Abstract: Apparatus for separating heavy particles of material from lighter particles, e.g. for separating impurities from powdery or fragmental material, such as fibers or chips. The apparatus includes a carrier surface (1) which is pervious to gas, onto which the material (2) to be treated is supplied, as well as a device for applying gas impacts through the carrier surface (1) to the material (2) to be treated. The apparatus includes special valve elements (4) disposed below the carrier surface (1) to produce gas impacts.

Abstract: An apparatus for scattering fibrous material, e.g., chips or the like, to form a precisely controlled blanket of chips, together with a binder, onto a scattering band conveyor or a mold, includes a scattering chamber including a dosing conveyor for transferring the material to be scattered toward the discharge end of the scattering chamber. The apparatus is further implemented by arranging to the discharge end of the scattering chamber, next to the dosing conveyor, a roll set comprised of at least three rolls aligned mutually parallel, whereby slots of individually adjustable width are formed between the rolls.