GB1232419A - - Google Patents

Abstract

1,232,419. Papermaking. BELOIT CORP. 17 April, 1968 [26 April, 1967], No. 18138/68. Heading D2A. In a headbox having an inlet, a variable slice and an overflow and recirculation system, the slice opening is bounded on the one side by the bottom wall (62) of the headbox or by the machine wire (66), and on the other by the front wall (41), and is variable by adjustment of the front wall or its lower portion (43), and the overflow and recirculation system comprises a baffle (68) secured to or pivotally mounted on the front wall of the headbox above the slice opening to form a chamber communicating with the zone in the headbox that, in use, contains a top layer of the stock, an overflow conduit (80) communicating with the chamber to remove stock and a vane (72) across the headbox and parallel to the baffle. This vane is so shaped and mounted that either (as shown) its uppermost part is always at the same height above the bottom of the headbox, or (Fig. 9, not shown) is also adjustable towards and from the bottom of the headbox. In the former case the vane may be pivotally mounted (as shown) or fixed (Fig. 2, not shown). The headbox may also have additional means for removing stock, which may be at a fixed height (Figs. 7 and 8, not shown) or variable height (Fig. 9, not shown). The apparatus enables the output of a headbox to be varied independently of input and pressure at the slice.