Sturtevant, Inc.

The FCM Air Classifier is a classifying impact mill capable of reducing powders down to 10 microns. It is fast becoming the workhorse in particle size reduction applications due to its combination of impact milling and air classification technologies in a single unit. The FCM’s flexibility of operation allows it to easily process a multitude of product categories requiring efficient and economical particle size reduction for a broad range of industries including pharmaceutical, food, chemical, mineral and others.

The FCM Classifier Mill is a high speed impact mill with an internal air classifier. The material enters the grinding chamber through the feed inlet where it comes into contact with a series of spinning impact pins or blocks smashing the material into fine particles. The fine particles must pass through a cage of spinning blades, known as the “classifier wheel”. The wheel acts as a screen and only lets the particles that are small enough to pass through, it also rejects the large particles causing them to stay in the mill for additional grinding. The fine particles then exit the mill and are collected in a bag house product collector. Particle size is easily adjusted by increasing or decreasing the classifier speed, without mill shutdown to achieve the desired PSD. Other system parameters are easily adjusted to allow for tight control of product size for grinding and classifying of a variety of materials.

The Micronizer is a fluid energy mill employing compressed air, steam or gas to produce particles less than one micron. The Micronizer advantage is in its very low particle size and narrow PSD (particle size distribution) making it the most popular jet mill available today. The Micronizer is used in a wide variety of applications where small particle size, increased surface area and narrow PSD are critical. Typical applications include TiO2, cosmetics, pigments, pharmaceutical powders, carbon black, agricultural chemicals, precious metals, resins, heat sensitive materials, and high performance materials.

The Micronizer utilizes fluid energy compressed air or gas to grind and classify, in a single chamber with no moving parts. Activated by high pressure air, the particles are accelerated into a high speed rotation in a shallow grinding chamber. As the particles impact on one another their size is reduced. Centrifugal force holds larger particles in the grinding rotation area until they have achieved the desired fine particle size. Centripetal force drags the desired particles towards the static classifier where they are allowed to exit upon achieving the correct particle size. The final particle size is controlled by varying the rate of the feed and propellant pressure.