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Free (almost) desalination


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Hey! I am new to the forum and I would like to share some of my designs. I apologize if this is a common knowledge, but I haven't seen such design so far despite being pretty obvious.

The idea is to boil salt water, feed steam to turbine, take water from turbine output.
I use metal refinery with crude oil (or petroleum) as a heat source. Producing iron/steel (tungsten, aluminium) and using passive cooling for turbines makes it power positive. But it can be any other heat source that is able to heat needed amount of salt water (for example regolith, volcano, glass forge, magma etc.) Basically almost any heat source where you would build turbines anyway is ok.
Screenshots are form my last run, so the build could be more informative and clean. But that's what I have for now..
Salt water is from geyser and is almost 95°C, it cools turbines. While 95°C water output from turbines can be taken away. To keep amount of steam in the steam chamber near constant I used pipe meters on both water output and salt water input wired with automation. Since we get only 465 kg of water with 500 kg of salt water, settings of meters should be 465 and 500 respectively (or 93 and 100).
If you want to collect salt from the steam chamber steel auto-sweepers and other transportation infrastructure is needed.
Refinery is shut off when temperature of steam is too high (higher than 139°C) or when output water pipe is full (and if I don't need more steel - that is controlled by manual switch).
I find this design to be more power effective (well, it is actually only 2x10W for the meters which are not working constantly) than for example cooling cold steam from 110°C.
Also it might be done without meters but with dedicated vent for salt water inside steam chamber. Though shut off logic for that dedicated vent is not evident (since atmo sensor works only up to 20 kg which is too low for stable steam chamber). So I haven't tried it.

Thanks for reading! I hope this was helpful for somebody..

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It's not really power positive as it's leaching power from the power of refining otherwise would give. How much power it actually uses is however rather complicated. Another way of making "power positive" salt boilers would be to use magma or other external heat sources in the same manor.

I'd recommend this thread that have salt boilers without an external heat source, called saltuners, that are still extremely power efficient.

 

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1 hour ago, Saturnus said:

It's not really power positive as it's leaching power from the power of refining otherwise would give. How much power it actually uses is however rather complicated.

It depends on salt water temperature. If it is near to 95°C difference with just self cooling turbine is very small. But of course with lower input temperature this design makes little sense. Very soon even desalinator building becomes more power effective.
Let's say we take away 1 kg/s of 95°C water from the system. We would have spent 1*4.179*(125-95)=125.37 kDTU/s to make it 125°C steam.
To make up for steam loss we have to add 1.075 kg/s of salt water. Let's say it is also 95°C. We have to spend 1.075*4.1*(102.7-95)=33.938 kDTU/s to heat it to 102.7°C (to boil) plus 1*4.179*(125-102.7)=93.192 kDTU/s to heat 1 kg/s of steam from 102.7°C to 125°C plus 0.075*0.7*(125-102.7)=1.171 kDTU/s to heat salt (in case we leave it inside) from 102.7°C to 125°C. Resulting in 128.301 kDTU/s.
Well, this is only 3 kDTU/s less effective. Considering that refining of steel gives more than 2300 kDTU/s in the worst case (no light and dupe without skill) I wouldn't consider 3 kDTU/s a big deal.
But again if we have salt water of let's say 80°C it turns to additional 1.075*4.1*(95-80)=66.113 kDTU/s which is not that nice already. It may be partially solved by heating input from output... I like to overcomplicate things, sorry =)

 

1 hour ago, Saturnus said:

I'd recommend this thread that have salt boilers without an external heat source, called saltuners, that are still extremely power efficient.

Thanks a lot! I will study it. Just didn't know right keyword to search..

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I would pump the salt geyser fluid onto a liquid sulfur geyser, and get fantastic results. Clean water and salt and sulfur that is safe to use. I tried with hotter geysers, but found it often makes the salt too hot and the water remains steam for an extended time, as long as I build a second chamber with gas floors separating them, and cooling on the top area of the second chamber, or a runoff from there to another chamber that flows into the fish aquarium. 

These methods look great, however. I will give a variation of it a try. 

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Interesting design, though there are a few odd choices:

  • The self-cooling turbines only use 5 cells of heat transfer. I'm not too sure what temperature you are reaching, but if you reach a higher temperature, this won't be enough. It's really advised to use all 15 cells of heat transfer to operate near the theorical maximum (cells of heat transfer is the single most important factor, provided the heat transfer atmosphere is good enough, like 2kg/cell oxygen or 500g/cell hydrogen)
  • 3 Turbines limit the throughput to 6kg/s. But that's even less since you mix water and salt water in pipes. I'd probably try to vent them separately. At least if you aren't using an infinite storage in the salt water geyser tamer.
  • I'm pretty sure the piping could be simplified a bit

All in all, I'm pretty sure that it's a more efficient method of refining Salt Water than a Saltuner when producing Steel (though I'm definitely not doing the calculations, like Saturnus said it's a bit complicated).

