摘要 |
A method and apparatus for continuously treating cellulosic chips to prevent degredation of the chips as a result of mechanical action exerted on the chips by a scraper. A false bottom is provided in a vessel with the scraper mounted for rotation about a vertical axis just above the false bottom, a large central opening being provided in the false bottom. The scraper removes chips from the vessel through the false bottom opening to a bottom portion of the vessel. The temperature within the vessel at the area of the scraper is maintained at a first temperature that is low enough so that loss of strength of the chips material does not result from mechanical action exerted on the chips by the scraper. Liquid is introduced into the vessel bottom portion at a second temperature that is approximately at the cooking temperature for effecting digestion of the chips, and substantially higher than the first temperature. The heated liquid entrains chips and flushes them out an outlet from the vessel bottom, the chips subsequently being fed to the top of a digester in operative communication with the vessel. |