| 摘要 |
1484307 Drying webs BELOIT CORP 7 Oct 1974 [10 Oct 1973 9 Nov 1973] 43303/74 Heading F4G A web drying apparatus comprises a plurality of groups of air delivery openings in an air cap, communicating with a heated air supply means and positioned adjacent a support, e.g. a Yankee-type drier roll 10, each group being positioned adjacent to an exhaust passage for used air. The openings of each group are provided in a plate supported in the mouth of a support 19 which may be bell-shaped, hot air being fed thereto from a stream 18. Exhaust gases pass through exhaust conduits 29 which flare outwardly from the exhaust passages and traverse the plenum 18. The openings in the plate constitute no more than 3% of the area of the plate and, in use, the ratio of the distance of the openings from the surface of the web to the diameter of the openings are: open area, up to 1%, greater than 1% up to 2%, and greater than 2% up to 3%; ratio of distance to diameter, 3-6, 2-5, and 2-4 respectively. The bellshape may be replaced by a truncated pyramid shape (Fig. 7, not shown). The web may pass rectilinearly beneath the cap (Figs. 8, 9, 10, not shown) in which case the plate supports are truncated-triangular in cross-section and the exhaust passages are formed therebetween. The exhaust conduits may be cylindrical when passing through the plenum of the cap (Figs. 8, 9) or flared outwardly from the exhaust passages (Fig. 10). Various dimensions and relative dimensions are given in the Specification. |
