GB841484A - Paper making machines - Google Patents

Abstract

841,484. Fourdrinier paper-making machines. DOMINION ENGINEERING WORKS Ltd. July 31, 1956, No. 23582/56. Class 96. A narrow, modified, high-speed Fourdrinier paper-making machine has a short wire-cloth 5, Fig. 1, the upper run C of which hangs as a catenary between the breast roll 6 and couch roll 7 so that water drainage from the pulp is aided by centrifugal force, and suction boxes and table rolls are not used. The breast roll 6 may be at the same height as, or higher or lower than the couch roll 7. A roll 8 may be tilted to act as a guide roll for correcting wonder of the wire 5, a feeler actuated by deviation of the wire-cloth depressing a plunger 85, Fig. 6, of a cylinder 84 to open a valve 78 and admit servo-fluid at 81, 80 to actuate a piston 73 in a cylinder 74, and move, against a spring 75, a lever arm 71 to tilt the roll 8, such movement depressing an arm 72 to shutoff the servo-fluid and avoid hunting. The roll 9, Fig. 1, is adjustably positioned for control of the amount of slack of the caternary C. The web S may be couched vertically upward with the aid of a water shower 13 an air blast 14 and centrifugal force as the wire moves around the roll 7, or couched at an angle, or vertically downwards. The wet press may have small diameter rolls 18, 19 each backed by two larger rolls 20, 21, and driven by a worm-type speed-increasing gear. No pressfelt is used, and the high speed of the small rolls 18, 19 ensures the web S leaves cleanly. The flow-box 11 may be trunnion-mounted and may have an internal paddle for whirling the pulp and delivering it under pressure. To facilitate wire-changing, the rolls 6, 7, 8 and 9, are cantilever mounted from the machine frame 23, each having a hollow outrigger, 28 or 29, secured at one end to the frame by bolts 30 and extending within the roll shell to support it adjacent its mid-point. The roll shafts 33, 34 pass through self-aligning bearings 32. Specification 841,422 is referred to.