Experimental investigation on the performance of vortex tube with non-freeze enhancement

The vortex tube is a temperature separating device. In some of its applications (e.g., pressure reduction of natural gas), low gas temperature in the cold end is required, which may freeze the impure gas. To solve this problem, a vortex tube with non-freeze enhancement was designed and an experimental system was built. The non-freeze design enabled a reverse flow ejection in the pipe of the cold end. Moist air was used as the working fluid and the performance parameters of five similar vortex tubes were compared in this experiment. The characteristics of freeze based on the experiment were presented. The results indicated that thermal conductivity and mixing process played the most important role to avoid freeze when this vortex tube worked in low level of cold fraction. A feasible way to extend the range of working cold fraction for vortex tube is proposed accordingly.