Device and process for controlling the consistency of the flow of a solution of paper pulp a paper making machine.

摘要

A device (42, 42a) for controlling the consistency of a flow of pulp (34) flowing from a header (44) to a slice lip (46) of a headbox (36) of a manufacturing machine paper such that the consistency of the cross profile with respect to the machine direction of the resulting paper is controlled such device comprises: a flow channel (48) disposed within the headbox (36) between the head (44) and the slice lip (46), said flow channel (48) having an upstream end and downstream end (50, 52) such that the flow of the solution of pulp (34) is in the flow direction (26) from said upstream end (50) towards said downstream end (52) of said flow channel (48); said flow channel (48) including: a primary channel (56) having first and second end (58, 60) such that the flow of the solution of pulp (34) is through said primary channel (56 ) from said first end (58) to the second end-mentioned (60) of said primary channel (56), a feed channel (40, 40b) has a first and a second end (64, 66), said feed channel (40, 40b) disposed being downstream relative to said primary channel (56) for the flow therethrough of a supply portion (68) of the flow of paper pulp solution (34); said second end (66) of said feed channel (40, 40b) is connected to the slice lip (46) so that said supply portion (68) of flow of the solution of pulp (34) to flow slice lip (46); one recirculation channel (38, 38b) has a first and a second end (72, 74), said recirculation channel (38, 38b) is disposed downstream connected to said primary channel (56) for flow through it a recirculation portion (76) of the flow of the paper pulp solution (34); said second end (74) of said recirculation channel (38, 38b) is connected to the head (44) so ​​that said recirculation portion (76) of flow of the solution of pulp (34) to flow to the head ( 44); a generator (10, 10c, 10d) disposed adjacent to said primary channel (56) for generating ultrasonic waves (12 to 14) within the flow of paper pulp solution (34) flows along said primary channel (56), said ultrasonic waves (12 to 14) moving fiber particles (18 to 20) suspended within the paper pulp solution (34) for controlling the consistency of the pulp solution (34) flowing through said primary channel (56); and a damper ultrasound (24, 24e, 24f) disposed adjacent to said primary channel (56) such that the flow of the solution of pulp (34) flows in said flow direction (26) within a region (R) disposed between said generator (10, 10c, 10d) and said absorber (24, 24e, 24f) so that in operation of said device (42, 42a), when the solution of pulp (34) is flowing within said region (R), said fiber particles (18 to 20) suspended within the paper pulp solution (34) are deviated from said flow direction (26) so that the consistency of the pulp solution paper (34) flowing from said primary channel (56) through said feed channel (40, 40b) is different from the high consistency pulp solution paper (34) flowing from said primary channel (56) to along said recirculation channel (38, 38b) so that the consistency of said supply portion (68) the paper pulp solution (34) flowing through the slice lip (46) is controlled and consequently controlling the consistency profile in the cross machine direction of the resulting paper.