On the other hand, you have Dupe labor, a more bulky build, and you need to ensure a constant input of materials to refine Steel. Those are non-negligible constraints when choosing which build to go for, though both choices are definitely good ones.

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On 1/4/2022 at 12:37 PM, Fradow said:

The self-cooling turbines only use 5 cells of heat transfer. I'm not too sure what temperature you are reaching, but if you reach a higher temperature, this won't be enough. It's really advised to use all 15 cells of heat transfer to operate near the theorical maximum (cells of heat transfer is the single most important factor, provided the heat transfer atmosphere is good enough, like 2kg/cell oxygen or 500g/cell hydrogen)

Good point thanks! 3 passive cooling turbines are not enough to cool down constantly working steel/iron refinery anyway. So here is some space for improvement. But if we don't rush for as much steel per second as possible, this works fine. Materials of turbines and radiant pipes make difference as well. With lead you can't go high. Aluminium is much better. Gold is fine but I wasn't able to go higher than ~134°C with it. Also it is faster for me to put one layer of water than mess with gases while building. I will try 2 or 3 layers of liquids next time.

On 1/4/2022 at 12:37 PM, Fradow said:

3 Turbines limit the throughput to 6kg/s. But that's even less since you mix water and salt water in pipes. I'd probably try to vent them separately. At least if you aren't using an infinite storage in the salt water geyser tamer.

It can work up to 6 kg/s since all water goes to output and no mixing therefore. With 5 turbines it might give up to 9.3 kg/s without additional vent (or not.. needs some calculations). But I don't need that much. To be honest I get bored at the point when I need more than 2-3 kg/s of water and just start a new colony =)
And since all 15 tiles of turbine exchange heat (it wasn't obvious for me somehow) separate vents shouldn't be a problem with 2 layers of liquid in turbine chamber. Haven't tried it as well..

On 1/4/2022 at 12:37 PM, Fradow said:

I'm pretty sure the piping could be simplified a bit

Absolutely!

On 1/4/2022 at 12:37 PM, Fradow said:

On the other hand, you have Dupe labor, a more bulky build, and you need to ensure a constant input of materials to refine Steel. Those are non-negligible constraints when choosing which build to go for, though both choices are definitely good ones.

Sure this build with refinery is not for latest "infinite" game. I meant it more like addition to any "heat source -> turbine" build that is built anyway. We can use it while we have that heat source and then switch to more sustainable options.

Also I like your idea in "Stoppable Saltuner" where salt water is taken from geyser without pump. Hm.. May be it could be also heated and put through turbines. That way we have no pumps at all. Another overcomplication though..

Thanks for your comments, highly appreciated!

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51 minutes ago, NikiHammerforce said:

Also I like your idea in "Stoppable Saltuner" where salt water is taken from geyser without pump. Hm.. May be it could be also heated and put through turbines. That way we have no pumps at all. Another overcomplication though..

The main point of Saltuners is to only heat Salt Water up to it's boiling point (around 102°C) and not up to 125°C to be used in a Turbine (barring split-turbine designs, which could be extremely efficient, but have yet to be designed by someone). Heating up to 125°C without an external heat source is going to be way more costly than pumping. And if you use an external heat source .... well you add more complexity and an important dependency.

You can't have your cake and eat it too.

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what i like about this is that i now have an use for my salt water geysir. i just make an chamber around it, put the pipes in and can start refining. Good for early refining if you don't have (or don't want to use) the ice biome for cooling. 

and later on you can just add the steam turbine ontop to recycle the energy. 

only reason to reopen it later is to remove excess salt and add ether an autominer or sweeper to automate it. 

It's neat and easy "fix it later" solution :D

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I like this; in fact I'm doing something similar in my first playthrough with the DLC. Sure it's not hyper-optimized but if you have a lot of excess heat from steel production it's a good way to get some usable water out of it, or (in my case, more importantly) get rid of some garbage. I think refinery-cooling turbines are perfect for dumping some used brine coolant from your drecko farm, or even bathroom output. For late game, sure, get something permanent in place that doesn't rely on the need to refine metal, but as a temporary solution (for a few hundred cycles or more) it's great.

 

On 1/3/2022 at 5:32 PM, NikiHammerforce said:

Also it might be done without meters but with dedicated vent for salt water inside steam chamber. Though shut off logic for that dedicated vent is not evident (since atmo sensor works only up to 20 kg which is too low for stable steam chamber). So I haven't tried it.

There's an implicit "logic" if you don't mind using a 1000kg steam room: vents will overpressurize. You could just have the pipe contine from the turbine return vent and take the excess water out of the system. At 1000kg/tile having to wait a bit for coolant won't make much difference in temperatures. And the "oops some oil got on that vent" trick works if you need to continue feeding in external liquid to be boiled.

