CO2 APS EF2 reactor with internal Venturi fitted - testing ATM

[Zeus.]

HI all

been thinking about how to improve my APS EF2 CO2 reactor

Venturi and Cones come to mind OFC so came up with 'rough' drawing of an internal venturi that will suck the gas (CO2) at the top of the reactor back into the main flow, plus and inverted cone to make more turbulence



So it works a bit like an inductor, The cone could be made with a plastic funnel and the venturi could be made from scratch or one of the many 'Venturi Fertilizer Mixer Injectors' on ebay.

Your thoughts guys

Zeus

 

[ian_m]

Keep up at the back there.....already done by Edvet, picture in link.
https://www.ukaps.org/forum/threads...th-drip-water-change.52693/page-2#post-519869

 

[foxfish]

Good idea but I would increase the cone sides to near the bottom & exit the water back out the top.
Which is what I did by using a plastic bottle inside a water treatment vessel.
However I found that during my experiments, there was a fair bit of fine tuning required ... it was not an easy project but fantastic (if expensive) fun.
I used plastic bottles but found that the shape and length of the bottle produced wildly varying results!
Certainly the key for my projects was a clear vessel.
I tried out a venturi but in the end discovered the perfect bottle & the Venturi was not required.
The cone shape certainly recirculates & aggravates the bubbles but I still got a certain amount of trapped gas, however I found that the build up was limited to around 25mm & that dissipated really quickly once the gas was tuned off.

Without doubt the best reactor I built used a vortex to spin the water & it worked flawlessly with zero build up but I was always nervous of the construction as it is really difficult to DIY an entry pipe at a tangent.
I think I could build one now that I have a better workshop & tools but as I don't actually have a C02 injected tank at the moment, that would be a bit pointless!

I have plans to build a back flushable filter similar to a Koi pond bead filter, I am sure it would also serve to dissolve huge amounts of C02 as well as filter the water.... just need to find the time....

 

[Zeus.]

Keep up at the back there.....already done by Edvet, picture in link.
https://www.ukaps.org/forum/threads...th-drip-water-change.52693/page-2#post-519869

Thats the PIC/thread that gave me the idea of moding my present reactor the only real difference is mine would be more compact and all within the APS EF2 chamber

Certainly the key for my projects was a clear vessel.

Yes thats an Issue with the APS EF2 as its not clear- been on to APS to see if they can do a clear chamber like in one of the pics they use to advertise the filter, only need one for R&D but the answer was white only

Good idea but I would increase the cone sides to near the bottom

Thought that also but just rough pic, all would be dependant on what I could use cheaply eg funnels of cones already made and for sale cheap

exit the water back out the top

Why as the CO2 bubbles that get past the rim of the funnel/cone would rise and then exit to the tank 😱 instead of getting sucked back in to the inlet flow of the venturi

Without doubt the best reactor I built used a vortex to spin the water & it worked flawlessly

Been thinking about that too, maybe a cheap pump taking water from the lower chamber and back in at the top to create a vortec/spin but it would mean modding the chamber walls and getting the right fittings.

Plus is having the time to sort it all out its all Alpha ATM

Thanks for the input 🙂 easier to do with input for like minded folk who have a good insight /experience

 

[foxfish]

If the cone or bottle or whatever goes right down to within 25mm of the bottom, then the water will then travel back up the outside and double the travel distance & contact time. If you could design another inner tube then the contact time would be trebled.

 

[AverageWhiteBloke]

Just regarding the clear canister, the eheim classic is opaque and you could maybe remove the impeller and just use it as a pass through or maybe you could cockle something up using the water purifiers that are available like in the pic.

Sent from my STH100-2 using Tapatalk

 

[foxfish]

Two other designs I have built .... reverse bottle and vortex ...

 

[foxfish]

This one worked very well ......

 

[foxfish]

I took it one step further with this spinning device ....

 

[Zeus.]

Thanks Foxfish nice work and thanks for sharing food for thought definaty.

Just regarding the clear canister, the eheim classic is opaque and you could maybe remove the impeller and just use it as a pass through or maybe you could cockle something up using the water purifiers that are available like in the pic.

Sent from my STH100-2 using Tapatalk

Bought one of those filter purifiers but thought it would never be up to the job on my tank plus the reviews I had seen on you tube they was always so noisy.

One thing I like about the APS EF2 is it's pretty wide so flow is slow internally, plus mine are pretty quiet IMO but they do collect a large bubble with my BPS rate.

 

[Zeus.]

Have been sat on this project far too long, the biggest issue was making the APS EF2 have some window I could see whats going on inside, lots of ideas on how to do it even had a spare APS EF2 ready to mod and use just for testing, however can never find the time to do it. I did however have the internal venturi sorted for months was waiting to make the window in the APS EF2.

So decided to go ahead without the window and see what happens to the pH Profile.

