GB535930A - Improvements in or relating to stock feed for paper making machines - Google Patents

Abstract

535,930. Pulp feed in paper-making machines. BELOIT IRON WORKS. July 25, 1939, No. 21591. Convention date, Jan. 20. [Class 96] Pulp, e.g. of high consistency, is made turbulent at a head-box 48 just prior to its deposition on a forming surface, e.g. the wire-cloth 10 of a Fourdrinier paper-making machine on which it is deposited before the fibres re-flocculate, excess pulp being recirculated to maintain the pulp in a constantly flowing condition. Pulp from the screens flows to a baffled flow-box and is pumped therefrom to a branched pipe to deliver half to each end of a conduit 34 divided into two compartments 32, 33 along which the half-streams flow in opposite directions so that there is uniform delivery of pulp across the machine, through openings 84 ... 87, baffled at 88, excess pulp reaching the ends of the compartments 32, 33 being re-circulated back to the flow box. The baffles 88 induce rotation of the flow of pulp which wipes and passes through openings 62 in an oppositely rotating cylinder 61, pulp then passing through an outlet nozzle 133 comprising an apron 90 and an upper lip 132 to the wire-cloth 10, excess pulp flowing along passageways 101, 150 and overflowing at 148 to telescopic stand-pipes 42 and back to the flow-box. The walls of the passage 150 have non-corroding linings and the rear wall 145 is adjustable vertically by threaded rods 152 &c. to a position allowing ready access for cleaning the passage 101. The front wall and lip 132 are adjustable horizontally by a rack 102 and pinion 107, the lip 132 has also general adjustment through worm gearing 137 &c. and local micrometer adjustment along its length by sockets 128 externally threaded in a plate 126 and internally threaded to receive rods 130, the difference in pitch of the two threads giving micrometer adjustment as the sockets 128 are turned. The breast roll 11 is supported on shake springs extending from a supporting base on the floor, and part of its surface is covered by walls of the head-box to form a suction compartment 96 to draw off water and air from the wire-cloth 10, sealing strips 94, 95 being supplied with water from jets 93. Deckle pulleys 115 are carried by levers 114 pivoted at 113 and slotted at 117 to receive bolts 118, thus allowing the deckles to be raised from or lowered to the wire-cloth 10, deckle boards 134 also being used at the ends of the outlet nozzle 133. In a modification the head-box is formed with an adjustable baffleboard wall, the rotating cylinder 61 dispensed with and turbulent flow induced by flowing the two half-streams through adjacent series of openings with oppositely directed baffles. The cylinder 62 may run in grooved water-lubricated bearings.