Apparatus for spreading a fluid onto a moving web of material

摘要

The invention relates to an apparatus for spreading a fluid onto a moving web of material, especially for spreading size onto a paper web. It is previously known to spread fluid substances onto a moving web of material by means of a comb nozzle. Especially when size is being spread, the size tends to harden during stoppages, thereby clogging the openings of the comb nozzle. The apparatus according to the present invention enables a fluid to be spread onto a moving web of material without the apparatus getting clogged even in a dusty environment. By means of the apparatus it is possible to spread even rapidly drying fluids without the risk of the substance being spread drying in the nozzle opening or openings during stoppages. The apparatus has an oblong trough, on the circumference of which there is longitudinally an oblong opening and inside or adjacent to the trough a pipe parallel to the longitudinal direction of the trough, the pipe having on its circumference, also longitudinally, one or several openings over a maximum distance of the length of the opening of the trough in order to spread the fluid which is in the pipe via the openings onto a moving web of material, and means for feeding into the pipe the fluid to be spread. In addition the apparatus has means for feeding another fluid and/or a gas into the trough and for removing it from there, and means for transferring the opening or openings of the pipe so as to have connection with the inside of the trough.