Abstract: A method and system are provided for controlling the feed of comminuted cellulosic fibrous material (e.g. wood chips) to a continuous digester utilizing a chips meter of variable speed. A quality of the chips related to mass flow--preferably density--is continuously determined, preferably while the material is in free fall, not immersed in liquid. The speed of the material meter is controlled in response to the quality determined to provide a target mass flow of material from the meter to the digester. A nuclear type density gauge may be utilized having a source and a detector mounted on opposite sides of a chip chute, and above the level of liquid in a chip chute so that density is determined during free fall of the chips, not immersed in liquid. A level sensor may also be associated with the chip chute with a shield between the nuclear source and the level sensor. The chip meter speed is controlled in the range of about 0-16 rpm.
Type:
Grant
Filed:
October 25, 1991
Date of Patent:
November 30, 1993
Assignee:
Kamyr, Inc.
Inventors:
Brian Greenwood, Andries Daamen, Gene Graham