The Air Jet Milling Services offered by Custom Processing Services, Inc., are based on the use of micronizing mills.
Fluid Bed Jet Mill
The fluid bed jet mill is ideal for, but not limited to, air jet milling abrasive materials using compressed air. In the fluidized bed jet mill, the high speed incidental wall collisions are reduced to near zero. In the mill, the air nozzles convert the pressure to velocity in a bed of material at the bottom of the mill, entraining and accelerating the particles within the bed. This grinding action utilizes the extreme edges of the bed as a wear liner, preventing contact at high velocities to parts of the machine. It prevents pick up of contamination to the material being ground.
The mill has an internal mechanical classifier to perform the particle sizing, and it is easy to change the particle cut required. The oversized material is rejected from the classifier wheel within the mill and returned to the grinding section of the mill for further size reduction.
This particular machine can also be run with hot gasses, making the mill more efficient by using heat to raise the escape velocity of the gas without requiring additional pressure, and thereby making the cost of compressing the gasses less. It still maintains the same velocity. It can also perform some drying of the material.
Steam Fluidized Bed Jet Mill
A version of the fluidized bed jet mill that can grind even finer than noted above utilizes superheated high-pressure steam to perform dry grinding of material. Some dense materials have been successfully ground using this dry processing method to 100% less than 1 micron. Traditionally, wet processing systems were the only method to process materials to less than 1 micron.
This system does not wet the product, and it can even initialize chemical reactions on some products or it can even dry other materials from some levels of moisture.
Below is more information about the air jet milling system used by CPS.