Web drying partic. for paper or cardboard - by passing drying air blown and extracted at fourdrinier zone to prevent lateral streams of moist air

摘要

To dry a moving web, partic. of paper or cardboard, drying air is delivered (61) to be blown into the fourdrinier zone (S) in an equal distribution across the machine width, and then sucked out (63) from the zone (S). The air drawn out (63) from the fourdrinier zone (S) is used as recirculating air to be blown back at the web (9). The drying air is blown (48) into the zone (S) where the web is in contact with the two adjacent drying cylinders (12, 13), and blown air can be delivered through the stabiliser (30) which holds the web (9) by suction to the porous carrier (10). Drying air is extracted from the zone (S) through the suction guide rollers (21, 22) where the blown air is delivered to the web (9) while carried by its support round the suction guide roller (21, 22), or external suction chambers are used. ADVANTAGE - The system gives added protection against lateral flows of moist air, and reduces energy consumption in drying the web.