Year: 1896

page_text: Date of Application, 3rd Jan., 1896
Complete Specification Left, 3rd Oct., 1896-Accepted, 3rd Apr., 1897

page_text: The broom may thus be crushed at different degrees of dryness; but it is
preferable that it should first have been partly (though not wholly) dried; for,
when it is unduly moist, the crushing cannot be conducted quite so satisfactorily as
is desirable, while, when too dry, it only yields dust.
(b) When the broom has thus been crushed, the material (riz., the broom proper,
which has fallen through the grates or sifting frames of the disintegrator, and the
small fibres interrupted by the suction device or fan) is transferred to a cylindrical
boiler, constructed of sheet metal and open throughout its top part. A grate with
narrow meshes, which may be arranged at the top of the cylinder if desired,
compels the ligneous substance to sink or steep in the bath which is next formed
by conveying suitable liquid into the said cylinler. The liquid for the bath
consists of a solution of diluted caustic soda (of from 1 to 20 Baumé specific
gravity). The boiler is heated either direct, or by the action of steam, through
the medium of a double bottom or jacket, or of serpentine pipe or coil, or other
suitable means.
Boiling is kept up for from 1 to 2 hours, after which the bath is
discharged, along with the broom it contains, through a lower orifice, into a roller
crushing mill, the spaces between the rollers of which should be variable or
adjustable, and which should be provided with brushes for removing the portions
of material apt to adhere to the rollers.
(e) The construction and arrangement of the roller crushing machine which it is
proposed to employ in carrying out this invention is hereinafter described.
The said machine is provided with a supply pipe; a hopper; roller; discharge
chambers; a discharge pipe; bearings; pinions for driving the brushes; and
bearings holding the brasses or collars of the brushes.
The material is first charged into the hopper, whence it drops between the
slightly grooved or fluted rollers. The portions of the material, bappening to
cling to the roller surfaces, are removed by the rotary brushes to which transverse
motion is imparted by means of cams driven by intermediate shafts.
After thus passing between the crushing rollers, both the crushed broom and the
liquid of the bath are conveyed into receivers provided with grates at their lower
parts. Thence the liquid, while it is still hot (and after having been made
stronger, or richer, if necessary), is transferred to a second boiler, exposed to the
open air, and similar to the one already mentioned, wherein the conversion of the
material into ligneous pulp has already been completed. The broom, on being,
after this, separated from the bath, is sent into closed ("auto clave") chambers
wherein it is lixiviated, or washed, under pressure.
The objects of the treatment just described are as follows:
(1) To enable the crushing operation to be more readily performed after the
action of the boiling soda bath, and the coarser ligneous particles, which have not
been divided to a sufficient extent in the disintegrator, and particularly the many
nodes which broom presents to be more thoroughly crushed; for these nodes would
otherwise offer great resistance to the subsequent treatment they have to undergo,
while, on account of their large number, a complete separation of them by reasonably
economical means is quite out of the question.
(2) As regards the broom itself, in consequence of the operation being conducted
only by boiling with comparatively weak alkaline solutions, as stated above, the
broom is freed from a large proportion of its extractive constituents, as may be
ascertained by examining the baths which become very much charged therewith.
Besides, by taking the course above indicated, the completion of the subsequent
processes, in the closed or autoclave boilers, under pressure, will be greatly
accelerated; while the thin fibres of the bars (or the "tow"), which enhance the
value of broon paper-pulp, are by such means turned to better account; and
(3) The volume or bulk of the broom, which, after passing through the disinte-
grator, was very considerable in comparison with its weight, is, by the operations
described, greatly reduced, so that, weights being equal, this method enables
closed chambers or boilers of considerably less size, or far less in number, to
be used.

