Backyard Aquaponics
A place to discuss aquaponics

Miles,
first of all:

I believe that, I -like you- am a hardy debater, which sometimes gives the impression that anger is involved.
Annoyance maybe, anger no.
So don't worry.
Only try to avoid underlying insults even if not meant that way.
Here is an example:

now that is a statement

you have not posted any links to any paper proving so
except for the theoretical one that in it's own conclusions admits to being theoretical
about this paper:
If one assumes to be able to concoct a set of guidelines for designing whatsoever, the least one must do is to put one's own theories to the test.
They have not done so and grudgingly but explicitly admit this.
I truly am sorry, but that doesn't strike me as being "scientific".
scientific would incorporate not one, but at least a "double blind" or comparative test.

I already have admitted that by themselves airlift pumps might be reasonably efficient.
In an optimal setup which cannot reasonably be expected to be reached by a layman or even an engineer 70%.
But airlift pumps don't exist by themselves.
they exist by the grace of the blower or compressor that is feeding them.
That is why I changed my statement into "airlift pump setups are energy inefficient"
so your statement:

means you are simply dodging the issues that might prove you wrong.
not very scientific.
the second part of this same statement:

reduces airlift pump setups to 60% * 70% = 42 % , which would make me very happy.
Because, much as you might think different, I like the concept of airlift pumps.
I have frantically searched the net for any paper that would allow me to make a positive calculation in favor of any airlift pump.
I have not found a single one.
You have not found a single one or you would have posted it.

Each and every result obtained has shown energy efficiency below 5% (and I'm being VERY generous).
Don't take my word for it, do the calculations.

saying that:

is absolutely unfair:
I have attacked centrifugal pumps almost just as hard as airlift pumps: they suck for AP because most of them are designed for higher heads than we need in AP. In that I have agreed with you, though you seem not to have noticed.
The only pump I have suggested (not stated!) as defendable is a propeller pump.

So why don't you be a "scientist" and instead of pretending you have

post links to these papers or quote the passages that prove me wrong instead of staying vague about them.
So I can either bow to your scientist knowledge or consolidate my statement.

is a statement belonging to someone who is running out of arguments.

are you?

friendly greetings

frank

Frank , youre a better man than me ,, i would have got down right angry and probabley agressive well before this juncture. That is one of my weaknesses

It is simply a fact a supported fact that axial propellor pumps are EFFICIENT and Air-lift SYSTEMS are not.. twist it turn it , hit it with a hammer ,, the facts still remain.

I've been doing a bit of reading on variable pitch propellor pumps that are being introduced into some of the worlds largest irrigation schemes ,, I guess they where chosen because they where less efficient than another type

You may want to re-display some of my efficiency links ,, I think Myles in his role as Scientist ,, has me on ignore.

Always remember ,, it was Scietists that said the world was flat ..... Scientists said the Sun revolved around the earth and Scientists told us it was a good idea to introduce the cane-toad.

I think you guys need to define your debate. You all seem to be talking about different things and different applications. Sometimes you are even using the same words but in different ways and hence with different meanings.

It very hard to have a meaningful debate when you are using different language.

What I want to know and I believe Myles is the same is where can we BUY a pump that is going to use less energy with the same or better output than the pumps we have (or are about to have in my case).

I dont know about the efficiencies of the two different pumps, I may have to read this whole discussion I missed. However, an airlift pump uses way less electricity to accomplish the same thing.

This is the pump I'm using click here. Its a Tetra Wisper 150, it uses 3.5 watts... In my system it moves about 1-5 gallons per hour, pumps down through 10" of water and lifts the water about 15".

Here is a hydrolic pump that uses 5 watts and pumps 65gph up to 20" click here

The hydrolic actually doesnt look bad... If I had know about a hydrolic pump that used only 5 watts I might have considered it. But it would have had more maintenance issues, especially since I'm using perlite.

I've posted a quote, and a link to a public domain paper - the quote suggests it - the paper actually includes real data that shows it - read it again!!!

I have access through various research databases to many Journals and scientific research papers - these are not public domain - I cannot link to them. If you want the information pay the money.

Yes, they have, re-read the paper - they have actual data of a real pump that shows higher efficiency than you will admit to. You seem to be looking for a magic formula that you can just plug numbers into - sorry its simply not that simple.

Where, I missed it - sounds like you've simply changed your complete argument and are now arguing for the sake of it.


How do you know this? Could a layman build even a reasonably efficient centrifugal pump, I couldn't - this, to me is completely irrelevant to the argument, but do continue.


As do all pumps - they require some driving force - what is your point!!!


No it does not - and I take exception to this - I've simply had enough of arguing with someone who continually puts up incorrect, unproven information, takes parts of other statements that suit, but are out of context, and, in my opinion - this is actually my opinion, so is not a personal attack, has no clue what they are talking about!


Buy a respectable journal, or purchase the paper online!!! They exist and you have admitted to it previously but are just unwilling to part with a few dollars.


This is a complete false accusation - please stop making them. I can't post links to articles that are not public domain.


You haven't actually bothered to show where you get you data from!!! Come to think of it, you haven't posted any data at all that relates to airlift pumps.


Where have you attacked centrifugal pumps - this is now bordering on complete BS Frank.
I'm sorry - you have stated that airlift pumps are the most inefficient pump that exists - or words to that effect - you are now changing your argument again - I really cannot keep up!


