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Abstract

A web-formed material (1), preferably a pulp web (1), is passed through a drying plant, comprising blow boxes arranged in a plurality of drying decks, floating above lower blow boxes, which at their upper sides blow out hot process air against the web-formed material (1). Water, in the form of steam, escaping from the web-formed material (1) is discharged by the process air, at least part of which is recirculated (43) whereas the non-recirculated process air is discharged as exhaust air (41) and is replaced by a corresponding portion of supply air (42) with a low water content. The temperature of the process air is controlled (4). If a deviation from the desired dry content of the dried web-formed material (1) is detected (6), the volume flow of the process air (40) is changed by increasing the volume flow of the process air (40) at too low a dry content in the web-formed material (1), and by decreasing the volume flow of the process air (40) at too high a dry content in the web-formed material, for the purpose of rapidly regaining the desired dry content of the dried web-formed material (1).