Chip feeding for a continuous digester

Abstract

A chip feeding system for a continuous digester provides for a greater rate of delivery of chip slurry to the digester, and is much less expensive than conventional chip feeding systems, typically being only 40-50% of the height of the conventional system. An atmospheric vessel may be connected at the bottom thereof to a slurry pump which pumps the chip slurry to a conventional high pressure feeder. A recirculation loop for returning liquid from the feeder to the vessel may include an atmospheric level tank, and a liquid cooler. The vessel may have one dimensional convergence and side relief, and instead of a conventional cylindrical chip bin, the chip bin may have a hopper having two transitions with one dimensional convergence and side relief. The chip bin also may be at atmospheric pressure so that no low pressure feeder between the bin and vessel is necessary. Alternatively, the vessel may be pressurized while an atmospheric-pressure level tank is provided, the high pressure feeder being mounted directly at ground level.

Dependencies are inferred from the claim text.