Year: 1895

page_text: Date of Application, 20th Mar., 18'5
Complete Specification Left, 7th Dec., 1895-Accepted, 11th Jan., 1896
The object of the present invention is a cylindrical engine for paper pulp which
(1) effects a thorough mixing of the pulp, (2) a perfectly uniformn and rapid flow
of the pulp in the trough, in consequence of which the individual particles of the
pulp pass an equal number of times over the bladed-roller, thereby (3) bringing
about better result in the pulping process.
On the accompanying drawing is shewn in
Fig. 1 a plan view,
Fig. 2 a longitudinal section, and in
Fig. 3 a cross section of the cylindrical pulp mill.
wall C.
The trough consists of two channels A and B, (Fig. 1), formed by the centre-
At the end of each of these channels, to better effect the flow of the pulp,
a bladed-roller D and E is arranged as in the ordinary cylindrical pulp engines,
and with the usual bearings etc. Behind the bladed-rollers D and E the so-called
breasting terminates in a conduit F (Figs. 1 and 2), the bottom of which is
circularly, or ovally, formed, widening and dropping from the outer wall of the
trough towards the centre-wall C (Fig. 1), and in this form gradually passing into
the other channel. The pulp which is thrown by the bladed-rollers D and E over
the breasting, falls into this conduit F and flows gradually into the other channel
in which it runs steadingly to the other bladed-roller. The pulp receives, in the
previously mentioned conduit, a thorough mixing, in a manner which cannot be
attained by any other arrangement.
a, b is
This may be shewn by explanation of Fig. 3. a, b, c form the conduit F.
its oval, or round bottom, a c the highest edge of the breasting, D the bladed-
rollers, H the channel into which the conduit F (a b) empties. Supposing now
that the pulp were not thrown by the bladed-roller D into the conduit F, but
flowed of itself, and was of such consistency that it could form layers, over the top
line ac in the conduit F, then the pulp which falls into the conduit at 1 will,
through its further flow in the conduit F towards the channel H, on arriving at 2,
be covered with pulp which at 2 flows over the breasting; on arriving at 3, this
material which consists of the two layers 1 and 2, receives the pulp which has
flowed over the breasting at 3, and so on. The pulp which is in the conduit at 8
will therefore consist of all the material, one layer upon another, which has passed
over the whole breasting from 1 to 8.
But as the pulp does not flow quietly over the breasting into the conduit, as was
assumed for the purpose of explanation, but is thrown by the bladed-roller into the
conduit, there therefore follows a mixing of the material such as cannot otherwise
be excelled.
•
It is very essential to have a rounded, or oval conduit in order to insure a uniform
flow of the pulp and to prevent a slower flow, or even stoppage, of a portion of the
pulp at the bottom, an occurrence which with flat bottoms, even when somewhat
rounded off at the sides, is very frequent.
With all cylindrical pulp engines in which the trough, or channels, are formed
гр.

page_text: more or less rounded, or circular, the pulp running along the outer wall, which is
longer than the centre-wall, has a greater distance to travel than the pulp lying
next to the centre-wall; consequently the material at the centre-wall will have
finished the course quicker, pass under the bladed-roller oftener, and be milled more
rapidly than the pulp running along the outer wall.
That this has long been felt to be a great drawback in all cylindrical pulp
engines of ordinary construction, and even with the so-called underground cylin
drical pulp engines, is shewn by the many experiments which have been made to
remedy it, by supplementary arrangements for mixing the pulp. But these
cylindrical pulp engines, even with a thorough mixing of the pulp, do not prevent
a part of the pulp, which on its first course (passage under the roller) was next to
the outer wall, returning there again, even at its second or third courses, thus
passing the bladed-roller less often and being less milled. This is entirely obviated
in the new cylindrical pulp engines. The pulp in the channels has no rounded, or
circular path to travel, but flows towards the bladed-roller uniformly over the
whole breadth of the channel, all parts of it, therefore, passing the bladed-roller an
equal number of times.
In order to keep the pulp in both channel A and B at the same level, the
channels are connected with each other by an opening in the centre-wall C. When
the level of the pulp is the same, this opening can be closed by the sluice G, which
is moved by the hand-wheel H. The distance from one bladed-roller to another
being small, the progressive flow of the pulp is a rapid one, which in modern
systems of cylindrical pulp engines is recommended as an advantage. Further the
straight form of the channels permits the employment of washing cylinders, which
are necessary in the manufacture of finer papers, but cannot be applied in many
modern cylindrical pulp engines.
Instead of placing a bladed-roller in each channel, the bladed-roller in one of the
channels may be replaced by a bucket-wheel J (Figs. 4 and 5) which lifts the pulp
out of the channel A (Fig. 5) and delivers it into the conduit F, where the
pulp receives the same thorough mixing as in the conduit F behind the bladed-
roller D. The bucket-wheel receives its motion from the shaft of the bladed-roller D,
as shewn in Fig. 5.
Instead of two bladed-rollers there may be only one, as shewn in Fig. 6. The
channel A then runs from the conduit F to the roller D.
Dated this 10th dow of March 1905
COMI LEIE DEEVITUATION.
Improvements in Pulping Engines for Paper-making.
I, GUSTAV HOFFSÜMMER of No. 52, Köln-Oberthor-Promenade Düren,
Germany, Manufacturer, do hereby declare the nature of this invention and in 4
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of the present invention is a cylindrical engine for paper pulp which
firstly effects a thorough mixing of the pulp; secondly a perfectly uniform and
rapid flow of the pulp in the trough, in consequence of which the individual 4
particles of the pulp pass an equal number of times over the bladed-roller, thereby
thirdly bringing about a better result in the pulping process.
On the accompanying drawing is shewn in
Fig. 1 a plan view, in
Fig. 2 partially a side-view, partially a longitudinal section, and in
Fig. 3 a cross section of the cylindrical pulning engine
5

