Patent ID: 6451171
Filing Date: 2002-09-17
Classification: D21F

Abstract:
A device for dewatering a fabric used in a paper machine, comprising:a leading guide roll rotatable about an axis thereof; a trailing guide roll rotatable about an axis thereof and parallel to the axis of the leading guide roll, the leading and trailing guide rolls being spaced apart such that the fabric passes over a portion of a circumference of the leading guide roll and then over a portion of a circumference of the trailing guide roll in the same rotational direction about both rolls so as to form a fabric loop between said leading guide roll and said trailing guide roll, said fabric loop including a trough portion having a position that falls below the axes of the rolls and having an optimal desired geometry, said position and geometry being such that the fabric loop has a radius of curvature sufficiently small to cause water to be expelled from the fabric by centrifugal force; and a control device including a drive connected to each of the rolls and operable to rotate each roll about the axis thereof in the same rotation direction, and a sensor for detecting the position of the trough portion of the fabric loop, said control controlling rotational speed for each roll so as to maintain the position of the trough portion below the axes of the rolls.