The internal self feeding ventri for the APS EF2 is simple



Bit of 15mm plastic mains water pipe with the metal ferrule in the end with a 1.5mm hole in it. the 1.5mm hole is at the highest point in the reactor chamber so should work well with the CO2 being pressured in the main flow of the water.
The bore diameter pre ventri is 12mm and the ferrule has in internal of 9mm. Does it work Yes tested it with a bit of saliva in the 1.5mm hole and just blow though it, the saliva was sucked in the hole np.
Just by chance the plastic pipe fits really snug in the lid of the APS EF2, so no need to glue😀

Lady luck was on my side
I did have some plans to get the water swirling round and funnels in the reactor, but decided on the KISS principle first and see how it goes.
Decided on a short pipe to start off with and see how it goes with a few side holes as well. Also decided the leave the lower black plastic sponge resting plate in as felt it might help stop the bubble jet from reaching the bottom, however might not be needed as the APF EF2 does have quite a large diameter of 120mm, this same large diameter will increase the Pressure of the water in the reactor, as the slower the water flow the higher the pressure as per Bernoulli's principle which is what I believe is the advantage of the APS EF2 over many off the shelf CO2 reactors as well as its price, its not just the length that helps its the width ( calm down boys ) as the wider the reactor chamber is the slower the water the higher the pressure and the higher the pressure the faster the uptake of CO2 by the water, plus more time for the CO2 bubbles to rise. This incresed pressure in the reactors chamber is why I believe I am able to get such quick pH drops along side duel CO2 reactors/injectors and insane BPS OFC
Took all the bio balls out of reactors as I dont think they will be needed.
pH pen calibrated and ready to start CO2 very soon😉

 

[Zeus.]

pH Profile so far


Which was a little of a surprise as it took 43mins for pH drop after WC with glass covers off yesterday and 53 mins the day before with glass cover on. The flow restriction on the bypass was a little lower than I have it normally so less flow through reactors than normal but not much.
The pH drop is always faster after a WC IME and always slower with the glass covers off also, so its taking about the same relative time IMO may be faster with the BioBalls in the reactors also OFC, but no fizz in tank and will see how the rest of the pH profile goes for rest of day, although I do expect it to drop very slowly till I get the glass covers back on, but after removing some Tenulus Brown from my carpet if time allows so after easy access

 

[Zeus.]

Full Profile for the day


Not too shabby. Will have to see how long the pH drop takes tomorrow which is pretty easy as PLC records it.


Kessils ramping down from 80% intensity and spectrum ATM. Not sure if the venturi is working well could do with that window in the spare APS canister to observe the bubbles OFC. A longer bit of plastic pipe might be all thats needed Plus do have another design which should create a swirling vertex as 'Foxy' suggested seemed to work well. Increased the pre on time for the CO2 Via PLC to 65mins 😉

edit- forgot to add DC colour

 

[Zeus.]

So after nearly a week the speed of the pH drop was on par with what it was before. So I made some viewing windows for testing



Nothing fancy just enough to test and see whats happening, I didnt trim the plastic measuring cups as they was a little brittle and one cracked when I did, but seeing as theirs no vortex in the reactor it would make little to no differerance IMO. I was a little concerned if they would hold



But they did so far anyway. The venturi does work when the gas goes off but it wasnt massive you can see a little bubble in the lower window, in the upper window you can just make out the surface of the water but was hard to get a decent pic. If I increased the flow though the reactors the venturi worked better with more bubbles, but it started to have a few bubbles make it to the bottom and came out of the spraybar.

So I creased the length of the plastic tube so it just reached the bottom of the reactor



To deflect the bubbles away from the output fitted a little deflector to the bottom of the reactor
pic little out of focus but the deflector was just a plastic tube trimmed to height and bit of silicone to hold in place, the 15mm pipe went into deflector a bit. stopped bubbles hitting bottom of reactor then being pushed toward the outlet pipe

This worked better with a slightly faster pH drop with similar flow as before and the pH has held steady at the same BPS, they do work better with higher flow but they do make some noise compared to what the reactors with the Bioballs fitted and no venturi, but a large bubble does get in the reactors

So not that good IMO would rather have them quiet and use more CO2

pH profile (only noted pH till shortly before CO2 off, I was having a quick check every 30mins or so and it was holding pretty stable)


In pic below you can see the large CO2 bubble at top of reactor and the bubbles rising in the water I had the CO2 injection off at the time


Plus 1 hour after CO2 being off the large CO2 bubble at the top of the reactor was still there, smaller but there all the same. No way near as fast as 'Foxys' swirling vortex at clearing the CO2 bubble ( his took about 15mins)

Next up the inverted funnel




Which does fit in the reactor quite nice, the hole in the funnel is to allow the gas to get back to the top of the reactor and venturi intake. Issue with this is it does shorten the height of the reactor but........... Only just silicone it up so will fit tomorrow and test
Might work well with a layer of bioballs between the sponge plates of the reactor!
ie

As you can tell I have spared no expense on this project

 

[Zeus.]

