and let the water flow, now the first buckets fill and overflow into the next and so on untill say 1/4 of them are completely full and then it starts to turn. Once the wheel starts turning it may not fill the buckets to the same degree during operation so its starting power is often more than its running power. They essentially have maximum power at zero revs which can be the most frightening thing about them, the torque at that point is huge and can twist shafts easily. Ours works well with its resistive load as the load is proportional to the revs so it starts easily and balances itself nicely. Dont show your wife our crazy flat belt gearing, Guys is much simpler , neater and less dangerous looking with his chain and vee belt set up. Cheers for now and happy xmas, Rob

[guydewdney]

the wheel looks to be in pretty good order.... would it take much to get it running ? or do you have any idea of it's design speed ?


most wheels have the same perifial speed - mine is 5rpm on a 15' wheel - so 7rpm would be about right


that would be the easiest way to work out the flow ?

no - see robs comment


tho I guess if it was only used part of the year, then it would be designed for the flow at that time of year only ?

probably.


if you intend to charge batteries... it should be pretty easy to use a big 48v alternator as a generator
(they're a bit like car alternators but bigger made for powering things like those big American motor homes)

they have to spin like billio to get them to work. thats quite difficult to achieve.


giving you an advantage an you'll have a very wide rpm range to work with, something like 1000 to 8000 rpm
(once it's geared up from the wheel)

you never want an 8 times overspeed on a waterwheel - that would be Very Bad.


if you use one which can generate more power than your wheel could possible produce then it would also prevent any problems with overspeed etc...

then efficiency drops off very quickly. I tried that.


but you would need some decent dump loads, and a decent dump load system to take all the extra power if your batteries were full)
(like some electrical heaters etc..)

yup.



Find a wind turbine 'head' that does 48v - try miniwind for example (I had the high voltage versions) they spin quite slowly, so the gearing is simpler.


My gearing is just a big (5 foot) sprocket on the wheel shaft, a small (6") sprocket on a 2" diameter layshaft (that you can see bending when its running at full whack) - the layshaft then has a big (4') pulley driving a small pulley on the wind turbine head. Its going to be replaced with a similar thing to Noah's gearbox - its a huge 1/2 ton mining machine gearbox with a 4" slow shaft and a 2" fast shaft. I bought mine cheap from llewellins gears in Bristol. http://www.llewellins.co.uk


Power - my wheel is 15' diameter and 6' across. I have generated 7kw max - but have calculated that I could do about 15 in theory. 7 is a scary amount of water. Lets say you take the 15 as right - your wheel is 10/15ths the diameter, and 1/6th wide - 15 x .6666 x .16666 = 1.666kW

Thats about right for one of the miniwind generators or a 1.8kW ginlong at 500rpm ish
http://www.ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-1800.htm

[Griffen]

I do not think we shall have problems with finding somewhere for a dump. We shall have approx 1500 sq ft to heat in the winter & the same to aircondition in the summer when temperatures can get upto 100 degrees F.All  substantial rebuilds now have to incorporate solar thermal hot water systems so there would be limited use for an immersion heater except perhaps in November & December which can be wet.
There is a Pria Fluvial (Council owned public swimming pool) opposite the Mill which is fed by river water. It might be good to see whether we could light the mill, wheel, bridge & the swimming pool on occasion.


The set up .If you look to the head of the valley you may spot a small white dot. It is a road bridge. The leat starts about 300 yards beyond it.





The feed for the Pria Fluvial.




It should be possible to find out the power needed to power the old machinery relatively easily .The water wheel can be moved by hand just  & inside the mill there is a big lever to disengage the shaft from the gearing of the Kollergang if necessary.
The wheel & buckets are in pretty good condition & the wheel pit just needs tidying up. The axle shafts look straight
and  the teeth on the gearing seem to relatively unworn from what we can see.

[billi]

I surely understand that it is a sensitive  subject   to deal with neighbors as a "blown in "

But perhaps its also worth  a consideration , to  look into  an option to have a combined micro hydro idea and  pipe the stream at a much higher head , than you can  only on your land

Just a thought ....


But  for now its not clear to me  what head and flow you have available on your land ! 

I personally love to walk in rivers   and explore