| 摘要 |
A device for drying or heat treatment of a material web (1), preferably a web of cellulose and/or wood fibre, such as paper, pulp or fibreboard, by means of blow boxes (2, 7) in a plant through which the material web (1) is being advanced. The blow boxes (2, 7) have walls (3a, 3b) facing towards the material web (1) and extending essentially in parallel therewith, and side-walls (4a, 4b) extending essentially perpendicularly to the material web. Said parallel walls (3a, 3b) extend over essentially the entire width of the material web. The blow boxes have in their said parallel walls (3a, 3b) a plurality of nozzle openings (6, 8) for heat transfer by convection to the material web (1). The walls (3a, 3b) facing towards the material web (1) and extending essentially in parallel therewith, and the side-walls (4a, 4b) extending essentially perpendicularly to the material web have a surface structure, which has an emission coefficient in the range of 0.7 - 1.0, for heat transfer by radiation from the surfaces of the walls (3a, 3b, 4a, 4b) to the material web (1). |
