Fluidized bed jet mill

Jet Mill. Jet mills are an alternative to hammer or pin milling, where the primary mode of action is the mechanical impact with the particle. With jet milling, microni-zation is accomplished through the action of fluid energy, resulting in particle-particle collisions and the subsequent reduction in size. Spiral jet mills, loop jet mills and fluidized bed jet mills are examples of fluid energy mills. 

Fluidized bed jet mills work in similar fashion, with the grinding chamber oriented as a fluidized bed. Specially designed nozzles introduce the grinding gas at the bottom of the fluidized bed, creating high-intensity collisions between particles... 

Figure 8.3 Fluidized bed jet mill with classification. (Photo courtesy of Hosokawa Micron Powder Systems.)...

Fig. 8.3). Vertical gas flow is in turn used to fluidized the milled material out of the grinding chamber. Typically fluidized bed jet mills are fitted with a classification wheel. Based on the rotational speed of the classifier wheel, particles of too large a size have a radial momentum imparted upon them returning these particles back to the grinding zone of the fluidized bed. This type of arrangement will typically lead to much narrower particle size distributions than other types of jet milling equipment. 

Heuer and Schweehten [15] designed a sampler for installation with a fluidized bed jet mill where the entire classifier product passed through a Sympatec laser measuring device. This system is suitable for use with... 

Hosokawa Micron Powder Systems (1996) Fluidized bed jet milling for economical powder processing. Ceram Ind. http //hmicronpowder.com/lluidized.pdf. Accessed Apr 1996... 

Opposed Jet Mills. These mills are, in some ways, similar to the fluidized-bed machine however, in this case two opposed nozzles accelerate particles, causing them to collide at a central point (Fig. 16). A turbine classifier is again used to separate the product that has achieved the desired fineness from that which must be internally recycled for further grinding. 

Fluidized-bed opposed-jet mills Hosokawa Micron Powder Systems Div.) differ from the Majac mill in that powder is not fed into the jets, but the jets impinge into a chamber mich contains suspended powder. The powder is entrained into the jets. This ehminates wear on the nozzles, and reduces contamination. Otherwise, construction and appheations are similar to the Majac mill. The fluidized-bed level is maintained a few inches above the jets. The Fluidized-bed mill is available in 13 sizes with air volumes ranging from. 50 to 11,000 mVh. One application is for toner grinding. 

Jet-milling with ultrafine classification of particles can be achieved using a Fluidized Bed Opposed Jet Mill 100 AFG (Alpine, Augsburg, Germany). It is a... 

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