09-11-2012, 04:24 PM
Vortex Tube
10_Vortex_Tube_Non_Conventional.pdf (Size: 85.66 KB / Downloads: 346)
Working:
Compressed air is passed through the nozzle as shown in Fig.6.9. Here, air expands
and acquires high velocity due to particular shape of the nozzle. A vortex flow is created
in the chamber and air travels in spiral like motion along the periphery of the hot side.
This flow is restricted by the valve. When the pressure of the air near valve is made
more than outside by partly closing the valve, a reversed axial flow through the core of
the hot side starts from high-pressure region to low-pressure region. During this
process, heat transfer takes place between reversed stream and forward stream.
Therefore, air stream through the core gets cooled below the inlet temperature of the air
in the vortex tube, while air stream in forward direction gets heated up. The cold stream
is escaped through the diaphragm hole into the cold side, while hot stream is passed
through the opening of the valve. By controlling the opening of the valve, the quantity of
the cold air and its temperature can be varied.
Advantages:
1) It uses air as refrigerant, so there is no leakage problem.
2) Vortex tube is simple in design and it avoids control systems.
3) There are no moving parts in vortex tube.
4) It is light in weight and requires less space.
5) Initial cost is low and its working expenses are also less, where compressed
air is readily available.
6) Maintenance is simple and no skilled labours are required.
Disadvantages:
Its low COP, limited capacity and only small portion of the compressed air appearing as
the cold air limits its wide use in practice.
Refrigeration Cycles Prof. U.S.P. Shet , Prof. T. Sundararajan and Prof. J.M . Mallikarjuna
Indian Institute of Technology Madras
Applications:
1) Vortex tubes are extremely small and as it produce hot as well as cold air. It
may be of use in industries where both are simultaneously required.
2) Temperature as low as –500C can be obtained without any difficulty, so it is
very much useful in industries for spot cooling of electronic components.
3) It is commonly used for body cooling of the workers in mines.