| 摘要 |
<p>A chamber (22) has an outlet (24) which opens downwardly to the atmosphere and an upwardly opening air return plenum (28). A duct (38) is inclined upwardly at approximately sixty degrees to the horizontal, and a fan (32) mounted therein directs moving air (36) into the chamber (22). An upwardly inclined ramp (40) is positioned within the duct (38), and communicates between the chamber (22) and a downwardly opening discharge opening (46) in the duct (38). A metered supply of wood chips (52) is fed down a sixty degree incline (56) onto the ramp (40) through the air stream (36) which is moving through the duct (38). Lightweight chips (55) become entrained in the air (36) and are separated from the rocks, tramp metal and knots (50) which slide down the inclined surface (40) and exit through the opening (46) in the duct (38). The entrained wood chips (55), together with the air (36) from the fan (32), are directed into a baffle (58) spaced within the chamber (22). By forcing the air (36) and chips (55) to move in a curved path, the baffle (58) separates the chips (55) from the air stream (36). As the air stream (36) expands into the chamber (22), its velocity drops then passes through the chip stream (52) up to the air return plenum (28). The chips (55), under the force of gravity, continue their downward flight, and exit the chamber (22) through the outlet (24). An inclined ramp (40) with a slowly moving conveyor (168) may be used to avoid a build-up of material (50) on the inclined ramp (40).</p> |
