Vortex tube converts an inlet gas flow's energy into two separate flows: cold and hot.

An energy separation in the highly rotating gas - the vortex phenomenon - was discovered in 1930s and since then remains an important part of cooling technology. Many companies have developed vortex cooling approaches, and one such company is Universal Vortex Inc., Hamilton, N.J.

The company offers the following tips about its system:
  • The vortex phenomenon takes place in the vortex tube (figure 1), a specially designed cylindrical device with no moving parts that operates out of expansion of the previously compressed gas.
  • The gas released in the vortex tube’s inlet nozzle undergoes energy and mass division, forming currents of different temperatures: low (far below the gas inlet temperature) in the vortex tube’s center, and high (far above the gas inlet temperature) at the unit’s periphery. In the conventional two-flow vortex tubes, the central and outer currents exit the unit from the opposite sides, forming the vortex cold and hot flows.
  • An extent of the temperature division in the vortex tube is measured by value of the temperature differential (ΔT) in the vortex cold and hot flows. Magnitude of the ΔT may vary. It depends on the ratio of the vortex tube’s inlet to outlet pressure and - at the given pressure ratio - on the ratio of the vortex cold to the vortex inlet flow. The maximal cooling capacity of the vortex tube takes place at the cold flow ratio of 0.6.
  • Prior to energy division, the working medium undergoes a temperature drop in the vortex tube’s inlet nozzles due to the Joule-Thomson effect in the depressurized gas. The value of the Joule-Thomson temperature decrease depends on the gas properties and on the actual vortex tube’s inlet and outlet pressures. The Joule-Thomson temperature drop decreases temperatures of both the vortex cold and hot flows.
Although the vortex tube has been known for decades, its commercial applications were restricted because the conventional vortex tube design requires high inlet gas pressure (pressure ratio) to produce significant ΔT. It also requires dried air (or dried process gas) to prevent freeze up in the unit.

According to Universal Vortex Inc., these negatives can be overcome, making the vortex tube fit for industrial applications. Proprietary features include:
  • Design parameters for the vortex tube's high and low-pressure application.
  • A "non-freeze" feature that makes the device insensitive to fully saturated gas.
  • No limits on the flow rate.
According to the company, the device can be used in series to produce "extreme temperature permutation."

To learn more, contact Lev Tunkel, COO and technical director, Universal Vortex Inc. at (609) 586-3702.