HOW DOES A VORTEX TUBE WORK?
How can you get cold air and hot air from one compressed-air stream? Lots of people have tried to explain it, including the French physicist who invented the Vortex Tube in the 1930's, Georges Ranque. Many different theories have been put forward.
Vortex Tubes behave in a very predictable and controllable way. When compressed air is released into the tube through the vortex generator, you get hot air out of one end of the tube and cold air out the other. A small valve in the hot end, adjustable with the handy control knob, lets you adjust the volume and temperature of air released from the cold end.
The vortex generator—an interchangeable, stationary part—regulates the volume of compressed air, allowing you to alter the air flows and temperature ranges you can produce with the tube.
“Cold Fraction”: an Important Term for Understanding Vortex Tube Performance
“Cold fraction” is the percentage of input compressed air that’s released through the cold end of the tube. As a rule of thumb, the less cold air you release, the colder the air will be. You adjust the cold fraction with the control knob. Cold fraction is also a function of the type of vortex generator that’s in the tube, i.e., a “high cold fraction” or “low cold fraction” generator.
Most industrial process applications use a high cold fraction (above 50%). A high cold fraction tube can easily give you cold outputs 50-90°F (28-50°C) below your compressed air temperature. High cold fractions give you a greater air flow, but they don’t give the lowest possible temperatures.
The high cold fraction combination of airflow and cold temperature produces the maximum refrigeration capacity, or greatest BTU/H (Kcal/H).
A low cold fraction (below 50%) means a smaller volume of air coming out that’s very cold (down to -40°F/-40°C). In short, the less air you release, the colder the air.
Just remember, your maximum BTU/H (Kcal/H) capacity (also called maximum cooling or refrigeration) occurs with a high cold fraction tube.
The chart to the right shows you the temperature drop (pink bar) and rise (grey bar) you can get at various inlet pressures and cold fraction settings.
Reliable, Predictable, Easy to Control Without Tools
A Vortex Tube turns factory compressed air into two airstreams, one very cold and one hot, using no moving parts. Simple and low-cost, a Vortex Tube can produce:
You just set the cold temperature output with the handy control knob and your thermometer. No tools are required.
- Temperatures from -40°F (-40°C) to +230°F (+110°C) from 70°F compressed air
- Up to 2800 BTU/H (630 Kcal/H) refrigeration
- Air flow rates up to 35 cfm (990 lpm)
Assuming your compressed air input pressure and tem-per-a-ture remain constant, a Vortex Tube will hold output temperatures ±1°F (±0.6°C). Our unique temperature control knob lets you adjust the cold air discharge without tools.
A simple, interchangeable part - the Vortex Generator - allows our Vortex Tube to deliver five different air flows: 8, 10, 15, 25, 35 cfm (220, 280, 420, 700, 990 lpm) — each with two ranges of cooling performance (high or low).