Inertial centrifugal separators

Impingement separators, 246, 257 Chevron style, 248, 255 Efficiencies, 246 Knitted wire mesh, 246 York-vane efficiencies, 248 Inertial centrifugal separators, 266, 268 Kinetic energy, pump system, 187 Lamella plate classifiers, 239 Line sizing work sheet, 107... 

Other Centrifugal Collectors. Cyclones and modified centrifugal collectors are often used to remove entrained Hquids from a gas stream. Cyclones for this purpose have been described (167—169). The rotary stream dust separator (170,171), a newer dry centrifugal collector with improved collection efficiency on particles down to 1—2 pm, is considered more expensive and hence has been found less attractive than cyclones unless improved collection in the 2—10-pm particle range is a necessity. A number of inertial centrifugal force devices as well as some others termed dynamic collectors have been described in the Hterature (170). 

Figure 4-56. Inertial centrifugal dust separator. Courtesy of American Air Filter Co.

Figure 4-55. Specification Sheet, gas phase centrifugal entrainment Figure 4-57. Inertial centrifugal dust separator. Courtesy of Univer-separator (liquid or solid particles). sal Road Machinery Co.

Centrifugal separators take the idea of an inertial separator a step further and make use of the principle that an object whirled about an axis at a constant radial distance from the point is acted on by a force. Use of centrifugal forces increases the force acting on the particles. Particles that do not settle readily in gravity settlers often can be separated from fluids by centrifugal force. 

If gravitational forces are inadequate to achieve the separation, the separation can be enhanced by exploiting inertial, centrifugal or electrostatic forces. 

Methods for the removal of particles from industrial streams rely on the same generic collection techniques used for sampling and collecting particles for examination and characterization. These methods include (1) gravitational settling, (2) centrifugal separation, (3) inertial capture by wet scrubbing, (4) filtration, and (5) electrostatic precipitation (see Fig. 1). 

The group of dry mechanical separators include sedimentation chambers, inertial, vortex and centrifugal separators. For dust separation in these units particularly gravitational and inertial forces are used. 

The forces such as electrical double layer, forces between emulsion droplets, hydrodynamic inertial forces, entropic (Diffusional) forces and the dispersion forces which act on the droplets or between the droplets separated at tens or hundreds of nanometers. Sedimentation and flocculation processes involve the forces such as the centrifugal force, applied electrostatic force and gravitational force. Before discussing the emulsion stability in terms of these forces, we would like to explain the thermodynamics of emulsion stabilization. 

In inertial separators, the separation of liquid from gas occurs mainly due to the action of inertial (most often, centrifugal) forces. Basic elements of orifice inertial separators are orifices of various constructions, which are installed in the final gas clearing section. Separators installed at oil fields are increasingly using, among others, the so-called string orifices, which are essentially sets of frames with 0.3-0.5 mm wire coiled around them. 

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