freeze dripper technological requirement?

[coppercone2]

So I am trouble shooting something that I read can be found by freeze spray (noisy transistor detection) and I had a futuristic idea.

So buying chemicals sucks, and liquid nitrogen is really cold. I imagined a battery powered 'wand' that could condense atmospheric air into a freeze drip for whatever cooling requirement, to replace the aerosol can.

It seems like something that might be around one day.

How far off are we from such a technology? Some kind of micro compressor to cool a drip spike, so kind of like a reverse soldering iron. I think I saw a 'Yautja' using a tool like this for fixing a console when I almost hitched a ride on a space ship once, but thats a long story.

[IanB]

There's no practical way to create liquid nitrogen instantly from air in a hand-sized device, however I think it would be possible to create something that makes liquid air that is small enough to fit in a home workshop.

The trouble is that liquid air contains liquid oxygen and is therefore dangerous (it would be a fire/explosion hazard). Separating liquid nitrogen from liquid oxygen takes a lot more effort and is not likely practical in a small package.

[coppercone2]

those missile coolers are pretty small, but their not cold enough.

I imagine it would need a moisture scrubber. But if the point is to make 1 drop of liquid air every say 15 seconds, I don't think thats a particular hazard....

So in addition to a adamantium compressor, you need some kind of micro nitrogen separator membrane, so you blow a stream of nitrogen over the tip like a tig torch shield.

Hopefully we can buy these in 5000 years, powered by 2 AA alkaline cells and sold for $20 by general tools near the engraver and disposable electric screw driver.

[IanB]

A drier to remove moisture is a necessary thing, but it's not the only barrier. To liquify air requires what is effectively a refrigeration circuit, and these things take time to cool down to operating temperature (think how long it takes your freezer to cool down after you switch it on from room temperature). So liquid air can be made, but it can't really be made instantly.

[coppercone2]

It says cryocoolers can run on as little as 3W and also have temps of -160. I think its kind of getting close to liquifying air. Just too damn big.

I hoped someone had some fun idea about miniaturization obstacles etc

Look at these
https://aerospace.honeywell.com/us/en/products-and-services/product/hardware-and-systems/air-and-thermal-systems/joule-thomson-cryogenic-minicoolers

google for that page showed this pic, but its not on the page


but the time graph shows like 2 hours to get to temp. needs improvement.
https://cryocoolers.eu/joule-thomson-cryocoolers-self-regulating/
https://www.sciencedirect.com/science/article/abs/pii/S1359431120339983

[Infraviolet]

Perhaps a "hand tool" where the wand in your hand was indeed small, but attached by a long wire and tube assembly to something sized more like a PC tower case. I have seen a youtube video where somebody got some surplus devices used within mobile phone masts for generating cryogenic temperatures for some of the radio equipment and had them able to drip out liquid nitrogen after about half an hour after startup. Might have been based on something like a stirling engine principle but used to refrigerate rather than extract energy from a temperature gradient.

[CatalinaWOW]

Freeze mist gets no where near liquid air temps.  Why push for something so difficult?  The technology exist today to accomplish what is needed for troubleshooting with nothing worse to handle than a hot air soldering station.

The simplest and lightest solution would be pencil size sticks of dry ice (frozen CO2) in an insulated handle.  Biggest downside is the need to replenish the dry ice which is not readily available in many places.

Next would be a high pressure 3 to 6 thousand psi bottle of nitrogen with a Joule-Thompson cryostat.  This setup actually can produce LN2, but would be more practical to just generate cold gas.

Another option is to pipe the output of a Hilsch tube to your test site.

All of these "suffer" from having to confirm to thermodynamic laws.  Pumping heat against a large temperature difference takes a lot of equipment and power.  Freeze mist and dry ice hide this by putting the equipment and power consumption at the manufacturers location. 
Same for high pressure nitrogen and the Hilsch tube requires a high volume air compressor.

[coppercone2]

I thought I made it pretty clear that its scifi technology. I wonder how close we are. Imagination

[Neomys Sapiens]

https://www.kager.de/en/problemloeser-2/kaltluft-erzeuger

Needs only something like a dental compressor or one of the larger airbrush-related models. Could also operate from a pressure vessel (small breathing air bottle). The only setback is the warm air coming out of the other end.

[coppercone2]

I thought the CFM requirement on those was massive

[CatalinaWOW]

I thought the CFM requirement on those was massive

One of these sized for troubleshooting would probably consume on the order of 5 cfm, perhaps a bit less.  They are widely available and at least from some sources not expensive, under $50.  But most of the makers are actually not very open about air consumption for fairly obvious reasons.  In their most common application, machine shops, high volume compressed air is widely available.  Some of those industrial vortex tubes consume 100 cfm or more.

[Overspeed]

Hello

How to make dry ice / cold spray at home



Regards
OS

[coppercone2]

thats getting better, since its two stable items that make cold

I was very surprised he got the result he did

compared to the usual setup, its very much cheapified