GB980858A - Improvements in water cooled rollers - Google Patents

Abstract

980,858. Hollow rollers. E. A. TIMSON. Jan. 9, 1964, No. 963/64. Heading F2U. [Also in Division F4] Relates to a water-cooled hollow roller 1 partly around which is lapped, for cooling, a web P such as paper, cloth, film, foil, such a web, after deposition thereon or application thereto of moisture, inks, stains, dyes, having been heated for drying as by solvent evaporation, polymerization or oxidization. In particular the water-cooled roller is used at the end of a heatset print drying apparatus. According to the invention, such a roller is carried in anti-friction bearings 2 having their inner races mounted on the external roller working surface diameter which is small, say six inches or less, and has extending thereto, for at least half its length, a stationary coldwater supply tube 3 having one or more orifices 4 from which the water may he projected laterally or sprayed. The roller may be free-running. The water is generally centrifuged to line the inner surface of the roller. With sufficient inlet pressure, the sprays or jets continuously penetrate to the inner surface of the roller forcing the hot water already there radially inwards. With roller speeds insufficient for centrifuging, the water builds up and rolls over until the outlet is reached. The orifices 4 may be in one or more straight rows, arranged, if desired, diametrically opposite to neutralize jet reaction and thereby relieve tube bending tendency. As shown, the tube 3 is connected by a union 11 to a supply inlet pipe 10 and coaxially extends through a rotary coupling 8 carried by a fixed bracket 9 and having a stem 8a screwed into an end plate 7 of the roller. At its end remote from the water inlet end, the roller 1 is fully open at 1a to provide a water outlet. The outlet end 1a extends into a spray collection box 12 in which water is caught and led away to waste or to a cooling tower. Flinger fins 13 on the roller end la, or on a short cylinder attached to the roller, promote spray and are interleaved with stationary fins 14 on the spray collection box to prevent water getting back to the adjacent bearing 2. Water getting past the flinger fins may pass down into the spray collection box through a channel 15. Where a series of cooling rollers is arranged following a fast press, a pipe 16 may be provided to exhaust steam from the first roller, and the rollers may be arranged with their inlet ends at alternative sides of the web path, to counteract the greater cooling effect at the inlet ends. For water economy the cooling rollers may feed one to another in cascade fashion and in contra-flow to the web travel direction. In Figs. 2, 3 (not shown) the roller is open at both ends for outlet flow into two fixed receptacles, and a plain fixed inlet water pipe extends coaxially into one open end. A longitudinal scraper blade is fixed to the inlet pipe to ensure that only a thin layer of continuously changing water remains on the inner roller surface in the vicinity of the scraper.