Pulp feed for a papermaking machine
AssigneeEscher Wyss Limited
InventorsAlfred Bubik, Rudiger Kurtz, Hermann Kutzelmann
Life of this patent
Estimating the term…
Abstract
A pulp feed for a papermaking machine, comprising a substantially slot-like guide channel having at least two step-like widened portions. Before and after each widened portion there is provided a linear channel section, and between the widened portions there is arranged a tapered section or portion. The slot widths before both of the widened portions can be of the same magnitude and conjointly adjustable by means of a translationally movable element. The slot-like guide channel has arranged forwardly thereof a perforated plate and a mixing chamber merging thereat. Also a pulp feed channel having an adjustable lip and merging at the guide channel can possess step-shaped widened portions.
Claims9
A pulp feed for feeding pulp from a headbox into a forming screen of a papermaking machine containing a guide device for a stock suspension, said guide device comprising:
- an elongate, substantially slot-shaped guide channel means having a predetermined lengthwise direction of extent;
- said guide channel means being bounded by side surfaces;
- one of said side surfaces having two substantially step-shaped widened portions;
- the other of said side surfaces being essentially flat at the region of the widened portions and between said widened portions;
- the other of said side surfaces defining a substantially flat counter surface;
- the one of said side surfaces having, before and after each widened portion, a respective surface section merging therewith;
- each said surface section being essentially flat and extending essentially parallel to said flat counter surface;
- said step-shaped widened portions defining a first widened portion and a second widened portion spaced from one another in the direction of flow of the stock suspension;
- a tapered channel section merging with the flat surface section following the first step-shaped widened portion in the direction of flow of the stock suspension;
- said tapered channel section having a boundary surface enclosing an angle which does not exceed 45.degree. with respect to the flat counter surface;
- a perforated plate, having substantially cylindrical bores, being connected forwardly of said slot-shaped guide channel means;
- a mixing chamber being connected after said perforated plate and having an enlarged cross-sectional area in relation to a starting region of said guide channel means;
- and
- the length of the flat section following the first step-shaped widened portion amounts to at least six times the height of said first step-shaped widened portion.
A pulp feed for feeding pulp from a headbox onto a forming screen of a papermaking machine containing a guide device for a stock suspension, said guide device comprising:
- an elongate, substantially slot-shaped guide channel means having a lengthwise direction of extent;
- said guide channel means being bounded by side surfaces;
- one of said side surfaces having two substantially step-shaped widened portions;
- the other of said side surfaces being essentially flat at the region of the widened portions and between said widened portions;
- the other of said side surfaces defining a substantially flat counter surface;
- the one of said side surfaces having, before and after each widened portion, a respective surface section merging therewith;
- each said surface section being essentially flat and extending essentially parrallel to said flat counter surface;
- said step-shaped widened portions defining a first widened portion and a second widened portion spaced from one another in the direction of flow of the stock suspension;
- a tapered channel section merging with the flat surface section following the first step-shaped widened portion in the direction of flow of the stock suspension;
- said tapered channel section having a boundary surface enclosing an angle which does not exceed 45.degree. with respect to the flat counter surface;
- a perforated plate, having substantially cylindrical bores, being connected forwardly of said slot-shaped guide channel means;
- a mixing chamber being connected after said perforated plate and having an enlarged cross-sectional area in relation to a starting region of said guide channel means;
- and
- the flat surface section directly forwardly of the second step-shaped widened portion having a length amounting to at least twice the gap width of the guide channel means at such location.
Dependencies are inferred from the claim text.