Wet press with vibration control

#The invention relates generally to a wet press of a paper making machine and more particularly to a wet press having a tiltable felt-tightening roll.

#Wet presses of paper-making machines having the following elements for treating paper webs are known: a pair of first rolls defining a roll or press gap through which the paper web is conducted, second rolls defining a closed loop path which includes the roll gap, a belt-shaped felt guided by and revolving around said second rolls in the closed loop path with the web and felt being simultaneously conducted through the roll gap, the second rolls including a tightening roll pivotally supported at one end with the felt being looped around the tightening roll with a section of the felt running toward the tightening roll and a section of the felt running away from the tightening roll and a manually operable means for tilting the tightening roll by a given tilt angle which lies in a plane located in the space between the felt sections and which passes through the longitudinal axis of the tightening roll.

#In such wet presses, as the felt and paper web to be drained are simultaneously conducted through the roll gap, water is pressed out of the paper web and is transferred onto the felt web. The absorbed water is removed from the felt at another point along its closed loop path by, for instance, a suction roll.

#FIG. 1 is a side view of a wet press of a papermaking machine constructed according to the principles of invention.

#FIG. 2 is a partial top view of the press taken along section IV--IV in FIG. 1.

#FIG. 3 is an enlarged partial view of the roll or press gap.

#The wet press, generally designated in FIG. 1 as 100, comprises a pair of rolls 10 forming a roll or press gap 1 between upper roll 2 and the lower roll 3. One or more of the rolls 2, 3 are flexure-controlled, i.e. comprise a stationary crosspiece extending through a hollow rotatable roll to form a clearance space therewith. The clearance space is supplied with a liquid for hydraulically supporting the hollow roll. The protruding ends of the crosspiece are supported in a paper-making machine frame by swinging levers or other guiding devices which are not shown in FIG. 1.

#Both the paper web 4 to be drained and the belt-shaped felt 5, which is at least as wide as the paper web 4, are simultaneously conducted through the gap 1. The felt 5 runs in the manner shown in FIG. 1 in a closed loop path generally defined by guiding and deflection rolls 6, 7, 8 and 9. Rolls 6 and 7 are arranged at about the same elevation relative to the upper roll 2 such that the felt 5 is looped around the upper roll 2 at an angle of about 140.degree. .

#The guiding and deflection rolls 8, 9 are arranged vertically above the pair of rolls 10. The felt 5 is guided by rolls 8 and 9 over a tightening roll 20 which is arranged such that the section 5' of the felt 5 approaching the tightening roll 20 and the section 5" leaving the tightening roll 20 form an angle of about 25.degree. with each other. The tightening roll 20 can be tilted in a plane 11 located within the acute angle formed by sections 5', 5" of the felt 5 and passing through the axis of the tightening roll 20. As can be seen from FIG. 2 the tightening roll 20 is pivotally supported at one end on a pivot 12 while the other end of the tightening roll can be displaced in plane 11 by a spindle 13 in the manner shown in FIG. 2. A controllable positioning device, such as electric motor 14, drives the spindle 13. The motor is automatically operated by a controller 30 or 40 which automatically varies the angle by which roll 20 is tilted.