Mills premier

In vertical disc-stirred mills the media should be in a fluidized condition (White, Media Milling, Premier Mill Co., 1991). Particles can pack in the bottom if there is not enough stirring action or feed flow or in the top if flow is too high. These conditions are usually detected by experiment. 

In the Premier Mill the rotor is shaped hke the frustrum of a cone, similar to that in Fig. 20-53. Surfaces are smooth, and adjustment of the clearance can be made from 25 [Lm (0.001 in) upward. A small impeller helps to feed material into the rotor gap. The mill is jacketed for temperature control. Direct-connected hquid-type mills are available with 15- to 38-cm (6- to 15-in) rotors. These mills operate at 3600 r/min at capacities up to 2 mVh (500 gal/h). They are powered with up to 28 kW (40 hp). Working parts are made of Invar alloy, which does not expand enough to change the grinding gap if heating occurs. The rotor is faced with Stellite or silicon carbide tor wear resistance. For pilot-plant operations, the Premier Mill is available with 7.5- and 10-cm (3- and 4-in) rotors. These mills are belt-driven and operate at 7200 to 17,000 r/min with capacities of 0,02 to 2 mVh (5 to 50 gal/h). 

Some mills of this type are Morehouse (More-house-Cowles, Inc), Premier (Premier Mill Corp), Charlotte (Chemicolloid Corp), Tri-Homo Disperser-Homogenizer (Tri-Homo Corp), Manton -Gaulin (Manton-Gaulin Co), and the Viscolizer (Cherry-Burrell Co)... 

Figure 7.7 Examples of (a) a colloid mill and (b) a ball mill used for the preparation of suspensions by the dispersion method. Figure (a) courtesy Premier Mill, Reading, PA Figure (b) courtesy Paul O. Abbe Inc., Little Falls, NJ.

Fig. 7 Schematic representation of colloid mill and microphotographs showing emulsion globule size before and after milling. (Courtesy of Premier Mill Corp., Reading, Pennsylvania.)...

Manufacturers There are many manufacturers of stirred media mills worldwide. Major manufacturers of stirred media mills include Netzsch, Buhller, Drais (now part of Buhler), Premier (now part of SPX), Union Process, and MorehouseCowles. Many of these manufacturers have devices specifically adapted for specific industries. For example, Buhler has some mills specifically designed to handle higher-viscosity inks, and Premier has a mill designed specifically for milling/flaking of metal powders. 

Figure 1. Metal and carborundum rotor and stator for colloid mill. Courtesy Premier Mill Corp.

Manufactured by Premier Mill Corp., Geneva, N.Y., and others. 

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