Types of Pulverizing Mills

Rotormills can be constructed in carbon steel or stainless steel. In addition, the grinding plates and liners can be furnished with hardened material for extended life when grinding abrasive materials. Units can be inerted or furnished in explosion-proof design if required to meet process conditions.

IPEC (International Process Equipment Company) began manufacturing Rotormills in 1984. Prater Industries acquired IPEC and its product lines in 2021. The acquisition enabled Prater to build on the IPEC legacy of excellence in equipment manufacturing and reach a wider range of industries.

IPEC Rotormills are known as “long-gap” mills because of the long annular gap between the mill’s inlet and discharge. Long-gap mills provide enhanced milling characteristics during material processing.

Rotormills are used in a broad spectrum of industrial applications. These industries include agriculture, chemical, pharmaceutical, energy, metallurgy, food processing, geotechnical, and waste management.

Features and Highlights

IPEC Rotormills come with several exceptional features that contribute to their efficiency and durability:

  • Heavy-duty construction with carbon or stainless steel fabrication
  • Dynamically balanced rotor with top and bottom rotor bearings
  • Easy access to the mill interior
  • Straightforward adjustment or replacement of internal parts
  • Hardened grinders available for abrasive materials

Rotormill Model Choices

Eight IPEC Rotormill models are available, ranging from 30 to 750 horsepower. These include:

Model 1300

Our smallest unit: 30 HP, 500 CFM, two-stage rotor. Approximately 45” tall and 900 lbs. Ideal for small-batch or low-throughput processing. Includes a stand with casters for added mobility and access to the drive components.

Model 3000-4

Considered our “base” model. 50 to 200HP, 2300 CFM, four-stage rotor. Approximately 68” tall and 5,500 lbs.

Model 4500

The “mid-size” model. Strikes a good balance between size and price. 150 to 300 HP, 6500 CFM, five-stage rotor. Approximately 93” tall and 16,500 lbs.

Model 6000

Created for customers who can accept lower process volume to save on price. 300 to 400 HP, 11000 CFM, six-stage rotor. Specifications: Approximately 105” tall and 20,000 lbs.

Model 7000

The “high-end” model. Manufactures for processes that require high throughput. 300 to 500HP, 13000 CFM, six-stage rotor. Approximately 115” tall and 40,000 lbs.

Model 9500

The largest unit we offer. For customers who want the best-quality, heavy-duty material processing. 500 to 750HP, 20,000 CFM, six-stage rotor. Specifications: Approximately 130” tall and 55,000 lbs.

Vertical Models

  • Built-in fan
  • No foundation required
  • Adjustable air intake port
  • Compact heavy-duty construction
  • Heavy-duty top and bottom bearings
  • Rotor assembly dynamically balanced for smoother operation
  • Large double doors provide easy access to the interior
  • Easy replacement or adjustment of internal parts
  • Available with a variable speed classifier

Horizontal Models

  • Built-in fan
  • No foundation required
  • Adjustable air intake port
  • Compact heavy-duty construction
  • Heavy-duty top and bottom bearings
  • Rotor assembly dynamically balanced for smoother operation
  • Easy replacement or adjustment of internal parts
  • Heavy dense materials
  • High-temperature applications
  • Large capacity units

Key Benefits

IPEC Rotormills provide outstanding capability and benefits. These include:

  • Usable with a wide variety of material types
  • Reduced cost and time of processing
  • Continuous fine milling at high output rates
  • Simultaneous coating and mixing
  • Fiber fluffing capability

Operational Theory

Particles are pulverized to small sizes by inter-particle collisions induced by extreme turbulence within the mill. This is accomplished by an internal rotor that spins at high speeds.  

Heavy-duty bearings provide stability during operation. These bearings are housed outside the grinding chamber to prevent product contamination.

The IPEC rotor is comprised of two sections:

  • A Lower Section that functions as a material distribution fan and air-flow provider, and
  • An Upper Section, where the material is finely ground.

Processing occurs at several stages within the upper section. A series of grinding plates accelerate the air and particles against the grooved interior of the rotormill. Miniature vortexes of high-velocity rotating air are generated within the mill during operation. This turbulence causes particle-to-particle collisions and pulverizes the material. The continuous flow of air absorbs internal heat.

Because of the unique design, which allows for varying airflows, the adjusting of the grinding plates, and the type of grinding plates, a wide variety of materials can be accommodated and rapidly processed.

Heat buildup is minimal during operation. Many heat-sensitive materials can be milled without cryogenic processing.

Prater Is Here To Help

Let us know how we can help your business succeed. If one of our rotormill models is insufficient for your needs, we can custom-build exactly what you require. If you already own a Prater Rotormill and require any maintenance or upgrading, contact us for immediate service.