Patent ID: 6978899

Claim:
An apparatus for sorting wood chips, said apparatus of the type involving chips in a variety of sizes and similar, substantially hexahedral pieces having a length and a width, as well as a thickness substantially less than the width, and possibly fines particles, by means of an impulse action such that the excess thickness chips or the fines particles, or both the excess thickness chips and the fines particles are separated from the wood chips to form a separate fraction, the miscellaneous chips and the fines particles being sorted from each other by means of one or more separating walls arranged to comply with various trajectories established by means of the impulse action, said apparatus comprising: a feeder providing controlled release of said wood chips onto a sloping support surface to slide along said support surface over a slit extending thereacross, said slit being configured to provide an impulse action therethrough which is essentially perpendicular to both the advancing direction of the wood chips and the support surface adjacent the slit, by means of a continuous gas flow on the chips or the fines particles presently in line with the slit, said feeder delivering the chips to the top end of the support surface in a substantially single layer, such that, in the process of sliding in contact with the support surface, a longitudinal/lateral surface of the chips is set against said support surface, wherein said support surface has its bottom end upstream of the slit provided with a section (a) diverging from the rest of said support surface in terms of its gradient, over which section an angle of inclination (β) relative to the horizontal plane is smaller than an angle of inclination a of the support surface upstream of the same in the advancing direction of the wood chips, said diverging gradient section (a) being dimensioned in such a way that the wood chips travelling therealong are subjected in a direction perpendicular to the surface of said section (a) to a force having a strength at least equal to earth gravity.