We need to pump for a firewater tank (min 10,000ltr) from our river to our house site + 20 metres, a head of 160 metres, horizontal < 1km, which we want to do by solar (slow is fine). Looking at doing a staged lift (80 metres * 2) but open to any advice/options.
Very high head water pump
(15 posts) (7 voices)-
David
Memberglmmph said:
a head of 160 metres, horizontal < 1km, which we want to do by solar (slow is fine). Looking at doing a staged lift (80 metres * 2) but open to any advice/options.Is that an actual 160m vertical lift, what is considered a reasonable flow rate rate or how long a period of time would be considered reasonable to fill it, does the pipe already exist, if so what is the size and type of it? ie green stripe or blue stripe poly 50mm for instance.
Posted Monday 17 Aug 2015 @ 11:36:59 am from IP # -
glmmph
MemberHello David, the vertical lift is 160 metres. I've read the Vinnidex site on poly pipe, not done any of the maths (and perhaps not understood it as well), but looking at 1.25in (31mm) internal diameter pipe. For lift & distance head is about 170 metre TDH. I believe rural (green stripe) has a pressure rating to 80 metres, so just short of requirement, but much cheaper than blue pressure pipe. Or could use a blue pressure pipe for the first run and then change to rural. One reason not to try to lift 160 metres in one stage is the high pressure at the lower end, which I would not feel comfortable working with. Flow rate of approx. 10 litres/min would be suitable, perhaps using a Dankoff Solar Slow Pump.
Posted Tuesday 18 Aug 2015 @ 12:26:04 am from IP # -
Oilburner
MemberDon't forget, Horizontal run counts towards lift as well. I forget the formula but it's something like 10M or 100M of horizontal counts as 1M of lift.
This is due to the resistance of the water to move in even a level pipe.If you don't factor this in,you could end up with a drizzle coming out the pipe or nothing at all.
Posted Tuesday 18 Aug 2015 @ 2:34:32 am from IP # -
Morbo
Memberhttp://www.nationalpump.com.au/calculators/friction-loss-calculator/
0.2m head at 10L per min and 31mm dia HDPE pipe. Remember, its really smooth, so next to no friction.
You said plus 20m, thats your difference in height? So you got 20.2m head.
Plus losses in fittings. But on 10L/min its negligible.
Then a bog standard 40m head pump will do. Mrs Anita Bonghead.
http://www.calculatoredge.com/mech/pipeline%20velocity.htm
but velocity is only 22cm/s. Maybe get a smaller pipe, otherwise it will not be moving at all.Posted Tuesday 18 Aug 2015 @ 6:29:18 am from IP # -
glmmph
MemberThanks for the replies. For those interested here is a schematic for the proposed works: https://www.google.com/maps/d/edit?mid=z27ThuKXz8Ms.khAo-746JasU&usp=sharing.
A few questions about the solar arrangement. Supposing I need 2 panels x 300watts for each pump, with the pump handling up to 400watts. Both have a controller to kick in at 60watts (minimum pumping power). What issues do I face with river pump solar panels being 110 metres from pump (staging pump much closer), and what other control mechanisms besides run dry and mppt units (that come/associated with the pump) do I need?. In reply to Morbo, not sure what your reply implied, but output to house will be rural ag pipe, not CFA standard, but sufficient for our needs with ~20m head. CFA need access to the top tank which has standard CFA outlet. Planning regulation, not necessarily intended for actual use.
Posted Wednesday 19 Aug 2015 @ 7:10:55 am from IP # -
Chip
MemberWe have 30 m total head over 200 m of distance from dam to header tank in bushfire prone area.
We used 50mm rural poly with a back up firefighter pump at the dam. We found a single impeller pump was cheaper to buy, cheaper to run and pumps more water at this pressure than a twin impeller pump.
Your solar pump at the river will do most of the work but if it's a high fire danger time then it will also be hot and dry and your gardens, etc will use a lot of water and you'll want the peace of mind of a full tank on an extreme day. In case of a big bad fire, assume CFA won't be there.
