APPARATUS FOR IMPROVING HEAT TRANSFER IN DRYING CYLINDERS OF A PAPER MACHINE AND METHOD FOR ASSEMBLING THE SAME

摘要

84-137 APPARATUS FOR IMPROVING HEAT TRANSFER IN DRYING CYLINDERS OF A PAPER MACHINE AND METHOD FOR ASSEMBLING THE SAME Apparatus for increasing the turbulence of a condensate layer formed on the inner surface of a mantle of a drying cylinder for use in the drying section of a paper machine to improve its heat transfer characteristics include a plurality of turbulence ribs attached to the inner mantle surface by a plurality of attachment bands, each attachment band being constituted by an assembly of at least three band parts. Spring devices are associated with pairs of adjacent free ends of the band parts of each attachment band to urge the adjacent free ends away from each other. The spring devices are tensioned by tensioning devices and the turbulence ribs are attached to the bands, which are preferably evenly spaced throughout the axial length of the mantle, by corresponding projections and cavities. The apparatus is installed according to a method wherein the band parts are inserted through an access opening provided in the drying cylinder mantle whereupon the attachment bands are assembled from the band parts within the cylinder mantle. The spring devices of at least one central attachment band are tensioned at a higher tensioning force than the other lateral bands.