Micronizer - The Legend Begins
In 1932 Norwood Andrews changed particle size reduction forever with his invention of the steam powered fluid bed jet mill (US Patent 1,948,609). This machine, capable of making particles to 5 micron and using a classifier wheel with either compressed air or steam jets to create particle-on-particle reaction is still used by a few manufacturers today. Norwood knew there was a more energy efficient way to create even finer particles with particle-on-particle reaction with less machine wear and lower contamination so in 1936 he invented the revolutionary spiral jet mill and named it the Micronizer (US Patent 2,032,827). Since its invention, Sturtevant has had eight generations of this legendary technology. Used by more manufacturers around the globe than any other jet mill, the Micronizer is the world leader in fluid energy milling technology. When performance and particle size control matter, the world’s manufacturers turn to the Micronizer for its guaranteed results.
Questions about the legendary Micronizer? Email us or call 1-800-992-0209
Models & Specs
|Mill Size/Diameter||1Compressed Air/Gas
|2bHP||Capacity lbs/hr (kg/hr)|
|Qualification||8 (13.6)||2||1/8 - 1 (.05 - .5)|
|2-inch||20 (34)||5||1/2 - 2 (.2 - .9)|
|4-inch||55 (93.5)||13||2 - 40 (.9 - 18)|
|8-inch||130 (221)||31||10 - 100 (4 - 45)|
|12-inch||260 (442)||62||30 - 250 (13 - 113)|
|15-inch||350 (595)||83||50 - 300 (22 - 136)|
|20-inch||550 (934)||130||100 - 1000 (45 - 453)|
|24-inch||1000 (1699)||236||250 - 1400 (113 - 635)|
|30-inch||1500 (2549)||354||60 - 3000 (272 - 1360)|
|36-inch||2250 (3822)||531||1000 - 6000 (453 - 2721)|
|42-inch||3300 (5607)||779||2000 - 10,000 (907 - 4536)|
1. Volume of free air at 60°F (16°C), 14.7 psi compressed to 100 PSIG. Includes air consumed by feed injector nozzle.
2. Approximate HP necessary to generate 100 PSIG compressed air.
Features & Benefits
- Narrow particle size distribution improves bioavailability, reactivity and dissolution
- Spherical uniform particle shape increases pack density
- No heat created during milling protecting heat sensitive products
- Variety of interchangeable liners for maximum product purity
- Easy disassembly of mill parts for cleaning and inspection
- Engineered for simple clean up and product change over
Sturtevant is more than an equipment manufacturer. We stand behind every product we sell. In addition to providing the best product for each and every application, we also test, evaluate, and maintain our products to assure our clients’ needs.
We offer a variety of services to assist with the development, maintenance, and testing of products:
- Lab Sample Testing
- Field Services
- Replacement Parts
What typical particle size does the Micronizer produce?
The Micronizer usually generates particle size distributions that range from 0.25 to 10 microns, depending on the incoming feed size, the friability of the material, and the feed rate. Micronizer does provide the flexibility to produce larger sizes.
What kinds of materials are suitable for Micronization?
The Micronizer can successfully reduce friable (brittle) powders. If the materials are not brittle, the particles will bounce off each other and eventually be discharged from the chamber without reduction. Alternative methods can be used to increase friability.
How is the particle size of a Micronized powder controlled?
Feed rate is the principle method of controlling particle size. Slower feed rates produce finer products and fast feed rates produce larger particles. Second to feed rate changes in grinding air pressure will change particle size. Additional methods are used to precisely control final particle size.
Will the Micronizer contaminate powder?
The Micronizer uses particle-on-particle impact to reduce a powder. Incidental contact will occur with the mill’s body. To further protect a powder from contamination, Micronizer® can be lined with stainless steel, alumina ceramic, tungsten carbide, and other materials.
Can Micronizer be used with other gases besides compressed air?
Any type of high pressure gas can be used. Nitrogen, argon, and superheated steam are common examples. To learn more about super-heated steam see the Steam Micronizer page.
Can Micronizer be used for explosive materials?
Yes, the Micronizer is designed to operate in various conditions including fully inert, explosion isolated and is able to be customized to meet your specific concerns. Compliance with local and national codes and knowledge of Kst and Pmax are ultimately the customer’s responsibility.
How do you Micronize heat sensitive materials?
The Micronizer does not generate any heat during milling. The operational temperature of the Micronizer® is controlled by the temperature of the compressed gas entering the mill.
What shape are Micronized particles?
Micronized particles are typically spherical. The particle-on-particle grinding method tends to round any irregular shapes.
Does the Micronizer have other uses besides size reduction?
The Micronizer intensely blends dry powders to create a uniform product. Deaglommeration and drying of powders are also common uses. Results depend on ingredient characteristics.
Does the Micronizer classify particles?
Yes, the Micronizer® classifies particles as they are milled. The centrifugal force in the milling chamber retains large particles to be further reduced. The vortex classifier controls the size of particles that can escape before being fully milled.
Can a cyclone be substituted for filter bags to collect my product?
This depends on the final particle size of the product and the type of cyclone being considered. Coarser product can be collected in a cyclone and the exhaust air can be sent to a central dust collector. Fine products require a secondary filter to ensure all of the product is collected. Typically cyclones are inefficient below 3 microns.