Backyard Aquaponics
A place to discuss aquaponics

No worries Rupe ..... I'm staying out of this one as it's getting a little heated. I've been a good boy for months now and trying to keep out of any contoversy.

I will add info links as i find them just so everyone gets valid information.

" Jai yen" as the Thai's would say ,, means cool heart ..... = don't get cranky.

it is exactly for this reason that I spend so much time in phrasing and reprasing before posting, Rupert:
to avoid the atmosphere that is now developing.

I refuse to fight these allegations. If you consider my efforts to clearly express myself as such, go ahead.
from your first post in this thread:


the article mentioned is not about bilge pumps but about modified bilge pumps (to my opinion that is a huge difference).
if you insist on hammering on the idea that a modified bilge pump stays a bilge pump,
I will gladly grant you that.
Can we go back to subject?

Frank

thanks for the links, Chappo
very interesting

frank

This link is quite comprehensive and includes info on most pump types including the air-lift and propellor / Axial types.
A fair bit of reading but a good source of accurate information,.....

http://edis.ifas.ufl.edu/WI001

while searching (for weeks now) for a suitable motor to make my own propeller pump, today I decided to dismantle a small heating fan to find out the characteristics of the motor and noticed the brand name.
With that I found this site:
http://www.johnsonmotor.com/
These guys must be one of the major (small) motor manufacturers both for automotive and for industrial applications.
And they are honest: almost with each type, the power efficiency of the motor is mentioned at different loads.
Browsing through their catalogue, I have found efficiencies varying from 40 to 80%.
What is also shown is that if the motor is not used at it's designs best efficiency load, the motor efficiency drops down dramatically.
This is completely new to me.
This means that a lot of the INefficiency of small pumps could simply be due to inappropriate motor choice.
This logically leads me to think that not only must all pumps and blowers be used for the exact purpose they were designed for, but also the characteristics of the motor are of utmost importance.

frank

From reading around the web, many sites suggest the points on a graph where water flow and power input cross is the most efficient.

Not always OBO That is a really interesting graph and explanation on that site. http://www.johnsonmotor.com/Performance ... 266.0.html

Not sure about my last post Still interesting.

Ok so having read this thread from start to finish I've got a question.

I want to lift water 10,000L/hr 1.4m straight up from my sump and into my FT. Therefore the only friction loss will be one elbow at the top and the bottom connected to the pump.

What pump should I use. I allready knew that axial pumps are efficient pumps at low heads but where do I get a pump for my particular application?

i'd say a propellor pump ,, relatively low - head ..... but GET RID of that elbow ..... smooth curves are your friend....

Heat the pipe with an air gun, and gently bend

A pondmax tornado pump would be ideal for you, if you cant find a propellor pump.

http://www.rockaroundtheblock.com.au/product.asp?pID=649&cID=63

Flow at 1.0m: 7320L/hr
Flow at 1.2m: 6910L/hr
Flow at 1.4m: 6500L/hr
Flow at 1.6m: 6070L/hr
Flow at 1.8m: 5610L/hr

here are the figures for this pump:

Tornado 10000
per hour per minute head in m head in bar pump effect input efficiency
9540 l/hr 159 l/min 0.20 m 0.020 bar 0.00530 kW 0.135 kW 3.9%
9180 l/hr 153 l/min 0.40 m 0.040 bar 0.01020 kW 0.135 kW 7.6%
8500 l/hr 142 l/min 0.60 m 0.060 bar 0.01417 kW 0.135 kW 10.5%
7800 l/hr 130 l/min 0.80 m 0.080 bar 0.01733 kW 0.135 kW 12.8%
7320 l/hr 122 l/min 1.00 m 0.100 bar 0.02033 kW 0.135 kW 15.1%
6910 l/hr 115 l/min 1.20 m 0.120 bar 0.02303 kW 0.135 kW 17.1%
6500 l/hr 108 l/min 1.40 m 0.140 bar 0.02528 kW 0.135 kW 18.7%
6070 l/hr 101 l/min 1.60 m 0.160 bar 0.02698 kW 0.135 kW 20.0%
5610 l/hr 94 l/min 1.80 m 0.180 bar 0.02805 kW 0.135 kW 20.8%
5160 l/hr 86 l/min 2.00 m 0.200 bar 0.02867 kW 0.135 kW 21.2%
4720 l/hr 79 l/min 2.20 m 0.220 bar 0.02884 kW 0.135 kW 21.4%
4300 l/hr 72 l/min 2.40 m 0.240 bar 0.02867 kW 0.135 kW 21.2%
3920 l/hr 65 l/min 2.60 m 0.260 bar 0.02831 kW 0.135 kW 21.0%
3610 l/hr 60 l/min 2.80 m 0.280 bar 0.02808 kW 0.135 kW 20.8%
3300 l/hr 55 l/min 3.00 m 0.300 bar 0.02750 kW 0.135 kW 20.4%
2840 l/hr 47 l/min 3.20 m 0.320 bar 0.02524 kW 0.135 kW 18.7%
2400 l/hr 40 l/min 3.40 m 0.340 bar 0.02267 kW 0.135 kW 16.8%
1960 l/hr 33 l/min 3.60 m 0.360 bar 0.01960 kW 0.135 kW 14.5%
1580 l/hr 26 l/min 3.80 m 0.380 bar 0.01668 kW 0.135 kW 12.4%
1200 l/hr 20 l/min 4.00 m 0.400 bar 0.01333 kW 0.135 kW 9.9%
720 l/hr 12 l/min 4.20 m 0.420 bar 0.00840 kW 0.135 kW 6.2%
240 l/hr 4 l/min 4.40 m 0.440 bar 0.00293 kW 0.135 kW 2.2%

greetings

frank

IF you need a bend, first fill the tube with sand, then heat the pipe with an air gun, then gently bend.
But it is better to over dimension the standing pipe and pump up to a wider open gutter, then let gravity do the rest: that is the most efficient.

frank

I hope you didn't all think I had given up on this discussion Just been away...

