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Question about transporting LOX


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So I discovered something on accident that I'm confused about. If you transport LOX using a minipump and its 1000g packets, it doesn't seem to burst the pipes if the LOX goes over the evaporation point. However if I use a full size liquid pump and its 10kg packets it definitely blows up the pipes when it goes above evap. Is this a bug or something?

It takes a long time to fuel a rocket this way, but as I'm struggling to make enough insulated pipes made out of insulation, this is how I'm working around it. 

 

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I actually did not get gas. It seems to stay liquid even at very warm temperatures. While testing my LOX delivery system I failed miserably to keep it cool. (Apparently normal pipes made out of insulation don't cut it). But I filled an entire rocket LOX tank with warm liquid oxygen. I was really scratching my head there. It did however take about 15-20 minutes to fill the tank. So it is slow. 

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1 hour ago, Entrails said:

It takes a long time to fuel a rocket this way, but as I'm struggling to make enough insulated pipes made out of insulation, this is how I'm working around it. 

You don't actually need insulated insulation pipes for LOX or LH2. They're nice, but with the correct setup you can get by with igneous insulation.

The key thing is to recirculate the fluid. Design the system so excess fluid goes back to the production room, and set up your production so you're not making more if enough is coming back from the return pipe. The pipe should not stop flowing, ever. The LOX or LH will warm a little bit during the round trip, but not enough to vaporize, and since it's going back to the production room it'll get re-chilled there.

An alternate solution, and one I don't do personally, is to use radiant pipe in a vacuum. It'll break repeatedly at first, and you'll lose LOX, but once the pipe reaches the target temperature, it will stay stable as long as it's in a vacuum, because vacuum is a perfect insulator. You use radiant pipe because it changes temperature rapidly and has a low specific heat, so it reaches equilibrium rapidly. This doesn't work so well for rocket silos because of the exhaust gasses, which is another reason I don't do it.

John Francis talks about this a bit here:

 

 

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Thank you!

Another thing that confused me, is I noticed that if I fill a liquid storage tank with liquid oxygen, the fluid rapidly warmed up, but the temperature of the storage container never went down. I had it in a vacuum and figured it would cool off.

 

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1 hour ago, Entrails said:

I noticed that if I fill a liquid storage tank with liquid oxygen, the fluid rapidly warmed up, but the temperature of the storage container never went down. I had it in a vacuum and figured it would cool off.

 

Reservoirs don't exchange heat with their contents. The contents of a reservoir exchanges heat with the tile directly below the output port of the reservoir. So if that tile is warm and not insulated, the contents of the tank will warm up, and that tile will cool down. Really, if it's anything but a mesh tile in a vacuum, the LOX is going to warm up eventually, unless you're moving new cold LOX through it.

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I made two major mistakes with my LOX:

1. I produced it inside the gravitas facility, some distance from the launch pad .Even with insulated ceramic, LOX packets still break the pipes before they can reach the rocket, let alone make the return trip.

2. My design only chills airborne oxygen. Once it condenses, the radiant pipe is left in a vaccuum. This prevents it from ever freezing, but means I can't chill it beyond the condensation point.

Fixing the second issue should also resolve the first, but I'll need to be cautious. Any heat introduced to the reservoir will cause it to vaporize and explode.

This whole kerfuffle did teach me that you get back the ceramic you use to repair the pipes, though. I'm not sure if that's a bug, but I like it. Am going to have to test with other auto-repair tasks, maybe I can stop micromanaging my repairs.

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39 minutes ago, Gus Smedstad said:

Reservoirs don't exchange heat with their contents. The contents of a reservoir exchanges heat with the tile directly below the output port of the reservoir. So if that tile is warm and not insulated, the contents of the tank will warm up, and that tile will cool down. Really, if it's anything but a mesh tile in a vacuum, the LOX is going to warm up eventually, unless you're moving new cold LOX through it.

Hah. This reminds me of my first time dealing with LOX and LH(?).

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6 hours ago, QuQuasar said:

This whole kerfuffle did teach me that you get back the ceramic you use to repair the pipes, though. I'm not sure if that's a bug, but I like it. Am going to have to test with other auto-repair tasks, maybe I can stop micromanaging my repairs.

The whole .. what ?? :)

That's good news (or bug) if repair is costless. Is it only ceramic?

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Confirmed. Pipe repairs are costless. The repair materials drop out of the pipe section after the job is complete.

WlGdveq.jpg

(Edit) I cannot replicate this behavior with a petroleum generator. 

Note the lack of copper outside the building after it is repaired: the generator ate it. This behavior may only apply to pipes.

Uccw9Gh.jpg

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