METHOD FOR REDUCING RUNNABILITY PROBLEMS CAUSED BY GAS FLOWS IN AN IMPINGEMENT DRYER FOR A FIBRE WEB AND AN IMPINGEMENT DRYER

摘要

The invention relates to an impingement dryer and a method for reducing runnability problems caused by gas flows in an impingement dryer for a fibre web, which impingement dryer has gas blowing opening and gas exhaust openings. The fibre web to be dried is supported with a support fabric. The support fabric and the fibre web to be dried are moved in the machine direction inside the impingement dryer past the blowing openings and exhaust openings. At the same time hot gas is blown from the blowing openings toward the fibre web to be dried and gas is removed from the vicinity of the fibre web to the exhaust openings. At least one edge control strip is moved in the machine direction edges of the impingement dryer in front of the blowing openings or the exhaust openings or both. With its aid a desired number of blowing openings or exhaust openings or both are covered and thus their effect is controlled.