Insulated CERAMIC instantly evaporates liquid oxygen! Help

[Tobruk]

This is my setup. Knowing that without tech-grade insulation from space my LOX will vaporise if left for too long in the pipes, I've made sure to:

• send to the final pipe section (the one that goes to the rocket) ONLY the required amount of LOX for a given trip (the two small boxes on the far right)
• not let the oxygen stay in pipes for too long

The problem is that even with INSULATED CERAMICS, the liquid oxygen instantly vaporises (see the damages piece of pipe on the right, that's the pipe section in question).

What do I do? The amount of space insulation I'd need (and amount of trips I'd have to make) is insane if I have to cover this much ground between LOX maker and rockets. It was already a lot with ceramics - I have probably stripped the entire map out of clay at this point.

I could shorten the distance between factory and rocket, but I can shorten it only this much, and that still would require a couple tons of the insulator!

[Moonshade]

create a vacuum pluming room and use radiant piping. the pipes will break initially until they reached the the temperature that liquid oxygen doesn't vaporise. well they don't have to be radiant but they reach the temperature faster and thus have less LOX loss.

[Tobruk]

Just now, Moonshade said:

create a vacuum pluming room and use radiant piping. the pipes will break initially until they reached the the temperature that liquid oxygen doesn't vaporise. well they don't have to be radiant but they reach the temperature faster and thus have less LOX loss.

I could probably do that for the majority of the route but at some point I'll have to enter the silo, which has space exposure for only the upper half, so I guess the LOX will vaporise right after entering the silo.

[Nightinggale]

You cool oxygen and once it becomes liquid, it drops down and you have LOX at boiling temperature. If you cool LOX say 5-10 C more, then you can accept the LOX being heated 2 C in the pipes without damaging the pipes.

[Tobruk]

Just now, Nightinggale said:

You cool oxygen and once it becomes liquid, it drops down and you have LOX at boiling temperature. If you cool LOX say 5-10 C more, then you can accept the LOX being heated 2 C in the pipes without damaging the pipes.

What do you mean boiling temperature?

[Moonshade]

close to it's evaporation point -183°C
instead make it colder to -188°C to  -193°C

[Tobruk]

Just now, Moonshade said:

close to it's evaporation point -183°C
instead make it colder to -188°C to  -193°C

The LOX in my storage room (see picture) is -193 like you say.

[Moonshade]

well if the vacuum doesn't help enough you could hide as much of the pipe behind insulated tiles too if it's otherwise in gas?I don't know how effective that is though. or make it even colder close to freezing point which is -218 which means you could cool it to -220 before it really freezes

[Nightinggale]

Another method is to make a constant flow of LOX and dump it back into the LOX creation room. If you use a valve to restrict the flow, you can make the flow less than what the pump can handle, meaning it can take both newly created and re-cooled LOX.

The idea with the constant flow is that you cool the pipes to prevent the LOX from boiling.

You can also experiment with insulator and lower LOX temperature.

[Nitroturtle]

Having LOX sitting in pipes behind a shutoff valve in a non-vacuum environment is going to cause you issues eventually.  I know those aren't the pipes you show breaking, but it's only a matter of time.

I feel like you're making things much more complicated than they need to be with trying to separate the required amount of fuel.  An easier method is just to create a loop from your LOX tank to your rockets then back to the LOX tank, once the rocket fuel tank is full, have the pump shut off and allow the remaining LOX in the line to return to the original tank via the loop.  If you do this along with running your pipes in a vacuum, you shouldn't have any more issues.

[Nightinggale]

1 minute ago, Nitroturtle said:

Having LOX sitting in pipes behind valve in a non-vacuum environment is going to cause you issues eventually.  I know those aren't the pipes you show breaking, but it's only a matter of time.

You pump 10 kg/s and then add a valve at the end, which is set to say 8 kg/s. That way you have 10 kg/cell for heating the LOX and 8 kg/s for cooling the pipe.

[Nitroturtle]

4 minutes ago, Nightinggale said:

You pump 10 kg/s and then add a valve at the end, which is set to say 8 kg/s. That way you have 10 kg/cell for heating the LOX and 8 kg/s for cooling the pipe.

Yeah you posted while I was writing mine.  I was referring to the OPs screenshot with the shutoff valves, not your suggestion.

[Tobruk]

@Nitroturtle The loop you proposed solved all my issues. Thanks. A small improvement I've made to it is that it turns pumping only once a rocket has returned from a mission and stops once it detects that the oxygen is on the returning route.