The hilsch vortex tube, cools and heats air at the SAME time with no moving parts, and NO electricity. cool huh? it's quite simple, and only a matter of getting the dimensions right! Not to mention the ability to produce EXTREME temperatures! all that's needed is compressed air!
So, let's demonstrate two simple scientific principles through this tube. That's right, two principles in one!
let's start with temperature. Temperature is an AVERAGE of how fast the particles are bumping into each other. Because it's an average, it means that air is composed of fast AND slow particles. It's hot and cold at the same time! (see right of third picture) How will this be proved? Well, I think that if we just separated the hot and cold, that'd do just fine for proving!
How's it going to work? By utilizing inertia! Which is defined as: "the property of an object to remain at constant velocity unless acted upon by an outside force." Basically, once you get a boulder rolling, it's not going to want to stop. And trust me, it'll resist you changing it's velocity!
There are two things that make up inertia- mass, and velocity. More of either means more inertia.
Now imagine, there's a wall that curves 90 degrees. A boulder and ping pong ball are rolling towards it. (see fourth picture for the explanation) now, as you saw, the pingpong ball was just pushed away with ease. Now, say the pingpong ball was the same size as the boulder (but still very much lighter) and on the right instead of the left. The boulder would still force its way to the wall. If you had a steady stream of boulders and giant pingpong balls, and this was a circle instead of just a curve, it wouldn't be long before there were only boulders rolling along the wall, and all the pingpong balls were all pushed to the inside.
Now, one step further, now because inertia = mass x velocity, say you had lots of molecules of the same weight going around that circle. But some were moving really fast, and others slow, because the faster ones are moving much faster (and have more inertia), they'll push the slower ones out of the way. (yes, just like the boulder and pingpong ball) and before you know it, there's the hot (fast) molecules around the edge, and slow (cold) in the center! (see left side of third picture) and that's exactly what the inside of the vortex tube looks like!
to put it very simply all the vortex tube does is get those molecules moving in one direction (rather then the chaotic right of the third picture) so that the separation will begin!
There ya go, you've learned two scientific principles, and the basic idea of how this machine works. If you want to know the history and a step by step process, go to step one! If not, and just want to build, just move to the step after that.
So, let's demonstrate two simple scientific principles through this tube. That's right, two principles in one!
let's start with temperature. Temperature is an AVERAGE of how fast the particles are bumping into each other. Because it's an average, it means that air is composed of fast AND slow particles. It's hot and cold at the same time! (see right of third picture) How will this be proved? Well, I think that if we just separated the hot and cold, that'd do just fine for proving!
How's it going to work? By utilizing inertia! Which is defined as: "the property of an object to remain at constant velocity unless acted upon by an outside force." Basically, once you get a boulder rolling, it's not going to want to stop. And trust me, it'll resist you changing it's velocity!
There are two things that make up inertia- mass, and velocity. More of either means more inertia.
Now imagine, there's a wall that curves 90 degrees. A boulder and ping pong ball are rolling towards it. (see fourth picture for the explanation) now, as you saw, the pingpong ball was just pushed away with ease. Now, say the pingpong ball was the same size as the boulder (but still very much lighter) and on the right instead of the left. The boulder would still force its way to the wall. If you had a steady stream of boulders and giant pingpong balls, and this was a circle instead of just a curve, it wouldn't be long before there were only boulders rolling along the wall, and all the pingpong balls were all pushed to the inside.
Now, one step further, now because inertia = mass x velocity, say you had lots of molecules of the same weight going around that circle. But some were moving really fast, and others slow, because the faster ones are moving much faster (and have more inertia), they'll push the slower ones out of the way. (yes, just like the boulder and pingpong ball) and before you know it, there's the hot (fast) molecules around the edge, and slow (cold) in the center! (see left side of third picture) and that's exactly what the inside of the vortex tube looks like!
to put it very simply all the vortex tube does is get those molecules moving in one direction (rather then the chaotic right of the third picture) so that the separation will begin!
There ya go, you've learned two scientific principles, and the basic idea of how this machine works. If you want to know the history and a step by step process, go to step one! If not, and just want to build, just move to the step after that.
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Signing UpStep 1: History and step by step explination
the history
Georges J. Ranque, a French physicist noticed temperature differences in vortex separators. He found that the center would get cool, and the outside quite warm. After some due thought, he wrote some theories up and moved on. These ideas, as well as maxwell's thoughts on the subject came to Rudolf Hilsch and he began actually researching and building a refrigerant system to try and beat the standard system for the German military. After building a few prototypes, and getting a very good hold on the dimensions, he left the idea alone, as, the conventional system was more efficient, and less noisy.
