Assembly to clean a roller surface at the gap between the roller and the departing fourdrinier/blanket has a structured suction channel and cleaning spray tube with a suction box and deflector bars

摘要

The appts. (1) to clean a roller in a papermaking or cardboard prodn. machine, between the departure point of a fourdrinier or blanket (4.1,4.2) and the roller (3), has a suction channel (6) at the triangular gap (2) between them, together with a suction box (5) across the machine width. A deflection bar (10) at the suction box (5) is against the roller (3) which carries the fourdrinier/blanket, and a second deflector bar (10) at the suction box (5) is at a gap from the fourdrinier/blanket (4.1,4.2). The side of the suction box (5) away from the triangular gap (2) has at least one suction connection (7), with at least one suction source (8), and also at least one liquid outflow (9). The second deflector bar (10) is at a gap of 1-10 mm from the fourdrinier (4.1) or blanket (4.2), and pref. 3-7 mm. The suction channel (6) within the suction box (5) has a tapering contour, away from the triangular gap (2), to a transit zone (6) where the contour changes into an expansion. The conical and expanding contours of the suction channel (6) are continuous. The suction channel transit zone (6) is formed by a pair of walls (6') at a vertical gap of /-100 mm and pref. /-50 mm and especially /-30 mm. The speed of the moving medium (25) in the suction channel (6) at the transit zone (6) is <= 10 m/sec. and pref. <= 15 m/sec. and especially <= 20 m/sec. At least one cleaning spray tube (11) is at the tapering section of the suction channel (6), on a swing mounting operated by a controlled swing mechanism. The first deflector bar (10) acts as a scraper blade of a cleaning scraper, in contact with the roller (3) surface, set against the roller around a pivot point directly close to the normals of the departing fourdrinier (4.1) or blanket (4.2) through the point of the second deflector bar (10) at a small gap from the fourdrinier/blanket (4.1,4.2). The assembly has pref. at least two suction connections (7) and/or at least two liquid outflows (9) at the suction box (5) across the machine width, which are operated separately and/or in groups and/or in sections.