The Chilter: sand-less PO2 purifier

[Fradow]

After building the Evapotuner, a pwater boiler for sand-less pwater cleaning, it’s time to do the same with Polluted Oxygen, which requires liquefying rather than boiling.
It’s not a new concept, that’s something @Yobbo did in his Spicy Tofu Bunkhouse, but it’s surprisingly hard to find an existing efficient early-game design you can just plop on a PO2 geyser.

Enter the Chilter!

It's a minimal build that can tame any PO2 geyser without super coolant or other advanced building materials and purify it to Oxygen without any filtration medium.
The goal is to be able to sustain a single Dupe (that’s about how much a PO2 geyser allows) on a planetoid where there is no water geyser, without using the more infrastructure-heavy ways to create Oxygen out of nothing.

 

How does it work?

• First, the PO2 from the geyser is door-pumped to an infinite storage above (that design is from @Saturnus).
• It’s then released as required in a one-cell wide tall heat exchanger. This heat exchanger needs to be vertical, as an horizontal one behaves totally differently due to gas mechanics and tends to equalize the temperature across it, while a tall one maintains a nice temperature gradient. Obviously, you want the Liquid Oxygen to drop at the bottom since it falls there naturally, so the cooling must be done at the bottom.
• It’s then pumped in packets of 1kg or less (500g/s in the test build to have more heat exchange) and counter-flowed, to be released as liquid. Be aware that the Liquid Vent overpressures at 1000kg/cell of Oxygen if you intend to have an infinite storage.
• The cooling is provided by a cooling box made of several Thermo Regulators with Hydrogen. Nothing revolutionary there. The Steam Turbine is barely used: you could replace it with a few Wheezeworts to avoid the need for plastic, and run it colder to avoid the need for Steel, to get a very early build.

Since I couldn’t fit everything in a nice rectangular box, I decided to instead have 2 nice rectangular boxes. It looks better and adds flexibility, as the cooling box can be placed anywhere around the main Chilter box. Just be careful to minimize connecting gas pipes heat exchange.

 

About the automation

• The door pump automation is for powered doors. The Atmo-sensor can be adjusted as long as you don't let the vent over-pressure
• The Atmo-sensor for the heat exchanger input can be adjusted a fair amount too. Once it's down to operating temperature, that door will stay open all the time anyway.
• The pump hydro-sensor is meant to avoid partial packets, something between 10kg and 20kg is perfect, I settled on 15kg.
• The Thermo-Regulators Gas Pipe Thermo Sensor should be somewhere between -180°C and -210°C (not 180°C/210°C, the Better Automation Overlay badly display the values on the screenshot), since you don't want to freeze Oxygen. It's up to you how you configure them, a single Thermo-Regulator will end up doing all the work anyway when they are placed in series.

 

What about ramp-up?
First, before starting the build, ensure there is only Polluted Oxygen or Oxygen in the main Chilter box, and prime the cooling box like you would for a standard ATST.

Thermo Regulators are notoriously slow at cooling. It’s really important to limit the thermal mass to be cooled down in the liquefaction chamber. That means using Gold for the metal tiles and radiant pipes, Gold Amalgam for the buildings, and Mafic Rock for the 2 Insulated tiles on the sides of the liquids. That’s because any tile in contact with Liquid Oxygen will cause flaking until it’s at -180°C.
By using those specific materials, the ramp-up can be done in as little as about 3 cycles, while higher thermal mass will cause a much longer ramp-up time (about 10 cycles for Copper, Copper Ore and Igneous Rock).
Once it’s down to operating temperature on the other hand, any material works, so feel free to use anything you’d like if you don’t care about that.

What about other materials?
In general, I used Aluminum/Aluminum Ore for radiant pipes, considering it’s easy to get in Spaced Out, and everything insulated is Igneous Rock. As an exception, every Insulated Gas Pipe inside the Steam Box should be Ceramic: Igneous Rock causes a visible efficiency drop there. As usual, it’s recommended to use Ceramic for the Steam Turbine floor as well.

What about power efficiency?
I tested around 200W all included for 200g/s of 30°C PO2 (close enough from the 60°C of an Infectious Polluted Oxygen Vent) when at operating temperature, the output O2 being around 15°C colder. The actual power isn’t that important, as you should have way more than needed with Solar Panels. To have a more efficient build, you need to use Supercoolant in an Aquatuner, which blows this power-efficiency out of the park.

