How can I recreate this pressure boiling experiment

[cazzuey]

Hi all,

I was just wondering how I could recreate this at home
What parts do I need?

Thanks,
Harry

 

[Vanadium 50]

I'm afraid if you have to ask, you don't have the expertise to do this safely. Sorry.

 

[cazzuey]

I'm afraid if you have to ask, you don't have the expertise to do this safely. Sorry.

What are the safety risks?

 

[berkeman]

What are the safety risks?

Well normally pulling a vacuum involves an implosion risk. That jar is not a good vacuum enclosure. But the simple water pump mechanism being used in the video pulls a pretty mild vacuum, so the implosion risk is probably minimal.

Get the water pump thing, and use epoxy to fasten a nipple onto a jar lid, I guess. I'm surprised that it takes such a soft vacuum to cause the water to evaporate like that.

 

[cazzuey]

Get the water pump thing, and use epoxy to fasten a nipple onto a jar lid, I guess. I'm surprised that it takes such a soft vacuum to cause the water to evaporate like that.

I was to, but some intelligent folks on here cleared it up for me; the vacuum caused by the aspirator is only limited by the vapour pressure of water. Basically, I need to get the pressure down to about 1kPa at room temp for evaporation to occur.

I was mostly wondering what the tubing he uses is called so I could get my hands on some. Also, I plan to add another chamber where the evaporated water can collect.

Thanks again all

 

[berkeman]

Why did you create a second thread on the same subject? That is against the PF rules...

 

[cazzuey]

Why did you create a second thread on the same subject? That is against the PF rules...

I asked how I could recreate it here - In the other one I asked about how the pump works. Sorry if I broke the rules. You can ban me or whatever the punishment is. Thanks for the help.

 

[Borek]

Take a syringe - the larger, the better. Suck a bit of hot water inside, plug the hole (even with a finger), pull the piston. Water will boil instantly, even if for a very short period of time. That's exactly the same effect.

 

[cazzuey]

Take a syringe - the larger, the better. Suck a bit of hot water inside, plug the hole (even with a finger), pull the piston. Water will boil instantly, even if for a very short period of time. That's exactly the same effect.

I need to do it on a bigger scale like in the video.

 

[DrDu]

But the simple water pump mechanism being used in the video pulls a pretty mild vacuum, so the implosion risk is probably minimal.

A water pump can get you near as low as the vapour pressure of water which is about 20 mbar while the outside pressure on the vessel is 1 bar.
Hence the pressure difference acting on the vessel is nearly 1 bar which is all what counts in terms of implosion risk. Even with a high vacuum pump it won't be higher.

 

[berkeman]

A water pump can get you near as low as the vapour pressure of water which is about 20 mbar while the outside pressure on the vessel is 1 bar.
Hence the pressure difference acting on the vessel is nearly 1 bar which is all what counts in terms of implosion risk. Even with a high vacuum pump it won't be higher.

In that case, this thread is closed.