GB1022789A - Improvements in or relating to a chip washer - Google Patents

Abstract

1,022,789. Washing wood chips. HARSHBERGER EQUIPMENT CO. July 30, 1964, No. 30254/64. Heading B2H. Apparatus for washing wood chips to remove foreign matter injurious to defibrating machines is provided with nozzles 18, 19, Fig. 3 (not shown), which direct jets of water supplied by a pipe 71 against chips delivered by a feeder 11 into a wash trough 10 in which movable baffle boards 25 serve both to remove the sunken foreign matter from the bottom of the trough and form a series of submerged weirs, the chips being arranged to float from the trough, on the water supplied by the nozzles, on to an inclined vibrating screen 46 via a duct 40. Turbulent flow over the baffle boards 25 in the trough 40 is produced by maintaining the level of the water in the trough above the upper edges of the baffle boards; this may be effected by arranging the bottom of the duct 40 at approximately the same level as the upper edges of the baffle boards and maintaining a shallow depth of water in the duct. The baffle boards may be conveyed either continuously or intermittently by chains 26 driven over sprockets 31, 32, 33, 34 by a motor 35, the boards discharging the foreign matter over an incline 28 into a receptacle 30 for disposal. The vibrating screen 46 is driven through an eccentric or crank shaft 47 by a motor 48 and serves to remove any remaining foreign matter and dewater the chips which are delivered on to a transverse screw conveyer 50 which in turn feeds an elevating conveyer 52, the conveyers being driven by a motor 55 and serving to overturn the chips for drying purposes. The conveyer 52 discharges on to a conveyer belt or receptacle ready for treatment in a defibrating machine. Matter passing through the vibrating screen is collected in a trough 67 and discharged by a conveyer 61 over an incline 63a into a receptacle 65 for disposal. Water overflows the trough 67 into a pit 60 whence it is recycled back to the nozzles.