Airgrader for Particles


  • Particle board industry
  • Separation of foreign materials such as sand, stones, metal or bark
  • Separation for core and surface particles
  • Separation of the flakes independent of the flake thickness


The air grader splits the incoming material into three fractions, acceptable, coarse material which includes high density contaminants, wood particles of undesirable geometry (needles, etc.), and material falling through the screen decks (mostly sand, minerals, glass, etc.). The product enters the suspension chamber (of the air grader) via a rotary valve and a central tube. Agitator arms distribute the material uniformly over the perforated plate through which air is drawn. Different grades of separation are achieved by varying the air velocity. The heavy coarse material is moved to the outside of the grader and leaves the suspension chamber via rotary valves. The accepted material is suspended in the air stream and separated from the air in high efficiency cyclones CS or type Hurritec.

Customer benefits

  • Precise separation according to particle thickness and complete thickness control
  • Continuous and consistent separation regardless of stop/start operation and variable material flow
  • Excellent removal of heavy contaminants
  • Maximum accuracy of accepted particles
  • Low maintenance costs due to pneumatic/mechanical cleaning system
  • Energy and steel structure savings in case of Hurritec type cyclones

Technical features

  • Up to 85 % of the air is recycled while the remaining volume is cleaned before venting into atmosphere
  • High efficiency cyclones CS or type Hurritec
  • Explosion protection system conforming to ATEX regulations
  • Air grader suspension chamber with:
    – Agitating device with pneumatic cleaning system
    – Quick change device for the upper screen
    – Conical drilled holes in upper screen deck