APPARATUS FOR DRY FORMING OF PAPER OR OTHER SHEET MATERIAL OF PARTICLES OR FIBRES

摘要

For distributing loose fibres on a moving forming web (2) in dry forming of paper an air fluidized fibre material is fed to and recirculated in a pipe circuit comprising two parallel, straight screen pipes (12) extending over the forming web (2) and provided with interior, rotating needle cylinders (34) operating to both convey the material axially in the pipe and effect disintegration of the material as well as to add to the material flow a radial component promoting the fibre outlet through the walls of the screen pipes (12). These pipes (12) themselves are rotatably mounted and adjacent an upper outside area of each pipe (12) is arranged a stationary nozzle system (44) for blowing compressed air against the pipe to thereby successively clean the screen perforations for maintaining a high distributor capacity and enable relatively long fibres to be used in the production.