Air Lift's to move vast amounts of water horizontal..

SnowT

Hiya..

I'm not sure if anyone as gone into Airlift here or not, but I thought I would start up a topic..

Airlift have started to surface a lot in the construction of koi ponds where all the filtration is on a same lvl playing field.. An airlift can move x amount of water dependent on the size of pipe work that is used in the construction of the airlift..

In my own design I plan to incorporate an airlift to help more solids off the bottom of my main fish tank.. do I think it will be an effective way to do so.. Yes..
The way I see it is the more Water you move thru your Fish tank the more movement of solids you have..

The background..
-- SLO using 100mm Sewer pipe and the outlet is a 100mm running down grade[@ 5-7 degree's]..
-- Air source for now 70l/min thru a 30cm membrane, I should be able to throttle the volume down to get the same flow rate..
== For this current setup a 6000l/hr pumping about .5m head height[max]

The normal operating height of my fish tank..

Air-stone dropped down the center pipe of SLO and the water level has drop about 2" of nominal operation levels..

Not the best pic to indicate the level of the water in the tank containing the pump but you should be able to see that it is roughly at the 2nd from bottom rung of the cage..

After a few more minutes the water level has hit the point that the SLO would not work at all as the outflow is higher than the water level..

I this photo you can actually see the complete 100mm "T" junction and even some exposed pipe.. About 4"+ of clearance in the pipe..

Thru out this whole process the pump has been running, returning water back to the fish tank.. But the amount of water being removed is far greater than the inflow..

Water levels in the Pump tank about to overflow, may of had about 5-10mm clearance of runoff..

Final photo of the set showing the max drain depth of the Air-lift.. With out spilling any tank water..

So in my final comment..

An airlift can be used too move large amounts of water vertically as long as you don't have to move that said water to far horizontally.
The less height you need to pump up the greater the volume you can pump..
-- Qualifier here.. The amount of water you can pump is always dependent on the cross-sectional area of the pipe.. The bigger the area the more volume you can move.
Also the depth of the pipe can have a factor as well.. A 100mm pipe that is only 0.5m long will not move as much as a 100mm @ 1m pipe..

When I get more time I'll see if I can get a video of the whole sequence of events..

Hope you have enjoyed this topic.. Let the discuss begin..

- And No I'm not an expert of Airlift's.. I stole all my knowledge from a guy who is doing active research into this topic on koiphen .. Kent Wallace - hope I got his name correct..
Actually Kent is the one guy's I really want to get a chance to hang out with, if/when ever I get back to America..

Juergen

Psst I just want an excuse to get some funky photo's up..
J

RupertofOZ

Yep, airlifts... discussed frequently on the forum in the past... can certainly move a fair degree of water... but only with a minimal head height...

Having said that... yeah, dropping an airstone down the SLO will certainly help move the solids out of the tank...

But crank the air volume up too much... and you could end up smashing the solids into suspension... which may mean they're not captured as well in the grow bed...

I've seen air lifts, within pipes used to lift solids into swirl filters where they drop out...

BullwinkleII

This stuff might apply to what I'm trying to do in making a solar system viable by only burning a tiny amount of power.

I was planning an IBC cut in half with half as a FT and half as a GB sitting side by side CF, and using a 13 watt 5000LPH powerhead to move my water.

It's still in the very speculative stages yet, but I wonder how much water I could move with an air lift instead.

I'd have around 450mm water depth to move water from the FT to the GB at zero head.

I'd want to move 1000LPH, What kind of wattage do you think it would take?

SnowT

hey BW this is the exact reason I wanted to start this thread..

Me I would go with a 1000lt tank and 1/2 that depth for a Growbed so maybe a total of 2 IBCs worth..
The reason I say 1000lt for the fish tank is to get the depth, I'm not exactly after the volume..
ie Tank depth of 900mm and 2 growbeds at 450mm.

Run the system as a constant flood system..

I can try a few different pipe sizes as in 40, 50, 80, 90 and 100..
I know I did a tiny test system at home where I used a 40mm pipe and a small 7l/m air pump and had the water rising to about 20mm above surface level, Volume of Flow I'm not to sure..

I have a small Resun 14l/min 6 outlet 12.8w pump I could try on 6 pipe system at the same time..

So if it works out you could try a fish tank in the middle and a growbed attached at each side of the tank..

So want me to try a test with my resun..?

