Steam heated drying drum for paper mill has rising array of inner ribs from drum centreline to condensate collection gully at end-faces

摘要

A paper mill has a steam-heated drying drum wall (1) has raised inner ribs (3) directed towards a condensate collection gully (5) near the drum end-face. The ribs are at least 1.2 times the height of the average condensate depth, and rise from the drum centreline towards the drum end-faces. The maximum rib height is ten times the average condensate depth. The change in rob cross sectional area from the centreline to the drum end faces maintains a roughly uniform rate of heat energy transmission at all points on the drum inner face. The ribs may be formed by a series of nipples or pins in straight or spiral array.