What Are the Best Practices for Testing Liquid Sodium Wicking in Sealed Tubes?

[dpage]

I need to test a system for liquid sodium wicking under high temperatures. The setup is as follows:

Solid sodium pellets are placed in a tube which is then purged of oxygen (replaced with Argon). The tube is sealed and then heated to 300-400 degrees Celsius and agitated with a shaking mechanism.​

My questions are the following:

Where can I find a good reference on setting up sealed tube experiments(i.e. materials, methods to seal the tube, etc...)?

It is preferable that the tube be transparent for observation. What type of tube might I use(is quartz o.k. with sodium at these High temperatures?)?

What additional safety precautions are needed in case the tube cracks? It seems like an outer metal cylinder is typically used for this, but this is not possible for an experiment involving agitation. Also we would like to be able to observe...Anything we can do besides have a fire extinguisher on hand??​

Much Thanks,
dpage

 

[chemisttree]

I need to test a system for liquid sodium wicking under high temperatures. The setup is as follows:

Solid sodium pellets are placed in a tube which is then purged of oxygen (replaced with Argon). The tube is sealed and then heated to 300-400 degrees Celsius and agitated with a shaking mechanism.​

My questions are the following:

Where can I find a good reference on setting up sealed tube experiments(i.e. materials, methods to seal the tube, etc...)?

It is preferable that the tube be transparent for observation. What type of tube might I use(is quartz o.k. with sodium at these High temperatures?)?

What additional safety precautions are needed in case the tube cracks? It seems like an outer metal cylinder is typically used for this, but this is not possible for an experiment involving agitation. Also we would like to be able to observe...Anything we can do besides have a fire extinguisher on hand??​

Much Thanks,
dpage

Review Schlenk line techniques. Don't use pure quartz! Use Pyrex. It's more better gooder... NEVER USE PURE QUARTZ! NEVER!

Only use a Class D fire extinguisher for reactive fires. Anything else will make it worse.
http://blink.ucsd.edu/safety/research-lab/chemical/specific/pyrophoric.html
REALLY BAD JU JU!

 

[nismaratwork]

oooohhh.. I'd use a secondary containment veseel around the tube and agitator too, again Pyrex or even thick Plexi. Keep at least 2 of those extinguishers too... do not mess around.

I was unfortunate enough to see a pellet of K burn its way through a friend's face... it's not something you want in life, trust me.

 

[dpage]

Review Schlenk line techniques. Don't use pure quartz! Use Pyrex. It's more better gooder... NEVER USE PURE QUARTZ! NEVER!

Only use a Class D fire extinguisher for reactive fires. Anything else will make it worse.
http://blink.ucsd.edu/safety/research-lab/chemical/specific/pyrophoric.html
REALLY BAD JU JU!

Will Quartz react with the sodium at high temperatures? We would like to be able to heat up to 350 or 400 C. Can Pyrex handle that?

 

[nismaratwork]

Will Quartz react with the sodium at high temperatures? We would like to be able to heat up to 350 or 400 C. Can Pyrex handle that?

Quartz will crack, and Pyrex can handle re-entry. Literally.

 

[Gokul43201]

NEVER USE PURE QUARTZ! NEVER!

What's the deal with quartz? I can't recall much in the form of specifics (it's been many years), but I'm fairly sure I've performed sealed tube reactions at 700C or higher, using quartz tubes, and perhaps also fused silica tubes.

 

[nismaratwork]

Well, you can also have a piezoelectric effect, I think... that would be unfortunate in the presence of Hydrogen gas.

 

[chemisttree]

What's the deal with quartz? I can't recall much in the form of specifics (it's been many years), but I'm fairly sure I've performed sealed tube reactions at 700C or higher, using quartz tubes, and perhaps also fused silica tubes.

Well, at 700C you would be forced to use quartz. I was thinking about the residual stresses at the fusion point. In this experiment OP will be shaking heavy dense liquid metal under pressure. Sounds... interesting. If the quartz is annealed after sealing there will be no problem and quartz would likely be the safer choice. Using pyrex OP will need to be careful as well during heatup and cooldown, even more so.

 

[Nemus]

I think there is some sorting out to do here:
1:What you get when you buy "quartz" tubes is not quarts but fused silica. Quarts is a crystalline form of silica but it forms under hydrothermal conditions not from melt.
Fused silica is preferred over pyrex (borosilicate glass) above 400 degress C. Pyrex slowly deforms at that themperature.
Use all kinds of screens and stuff you can think of, things break.
Normally fire extingushers are not so good for sodium fires. Sand is preferred. Not wet sand though, it shoud be quite fine grained and get a big bucket and a shovel with a long handle. Sodium burns hot!
Good luck, and be really careful. This is dangerous stuff.

 

[nismaratwork]

I think there is some sorting out to do here:
1:What you get when you buy "quartz" tubes is not quarts but fused silica. Quarts is a crystalline form of silica but it forms under hydrothermal conditions not from melt.
Fused silica is preferred over pyrex (borosilicate glass) above 400 degress C. Pyrex slowly deforms at that themperature.
Use all kinds of screens and stuff you can think of, things break.
Normally fire extingushers are not so good for sodium fires. Sand is preferred. Not wet sand though, it shoud be quite fine grained and get a big bucket and a shovel with a long handle. Sodium burns hot!
Good luck, and be really careful. This is dangerous stuff.

Chemisttree specified a class D extinguisher... that's a heck of a lot more effective than slinging sand.

On the other hand, "things break" is a pearl of wisdom that cannot be repeated enough, truly.