I experimented with adding a 1-tile wide hydrogen spire to the side of a high pressure steam room. The idea is that if you know the amount of H2 put in, and you can measure how many tiles it currently takes up, you can have a good guess about the pressure that the steam exerts on it. I abandoned it because it was very slow to react, and I ran the risk of taking out too much water too quickly. But in a high pressure room where the relative amounts change slowly, it might be a workable thing.

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5 hours ago, FenrirZeroZero said:

what i like about this is that i now have an use for my salt water geysir. i just make an chamber around it, put the pipes in and can start refining. Good for early refining if you don't have (or don't want to use) the ice biome for cooling. 

and later on you can just add the steam turbine ontop to recycle the energy. 

only reason to reopen it later is to remove excess salt and add ether an autominer or sweeper to automate it. 

It's neat and easy "fix it later" solution :D

Very nice idea! I always rush for plastic (by dreckos) to have turbines. But this way good amount of metal can be refined early and safe enough.

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23 hours ago, Fradow said:

(barring split-turbine designs, which could be extremely efficient, but have yet to be designed by someone)

I could be wrong, but I don't think split-turbine designs are that energy efficient.  

Your post inspired me to play with split-turbines.

Split-Turbine Cool Steam Tamer

The Aquatuner averages 60% run time despite it's only job being to keep the central chamber at 130C to feed the 4 turbine ports.  When the pressure there drops below 20 kg 95C water is dropped in.  About 300W total is refunded by the 3 turbines that run in this example, so this system still averages ~420W and this doesn't include distilling water. Even as a Cool Steam Vent Tamer any (small) energy savings would be outweighed by start up material cost and a waste of space.  As a saltuner its maximum output is only 4.8 kg/s ~85C water, although it could be raised to 6.4 kg/s if salt water is fed into the central chamber as well.

Honestly the Desalinator is an overpowered building.  Its output temperatures are close to the input temperatures, it only costs 200 metal ore to build, any water can go through it and it only costs 480W to process 5 kg/s salt water/brine.  The only real short coming is it has to get full to be emptied by a duplicant. (A % slider like Oil Wells would be nice.) If you need 10kg/s water constantly, just build 4 desalinators.  It's just sooo good, it discourages players from bothering to make their own dedicated desalination system.  Unlike the Oil Refinery where you lose half the mass, which encourages players to make petroleum boilers.

Most examples of water purification seen in ONI (by me at least) involve a geothermal steam power plant (their primary function) and purifying water is just a side benefit often adapted in later when players realize it's not hard to do.

I hope I am wrong and perhaps there is a flaw in my design or an improvement to be made, please let me know.

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48 minutes ago, tuxii said:

I hope I am wrong and perhaps there is a flaw in my design or an improvement to be made, please let me know.

First of all you don't need 4 steam turbines. CSVs that output over 2400g/s average occur once out of about 120.000. So unless your specific CSV has that there's no real to account for it.

Second, something is way off in your deisgn. Heating 400g/s steam by15C is about 25Kdtu. Even with 4 ports (instead of the 2 that is actually needed) that would still only be17% AT uptime, not 60%. That's 204W that has to be countered by the STs (102W with the actually needed 2 STs).

I also don't think you really read into the saltuners enough. The only real advantage of the desalnitor is that it's a single building. The Infinite saltuner can handle 10kg/s continuous output. That's 10.75kg/s input while using less power than a single desalinator and not requiring dupe labour. It's also less space than two desalinators.

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10 minutes ago, Saturnus said:

I also don't think you really read into the saltuners enough. The only real advantage of the desalnitor is that it's a single building. The Infinite saltuner can handle 10kg/s continuous output. That's 10.75kg/s input while using less power than a single desalinator and not requiring dupe labour. It's also less space than two desalinators.

I didn't read into them at all as I wanted to attack it from a fresh angle, and I wanted to primarily test the split-turbine.  Split-turbines are not worthwhile, imo.

The Desalinator has a massive advantage (maybe it's not "real" though) that it can process salt water at temperatures less than 95C easily, without affecting its performance.

The Infinite Saltuner is an awesome contraption, but I see a Salt Water Geyser Tamer because it'll perform worse the cooler the feed is.  A Cool Salt Slush Geyser would slow it down to an infinite crawl, while a desalinator would only need the feed warmed up a little bit.

Thanks though.

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8 hours ago, tuxii said:

I could be wrong, but I don't think split-turbine designs are that energy efficient.  

That's not what's said. What's efficient is only heating salt water to 102°C instead of 125°C, and potentially using split-turbines as a pump rather than a power-generator.

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Your post inspired me to play with split-turbines.

