GB733441A - Improvements in or relating to a paper making machine - Google Patents

Abstract

733,441. Flow boxes of paper-making machines. PAPER PATENTS CO. Oct. 20, 1952, No. 26244/52. Class 96. Screened pulp flows to a flow-evening compartment 145 adjoining a suction compartment 159 exhausted at 165 &c. to remove entrained air, to a flow-spreading conduit 33, under the curved tip 119 of a vertically adjustable slice 37 into a ponding chamber 49 pressurized by an air duct 77 to aid in maintaining the depth D at 12 inches or less, a side-compartment connected to the ponding chamber below and above the pulp level and having an outlet pipe with a tapered open end also controlling the depth D; the pulp then passing, in a state of finescale turbulence, beneath an outlet slice 57 to the wire-cloth 11. The slice 57 is adjusted vertically at 71 &c. and has a projecting tongue 131 which is also adjustable in height and which can be flexed slightly by adjusting screws spaced across the machine. The slice 57 is immediately preceded by a rotating flow-evener roll 73, e.g. with ¢ inch diameter holes occupying 42 per cent of the area of the shell. The walls of the ponding chamber 49 may be sprayed at 127 &c. to prevent the accumulation of fibre thereon. In modifications, (a) the inlet to the ponding chamber may be from a cross-flow pulp-mixing compartment and an evener-roll below the ponding chamber via two perforated plates with hit-or-miss type adjustment separating the mixing compartment from the ponding chamber; and (b) the pressurized ponding chamber is preceded by a flow box having a succession of substantially vertical baffles &c.