Improvements in Purifying Wood-pulp and in Apparatus therefor.
Year: 1891

page_text: :
COMPLETE SPECIFICATION.
Improvements in Purifying Wood-pulp and in Apparatus therefor.
We, JULIUS CHRISTIAN JUEL, Merchant, and' ELLING RYAN, Factory Manager,
both of Fredrikstad, in the Kingdom of Norway, do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our invention relates to a method of and apparatus for purifying cellulose or
wood-pulp, whereby the said substances are freed in a continuous manner by
centrifugal force from all extraneous matters such as splinters, bark, etc., the process
resulting in the production of a new material.
In the accompanying drawing,-
Figure 1 is an elevation partially in section of an apparatus for purifying wood-
pulp according to our invention; and,
Figure 2 is a plan of the same.
Through the tube a the pulp is conducted from the vessel in which it is kept to
the vessel which rotates inside the centrifugal apparatus A.
Motion is imparted to the vessel 6 by means of a pulley c and a shaft d. The
top of the vessel is provided with a bent rim comprising the parts b¹, b³, b³, of
which the part is provided with long slots or holes e, provided with movable
covers or valves e', the part 62 is perforated while the part 6 is left intact.
The pulp which by virtue of the centrifugal force accumulates along the wall or
side of the vessel b, arranges itself in such a manner that the heavier parts such as
splinters, sand, bark, etc. come outwards and remain in that position and as the
pulp, (as the supply increases) rises up the sides of the vessel b the said heavier
parts are eventually ejected through the holes e into the surrounding cylinder f
while the lighter part or purified pulp passes up over the top part of the bent edge
and on its way is freed from a portion of its water which passes through the holes
in the part 2, and the purified pulp is finally expelled into the cylinder g, from
which it is conveyed by the tube either to the bleaching or pasteboard-making
machine.
The water separated by the part 2 of the bent rim from the purified pulp mixes
with the impure pulp in the cylinder, and the two together amount to about 50%
of the pulp introduced through the tube a, this mixture then passes through the
tube i into the centrifugal apparatus B, where the process is repeated, the pulp
there purified being led through the tube k to the bleaching or pasteboard-machine,
while the still impure pulp passes along the tube either to a third centrifugal
machine or to the waste receptacle.
The cylinders and g are provided with inwardly bent rims or edges fl and y'
respectively, the rim f1 serving to catch the impure pulp and water ejected through
the perforated parts 61 and 62 of the bent edge of the vessel b, and the rim g' serving
to prevent the loss of the purified pulp ejected over the part 63 of the said edge;
there is, however, sufficient space left between the edges or rims to allow the vessel b
to rotate without friction and to be entirely removed.
To allow control to be exercised over the progress of the operations, and to
enable the apparatus to be cleaned after use the centrifugal apparatuses are
surrounded by a platform provided with steps.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1. The herein described method of purifying wood-pulp, consisting in separating
by centrifugal action the heavier and impure constituents from the lighter and
Durer constituents

page_text: 2. The employment, for the purpose of purifying wood-pulp, of an apparatus
consisting of an inner revolving vessel 6 with a bent rim or edge 61, 62, 63 into
which the pulp to be purified is introduced and acted upon by centrifugal force in
such a manner that the heavier and impure constituents are caused to come outwards
and take up a position against the walls of the vessel and are ejected through the
part 6 of the bent rim or edge, (which is furnished with controllable openings e,)
into, the cylinder f which surrounds the vessel b while the purified pulp collects
inwards and passing through the perforated part 6 of the bent rim or edge is freed
from a portion of its water, and is finally thrown out over the part 3 of the said
rim or edge into the cylinder g which surrounds the cylinder f, substantially as set
forth.
3. The improved apparatus for purifying wood-pulp hereinbefore described and
illustrated in the accompanying drawing.
Dated the 9th day of February 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.