Separators mechanical centrifugal

Mechanical Centrifugal Separators A number of collectors in which the centrifugal field is supphed by a rotating member are commercially available. In the typical unit shown in Fig. 17-45, the exhauster or fan and dust collector are combined as a single unit. The blades are especially shaped to direct the separated dust into an annular slot leading to the collec tion hopper while the cleaned gas continues to the scroll. 

FIG. 17-45 Typical mechanical centrifugal separator. Type D Rotoclone (cutaway view). (American Air Filter Co., Inc. )... 

Design mode, which can be (a) a scroll or swirl vane inlet instead of the tangential duct, (b) straight-through flow, without the conical portion, (c) insertion of various kinds of internal vanes, or (d) mechanical centrifugal separators... 

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.). 

Gas cleaning may be accomplished either by mechanical methods (such as gravitational settling, centrifugal separation, filtration, ultrasonic precipitators, spray towers, mechanical scrubbers, etc) or by electrical me tbods (such as electrostatic precipitation by Cottrell Method, etc)... 

A second type of impingement separation device is a knitted wire mesh pad. The primary mechanism of separation in the knitted wire mesh is impingement. It also utilizes centrifugal and gravitational force in the collection of small liquid particles. 

A number of techniques are used commercially to accelerate emulsion breakdown. Mechanical methods indude centrifugal separation, freezing, distillation and filtration. Another method is based on the principle of antagonistic action - i.e. the addition of O/W-promoting emulsifiers tends to break W/O emulsions, and vice-versa. Emulsions can also be broken by the application of intense electrical fields, the principal factors involved being electrophoresis in the case of O/W emulsions and droplet deformation in the case of W/O emulsions. 

Expression is the use of a crushing, mechanically applied pressure to squeeze oils from plant material. It was originally done by hand but is now mechanized, with use of centrifugal separators. Expression is used almost exclusively for citrus fruits with oil glands in the outer rind of the fruit. 

In Method 3, after centrifugal separation of the gel mixture from the mother liquor, the gel was mechanically ground in a mortar for 15 min. This procedure was repeated twice and the final mortaring time was prolonged for another 15 min. The ground gel mixture was returned to the mother liquor in an autoclave. The crystallization conditions were the same as for Method 2. 

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