| 摘要 |
Comminuted wood is converted to a colored wood product useful as a mulch by feeding the comminuted wood into the lower end of an angularly upward positioned screw conveyor having an internal auger. The comminuted wood is contacted in a basin in the lower end of the conveyor by a liquid color-imparting agent, preferably an aqueous solution containing iron oxide pigment, carbon black pigment or a mixture of both pigments. After contacting, rotation of the auger draws the moist colored wood product towards the upper end, permitting runoff of excess liquid agent, which returns by gravity to the basin for further contacting with newly-fed comminuted wood. The liquid level in the basin is monitored and additional liquid agent is blended from water and pigment concentrate to maintain the level in the basin. Colored wood product discharges through a chute at the upper end of the conveyor for further drying, if necessary. |
