Air impingement web drying method and apparatus
AssigneeBeloit Corporation
InventorsGeorge H. Wong, Lamar Embry, Donald A. Ely, Peter F. Pantaleo, Ronald D. Cooke, James L. Chance, Edward D. Beachler
Life of this patent
Estimating the term…
Abstract
A method and mechanism for dewatering a web in a paper making machine having press means, a first thermal dryer section having a long continuous support looped belt carrying the web along a first drying run with rolls and suction zones beneath the web and a hot air generating means for directing a flow of air onto the web in the first thermal run with the web being received substantially 40% bone dry at the beginning of the first thermal run and being delivered substantially 50% bone dry at the end of the run onto a heated drum dryer section.
Claims11
The method of dewatering a web in a paper making machine, which comprises:
- pressing the web for removal of water therefrom;
- thereafter immediately continuously supporting the web on the upper surface of a continuous belt supported on a long convex arcuate run defined by a series of horizontal rolls with the belt depending downwardly between the rolls while subjecting the web to a downward flow of heated air along said run with the belt being curved arcuately upwardly and the web thereby being maintained taut on the upper surface of the belt preventing flutter and wrinkling of the web;
- and
- thereafter passing the web over a second thermal drying run over a plurality of heated dryer drums.
In a paper making machine, a dryer section for thermally drying a wet web between a press section and a dryer drum section, comprising in combination:
- press means for dewatering a fibrous web in a press section;
- a first thermal dryer section positioned to receive the web from the press means and including a belt having an elongate continuously upwardly facing support surface extending over a dryer first run for continuously carrying the web and providing continuous support without flutter and wrinkling;
- support means supporting the belt along said run including a plurality of spaced horizontal rolls successively arranged to support the belt in an upwardly convex arc of curvature for tensioning the belt without flutter and so that the web follows the same on the surface of the belt and the web is taut on the belt to avoid wrinkling;
- said belt depending downwardly between rolls with the web remaining supported on the belt surface;
- hot air generating means positioned above the web on the belt for directing uniform flow of air over the exposed surface of the web along said run;
- first transfer means at the lead end of the run for transferring the web onto the belt;
- a second thermal dryer section having a plurality of heated dryer drums with felts threaded over the drums for forming a second dryer run positioned for receiving the web from the first run;
- and second transfer means at the terminal end of said dryer first run for transferring the web off the run to the second dryer section;
- said hot air generating means thermally drying the supported web continuously along said first run without flutter and without wrinkling.
In a paper making machine, a dryer section for thermally drying a wet web between a press section and a dryer drum section comprising in combination:
- a belt having an elongate continuously upwardly facing support surface extending over a dryer run for continuously carrying the web and providing continuous support without flutter and wrinkling;
- means supporting the belt along said run;
- hot air generating means positioned above the web on the belt for directing uniform flow of air over the exposed surface along said run;
- first transfer means at the lead end of the run for transferring the web onto the belt;
- second transfer means at the terminal end of the run for transferring the web off the run to a dryer drum section;
- said hot air generating means thermally drying the supported web continuously along said run without flutter and without wrinkling;
- said supporting means being provided by a plurality of alternate rolls and means defining suction zones;
- the belt forming a catenary curve between each of the rolls and the suction means;
- said suction means having boxes having belt facing surfaces having a curvature conforming to the curvature of the belt;
- and wherein the edges of the curved boxes have plastic shoes having the curvature of the boxes.
Dependencies are inferred from the claim text.