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Single Knife DE-STONER® Air Classifier

The GK Single Knife DE-STONER® is a fully proven design operating efficiently in many tough separating applications. It is the only dry classifying system capable of handling continuous, high volume production.

The completely dry system eliminates water handling and other “wet” system problems, yet can easily handle moist materials.

Vibratory action and high velocity / low pressure air streams fluidize and stratify material according to difference in terminal velocity of particles to remove heavy items such as glass, metallics, stones, dirt, etc.

How it works

1. Vibratory action moves material, with high density material settling to the bottom of the trough.
2. Fines drop out section (optional) removes smaller particle sizes like broken glass or dirt before reaching air fluidizer.
3. Air fluidizing section assists in stratifying material.
4. High velocity, low pressure air stream is directed through material flow.
5. Material conveys into air stream. Heavier materials fall through air stream to discharge chute.
6. Marginal density material is caught on adjustable slope plate and falls back into discharge chute.
7. Acceptable lighter materials are carried beyond plate and travel to product discharge.
8. Ultra light or thin film materials like paper and plastic film are removed through air exhaust on stationary hood over discharge.

Successful separating and classifying applications include:

  • Commingled materials
  • C&D materials
  • Shredded MSW
  • Shredded auto scrap fluff
  • Bio-mass fuel
  • RDF fuel


  • The DE-STONER® uses air instead of water to separate heavy product from light product, eliminating the mess and environmental hazards water separation creates.
  • Adjustable to obtain varying degrees of separation. Adaptable to a wide variety of products.
  • Separates material of different density, or of same density with different particle size.
  • Virtually jam-proof. No moving separator parts.
  • Low energy demand with single low HP motor and GK’s proven Two-Mass design.
  • Heavy-duty, built to last construction.
  • Inherently simple, fully isolated design minimizes foundation requirements.

Case Studies

Additional Info

Download the brochure here.