Classifiers rotor blades

Rotor blades also form an element of several external classifiers that are used in closed-circuit dry milhng. These are generally called mechanical air separators or classifiers. Examples are the Whirlwind classifier Sturtevant Inc.), the Gayco centrifugal separator Universal Road Machinery Co. (see Fig. 20-41), and the whizzer separator Raymond Division of Combustion Engineering Inc.). 

Some mechanical air classifiers are designed so that the fine product must pass radially inward through rotor blades instead of spirally moving across them as with whizzer blades. Examples are the Mikron separator Hosokawa Micron Powder Systems Div.), Sturtevant Side Draft separator, and the Majac classifier shown attached to the Majac jet mill (Fig. 20-55). 

Two main types of these classifiers are known, distinguished by method of creating air rotation. In vortex classifiers the air is rotated by stationary vanes (or tangential pipes) in rotor classifiers this is done by rotating blades. The latter devices may have open or closed aerodynamic cycle. 

Fig. 5. (a) Rotor classifier, (b) classifier with profiled blades, (c) circulating air classifier. 

Fig. 30b Bladed rotor separator, with drive, as an independent classifying unit fed through a riser duct (Loesche GmbH)...

For a dynamic compressor, a continuous totfUtng element (rotor) js used to increase gas velocity. Then, gas velocity is converted to static pressure at compressor outlet. Dynamic compressor is classified as centrifugal or axial compressor. For centrifugal compressor, the rotating element is an impeller, and gas flow is in either radial or mixed flow direction. For axial compressor, the rotating element is a bladed rotor and gas flow is in the axial directioa... 

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