SnowT

On a side Note.. I timed the flow from start to finish..
7m44.34sec to fill from the second bottom bar to overflow status..

Mind you the last 2/3 of the flow are all above water lvl..
- the last bit before I turned off the air the height was about 6" above Final water level.. So the airlift is moving the water up above but it slows down..

0:.0000 - Start of Air..
1:16.03 - Next Cage Bar..
4:02.56 - 2nd Bar..
7:44.34 - Overflow status..

Oh yeah one added factor A pump is running in the IBC moving about 4-5000lt/hr..
- you must remember that the higher the water in the tank the better the pump work's..

Juergen

Hope this helps you..

BullwinkleII

I'm not sure I follow (I've been having that problem a lot lately)

But I'm excited!

Are you shifting water uphill (ie above the water level the bubbles are in) and having it fill a second container?

if so what do you think that means your flow rate is?

And what wattage are you using to do it.

I've been trying to design a system that BYAP (or anyone else) could sell as solar powered

So wattage/flow is everything.

SnowT

Ok here goes..

the pump I have is a 6000l/h water pump..I'm not sure on the stat's of it, but I'm taking a punt that when the tank is at it lowest the head the pump has to overcome is about 1m, so when the cycle starts the pump has to overcome a head of 1m[I'm guessing that the flow at the start is about 4or5k]..

As the head decreases the pump flow increases..

Ok here is the kicker.. A 80l/min for 60w
I can lift the water about 6" in the last photo of the initial post the gap from the side exit to the water level is 6"[At a glance]

If I had a water source that was coming in at the rate of flow out..

volume 1.2 x 1 x .2 = 0.24 Figure may bot be correct but If they are I flowed in 240l in 1m16s Say 1m15 to make the sums easy..
so the figure pump out at 60m/1.25 = 48

So 48 x 240 gives me a figure of 11520..
The magic number is 11k520lt per hr.. for a figure of 60w.. but What other factor are involved..
If at 1m head the pump is only pumping at 4000lt/hr[Start] then the actually figure is something like 15K per hour..The figure may be out But even if at half the flow rate 7.5kl/h is a fantastic figure..

the fact that it can also pump above water to an extent means that you can use the system to operate a growbed at the same water level as the fishtank..
As water is pumped into the growbed the excess water should make it way back into the fishtank..
the only real issue is to make sure that the water level in the whole system has to stay constant with little or no variation..

Juergen

BullwinkleII

I'm still not sure.

Are you using a conventional pump to pump DOWNhill from water that is raised slightly by an airlift?

If not I've just had an idea

Ao+

I use to do something like this.
But volume of water out through SLO is equal to the volume of water enter to the tank, at steady state.
To get benefit from air lift water level in FT, GB, ST must be set at same level, or nearly same.
But the pictures look like you have pump from sump.

SuperVeg

we need a diagram

BullwinkleII

that we do

BNDYBEAR

I have always had this concept in the back of my mind since being introduced to a septic treatment system that works by moving water through its chambers using an airlift.

So let me get this straight, you have a 60w air pump (with stones) in an 100mm SLO creating an airlift that is capable of lifting up the riser 6" above the existing water level with a return pump returning approx 4000lt per hour back to the tank. So the 60w airlift is capable of moving 4000lt per hour?

I might be missing something but would that mean that you could have the 2 tanks side by side on a level base and using the airlift to lift water from one tank flowing into the second tank, then the 2nd tank overflowing back into the first tank.

The way I see this working is to use a much lower wattage airpump compared to a 4000lt submersible pump to able to move water through a constantly flooded system.
Not sure if what I am picturing in my head is being conveyed in text here properly however.

SnowT

Ok here are a few photo's..

First photo..

2nd Photo.. to give indication of the media filter barrel height.

To give you an indication of the setup..
- Green tank is the main fish tank..about 5800lt at what I would call a safe full capacity..
- the Blue Barrel is the Moving Media Filter..[ in the second photo the top of the blue barrel is equal to the height of the Fish tank..
- The IBC is the settlement chamber..

the Water flow is Fish tank >>SLO>> Settlement tank >>6000lt Pump>> Moving media Barrel >>Gravity>> Back to Fish Tank.. The endless cycle..
-- the current cycle is so I can cycle the media in the filter.. I have not added Growbeds yet they are soon and the cycle will change..

When I turn the power off for the pump the water levels equalise.. they get to the height of the outlet from the T and stop..
where the water level is in the SC I'm not sure.. but there is no Flow..