Nice, I love that more people use those sort of mechanisms! :encouragement:

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[SNIP CSV taming image]

See Saturnus comments, but it's not really comparable to a Saltuner, which use 95°C Salt Water as an input, not Steam. Note that CSV taming with split turbines is pretty much figured out, there are several working designs out there.

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Honestly the Desalinator is an overpowered building.  Its output temperatures are close to the input temperatures, it only costs 200 metal ore to build, any water can go through it and it only costs 480W to process 5 kg/s salt water/brine.  The only real short coming is it has to get full to be emptied by a duplicant. (A % slider like Oil Wells would be nice.) If you need 10kg/s water constantly, just build 4 desalinators.  It's just sooo good, it discourages players from bothering to make their own dedicated desalination system.  Unlike the Oil Refinery where you lose half the mass, which encourages players to make petroleum boilers.

It's not in my opinion. The Water Sieve is, as it's 4x more efficient and doesn't require Dupe operation. As shown with the Saltuner design, you can do better than the Desalinator: no dupe operation, half the power cost, in a reasonnable space.

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Most examples of water purification seen in ONI (by me at least) involve a geothermal steam power plant (their primary function) and purifying water is just a side benefit often adapted in later when players realize it's not hard to do.

Indeed, when doing so the opportunity cost of using 95°C pwater or salt water instead of plain water is very low. The Saltuner aims to be self-contained though.

6 hours ago, tuxii said:

I didn't read into them at all as I wanted to attack it from a fresh angle, and I wanted to primarily test the split-turbine.  Split-turbines are not worthwhile, imo.

They are worthwhile in a Saltuner-type of design where you'd use them as a pump replacement if you don't value the infinite storage part of the Infinite Saltuner, lowering even further the total power cost (note that my calculation in that thread assume you want to pump to an infinite storage).

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The Desalinator has a massive advantage (maybe it's not "real" though) that it can process salt water at temperatures less than 95C easily, without affecting its performance.

Indeed, no one is debating that.

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The Infinite Saltuner is an awesome contraption, but I see a Salt Water Geyser Tamer because it'll perform worse the cooler the feed is.  A Cool Salt Slush Geyser would slow it down to an infinite crawl, while a desalinator would only need the feed warmed up a little bit.

The Saltuners were made in vanilla at a time when Cool Salt Slush Geyser where not available to vanilla (and it was not believed it would make it down into vanilla either). They are indeed a very poor fit for those, and you should definitely use a Desalinator for those.

 

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37 minutes ago, Fradow said:

They are indeed a very poor fit for those, and you should definitely use a Desalinator for those.

Or you use the full cooling potential of them heating the slush to above 90C at least in the process which does then make it suitable for saltuners. 

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On 1/5/2022 at 10:51 PM, Fradow said:

The main point of Saltuners is to only heat Salt Water up to it's boiling point (around 102°C) and not up to 125°C to be used in a Turbine (barring split-turbine designs, which could be extremely efficient, but have yet to be designed by someone). Heating up to 125°C without an external heat source is going to be way more costly than pumping. And if you use an external heat source .... well you add more complexity and an important dependency.

You can't have your cake and eat it too.

You could also use an heat chamber design to limit the heat in the steam chamber. that way you can keep the steam in the optimal range. (The Water of the engine is reinsertet in the lower chamber. Alternative you could add an steam funnel from the lower part to add steam to the top. -> design b)

Temp shift plates are optional in the upper chamber but helpfull. 
Adding some statues for head capacity also helps to reduce jumping temps on higher C° differences. and if the temp just increases in the lower chamber you can add more steam engine to the side. 

I use this kind of chamber as a heatsink for the whole base with steel and later niobium aquatuners in the lower chamber. also i tent to build it with ether an cold steam vent in the upper chamber or an hot steam vent in the lower chamber (Made with https://blueprintnotincluded.com/)

Spoiler

image.thumb.png.628f7c2db2d0f54df7dc601569097bd8.png

Doppel Chamber Steam Funnel. Second chamber obens to the top if the pressure goes to low. This design has reduced energy effeciency but allows the use of the chambered steam as an water source. The lowest chamber would mostly contain an endless water source. (Poo Water overflow, Geysir etc.)

Spoiler

image.thumb.png.7ad51f5150e7587c92dc0caf6029fada.png

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On 1/7/2022 at 2:12 AM, tuxii said:

I could be wrong, but I don't think split-turbine designs are that energy efficient.  

Your post inspired me to play with split-turbines.

...

I hope I am wrong and perhaps there is a flaw in my design or an improvement to be made, please let me know.

One of most important tricks of split turbines is amount of hot steam. Try to heat up just 20 grams of water in central chamber and efficiency jumps up.

There is no need for AT at all, you can use Power Transformer to heat up couple grams of steam.

There even was Mathmanican's design, using just pool of hot petroleum to heat up milligrams of steam without loosing any temperature due clamping mechanic

 

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