This means only one Thermo-regulator is actually used when ramped up: the others are there to help shorten the ramp-up time, and to handle any above-average geyser you could find.

When comparing with Deodorizers, you would need 2 deodorizers and 266.6g/s filtration medium for 200g/s (and you’ll get 20g/s less Oxygen output). When using the Rock Crusher (using wiki numbers), that means only 34W (10% Rock Crusher uptime). This means if you have a renewable source of minerals to feed the Rock Crusher and enough Dupe labor, Deodorizers are superior.

For a Hot Polluted Oxygen Vent, you can either pre-cool the Oxygen by passively exchanging heat to a Steambox down to ~125°C using a single SCST, or accept a higher power consumption for the same throughput.

Conclusion
This is a really simple build I wanted to publish to give a reference. I didn’t test the upper throughput limit, as a PO2 geyser doesn't go that high in the first place. By tweaking the liquid Valve, you should easily be able to get up to 500g/s, and going above 600g/s will probably need more thermo regulators, while the absolute limit is the 1kg/s of the 10% packets.

All in all, I think it’s a nice taming build if you want to build an outpost on an inhospitable planetoid.

 

[Ceos]

Awesome, I was also looking at something like this to convert morb output. Depending on game speed a few dozen morbs can be the PO2 input. With space materials and a bit more volume for heat exchangers the energy cost goes way down as you mention.  Great build, thanks for posting!

[Fradow]

While the form was tailored around a geyser size and its neutronium floor, it should work just as well with Morbs, as long as you don't exceed the cooling capacity of your cooling box and the absolute 1kg/s limit of the output pipe.

I doubt a bigger heat exchanger is going to make much of a difference, but on the other hand Supercoolant in an Aquatuner should easily make the power consumption nearly negligible.

[ghkbrew]

I've been toying with a similar design for a self-sufficient rocket only with the gas in a pipe. It very effective, but does take forever to warm up (cool down).

 

 

[Ceos]

On 2/26/2022 at 2:10 PM, Fradow said:

I doubt a bigger heat exchanger is going to make much of a difference...

Yeah, my build was much more along the lines of @ghkbrew design where it was a counter flow gas and liquid lines. For power efficiency you win though since I used a gas pump for the PO2.

Since I was using morb production I did not have to delete heat after it was up and running so used the output gas to cool the thermo regulator (and heat the oxygen). Interesting side note that the, aquatuner and thermo regulator create no heat just pure heat movement (as I am sure you know but was interesting to find in my process) so any infinite source (morb, geyser) will come to equilibrium even with massive temp shifts. With an infinite heat exchanger the temp shift (and power cost) goes to 0 (assuming the heat capacity is the same, which luckily PO2 and LO2 are). 

I wonder with extra space if there would be a way make it completely passive (no doors... never had a problem with infinite storage but door pumps are too noisy for me) and output clean O2. Would need some automation on when the LO2 is allowed out and probably really long startup to get enough cold.  Well drat there goes the next few days. Thanks again for the build, great stuff.

[suicide commando]

Nice build, however, considering that pO2 cleaning is a prime source of clay, using a contraption to clean it without the resultant clay is a little counter productie in my opinion. I'd rather build a claymator.

[Neotuck]

On 2/26/2022 at 7:41 AM, Ceos said:

Awesome, I was also looking at something like this to convert morb output. Depending on game speed a few dozen morbs can be the PO2 input. With space materials and a bit more volume for heat exchangers the energy cost goes way down as you mention.  Great build, thanks for posting!

That reminds me of early release versions of the game were most players were looking for ways of turning morb farts into breathable air by super cooling, back then we didn't have steel or steam turbines so we had to get creative exploiting game mechanics to get liquid O2

Who else remembers the borg cube?

[blakemw]

I've also played around with such things. Like this one:

The Thermo Regulator uptime is about 50%, though that is going to depend on the quality of the insulated tiles since I believe heat leakage has a significant effect on the efficiency of such a build.

Some notes: Infinite compression seems pointless. The polluted oxygen itself is emitted at such a low rate that a POxygen vent only produces about 100 kg of poxygen per eruption, this is buffered in about 20 tiles at 5 kg/tile. In my above build there are 38 tiles in the Vent room.