Got the inverted cone/funnel fitted and left some air in the top of the reactor for seeing how it worked and so far with visual inspection I was impressive and not too noisy either as if I let the air go into the other reactor is was noisier than the inverted cone. The venturi draws the air in so lots of bubbles in the lower window


the higher the flow the more bubbles OFC but even on its lowest flow there was a steady flow of bubbles and pretty quiet too.

In the upper window can see the water level in the inverted funnel and the bubbles coming out of the 6mm hole in the side of the funnel


Obvious its just atmospheric air ATM and the real test will be with the CO2 and pH profile, plus only had one funnel that would do the trick,I have fitted it to the trickle CO2 line ATM so if it does increase CO2 uptake the pH profile wont be steady today it should keep decreasing pH and will have to decrease BPS or in my case working PSI

Bioballs and sponge plates wont fit the the testing reactor with the windows

 

[Edvet]

Impressive testing!!

 

[Zeus.]

Impressive testing!!

Cheers m8 🙂 I would just like to try and improve my system and sharing how it goes 😀.

Well thought this was going to better as not as noisy IMO so it is the best so far out of the Test but during the test pH valves was more or less the same and pH holding steady for so increased the flow though the reactors and noise OFC but no change in pH 😱 that surprised me. The reactor was filling up with a large CO2 bubble at the top too, you can see the level on the upper window

So extended my light period for the rest of test. and fitted the reactor with bioballs and internal venturi pipe


ran it for 45mins and no decrease in pH but quieter. So was running out of CO2 period so extended photo period ( which thanks to Ians brill software auto adjusts the CO2 period on PLC) and fitted the inverted funnel and Bioballs


only the lower sponge plate was fitted and the bioballs was going up into the funnel too. This was the quietest so far IMO or was that the emperors new clothes kicking in 🙄. Not really enough time to see if it effect the pH

pH profile for day

speed of pH drop about the same, but only one funnel fitted - ordered some more funnels 😉
But the speed of the drop of about 1.0pH was about 15mins 😱


Run again tomorrow

Some things may need some change like a smaller hole for the venturi as 1.5mm is quite big. Also with me having a 500l tank and such a big pH drop and High [CO2] there are limits to what can be achieved and the higher the [CO2] we will see diminishing returns for any increase in CO2 injection rate to to loss of CO2 from the surface OFC. I do think the inverted funnel with the venturi pipe is the way and if it wasnt for such a big pH drop and corresponding Massive BPS I dont think it would get the large bubble. If nothing else I have a stable pH once lights on 😀
The other thing I could do is have the injected CO2 from both injectors feeding both reactors then that will double the surface area of CO2 in contact with the water for the whole CO2 injection period and not just the pH drop period 😉 just need a few fittings and to do it OFC

 

[goldscapes]

Have you thought about creating a vortex by directing the flow round the inside of the canister using some filter hose? You could attach it to the end of the short Venturi nozzle then twist it round in a spiral so the water exits the tube at the edge of the canister.
It might get in the way of itself but just a thought. Loving the enthusiasm and determination to make this work! Go Zeus! 🙂

 

[ian_m]

Going to reveal my hand here, as I have not got round to building "my idea" but Zeus's activity on CO2 dissolution reminded me. This is what the extra relay output "CO2 Pump" was for on my PLC controller, in 2016 but not ever got round to it 🙁.

Basically CO2 doesn't dissolve very fast in water, so what all these reactors, injectors etc all try and do is prolong the contact time between CO2 bubbles and the water.

So you get a length of pipe and pass the water and injected CO2 along it, allowing time for the CO2 to dissolve. You will probably need to put smaller diameter tubing in the big tubing, to stop the CO2 forming a big bubble.

So picture below shows a pump pumping water via a CO2 injector, then into a coil of tubing, say 2-3 meters, filled with smaller diameter tubes.


Use this calculator to see how many smaller pipes you can get in a bigger pipe. In my picture I have 7 off 5mm pipes (outside diameter) inserted in a 16mm (inside diameter) pipe.
https://www.engineeringtoolbox.com/smaller-circles-in-larger-circle-d_1849.html
This reduces the cross sectional area from 200mm2 (16mm) to 113mm2, which is nearly the same as 12mm2 tube, so you could get away with a 12mm2 pump. A valve to regulate flow before going into the tank might be helpful to slow the flow as well.

So Zeus, throw your reactors in the bin and use PVC tubing. 🙄

Oh, not tested this idea, but I bet Zeus is up to the task. 😀

 

[Andrew Butler]

Well if we're revealing our ideas the here's my hand....
Either a spiral cone nozzle (first pic) which would create a vortex within the chamber or an eductor (2nd pic) which works using a venturi effect.
Nothing new; just parts that could ease what you're trying to achieve.