Ok, enough history, now how the tube actually works in a step by step process. This is for those science nerds who really want to know how the air separates in this cool machine. Be warned, this is complicated, and I tried to explain it as well as I could. If you've got a good enough idea from the scientific principles above, you may just want to go to the next step.
-First you have the vortex chamber, this is simply where the air starts to spin. the better this is designed, the better your tube works. for the best tube, the faster you can get the air to spin the higher the temperature change.
-Second the air moves down the long hot tube and the hot air separates outward, and the cold air is pushed to the center of the vortex. (effects of inertia)
-Third, the air makes it to the end of the pipe, and, because the ball valve is opened slightly, with a small opening near the WALL of the hot pipe, it siphons off hot air, but, because the pressure is too great to go out that single opening, some of the air must rebound and travel through the center of the vortex, and exit back through the hole in the middle of the vortex chamber.
Why wouldn't it just go through there in the first place? simply because in the vortex chamber, the air is moving so fast, it's being smashed on the walls of the pipe and can't "pull" itself to go through it. If the ball valve is closed, enough pressure builds, and the air just exits there, as, there's nowhere else to go. Because the ball valve is slightly opened near the wall where the air is being smashed, it tries to exit there first. If it can't make it out there, it is forced to go back through the center of the vortex and exit at out the cold tube.
-fourth as the air goes back through the center of the vortex, the faster molecules push back out towards the edge of the tube, and the colder are forced to the inside. Because there is too much air to exit out the hot tube, the air is forced to escape out the cold tube, and your separation is complete. hot air out one end, cold out the other.
Now we're done with theory, thank goodness! Back to the hands on build it part!
Next step: the materials!
EDIT: due to many people asking what "practical" use this might serve besides teaching a principal, once tuned to achieve temperatures below freezing, you can use the tube to freeze all sorts of stuff! Scientists use it for tissue sample freezing, what can you use it for? Just think carefully. Because you're producing a concentrated blast of cold air, you can freeze things REALLY quickly! Honesly, if you've got a large air compressor that's just sitting there, this is worth a build. In my experience, uses come after it's built, not before.
Georges J. Ranque, a French physicist noticed temperature differences in vortex separators. He found that the center would get cool, and the outside quite warm. After some due thought, he wrote some theories up and moved on. These ideas, as well as maxwell's thoughts on the subject came to Rudolf Hilsch and he began actually researching and building a refrigerant system to try and beat the standard system for the German military. After building a few prototypes, and getting a very good hold on the dimensions, he left the idea alone, as, the conventional system was more efficient, and less noisy.
Ok, enough history, now how the tube actually works in a step by step process. This is for those science nerds who really want to know how the air separates in this cool machine. Be warned, this is complicated, and I tried to explain it as well as I could. If you've got a good enough idea from the scientific principles above, you may just want to go to the next step.
-First you have the vortex chamber, this is simply where the air starts to spin. the better this is designed, the better your tube works. for the best tube, the faster you can get the air to spin the higher the temperature change.
-Second the air moves down the long hot tube and the hot air separates outward, and the cold air is pushed to the center of the vortex. (effects of inertia)
-Third, the air makes it to the end of the pipe, and, because the ball valve is opened slightly, with a small opening near the WALL of the hot pipe, it siphons off hot air, but, because the pressure is too great to go out that single opening, some of the air must rebound and travel through the center of the vortex, and exit back through the hole in the middle of the vortex chamber.
Why wouldn't it just go through there in the first place? simply because in the vortex chamber, the air is moving so fast, it's being smashed on the walls of the pipe and can't "pull" itself to go through it. If the ball valve is closed, enough pressure builds, and the air just exits there, as, there's nowhere else to go. Because the ball valve is slightly opened near the wall where the air is being smashed, it tries to exit there first. If it can't make it out there, it is forced to go back through the center of the vortex and exit at out the cold tube.
-fourth as the air goes back through the center of the vortex, the faster molecules push back out towards the edge of the tube, and the colder are forced to the inside. Because there is too much air to exit out the hot tube, the air is forced to escape out the cold tube, and your separation is complete. hot air out one end, cold out the other.
Now we're done with theory, thank goodness! Back to the hands on build it part!
Next step: the materials!
EDIT: due to many people asking what "practical" use this might serve besides teaching a principal, once tuned to achieve temperatures below freezing, you can use the tube to freeze all sorts of stuff! Scientists use it for tissue sample freezing, what can you use it for? Just think carefully. Because you're producing a concentrated blast of cold air, you can freeze things REALLY quickly! Honesly, if you've got a large air compressor that's just sitting there, this is worth a build. In my experience, uses come after it's built, not before.
