Fluid energy grinding

However, because it is important that a majority of drug particles in parenteral suspensions are below 10 pm, fluid energy grinding is the most convenient method for their production. 

Jet milling, also called fluid-energy grinding, is an increasingly used process in the chemical industry for processing brittle, heat-sensitive materials into very fine powders with a narrow size distribution. For more than 90 years jet mills have been built and applied successfully on a semilarge scale in the chemical industry. A number of famous designs are extensively described in a number of patents and publications. 

The general pieces of equipment used in grinding flake mica or mica concentrate into saleable mica products are hammer mills of various types, fluid energy mills, Chaser or Muller mills for wet grinding, and Raymond or WiUiams high side roUer mills. Another method is being developed, called a Duncan mill (f. M. Huber, Inc.), that is similar in many respects to an attrition mill. AH of these mills are used in conjunction with sieves, and all but some types of hammer mills incorporate air classifiers as a part of the circuit. 

The majority of applications for fluid energy mills are for producing powders in the sub-sieve range, of the order of 20 p,m and less, and it may be noted that the power consumption per kilogram is proportionately higher than for conventional milling systems which grind to a top size of about 44 p,m. 

CRUSHING AND GRINDING EQUIPMENT FLUID-ENERGY OR JET MIUS... 

---