Vortex tubes

H2—HD and Ar— Ar binary gas mixtures have been measured (34,35). A vortex tube has been used for isotope separation (36), and for the separation of gases in nuclear rocket or ramjet engines. 

A vortex tube process has been developed in South Africa and is being used there for the enrichment of uranium (37). It appears that cascades of this type are characterized by an extremely high power consumption. 

Atobiloye, R. Z. and Britter, R. E., On flame propagation along vortex tubes, Combustion and Flame, 98, 220-230, 1994. 

Umemura, A. and Tomita, K., Rapid flame propagation in a vortex tube in perspective of vortex breakdown phenomena. Combustion and Flame, 125,820-838, 2001. 

Hasegawa, T., Nishikado, K., and Chomiak, J., Flame propagation along a fine vortex tube. Combustion Science and Technology, 108,67-80, 1995. 

Hasegawa, T. and Nishikado, K., Effect of density ratio on flame propagation along a vortex tube. Proceedings of the Combustion Institute, 26, 291-297, 1996. 

Cyclone Roughness Large weld beads, etc., can also reduce cyclone efficiency. If the solids flow along the wall of a cyclone encounters a large protuberance such as a weld bead, the weld bead acts as a type of ski jump and causes the solids to be deflected farther into the center of the cyclone, where they can be thrown into the vortex and carried out of the cyclone. In small pilot or research cyclones, this is especially common, because the distance between the wall of the cyclone and the vortex tube is very small. Because of their... 

Total protection from liquids and vapors can be provided by an impervious hood incorporating a glass or plastic window. Unfortunately, these are very hot and may require additional ventilation directly from an air line, or perhaps through a device known as a vortex tube that converts supplied compressed air to either a cool or warm flow as required. 

Vortex tubes for 10s and then store in ice till other samples are processed. 

If temperatures no lower than approximately -40°C are required, the use of a Ranque-Hilsch vortex tube should be considered.6-8 This device requires a source of clean, dry compressed air at a pressure of approximately 0.70 MPa (100 psi) for proper operation. The flow rate of air that is required depends on the volume of space to be cooled. 

Incubate tubes, closed, at 56°C for 10 min in the water bath. Vortex tubes every 3 min, to assure optimal elution of the RNA from the silica. 

Carefully, inject 0.125mL of ethanolic DOPE into the vortexing tube in one swift motion with the tip of the pipettor below the surface of the vortexing liquid. 

This shows how the vorticity of a fluid is affected by the forcing and by the diffusion of vorticity. In addition, the first term on the right-hand-side representing vortex stretching also affects the vorticity field and the intensification of vorticity by the stretching of vortex tubes allows the transfer of vorticity and energy from large to smaller scales. 

Second, calculations can be performed in a semiclassical regime, and the results plotted on a Poincare section in action-angle (I, 0) coordinates. Such diagrams may seem complicated (see figs. 10.16 and 10.17), but are at least in principle readily understood a near-horizontal line across the (1,0) plot corresponds to a torus in ordinary phase space. When periodically extended in the time coordinate, each line corresponds to a vortex tube embedded in the extended phase space of the periodically... 

During testing in the glass furnace environment, the detector assembly was cooled using a vortex tube cooler, with an adjustable air flow rate, in order to minimize the temperature excursions. Additionally, the temperature of the detector assembly was measured and documented for later use in data reduction. A statistical analysis of all calibration data including the temperature dependence of the detectors reveals an estimated uncertainty in measured temperature of +2% of the total measured absolute temperature. 

According to Baldyga and Bourne (1986), vortex tubes of stable scale 6 incorporate fluid from the environment via the convective process termed by them an engulfment. Figure 6.7. The engulfment leads to the growth of volume spots, K of substance i at the expense of the environment... 

A vortex tube has certain advantages as a chemical reactor, especially if the reactions are endothermic, the reaction pathways are temperature dependent, and the products are temperature sensitive. With low temperature differences, the vortex reactor can transmit enormous heat fluxes to a process stream containing entrained solids. This reactor is ideally suited for the production of pyrolysis oils from biomass at low pressures and residence times to produce about 10 wt % char, 13% water, 7% gas, and 70% oxygenated primary oil vapors based on mass balances. This product distribution was verified by carbon, hydrogen, and oxygen elemental balances. The oil production appears to form by fragmenting all of the major constituents of the biomass. 

The vortex tube of interest has a tangential entrance into one end of a cyclindrical tube and an axial exit at the other end of the tube. Research into the aerodynamics of the vortex tube revealed that the pitch of the vortex near the cylindrical wall was about 1.2 times the diameter of the vortex tube. This results in a coarse helical path of the gases near the wall, as measured by Pitot tubes (9-10). This coarse helical path on the wall also... 

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