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http://ottobelden.blogspot.com/2010/12/another-home-made-ranque-hilsch-vortex.html
I have instructions of how I built it along with a video and some thermal images I took with a FLIR camera showing the temperature gradients. The details of the other tubes I built are also there on my blog:
http://ottobelden.blogspot.com/p/various-projects.html
Scroll down to the Vortex Tube links. I'm more than happy to help folks build these tubes. Leave a comment on my blog or email me!
- Otto Belden
on step 6 do you use the drill bit to "route" the holes for your air line and could you just clamp the 2 pieces of acrylic together and drill into the seam where they meet thus "routing" the air line?
thanks
fidgety2
You explanation of a Vortex only separates the hot molecules from the cold ones I cannot disprove, but I have read of other theories like this one......
"While one airstream moves up the tube and the other down it, both rotate in the same direction at the same angular velocity. That is, a particle in the inner stream completes one rotation in the same amount of time as a particle in the outer stream. However, because of the principle of conservation of angular momentum, the rotational speed of the smaller vortex might be expected to increase. (The conservation principle is demonstrated by spinning skaters who can slow or speed up their spin by extending or drawing in their arms.) But in the vortex tube, the speed of the inner vortex remains the same. Angular momentum has been lost from the inner vortex. The energy that is lost shows up as heat in the outer vortex. Thus the outer vortex becomes warm, and the inner vortex is cooled."
I bought a Vortex Tube in the 1980's and used it to cool carburetor choke bimetal coils to test them and the choke linkage. Also was handy to cool temperature sensors to test their accuracy instead of waiting overnight or removal and install in freezer etc. Here is a video I did on my old Blue-Point Vortex. http://www.machine-history.com/Vortex%20Tube
What exactly am I supposed to be dremeling? After I drill the holes and use the paddle-bit, what piece am I supposed to dremel and what am I trying to remove/smooth/etc.
Please reply if you get a chance, I would be very thankful!
And Great instructable btw, so far this is the only informational tutorial I've seen for making a vortex tube!
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Normally, when you drill into wood with them, the center point digs in first, then the two outer points dig in (and the circle appears), then the flat part digs in & starts tearing out wood. Here, the purpose of the paddle bit is just to dig the perimeter of the circle. You're only using those two outer points of the bit. At least I hope that's what he means, since I'm starting the project tonight.
I find it easiest to start first with the large shallow bore so I still have material in the hole with the centering pilot from the big bit to target the smaller bit with.
In the picture, there is a weirdly shaped white space in the center of the design, is this supposed to be cut out? Left intact? or is the white space just unnecissary?
From the look of it, the Archamedes design looks like the Opposing jets but with only 1 tube (that is double the size). Other then the number of tubes leading into it, it looks pretty much the same. If you've had a chance to compare the 2, I would be really appreciative if you could share your findings, and also if you could explain the white space in the Archamedes design..
Thankyou!
And great instructable! Very informative and very well put together
It's so noisy that without mufflers, I suspect it goes above 120 decibels!
The plan specifies an input of 75 to 100 PSI
Output is claimed as "hot end too hot to touch, and cold end gathered frost."
A photo is shown with 2 thermometers reading 68 and 110 degrees respectively. the nature of the tube is that it is adjusted to maximize either heat or cold, you can't have both at the same time.
the entire tube is 12 inches long and made from 9/32" brass tubing.
Unfortunately, this issue is missing from Google book search beta, although all the other issues are there.
http://books.google.com/books?atm_aiy=1940&ie=ISO-8859-1&id=9CkDAAAAMBAJ&q=hilsch#search_anchor
The article was reprinted in "mammoth home workshop manual" 1950, by popular science publishing. A great book, chock full of the sort of home handycrafts common in the "mens magazines" of the day. those WWII era magazines like pop. sci, pop. mechanics, mechanix illus. kinda seem to me like Make magazine's eccentric uncle.
Pop sci just released their entire archive online (searchable by keyword). Found that appropriately named article.
It depends on the settings. For maximum heating and or cooling temperature you can adjust the flow proportions. But for maximum heating and cooling btu's, (different than temperature) adjust for 50/50 flow, and indeed you will have heating and cooling at the same time.
The higher your input temperature the lower your cold temperature and the higher your hot temperature.
-- JP
The hilsch vortex tube, cools and heats air at the SAME time with no moving parts, and NO electricity. cool huh? it's quite simple, and only a matter of getting the dimensions right! Not to mention EXTREME temperatures!