Guiding device for guiding webs

摘要

A papermaking assembly has an airturn guide rod (10) emitting compressed air through its porous surface to form an air cushion between the rod and a wet moving paper or carton web (28). The web moves over the airturn guide with a sieve belt (40). The airturn rod guide is located after a machine press, press arrangement or press section, and/or prior to an air drier e.g. an impingement drier. The rod-shaped guide has an outer air-porous surface (12) supported by an air-porous tubular supporting rod (24) with an internal feed of compressed air. Separation between the web and rod is maintained by an air cushion. The air pressure is maintained above 1 bar in the pressure chamber. The specific volume flow in the porous material is in the range 10 to 5000 Nm/h m. The intervals between adjacent pores is less than 1 mm. The average pore diameter is less than 0.1 mm. The drop in pressure between the pressure chamber and pore outer surface is greater than 0.8 bar. The air cushion between the pore outer surface and moving web is less than 3 mm. The rod rotates about its longitudinal axis. The rod diameter is 500 to 1500 mm.