GB956588A - Improvements in or relating to rotatable vessels - Google Patents

Abstract

956,588. Steam-heated cylinders. KINS DEVELOPMENTS Ltd., and WIGGINS TEAPE RESEARCH & DEVELOPMENT Ltd. June 19, 1962 [March 22, 1961], No. 10509/61. Heading F2U. [Also in Division F4] In a steam-heated drying cylinder in a paper-making machine, condensate rimming therein is constrained to flow towards the cylinder ends where collecting means are provided. As shown, the internal diameter of the cylinder gradually increases from a mid-point 7 towards the ends. The resulting thermal conductivity variation across the cylinder may be compensated for by altering the thermal pattern of the associated drying system. In Figs. 3, 4, (Prov., not shown), the depth of the bottoms of parallel-walled grooves machined in the internal surface of a non-tapered cylinder increases towards the cylinder ends. The internally facing lands between the grooves are chamfered to encourage shedding of the condensate. The condensate may be drawn off by stationary, outwardly perforated, annular extractor pipes 8 connected, by radial support pipes, to an outlet pipe 5 coaxial with a perforated inlet pipe 3. Alternatively, Fig. 5, (Comp.), nozzles 20 inserted in the peripheries of the cylinder ends extend into continuous openings 23 of stationary, annular collecting ducts 22 coaxial with the cylinder. Preferably, to maintain an interior/exterior pressure differential, the bores of the nozzles are reduced at their outer ends, or are of constant section and filled with a porous material such as sintered metal.