Reverse vortex flow

Figure 4-59. Plasma stabilization by (a) forward vortex and (b) reverse vortex flows.

Figure 10-1. Schematic of a reverse vortex flow system (1) cylindrical chamber walls (2) major tangential gas flow inlet (3) axial gas flow inlet (4) axial flow exit (from the same side as major tangential inlet) (5) dashed lines representing the flow streamlines on the axial plane ...

Figure 10-2. Reverse vortex flow system for gliding arc discharge stabilization (a) eonflgu-ration with a movable ring electrode (b) configuration with a spiral electrode. In the figures, (1) quartz tube (2) cylindrical reactor volume (3) swirl generator with tangential inlet holes (4) additional axial gas flow inlet (5) gas flow exit ...

Figure 10-3. Photo of the ghding arc tornado discharge in eonfiguration with the movable ring electrode (high power, but you ean toueh it beeause of effeetive heat insulation of the walls by the reverse vortex flow).

At the bottom of the vortex, there is substantial turbulence as the gas flow reverses and flows up the middle of the cyclone into the gas outlet tube. As indicated above, if this region is too close to the wall of the cone, substantial reentrainment of the separated solids can occur. Therefore, it is very important that cyclone design take this into account. 

Figure 1—8. Gliding arc discharge stabilized in the reverse vortex ( tornado ) gas flow.

I. Special Configurations of Gliding Arc Discharges Gliding Arc Stabilized in Reverse Vortex (Tornado) Flow... 

Interesting for applications is gliding arc stabilization in the reverse vortex (tornado) flow. This approach is opposite that of the conventional forward-vortex stabilization (Fig. 4-59a), where the swirl generator is placed upstream with respect to discharge and the rotating gas provides the walls with protection from the heat flux (Gutsol, 1997). Reverse... 

Figure 4-60. Non-equilibrium gliding arc discharge moving along a spiral eleetrode and stabilized in the reverse vortex (tornado) flow.

In a tangential-inlet reverse-flow cyclone, the cyclone inlet translates the linear inlet gas flow into a rotating vortex flow. As shown in Fig. 1, the gas solids mixture enters an annulus region between the outer wall of the cyclone and the outer wall of the gas outlet tube. As the gas solids mixture spirals downwards, it sets up a vortex with an axial direction downward toward the solids outlet. 

The lighter oil droplets migrate toward the inner central core where an axial reversal of flow occurs, resulting in the removal of the lower-density oil-enriched phase through a small-diameter orifice (the reject port or the vortex finder) located in the center of the inlet head. This stream is also known as the reject stream or the overflow. The oil-depleted water stream exits from the downstream end (also known as underflow). 

On the reverse, how does the presence of particles affect local and global flow features in the vessel such as the vortex structure in the vicinity of the impeller, power consumption, circulation and mixing times, and the spatial distribution of turbulence quantities more specifically colliding particles have an impact on the liquid s turbulence (Ten Cate et al., 2004) while local particle concentrations affect the effective (slurry) viscosity which may be useful in the macroflow simulations ... 

There are a number of different forms of cyclone but the reverse flow cyclone represented in Fig. 1 is the most common design used in the industry. The cyclone consists of four main parts the inlet, the separation chamber, the dust chamber and the vortex finder. Tangential inlets are preferred for the separation of solid particles from gases [1]. In this study, the numerical simulation deals with the standard case of reverse flow cyclone with a tangential rectangular inlet. Cyclone dimension used in this simulation are as shown in Table 1. 

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