GB1059410A - Drying apparatus for drying paper-and pulp-webs - Google Patents

Abstract

1,059,410. Drying cylinders. WARTSILA-YHTYMA OY WARTSILA-KONGERNEN AB. March 18, 1964 [March 19, 1963], No. 11373/64. Heading F2U. In a rotating steam-heated drying cylinder for drying paper and pulp webs, wherein steam is introduced through an inlet pipe 15 and condensate is removed by syphon pipes 23 connected to an outlet pipe 10, the inlet pipe 15 feeds a single longitudinal or, as shown, several equally spaced adjustable nozzles 21 which extend over substantially the entire cylinder drying width and discharge steam in a direction opposite to that of the cylinder rotation at high velocity so as to obtain an effective heat transmission to the cylinder shell 2 and loosen the rimming condensate. The cylinder is mounted by trunnions 5, 6 integral with the cylinder ends 3, 4. The internal surface of the shell is machined rough or grooved to increase internal surface area. To regulate the drying effect across the cylinder the nozzles 21 are adjustable or closable by pneumatic or hydraulic membrane or plunger servomotors controlled outside the cylinder when the machine is running, or, as shown, by needles 22 when the machine is stopped. When the nozzles are closed at some part the condensate forms an unbroken ring locally preventing effective heat transmission. The nozzles are arranged on a longitudinal duct 20 connected to branch pipes 19. The branch pipes 19 and the syphon pipes 23 are respectively connected to compartments 13, 14 of a divided chest 7 which is stationarily supported by a pipe 8 and the outlet pipe 10 in bearing housings 9, 11. Alternatively, the chest 7 may be supported from outside the cylinder at one end only, its other end being supported by a bearing inside the cylinder, thereby providing for steam inlet and condensate outlet through the same trunnion. The inlet pipe 15 is connected to the compartment 13 through an injector 16, 17 by which remaining uncondensed steam may be re-circulated, to reduce pressure, through holes 18 in the pipe 8. Alternatively, the remaining steam may be led away with the condensate for use with reduced pressure parts of the system.