US 4,737,274 A · Tramp material separator

Abstract

Effective separation of unwanted particles, such as tramp material, is effected from a paper pulp suspension (typically a medium consistency suspension, e.g. having a consistency between 5-15 percent). A generally annular opening is defined by a disc connected to a rotating shaft, and a ring stationarily mounted to a housing. The housing includes a pulp inlet, a pulp outlet, an inlet chamber, and an outlet chamber, with a separated-out particles outlet communicating with the inlet chamber, preferably extending downwardly from it. A rotating element having a plurality of generally radially extending projections, is also mounted on the shaft, adjacent the disc, and the projections cover the annular opening (radially spanning it) at spaced locations along its circumference. The projections may be teeth-like structures, or pegs, and preferably have their leading edges, viewed in the direction of rotation, sloping with respect to the radial direction. A plurality of vanes are also connected to the shaft in the outlet chamber. The shaft rotates at such a speed that fluidization of the pulp by the rotating element takes place. Not only are particles having their largest dimension equal to or greater than the radial dimension of the annular opening separated-out, but also particles that are considerably smaller than that.

Claims20

Dependent claims

An apparatus for separating unwanted particles from a fluid suspension, comprising:

a housing having a suspension inlet, a suspension outlet, and a separated-out particles outlet, and an interior chamber communicating with said suspension inlet and an interior chamber communicating with said suspension outlet;
and a transisition between said chambers;
a rotatable shaft mounted for rotation with respect to said housing, said shaft mounting a rotatable disc thereon extending generally perpendicular to the axis of rotation of the shaft, said shaft mounted within said housing so that said disc is approximately at said transition between said chambers;
means associated with said housing for defining, with said disc, an opening extending between said chambers;
and
a rotatable element having a plurality of projections extending generally radially outwardly therefrom, said element mounted on said shaft, closely adjacent said disc, for rotation with said shaft, and said projecting elements extending so that they extend over portions, but only portions, of the opening along the extent thereof for providing a flow area sufficiently small to separate out said unwanted particles.

3 more elements

A method of acting on a suspension of comminuted cellulosic fibrous material having undesired particles therein, utilizing a separator having a suspension inlet, a suspension outlet, structure defining an annular opening between the inlet and the outlet through which suspension must pass and through which particles to be separated do not pass, the opening formed by means associated with a housing and rotatable element and having a radial dimension as its smallest dimension, d, and a separated pipe and particles outlet;

said method comprising the steps of:
(a) acting on the suspension as it is flowing from the inlet to the outlet through the opening so that particles having as the largest dimension thereof d', which is significantly smaller than d, are separated out from the suspension flowing to the suspension outlet, in addition to particles having as the largest dimension thereof a dimension equal to or greater than d;
and
(b) discharging the separated-out particles through the separated particles outlet.

1 more element

Dependencies are inferred from the claim text.

Tramp material separator

Life of this patent

Tramp material separator

Life of this patent

Abstract

Claims20