Vortex tube recirculation

[Wo Wala Moiz]

If we took a vortex tube and redirected the cold exhaust back into the initial compressed air flow, would it act as a positive feedback loop, causing the hot exhaust to become colder with time (up to a point!)?

Conversely, if we took a vortex tube and redirected the hot exhaust back into the initial compressed air flow, would it cause the cols exhaust to become hotter with time (up to a point)?

 

[berkeman]

What kind of vortex tube? Can you post links or diagrams about what you are asking about?

 

[Wo Wala Moiz]

What kind of vortex tube? Can you post links or diagrams about what you are asking about?

https://en.m.wikipedia.org/wiki/Vortex_tube

 

[Ivan Nikiforov]

https://en.m.wikipedia.org/wiki/Vortex_tube

The vortex tube does not heat or cool the air. It creates a temperature gradient (difference) relative to the temperature of the incoming air. The higher the temperature of the incoming air, the higher the temperature of the cold and hot fractions.

 

[Ivan Nikiforov]

If you are going to design a real device, please consider the following. The vortex tube works correctly provided that its ends are open and the air flows freely out of them. Simply connecting either end of the tube to the compressor inlet will cause resistance or discharge to appear at this end of the vortex tube, meaning the operation of the vortex tube will be disrupted.

 

[Wo Wala Moiz]

If you are going to design a real device, please consider the following. The vortex tube works correctly provided that its ends are open and the air flows freely out of them. Simply connecting either end of the tube to the compressor inlet will cause resistance or discharge to appear at this end of the vortex tube, meaning the operation of the vortex tube will be disrupted.

Why would it cause resistance? The compressor inlet would have lower than atmospheric pressure since it has the draw in air.

 

[Ivan Nikiforov]

Why would it cause resistance? The compressor inlet would have lower than atmospheric pressure since it has the draw in air.

It depends on the specific design. If the air from the outlet of the vortex tube is passed through an additional pipe and directed by a jet to the compressor inlet, additional resistance will result. If the air from the outlet of the vortex tube is hermetically supplied to the compressor inlet using an additional tube, a vacuum will result. In any case, the correct operation of the vortex tube is disrupted. It seems to me that the air from the outlet of the vortex tube needs to be supplied to the compressor inlet in such a way that the flow and pressure parameters at the outlet of the vortex tube do not change.

 

[Ivan Nikiforov]

In addition, the following must be taken into account in the design. The vortex tube divides the air into two streams, so the air flow at each end will be less than at the inlet. Therefore, if air is supplied from the outlet of the vortex tube to the compressor inlet, this air must be mixed with atmospheric air so that the total amount of air supplied to the inlet of the vortex tube does not decrease. It seems to me that this is easiest to do if you supply air from the vortex tube to the compressor inlet with a free jet. This will also allow you to take away some of the cold (or hot) air for the main technological process.