Improvements in or relating to Apparatus for Separating Impurities from Cellulose or Paper Pulp and the like.
Year: 1898

page_text: Date of Application, 27th May, 1898-Accepted, 16th July, 1898
COMPLETE SPECIFICATION.
Improvements in or relating to Apparatus for Separating Impurities
from Cellulose or Paper Pulp and the like.
I, ALBERT ABERG, of Gorz, in the Empire of Austria, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement;
1
The device for treating paper or cellulose pulp and the like forming the subject
of the present application consists chiefly of a hopper or vessel tapering down-
wards. The paper or cellulose pulp to be treated is introduced into it and caused
to rotate in any well known manner. In consequence of this rotation good fibres
surrounding or mixed with splinters, twigs, knots or other impurities gradually
separate from them and being of a smaller specific gravity than water, rise to the
surface and overflow at an overflow device at the upper edge of the vessel from
whence they are led away.
Cellulose or paper pulp differs from other pulps by the chief impurities being
constituted by splinters, twigs or knots, the specific gravity of which is only
slightly greater than that of the fibres themselves. The knots are of course so
light that as long as they are surrounded by fibres they also have the same upward
tendency as the fibres. It is only after the fibres have been separated from the
knots, that the difference in the specific gravity of knots, splinters, twigs etc., on the
one hand, and that of the fibres on the other hand becomes operative. This differ-
ence is, however, so small that the knots, splinters and twigs rotate along the
walls of the vessel and a considerable portion of them would even rise upwards,
if it were not prevented by laths or ribs on the interior of the vessel at certain
distances apart. The mass immediately in front of the ribs is caught by the
latter in its movement, whereby eddies are produced and also so-called dead
corners" in which the specifically heavier portions settle down. Portions of the
cellulose or paper pulp that may have passed down into the lower part of the
vessel may be again conveyed upwards by means of a rotating worm.
6
An application of the invention is shown in the accompanying drawings in
which Figure 1 is a longitudinal section and Fig. 2 a plan partly in section.
The mass is admitted at the top, preferably in the centre of a stone-trap or box
in the vessel in which its initial entering speed is checked. The fluid mass flows
over the walls of said stone-trap stones and heavy impurities settling down in
it and strikes the walls of a casing or deflector b which is larger than the trap
and concentric with it. In this deflector the mass comes in contact with a stirring
device rotating in a horizontal plane and constituted by a paddle wheel or
screw propeller secured to a central rotating spindler and is thus caused to rotate.
The conical or hopper shaped main vessel is provided on its inner walls with

page_text: apparatus for use in treating paper or cellulose pulp and the like substantially as
described or illustrated in the accompanying drawings.
BOULT & WADE,
Agents for the Applicant.