The Vortex Tube
Vortex tube cooling is a technology that separates compressed gas into hot and cold streams. Pressurized gas is injected into a swirl chamber and accelerated so that it rotates. A conical nozzle at one end of the tube only allows the outer portions of the gas to exit. The other particles of gas are forced into an inner vortex that has a smaller diameter inside the outer vortex.
The vortex tube came about in 1931 and was discovered by a French physicist. Other physicists improved on the discovery culminating in its use in different industries. It has been used to separate oxygen from nitrogen, carbon dioxide from helium, and carbon dioxide from air. The vortex tube has been helpful in separating liquids from each other also.
Vortex Tube Operation
This tube is capable of reducing the temperature of gases to below zero. It is capable of this by creating a vortex action wherein the outer portion of the vortex is rotating faster than the inner portions. High velocity air is on the outside and lower velocity air is on the inside. The air molecules that are rotating slower in the inner portions are also at a lower temperature. This creates a situation wherein the inner portion of the swirl is cooler than the outer areas.
A great deal of compressed air traveling at high speeds is needed for this action. Fresh air and cooling are achieved at the same time using a vortex tube refrigeration process.
Vortex Tube Applications
In commercial industries, vortex tubes are used for processes that will produce temperature drops up to 127F. This type of refrigeration process does not use mechanical parts, electricity or any kind of refrigerant. Because of this, it is economical.
This process is also used in computerized numeric control machining processes. These machining centers produce a great deal of heat due to friction and liquid coolants have been used historically. With the use of a vortex tube, a cold blast of air can be directed to tooling that will immediately reduce the temperature of the tool being used.
The vortex tube is often made of stainless steel and can be used in the following areas.
- Cooling CCTV cameras
- Setting hot melts
- Cooling soldered parts
- Cooling gases
- Cooling electronic components
- Cooling environmental chambers
- Cooling electronic controls
The vortex tube is economical and has the following advantages.
- No electricity or chemicals needed
- Small and lightweight
- Maintenance free
- Provides instant cold air