Swirl-Flow Devices

Swirl-flow devices include a number of geometric arrangements or tube inserts for forced flow that create rotating and/or secondary flow inlet vortex generators, twisted-tape inserts, and axial-core inserts with a screw-type winding. 

FIGURE 11.32 Representative heat transfer data for swirl-flow devices with uniform wall temperature. 

It also differs essentially from Shell device, since from the beginning of the process 3S unit operates with the swirled flow. Swirling flow also facilitates achieving the temperatures for the central part of the flow that are lower than ones achieved through isentropic expansion. 

The burner is equipped with a flexible swirl setting device to adjust the flame shape. Quasi whole amounts of primary air flow through the flexible hoses. The swirl intensity of primary air stream is determined by the angle of deflection of the hose nozzles, which are easily adjustable from cold end of the burner. The total primary air is internally divided in the air circuit to the flexible hoses and the central air circuit. It is particularly important that the fuels, the burner primary air, and the kiln secondary air mix properly to ensure... 

Another novel concept is the Air-Sparged Hydrocyclone developed at the University of Utah. In this device, the slurry fed tangentially through the cyclone header into the porous cylinder to develop a swirl flow pattern intersects with air sparged through the jacketed porous cylinder. The froth product is discharged through the overflow stream. 

Vortex gas flow is a complex form of movement is entirely dependent on the design parameters are tightening devices. These devices determine the aerodynamic characteristics and flow chambers the degree of twist, hydraulic resistance, structure and uneven speed, features recirculation zones, injection capacity, turbulence intensity. Possibility of a tangential inlet gas into the unit and the formation of internal swirling flows are extremely diverse. However, despite the differences of known devices in design, size and purpose, formed in these gas streams have common patterns. 

Reducing the length of the inlet pipe reduces the eccentricity of the axis of rotation of the gas flow from the geometrical axis of the apparatus. Even in this case, the center of the rotational flow does not coincide completely with the geometric axis of the machine. There is some minor eccentricity, the value of which does not exceed 6-8% of the radius of the device. The presence of such eccentricity swirling flow, there are also researchers [8]. 

Other Flow Straightening Deviees Other devices designed to produce uniform velocity or reduce swirl, sometimes with reduced pressure drop, are available. These include both commercial devices of proprietaiy design and devices discussed in the hterature. For pipeline flows, see the references under flow inverters and static mixing elements previously discussed in the Tncompressible Flow in Pipes and Channels subsection. For large area changes, as at the... 

Figure 19.1 Annular flow arrangement and devices to oscillate fuel flow AR — annular ring BS — backward-facing step FI — fuel injector ID — inner duct MD — main duct PT — pressure transducer SR — swirl register (all dimensions are in mm), (a) annular flow arrangement (6) needle valve arrangement to oscillate fuel flow 1 — vibrator, 2 — receiver, 3 — needle, 4 — spider (c) arrangement to deliver oscillated fuel to inner duct and (d) arrangement to oscillate fuel flow with three circumferentially equispaced injectors...

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