An Improved Process and Apparatus for Preparing the Wood in the Manufacture of Wood-fibre.
Year: 1891

page_text: COMPLETE SPECIFICATION.
An Improved Process and Apparatus for Preparing the Wood in the
Manufacture of Wood-fibre.
I CARL KELLNER of Hallein in the Empire of Austria Chemist do hereby
declare tire 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 :-
This invention relates to a process, the object of which is the elimination from
the wood intended to be transformed into cellulose, of the knotty parts it may
contain; the invention further relates to an apparatus for carrying out the said
process.
The separation of the knotty portions of the wood has been obtained heretofore
either by cutting up the wood into discs and by cutting out by hand the knotty
parts before or after the boiling; or by splitting the wood and removing the said
parts by boring or countersinking; both of these operations involving a con-
siderable expenditure of labor and time whereby the cost of production was
increased.
This invention has for its object the elimination of the knotty parts from the
wood, which is being prepared for further treatment, by means of mechanical
appliances, the salient parts of which are two surfaces provided with pins or teeth,
between which the wood, previously cut, as usual, into small pieces, is given a brisk
motion whereupon the parts of the wood suitable for use are separated from the
knotty parts by means of a separating mechanism.
For carrying out this operation, the wood is cut up into discs, or split in small
pieces by any of the means used in the manufacture of cellulose; and then
conveyed between two plane, conical or cylindrical surfaces, having pins or teeth
set into them, one of said surfaces receiving a rotating motion. Thereby a very
brisk motion is imparted to the small pieces of wood the result of which is that all
parts suitable for the manufacture of cellulose are detached in the shape of regular
and uniform flat leaflets, whereas the knots, and the cells adjoining the knots, which
are not so easily detachable assume the shape of irregular, larger lumps. The
latter can afterwards be separated with ease and precision from the regular wood
particles by means of a double sifting apparatus.
The accompanying drawings represent several modifications of an appliance
designed for carrying out the aforesaid process.
Fig. 1 is a form of this apparatus, showing the driving and the adjusting
mechanisms.
Fig. 2 represents a modified form of the apparatus in combination with a
separating mechanism.
Figs. 3, 4 and 5 are other modifications of the apparatus.
As shown, this apparatus comprises a surface a, of a conical, double-conical
cylindrical or other suitable shape; or if preferred the shape of a flat disc. To this
surface a a rotating motion is imparted by the shaft and it is enveloped by a
corresponding stationary, conical, cylindrical or disc-shaped casing b.
The surface a and the inner side of the casing bare provided with pins or with
prismatic teeth a' and ', the clearance between these two opposite sets of pins or
teeth being lessened or increased at will by means of a suitable regulating device
having for its effect to displace the surface a in the direction of its axis (Fig. 1).
The stationary casing carries a feed-hopper d and the outlet e.
The wood, pre-
viously cut into small pieces, is delivered in the hopper by a suitable feeding device f
and is thereby dropped between the pins or teeth a' and 6' and receives from them
a very brisk motion, whereby the regular shaped wooden particles are detached from

page_text: the knotty particles, the whole mass being thereupon discharged from the outlet e
and conveyed to the sifting apparatus illustrated in Fig. 2.
The latter consists of two shaking sieves g and the uppermost of which has
large meshes, and allows the regular wood particles to fall through them on the
lower sieve h, which, having smaller meshes, frees the wood from the dust and the
chips it may contain.
By the effect of the shaking motion of the sieves the knotty parts are thrown off
at g' and they can, if required, undergo for a second time a subsequent treatment
between the surfaces a and b whilst the cleaned wooden particles fall at h' on to a
transporting device i.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1) A process for removing the fragments of knots from the wood intended for
use in the preparation of wood-fibre, said process consisting in imparting to the
wood, previously cut into small pieces, a very brisk motion between two surfaces
set with pins or teeth whereby the wood suitable for use is detached from the knotty
parts, from which it is afterwards easily separated by separating-sieves, substantially
as described.
b
2) An apparatus for carrying out the aforesaid process said apparatus consisting
of a conical cylindrical or plane surface a, having pins or teeth set into it, and
revolving inside a casing equally provided with pins or teeth, and in combination
with said device, a sifting apparatus consisting of a sieve provided with large
meshes, and of another sieve provided with small meshes, substantially as described
and illustrated by the drawings annexed.
Dated this 30th day of July 1891
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.