A-swirls

Satisfactory performance is obtained with tubes having helical ribs on the inside surface, which generate a swirling flow. The resulting centrifugal action forces the water droplets toward the inner tube surface and prevents the formation of a steam film. The internally rifled tube maintains nucleate boiling at much higher steam temperature and pressure and with much lower mass velocities than those needed in smooth tubes. In modern practice, the most important criterion in drum boilers is the prevention of conditions that lead to DNB. 

Inlet vanes Specially-designed adjustable vanes inserted in the airstrearn entering a fan inlet to control fan performance by producing a swirl of the gas in the direction of the rotation of the impeller. 

Swirl nozzles Nozzles used to distribute primary air into a space by creating a swirl. This arrangement provides good entrainment and mixing of the air. 

Wrong Positions A Swirl ond Vortex Will Result... 

Before discussing about the flame speed along a vortex core, it is first necessary to be familiar with the flames in various vortex flows. To date, four types of vortex flows have been used to study the flame behaviors. They are (1) a swirl flow in a tube [1,10], (2) vortex ring [2,3,12,13,16], (3) a forced vortex flow in a rotating tube [11], and (4) line vortex [22]. 

The rotating-disk CVD reactor (Fig. 1) can be used to deposit thin films in the fabrication of microelectronic components. The susceptor on which the deposition occurs is heated (typically around lOOOK) and rotated (speeds around 1000 rpm). A boundary layer is formed as the gas is drawn in a swirling motion across the spinning, heated susceptor. In spite of its three-dimensional nature, a peculiar property of this flow is that, in the absence of buoyant forces and geometrical constraints, the species and temperature gradients normal to the disk are the same everywhere on the disk. Consequently, the deposition is highly uniform - an especially desirable property when the deposition is on a microelectronic substrate. 

Pyrolysis for the Recycling of Polystyrene Plastic (PSP) Wastes in a Swirling Fluidized-Bed Reactor... 

Recycling to monomers, fuel oils or other valuable chemicals from the waste polymers has been attractive and sometimes the system has been commercially operated [1-4]. It has been understood that, in the thermal decomposition of polymers, the residence time distribution (RTD) of the vapor phase in the reactor has been one of the major factors in determining the products distribution and yield, since the products are usually generated as a vapor phase at a high temperature. The RTD of the vapor phase becomes more important in fluidized bed reactors where the residence time of the vapor phase is usually very short. The residence time of the vapor or gas phase has been controlled by generating a swirling flow motion in the reactor [5-8]. 

In the present study, the pyrolysis of a waste polystyrene plastic (PSP) has beat investigated in a swirling fluidized-bed reactor to develop an effective reactor. Effects of the reaction time, temperature, ratio of the swirling gas and the gas velocity on the yields of an oil and a styrene monomer have been discussed. 

Fig. 5. Effects of temperature on the yields of oil and styrene monomer in a swirling fluidized-bed reactor(U, =0.3m/s).

In those cases where stirring for short periods is necessary, this may usually be accomplished by gentle rotation of the vessel thus imparting a swirling motion to its contents. If the vessel cannot conveniently be moved, a hand-operated stirrer constructed entirely of glass (compare Fig. II, 10,4 and Fig. II, 10, 2) will be found satisfactory provided the glass loop is not too large. 

Induced swirl, as shown in Fig. 27, which imparts to the solids-gas flow a swirling action and also controls the rate and direction of rotation of swirl via tangential nozzles. However, the residual swirl that would occur in the downstream pipe branches may cause problems if several swirl inducers follow one another (Selves et al., 1995). This problem could be eliminated by introducing the dropout box splitter shown in Fig. 28. 

The liquid properties of primary importance are density, viscosity and surface tension. Unfortunately, there is no incontrovertible evidence for the effects of liquid viscosity and surface tension on droplet sizes, and in some cases the effects are conflicting. Gas density is generally considered to be the only thermophysical property of importance for the atomization of liquids in a gaseous medium. Gas density shows different influences in different atomization processes. For example, in a fan spray, or a swirl jet atomization process, an increase in the gas density can generally improve... 

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