A firefighter pump into 50mm poly gives us about 20,000 litres on a tank full of fuel but it would be a lot less in smaller pipe.
You'll need to bury the pipe to protect from fire.
Looks like a great spot you have there!
Posted Wednesday 19 Aug 2015 @ 10:15:57 pm from IP # -
glmmph
MemberThanks Chip. The locals recommend some version of fire pump as well, but we're pretty keen not to use fossil fuel. Solar arrays will be most efficient in summer when we need the most water, and slow and constant will suit us better than fast and intermittent.
Part of my interest in doing this topic is that there is little on the web that covers this situation. For instance, we've found the local pump suppliers are literally 'out of their depth' on this, so I'd like to follow this through to a workable solution as a reference for forum users.
Posted Wednesday 19 Aug 2015 @ 11:37:44 pm from IP # -
Chip
MemberI think you are on the right track to listen to local advice rather than just take the word of a retailer. A fire pump and fossil fuel would only be used as a back up in case of fire or a few cloudy days in summer reducing solar flow. It might also be a cheap and quick start up option that allows you to do the solar bit over a longer period to spread costs.
If your fire plan is to leave rather than stay and defend then your water needs won't be as high but if you want the option of defending or having a header tank connected to a sprinkler system then you'll need to plan that. But sometimes things go awry with fallen trees, someone still at home without a car, etc so some sort of defendable safe place plus water is a must just in case. A fire pump also gives you extra pressure if it's running and tap to tank is closed.
Usually best to run water in and out of tank in same line then you can plan that line with take off points which will have higher pressure when solar or other pumps are operating.
Plumb in enough good quality ball valve taps (not metal gate valves) in the main line to allow isolation of sections that may need maintenance and always have a ball valve at the pump/s plus a garden tap as well so you can get water for priming plus run a small sprinkler there if a fire is approaching. Don't want those pumps and panels to be lost!
Posted Thursday 20 Aug 2015 @ 12:49:57 am from IP # -
We have nearly a 300m head over a distance of 2km along one and a quarter inch poly pipe. At best the delivery is about 4000 litres an hour. Which is fine, as has been said, slow and steady is more reliable and cost effective. We use a single helical rotor pump powered by solar panels on a tracker. We have been pumping more than one million litres a year. The system is simple and reliable.
Posted Thursday 20 Aug 2015 @ 1:00:19 am from IP # -
scott drew
MemberGlmmph, have a fire pump on hand in the system. You may never use it but a 5l tin of fuel for the oump may just save you cost/pain/annoyance of replacing your property. Its cheap personal insurance you have control over (not suggesting you not have house insurance as well).
Try this worst case scenario. .. hot summers day, your solar pump works well in full sun. Fire starts somewhere and as it's a hot windy day the thick black smoke fills the air... blocking the sun... and guess what your pump now doesnt work so well. Or a fire starts in the day but doesnt get to your house till after dark?
Usually fire sprinkler systems require fairly high pressure to give out large droplets of water via the sprinkler rather than a slow steady stream of filling a tank. You may find that it isnt possible to have 1 type of pump for all the requirements of your system.
Posted Thursday 20 Aug 2015 @ 3:41:13 am from IP # -
glmmph
MemberThanks RuffTuff, do you do the 300m in one lift, and what are the specs for your solar panels/pump? Looking at the Mono AGM 640 would need about 8kw input power for maximum power. Doing a bit of research and will get back with questions, but liking the idea now of single lift.
Posted Thursday 20 Aug 2015 @ 8:24:23 am from IP # -
glmmph
MemberThanks also to Chip and Scott.
The idea of the fire tank is to gravity feed back to the house so we're not dependent on pumps for that water. The pipe will be buried, and should be relatively safe in a fire as it runs along a road. That said, we have a comprehensive fire plan that includes strategies, protection and pumps.
The earlier comment about CFA access to the tank is a requirement of the planning approval process with council for new/extension building works (that is, a bureaucratic imposition that may also be practical). We will also use the water on our (small) vege garden.
Posted Thursday 20 Aug 2015 @ 8:37:31 am from IP #