Furthermore, per active period we're only looking at about 3000 kg of oxygen, so even the 5 tiles for a Liquid Vent and a single Gas Pump is more than adequate to provide continual oxygen output at something like 70 g/s.

So finite storage seems perfectly adequate to buffer things over reasonable time periods, especially considering the system doesn't even produce enough oxygen for one dupe at full oxygen intake.

Overall, I've never bothered building one of these outside of Sandbox... even with Infectious there's always the option of just letting the "caretaker" dupe breath it straight, since Yucky Lungs isn't a big deal. In most cases germs are EASILY eradicated by making a "radiation window" to space, even if the solar radiation is reduced by 95% it's still likely more than enough to completely obliterate the slimelung over a short distance.

[suicide commando]

15 hours ago, Neotuck said:

That reminds me of early release versions of the game were most players were looking for ways of turning morb farts into breathable air by super cooling, back then we didn't have steel or steam turbines so we had to get creative exploiting game mechanics to get liquid O2

Who else remembers the borg cube?

This is what I used, it could process a ton of pO2 and turn it into liquid O2.
https://imgur.com/gallery/7VBmWuh

Oh, and lest we forget.. this is what 8KW of power production looked like:
https://imgur.com/gallery/ksEJ9

[Neotuck]

3 minutes ago, suicide commando said:

This is what I used, it could process a ton of pO2 and turn it into liquid O2.
https://imgur.com/gallery/7VBmWuh
 

ahh it was a simpler time in ONI when almost all recourses were finite, the only geysers were steam, natural gas, and sometimes chlorine.  Everything else we had to make due with what we got under our neutronium roof :P

[Fradow]

4 hours ago, blakemw said:

The Thermo Regulator uptime is about 50%, though that is going to depend on the quality of the insulated tiles since I believe heat leakage has a significant effect on the efficiency of such a build.

As far as I know, it's mostly insulated gas pipes that have heat leakage, but yeah since the heat is minimal, any leakage has a disproportionate effect on the efficiency.

4 hours ago, blakemw said:

Some notes: Infinite compression seems pointless. The polluted oxygen itself is emitted at such a low rate that a POxygen vent only produces about 100 kg of poxygen per eruption, this is buffered in about 20 tiles at 5 kg/tile. In my above build there are 38 tiles in the Vent room.

It's only useful during the build ramp-up time, or if you would like to make the build stoppable. It might be useful for an abnormal geyser that would have an especially powerful eruption, though I'm not sure one that could do that exists. In any case, yeah, if you don't care about either of those situation, it's safe to remove that part of the build.

4 hours ago, blakemw said:

Overall, I've never bothered building one of these outside of Sandbox... even with Infectious there's always the option of just letting the "caretaker" dupe breath it straight, since Yucky Lungs isn't a big deal. In most cases germs are EASILY eradicated by making a "radiation window" to space, even if the solar radiation is reduced by 95% it's still likely more than enough to completely obliterate the slimelung over a short distance.

The additional 30% oxygen consumption of Yucky Lungs is the difference between a Geyser providing for a Dupe or not being enough. So far, it's a sandbox only build, but I do intend to build one in survival soon.

[blakemw]

5 minutes ago, Fradow said:

The additional 30% oxygen consumption of Yucky Lungs is the difference between a Geyser providing for a Dupe or not being enough. So far, it's a sandbox only build, but I do intend to build one in survival soon.

But it's not... a dupe needs about 20 g/s to stay alive (putting aside empty suit exploit), and breathes up to 100 g/s (or 130 g/s with yucky lungs) if given limitless access to adequately pressurized oxygen. Giving them over about 50 g/s of oxygen improves productivity because it eliminates the need to catch breath, but adds a small "low oxygen" stress penalty - not enough to matter unless playing on max stress. Basically whether they're breathing poxygen or poxygen, as long as you regulate the oxygen release to the duplicant so they have say, 70 g/s all the time, rather than 100 g/s 70% of the time and 0 g/s 30% of the time (thus being dead), they'll be fine.

[Fradow]

What can I say, I like to spoil my Dupes and give them 100g/s of clean Oxygen