page_text: Fig.
is partially a side-view, partially a longitudinal section and
Fig. 5 the top-view of a modified construction and
Fig. 6 the top-view of a third modification.
The trough of the pulping-engine shewn in Figs. 1, 2 and 3 consists of two
channels A and B (Fig. 1), separated by a centre-wall C. At the end of each of
these channels, to better effect the flow of the pulp, a bladed-roller D and E is
arranged as in the ordinary cylindrical pulp engines, and with the usual bearings etc.
Bebind the bladed-rollers D and E the so-called breasting terminates in a conduit F
(Figs. 1 and 2), the bottom of which is circularly or ovally formed, widening and
dropping from the outer wall of the trough towards the centre wall C (Fig. 1), and
in this form gradually passing into the other channel. The pulp which is thrown
by the bladed-rollers D and E over the breasting, falls into this conduit F and
flows gradually into the other channel in which it runs steadily to the other
bladed-roller. The pulp receives in the previously mentioned conduit, a thorough
mixing, in a manner which cannot be attained by any other arrangement.
This may be shewn by explanation of Fig. 3. In this figure a, b, c form the
conduit F. a, b is its oval, or round bottom, a, c the highest edge of the breasting,
D the bladed-rollers, A the channel into which the conduit F (a, b) empties.
Supposing now that the pulp were not thrown by the bladed-roller D into the
conduit but flowed of itself, and was of such consistency that it could form
layers, over the top line a, c in the conduit F; then the pulp which falls into the
conduit at 1 will, through its further flow in the conduit F towards the channel A,
on arriving at 2, he covered with pulp which at 2 flows over the breasting; on
arriving at 3, this material which consists of the two layers 1 and 2, receives the
pulp which has flowed over the breasting at 3, and so on. The pulp which is in
the conduit at 8 will therefore consist of all the material, one layer upon another,
which has passed over the whole breasting from 1 to 8.
But as the pulp does not flow quietly over the breasting into the conduit as was
assumed for the purpose of explanation, but is thrown by the bladed-rollers into
the conduit, there therefore follows a mixing of the material such as cannot
otherwise be excelled.
It is very essential to have a rounded, or oval, conduit in order to insure a
uniform flow of the pulp and to prevent a slower flow, or even stoppage, of a
portion of the pulp at the bottom, an occurrence which with flat bottoms, even when
somewhat rounded off at the sides, is very frequent.
With all cylindrical pulping engines in which the trough, or channels, are
formed more or less rounded, or circular, the pulp running along the outer wall,
which is longer than the centre wall, has a greater distance to travel than the
pulp lying next to the centre wall; consequently the material at the centre wall
will have finished the course quicker, pass under the bladed-roller oftener, and be
pulped more rapidly than the pulp running along the outer wall.
That this has long been felt to be a great drawback in all cylindrical pulping
engines of ordinary construction, and even with the so-called underground
cylindrical pulp engines, is shewn by the many experiments which have been
made to remedy it, by supplementary arrangements for mixing the pulp. But
these cylindrical pulp engines, even with a thorough mixing of the pulp, do not
prevent a part of the pulp, which on its first course (passage under the roller)
was next to the outer wall, returning there again, even at its second or third
courses, thus passing the bladed-roller less often and being less pulped. This is
entirely obviated in the new cylindrical pulp engines. The pulp in the channels
has no rounded, or circular path to travel, but flows towards the bladed-roller
uniformly over the whole breadth of the channel, all parts of it, therefore passing
the bladed-roller an equal number of times.
In order to keep the pulp in both channels A and B at the same level, the
channels are connected with each other by an opening in the centre-wall C. When
the level of the pulp is the same, this opening can be closed by the sluice G, which
is moved by the handwheel H. The distance from one bladed-roller to another

page_text: being small, the progressive flow of the pulp is a rapid one, which in modern
systems of cylindrical pulp engines is recommended as an advantage. Further
the straight form of the channels permits the employment of washing cylinders,
which are necessary in the manufacture of finer papers, but cannot be applied in
many modern cylindrical pulping engines.
Instead of placing a bladed-roller in each channel, the bladed-roller in one of the
channels may be replaced by a bucket-wheel J (Figs. 4 and 5) which lifts the pulp
out of the channel A (Fig. 5) and delivers it into the conduit F, where the pulp
receives the same thorough mixing as in the conduit F behind the bladed-roller D.
The. bucket-wheel receives its motion from the shaft of the bladed-roller D, as
shewn in Fig. 5.
Instead of two bladed-rollers there may be only one, as shewn in Fig. 6. The
channel A then runs from the conduit F to the roller D.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
F
1. In a pulping-engine for paper-making the combination of two channels A
and B, the separating centre-wall C, the bladed-rollers D E and the conduits
as and for the purpose set forth.
2. In a pulping-engine for paper-making in combination with the channels AB
and the centre-wall the sluice G as and for the purpose specified.
3. In a pulping-engine for paper-making the combination of the two channels A B
the separating centre-wall C, the conduits F F, a bladed-roller D and a bucket-
wheel J, as described.
4. In a pulping-engine for paper-making the combination of a channel A, a
bladed-roller D and a conduit F, as set forth.
Dated this 29th day of November 1895.
GUSTAV HOFFSUMMER.