Frank, I asked you to provide details of a pump that outperformed my airlift pump some time ago, and you accused me of being silly - now your just being an ass. I have provided you with enough information, you just refuse to see it.


Nope, just running out of patience with you Frank.


I'm sorry but I don't think I can accept that you mean this with the tone and accusations in your previous message.

I can now only hope that others are reading this discussion for a bit of a laugh.

Frank, can I just ask you to consider the following, because I think there are some things that you may not fully grasp that you have used in your arguments.

If a centrifugal pump is 85% efficient, how much more efficient can a propeller pump be? You have shown an example of a pump which shows a 5 fold improvement in water turbulence when a propeller was added - how efficient must this pump have been to begin with?

Stuart and Burtonridr,
welcome to the discussion
I only wonder what motivates you both to make impulsive statements out of the blue.
Stuart,
If you have read the thread, you will know that my criticism of airlift pumps concerns ALL possible applications (except maybe protein removal).
I have repeated that all through the thread.
Though English is not my mother language, there has never been an issue of "speaking different languages".
I am quite sure every attentive reader has perfectly understood what I am writing.

your personal slogan, Stuart, is: "proof only exists in mathematics"
This is exactly what I have been doing along the whole thread. see below.

As for an alternative, I also have admitted to not having found an affordable one yet.
That does not contradict my findings on airlift pumps in any way.
I have asked you all, equipped with the tool I provided, to help me find one.

Burtonridr,

how can you possibly make such a statement without blushing after I have given you the tool to check it?
I have used the data you provided to the best possible advantage of the airlift pump: 5 g/hr and a head of 15" (though I think you mean a head of 15" - 10" = 5").

burtonridr
per hour per minute head in m head in bar pump effect input efficiency
19 l/hr 0.32 l/min 0.380 m 0.038 bar 0.00002 kW 0.0035 kW 0.57%
246 l/hr 4.11 l/min 0.508 m 0.051 bar 0.00035 kW 0.005 kW 7.0%
the calculation shows the hydraulic pump to be not less than twelve times as efficient as the airlift pump !!!
If you are happy with this, that is perfectly fine with me.

please, please both do your homework before you butt in !

still, friendly greetings and welcome

frank

I agree with Chappo

Prove it! Why should it be left to me to disprove it - others already have - if you doubt them, then disprove them!


Common chappo, I don't have you on ignore - but if you read my posts you'll see that I agree with you in relation to propeller (axial) pump efficiencies.

Well said Stuart.

http://www.messnerpumps.co.uk/eco_x.htm

There you go Myles, I know its 45w but it does 4800lph

Any chance of the link to the greater than 60% air pump?

Myles,
I think it is best if we agree to ignore each other.

You, the scientist, obviously don't consider me as a party worthy of discussing with.
That is all you have tried to prove in your last two posts.
I think you have not succeeded.

And no, I simply refuse to pay for proving that my suspicions are correct which is what you challenge me to.
You pretend to have access to these papers.
Nothing prevents you to quote out of them as long as you do so correctly and mention the source.
As a scientist you must know that is common practice and perfectly correct.
Nothing prevents you to use the data found in these papers.

I repeat I have not found a single example of an airlift pump setup that reaches even 5% energy efficiency.
And I have clearly stated all along that the centrifugal pump you tried to compare your airlift pump with was, like all available centrifugal pumps found so far, not designed for the low heads that AP needs.

you choose to ignore all that.

now you choose to even doubt my "friendly greetings"
how is that for keeping a discussion amiable?

well, believe it or not:
friendly greetings (I still am sincere when I write this)

Frank

best performing @ 1 m head centrifugal pumps found so far, Sleepe

Mesner Eco-X
per hour per minute head in m head in bar pump effect input efficiency
4500 3500 l/hr 58.33 l/min 1.000 m 0.100 bar 0.00972 kW 0.045 kW 21.60%
7000 6000 l/hr 100.00 l/min 1.000 m 0.100 bar 0.01667 kW 0.085 kW 19.6%
10000 7500 l/hr 125.00 l/min 1.000 m 0.100 bar 0.02083 kW 0.120 kW 17.4%
13000 10000 l/hr 166.67 l/min 1.000 m 0.100 bar 0.02778 kW 0.140 kW 19.8%
16000 12000 l/hr 200.00 l/min 1.000 m 0.100 bar 0.03333 kW 0.190 kW 17.5%
20000 13200 l/hr 220.00 l/min 1.000 m 0.100 bar 0.03667 kW 0.205 kW 17.9%

greetings

frank

first column is pump type, not mentioned, sorry

frank

This is a link to an air pump (with performance graph) http://www.keetonaqua.com/products.asp?product=HK-40L

Would someone else like to calculate the water lifted? I may be in error but I cannot see it lifting close to 3000lph. At one meter its only doing about 45lpm.

Blowers are probably more efficient than this pump but I have not seen one at 35ish watts.

Ok this is doing my head in, according to Zenz formula, yes it will easily .

If anybody is interested there is an excel spreadsheet at this link http://www.airliftpump.com/ap_calc.htm

If its accurate and the formula makes sense (math isn't a strong point ) it should allow you to optimise your airlifts.

I guess the obvious way to reach a conclusion on which pumps are the most effective ... would be to ask someone that has extensively researched them....

So Frank..... just which pumps do you use in your AP system?.... and where specifically are they located within your system and what specific functions do they perform??