Textiles Talk

WARM AIR/COLD AIR PLEASE HELP

Question:

I’m probably late on this thread, But in case you haven’t recieved a reply to your question of the Hot/cold air generator. It’s called a "Hilsch" vortex tube. As you describe, the input of copressed air comes out of the swirl chamber in two pipes. One is hot and the other is cold. By controlling input pressure and the back pressure on the hot tube, you can controll the output at the cold side. It’s thought that the Germans snagged it from the French during WWII. It was developed by a German physicist named Rudolph Hilsch. It’s a neat device but is not any more efficient ( in current designs) than existing refrigeration/heater designs. I have an old article ( a photocopy of a mimeograph of a copy of a book ) It has good data for construction of these devices, but does require a little thought. I can copy it to anyboy who wishes.

Response:

What’s being described is the Joule-Thompson, or JT Effect–a gas drops in temperature when throttled.  But depending on the gas and the pressure, there is also a range where the temperature will rise.  This line is known as the inversion curve.  Any thermodynamics book should have info.  There is also mention in Mark’s and Perry’s Handbooks.  This effect is used in the liquification of gases. On a more practical level, for about $100, Snap-On Tools will sell you a choke tester (YA862), which you’ve described below.  They claim 0 F from one end and 160 F from the other. – Hide quoted text — Show quoted text – I read some years ago of a device consisting of two pipes one of which is mounted at 90 degrees to the second pipe which is the larger of the two. The smaller pipe enters the larger pipe about halfway down the length of the larger one. When compressed air is pumped into the smaller pipe it (the air) swirls inside the larger pipe and emerges hot from one end and cold from the other end. snip

Response:

- Hide quoted text — Show quoted text – YOU ARE CRAZY!!! No, Just kidding.  I know what you are talking about, I have seen the same things.  I have also seen a web site selling these things.  Biggest problem is, I cannot for the life of me remember where the information was obtained from. I will look for it in my archives. BTW, I am pretty sure that this device/principle is the same as what is used to provide cold air for airplanes and passenger jets (I am positive of the latter).  As a matter of fact, those things get so cold that they tend to freeze up.  Exhaust gases (from the turbines) are passed around the device to keep it from freezing and to deice it. I will forward the information when I find it Sheldon

The device used on jets, takes not exhaust air but high presure air from the compressor and runs it through a heat exchanger.  The exghanger runs the hot air though the considerably colder ambiant air, which cools it off, then alows the air to expand, which causes a drastic temp drop (universal gas law).  That’s the aircraft system anyway, I don’t know if it is what you were looking for. Hawk

Response:

My problem is that everyone I mention this to thinks I’m nuts. I remember the book I saw it in at the local library (probably a physics book) even had diagrams showing a valve in one end of the larger pipe which adjusted how much air was released from that end and thereby controlled either the amount of hot (or cold) air that came out. Can anyone refer me to a specific book or at least give me the correct name for the principle?  I have spent hours and hours at the library but cannot find anything on it or the original book I saw it in. Please help!!!

Vortex nozzles and I believe the company we bought such from was/is called Vortec Technology. We used them in a machine shop to cool cutters and I know they are used extensively in the textile industry to cool thread guides. They are not very efficient but are fascinating. DCK

Response:

YOU ARE CRAZY!!! No, Just kidding.  I know what you are talking about, I have seen the same things.  I have also seen a web site selling these things.  Biggest problem is, I cannot for the life of me remember where the information was obtained from. I will look for it in my archives. BTW, I am pretty sure that this device/principle is the same as what is used to provide cold air for airplanes and passenger jets (I am positive of the latter).  As a matter of fact, those things get so cold that they tend to freeze up.  Exhaust gases (from the turbines) are passed around the device to keep it from freezing and to deice it. I will forward the information when I find it Sheldon

Response:

- Hide quoted text — Show quoted text – I read some years ago of a device consisting of two pipes one of which is mounted at 90 degrees to the second pipe which is the larger of the two. The smaller pipe enters the larger pipe about halfway down the length of the larger one. When compressed air is pumped into the smaller pipe it (the air) swirls inside the larger pipe and emerges hot from one end and cold from the other end. My problem is that everyone I mention this to thinks I’m nuts. I remember the book I saw it in at the local library (probably a physics book) even had diagrams showing a valve in one end of the larger pipe which adjusted how much air was released from that end and thereby controlled either the amount of hot (or cold) air that came out. Can anyone refer me to a specific book or at least give me the correct name for the principle?  I have spent hours and hours at the library but cannot find anything on it or the original book I saw it in. Please help!!!

You’re looking for a Hilsch Vortex tube.  I saw an article in Scientific American in the late Sixties, and actually built one for my high school physics class.  Takes a fair amount of pressure to run a small one, I don’t know how they scale up.  But it IS a real concept and amazingly simple(which is how I managed to make one!).  It’s a real-life Maxwell’s Demon. Cool-and hot, too. Robin — "There’s a Time and a Place for everything…and this is neither!"

Response:

I read some years ago of a device consisting of two pipes one of which is mounted at 90 degrees to the second pipe which is the larger of the two. The smaller pipe enters the larger pipe about halfway down the length of the larger one. When compressed air is pumped into the smaller pipe it (the air) swirls inside the larger pipe and emerges hot from one end and cold from the other end. My problem is that everyone I mention this to thinks I’m nuts. I remember the book I saw it in at the local library (probably a physics book) even had diagrams showing a valve in one end of the larger pipe which adjusted how much air was released from that end and thereby controlled either the amount of hot (or cold) air that came out. Can anyone refer me to a specific book or at least give me the correct name for the principle?  I have spent hours and hours at the library but cannot find anything on it or the original book I saw it in. Please help!!!

Response:

Filed under: Textile Industry

Related Posts

• Discussion With Workers In Havana
• NATIONAL DEBT: Fact and Myth
• tapestry ?
• Seeking Guide for Italian Lake District
• Pickup rewinding available
• A sad day
• 07Papa is declaring an emergency at this time
• THE AFL/CIO HAS BEEN BRIBED!
• PWW: Gus Hall on CP 75th B'day
• Children have a right to food.