Frank, I don't know how it is that you can say something without any real supporting information and flag it as fact, whilst if anyone else does the same, it is fiction. Your style of argument intrigues me?

Since you have let me in on a secret, I will let you in on one - the centrifugal pump in the comparison that I have used to try to illustrate where an Airlift pump works more efficiently, was designed for a head height from 0 m to 2.5 m, with one of the stated designs of the pump being recirculation (zero head - this is height above water level - just to be clear).

Since I can see now that you are not willing to accept anything but your own heresay, I provide the following to hopefully loosen your grip...even if only a little. It is a large quote, but there are parts of it that others will find useful - unfortunately I cannot access/find the original studies, but they have been cited widely:



I have some details indicating efficiencies of up to 70-80% for airlift pumps - but I'm not going to follow up on that - too time consuming and it will probably be wasted info...

Moving away from airlift pumps...

One thing that hasn't been mentioned in this discussion is that in general large pumps are much more efficient than smaller pumps. This is due mainly to the mechanical and frictional losses involved. Picture a 1 meter diameter pipe and a 20mm diameter pipe - how much more friction do you think there is in the smaller pipe in proportion to the water flow - similar frictional losses occur inside smaller pumps. I only quickly looked at some of the links that Chappo provided - most are discussions around larger pumps. I'm just trying to flag that what is written about large pumps may not necessarily be meaningful for much smaller pumps. I think in your quest for the holy grail of pumps Frank, you need to set your sights a little lower for the achievable efficiency of a typical AP sized pump. Understand that I agree that propeller/axial pumps are most likely the better choice in some situations, but not necessarily all. As I think Lynx suggested, the right pump for the right job is a much better approach than simply looking for maximum efficiency...

A quick revisit of the airlift pump - the above does not apply to airlift pumps - they have a completely different set of rules...

Hope you find the above of some use.

Myles,
this is the second personal attack I have to counter on this thread, while I have always stayed civil and still am.

My conviction is solely based on the research I have done so far, and I can promise you it has been very intensive.

I like a challenge, so I study every post very intensely.

And I constantly question my own results as a challenge to myself.

So far I have been the only one to provide facts and figures (which have sometimes been backed up by others, some hesitantly, others overtly).

I have provided you all with a tool to calculate pump efficiency and check what manufacturers write.
We all know they tend to illuminate their product's sunny side and to obscure anything which might question this.
More: this tool allows you to check your own impressions and adjust them.

I have done so in all serenity, but with constancy.
I know it is hard to have your beliefs shaken (I am experienced at this, believe me, I could tell you stories. ).

I too have read the papers quoting other "widely cited" papers that pretend airlift pumps can reach an efficiency of 70%.
Unfortunately I have no access to the originals unless I pay for them.
But why should I pay for them?
Let me tell you why I don't:
If airlift pumps would be efficient (and I truly am ready to accept this, but not solely on the manufacturer's word), surely other papers would confirm this.
So far I have found not a single one: if put to the test, the ice has shown much too thin for each and every one of them.
And if I would have found but one single paper to acknowledge this efficiency, rest assured I would have bought the original papers.

Because I want to know, not to assume.

I have backed up my findings with arguments, elaborate explanations and calculations.
the only thing I have "flagged as fact" is the results of these calculations.
Too bad they are not in favor of airlift pumps.

I have tried to contact the few manufacturers of airlift pumps (in fact I found only one who pretended to be soo much more efficient than all others, namely Geyser pumps), asking them for more information.
(while I had noticed several contradictions on their website, I didn't mention this, for them not to think I am an enemy).
Because, much as you might think so, I am not.
I am merely in search of the truth (NOT the holy grail).
If faced with facts and figures that prove me wrong, I will gladly admit that I was erroneous (but not without checking ).

They (Geyser pumps) simply ignored me.

You have not let me into a secret (much as you seem to believe), quite the contrary: my experience with pumps is substantial.
Let me explain:
You are confounding design with performance.
ALL pump manufacturers will show graphs from zero to maximum head. Those are called performance charts.
In industry, bona fide manufacturers always show a connected graph on which you can read energy efficiency (that is how you select the corn from the chaff).
Only from the combination of these graphs you can deduct for what head and flow a pump is truly designed.
Else you MUST calculate it.
see this paper on pump charts:
http://www.oznet.ksu.edu/library/ageng2/L886.PDF

I never described anyone's contribution as "fiction", nor even insinuated it to be, merely pointed out it lacked facts and figures.

I'm sorry if you don't like my style.

Though it might sometimes sound "harsh" (but isn't that too often the opposition's perception?), it is never meant that way.
And I wonder why you consider it offensive or even "intriguing".
Unless you are opposed to me exposing what I have found.
I would describe it as "accurate".

So far I have had no problems with your style, as you stayed civil.
Let's keep it that way.

Don't shoot the piano player.
If anything, play a better tune.
If not, just sit back and relax and enjoy the music.
I'm sure a silent majority is doing so.

If airlift pumps are the most efficient, I want airlift pumps !!!
Just show me they are, because I have not found any evidence of this, to my own regret.

No hard feelings

Frank