In the 2nd photo you should note that the outlet of the T[the pipe] is angled down to help gravity..

Now with the pump Running I'm cycling about 4000lt an hour..
- This is to allow for the height that the water is being pushed up above the water level in the SC..
AS the water level is constant in the SC the amount of water leaving the SC is equal to the flowing in..

now with the Air going to the air stone in the SLO the water level is rising in the SC but the amount of water being pumped from the SC is still around 4000lt/hr.
--> So you end up with [Water in to SC] > [Water out of SC] AS this is a closed loop cycle the water level in the fish tank are dropping..
ie More water in the Settlement chamber and less water in the fish tank..

At a point in this cycle the Water level hits the point that the normal gravity flow stops and the water is being pumped out of the fish tank to a point that is higher than the normal outflow..

in the above photo you can see that point has been reached..
so at this point the water is only being moved via the airlift..

At this point the water is being lifted about 1" above the water level..

Here the distance from the outlet to the water level is about 5-6".. so the water that is exiting the fish tank has to be raised that height..

I hope this helps out..

juergen

SuperVeg

ahh now I've got it

i think
So basically when the system is running without the air lift, the water is exiting the FT via the SLO as per normal.
When you turn the air on, additional water is moved from the FT and so the level of water starts dropping.
This continues until the water level in the FT is about 6" below the level of the SLO.
At 6" the airlift flow rate has dropped so much that it reaches equilibrium with the water flowing into the FT.

does that sum it up ?

SnowT

BNDYBEAR wrote:

I have always had this concept in the back of my mind since being introduced to a septic treatment system that works by moving water through its chambers using an airlift.

So let me get this straight, you have a 60w air pump (with stones) in an 100mm SLO creating an airlift that is capable of lifting up the riser 6" above the existing water level with a return pump returning approx 4000lt per hour back to the tank. So the 60w airlift is capable of moving 4000lt per hour?

Actually Bundy the airlift is actually moving more than 4000lt/hr of water..
At the start of the cycle I would guesstimate that the flow is actually around 10,000+, until I hit the point that the water has to move higher than the water level of the fish tank..

I might be missing something but would that mean that you could have the 2 tanks side by side on a level base and using the airlift to lift water from one tank flowing into the second tank, then the 2nd tank overflowing back into the first tank.

Correct if 2 tanks are at the same height and the Airlift is moving water from Tank 1 to tank 2 the water level in tank 2 should rise and if they are interconnected the over flow from tank 2 should go back to tank 1..
This way tank 2 has water cycling thru it while the airlift is operational..

The way I see this working is to use a much lower wattage airpump compared to a 4000lt submersible pump to able to move water through a constantly flooded system.
Not sure if what I am picturing in my head is being conveyed in text here properly however.

In my system I'm using the air-pump I have due the the fact it is the only large flow air-pump I have..
You could even go with a smaller air-pump to do the same thing..
I'm going to be buying a smaller model around 35-45lt/m as an emergency backup for my system..

SuperVeg..
ahh now I've got it

i think
So basically when the system is running without the air lift, the water is exiting the FT via the SLO as per normal.
When you turn the air on, additional water is moved from the FT and so the level of water starts dropping.
This continues until the water level in the FT is about 6" below the level of the SLO.
At 6" the airlift flow rate has dropped so much that it reaches equilibrium with the water flowing into the FT.

does that sum it up ?

in your comment At 6" the airlift flow rate has dropped so much that it reaches equilibrium with the water flowing into the FT.
No it does not, I actually have to stop the airlift.. Because I don't have an overflow hooked up to the Settlement chamber at this stage.. If I left the air-lift Running I would be pumping/moving good water onto the ground therefore wasting it..
So I'm still moving more water than the pump can pump..
Ok just went out and measured the height of the elbow on the line from the pump to the media filter.. At Full Settlement tank the height to the elbow is 34cm so If I understand head height[from water level to heights point of exit] I have 34cm..

so taking the assumption that the lose due to head height is minimal I'm actually pumping about 5.5-6kl/h..
So water into the settlement is > than what the pump is pumping out..

I hope this helps you out..

On a Side note.. As an emergency Backup for my system I'm going to have 2-4 mini airlift running off a backup system.. the sole purpose of the backup is to move dead water from the bottom of the tank to the surface to get oxygenated.. As my tanks is about 1.7m deep I think I need to move that water if I want any chance of Keeping my fish alive..

Juergen

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