Dynamic Classifier Mill (DCM)
The Atritor Dynamic Classifier Mill is one of the most universal milling systems available, with independently-driven grinding and classifying sections.
It has a wide range of applications producing materials in some instances to less than 15 microns.
Feed material is metered into the mill pneumatically and first passes into the classifier zone where any fraction of the feed that is already inside specification is removed as product, thus avoiding any over-grinding. Oversize is recycled internally to the grinding zone and is returned to the classifier after further size reduction. This process produces a steep particle size distribution curve.
The size of the product leaving the mill is controlled by adjusting the classifier speed. The product is conveyed pneumatically to a collecting cyclone and/or bag filter. With the application of heat to the inlet air flow, simultaneous drying can be undertaken.
Cross section of typical DCM showing flow of material through the mill
| Fine product and air | 1 | Grinding rotor | |
| Feed material inlet | 2 | Grinding zone | |
| Main air inlet | 3 | Baffle | |
| 4 | Classifier rotor | ||
| 5 | Bearing housing and shafts | ||
| 6 | Belt drive | ||
Brochure and Publication Downloads
- Dynamic Classifier Mill (PDF, 1.79 MB)
- Food and Pharmaceutical Technology (PDF, 821 KB)
Typical Feed Materials
| Activated carbon | Carbon black | Chocolate crumb | Cocoa | Food colourings |
| Lactose | Pesticides | Pharmaceuticals | Pigments | Powder coatings |
| Resins | Silica gel | Sugar | Vitamins | Zeolites |
Technical Data
| Units | 100 | 200 | 250 | 300 | 400 | 500 | 600 | 800 | 1000 | 1200 | 1400 | 1700 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mill power | kW | 1.1 | 3 | 5.5 | 11 | 22 | 37 | 55 | 90 | 160 | 250 | 315 | 400 |
| Classifier power | kW | 0.37 | 0.55 | 1.1 | 1.5 | 2.2 | 4 | 5.5 | 7.5 | 11 | 30 | 37 | 90 |
| Mill speed | rpm | 18,000 | 10,800 | 9,400 | 6,200 | 5,000 | 4,300 | 3,300 | 2,600 | 2,100 | 1,850 | 1,650 | 1,400 |
| Classifier speed | rpm | 10,000 | 5,400 | 4,600 | 4,000 | 3,250 | 2,920 | 2,850 | 2,650 | 2,400 | 2,200 | 2,000 | 1,860 |
| Airflow | m3/h | 100 | 320 | 600 | 1,300 | 2,600 | 4,450 | 6,500 | 10,500 | 18,000 | 28,000 | 36,000 | 52,000 |
| Output factor | - | Lab mill | 0.25 | 0.5 | 1 | 2 | 3.4 | 5 | 8 | 14 | 22 | 28 | 40 |
The DCM is manufactured in a range of sizes from 1 to 450kW mill rotor drive. For pharmaceutical applications the common mill sizes are the DCM 100, 200, 250 and 300. Special design larger mills are available.