page_text: If desired, a closed boiler may be employed even for the preparatory treatment,--
instead of a boiler that is open and made accessible to the external air in the
manner stated, but it would be superfluous and would only render the process
unnecessarily complicated.
Ordinary treatment. After the preparatory treatment referred to, the broom is
Jixiviated in closed vessels in the ordinary manner, at pressures varying between +
and 6 atmospheres; whereupon it is washel, passed through rollers or other well-
known apparatus and finally decolorated by the nsual methods. The lixiviation,
in closed boilers or pans (as stated), may be effected either by means of soda or
other alkalies, or by the aid of sulphites.
B. THE MANUFACTURE OF PAPER PULP FROM NON-DECORTICATED BROOM,
COMBINATION OF CHEMICAL AND MECHANICAL MEANS OR
BY A
METHODS.
In this case, the first crushing of the broom may be performed by means of
crushing apparatus similar to those which have been hereinabove described in
connection with the "chemical" broom paper-pulp. Or, instead of disintegrators,
pulverizers may be employed wherein the whole of the crushed material is drawn
out by means of suction devices or fans, without leaving any fraction thereof to
drop through the grates or sieves. After this, the broom would simply have to be
subjected to the preparatory operations described. It would, however, be necessary,
in that case, to send the broom back to the open boiler after it has passed through
the crushing mill once; and there it would have to be once more boiled in the
alkaline bath, for a certain interval of time. Then it would, for the second
time, undergo crushing, and so forth, until it is thoroughly disintegrated in all its
parts.
The fibres of the tegumen or hark, in this case, will yield a "chemical"
pulp,
which, on being mixed with mechanically prepared ligneous pulp, would greatly raise
the value of the latter.. Were it desirable still further to increase the proportion of
chemical pulp, this might be done by an identical operation, but in that case a closed
boiler or vessel should be adopted, and also more concentrated lyes used than in
the other case. By such means not only would the fibres of the bark yield a
"cherical" paper pulp, but the thin ligneous stalks or stems of the broom plant
would also produce pulp; so that a mixture of "chemical" and "mechanical" pulp
would be obtained as a result, wherein the proportions of either might vary at will,
within reasonable limits.
The remaining operations, viz., washing, decolorating and the like, would be
performed in the usual manner.
2. THE MANUFACTURE OF PAPER-PULP FROM DECORTICATED BROOM.
THE MANUFACTURE OF "CHEMICAL" PULP FROM DECORTICATED BROOM.
With decorticated broom, the operations for the production of chemical pulp are
Etarted in the same way as in the case of the non-decorticated plant; except that
here the crushing of the same in the disintegrators will be easier, as there will be
less "tow." As, however, there will always remain some, after decortication, it
will nevertheless be wise to provide the disintegrating apparatus with fans.
I will now describe the manufacture of mechanically prepared pulp from
decorticated broom. "Mechanical" pulp may be obtained from decorticated
broom in the manner described above in reference to the combined chemical and
mechanical treatment of non-decorticated broom, i.e. by treatment in open boilers
or in closed or autoclave vessels, by means of weak alkaline solutions, and by
sending the material through crushing rollers several times in succession.

page_text: THE MANUFACTURE OF PAPER PULP FROM DECORTICATED BROOM BY A
COMBINATION OF MECHANICAL AND CHEMICAL METHODS.
Paper pulp may also be manufactured from decorticated broom by a combined
mechanical and chemical treatment; for which purpose the material would have to
be treated with somewhat stronger alkaline solutions in autoclave vessels or
chambers, at from 4 to 5 atmospheres pressure, and then sent through crushing
rollers; when the small stems or stalks would be converted into "chemical"
pulp equally with the rest.
Dated this 3rd day of January 1896
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in the Manufacture of Paper Pulp from the
Broom Plant.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 :-
This invention relates to the application of non-decorticated or decorticated
broom for the manufacture of paper pulp, as well as to the processes and means of
treatment, either chemical or mechanical or mechanico-chemical used for obtaining
this result.
We will now describe the manufacture of paper pulp, from non-decorticated
broom.
(A) MANUFACTURE OF CHEMICAL PULP FROM NON-DECORTICATED BROOM.
(a) In order that the lixiviation of the thick broom wood will take place
sufficiently without changing the fibres of the bark (harl) and the small stems, it is
expedient to separate first the thick broom wood from the small wood and to
subject to distinct operations: (1) the small stems, (2) the thick wood, the latter
requiring of course to be less spared during the several operations than the small
stems. This separation, which may be easily effected, and which may also be
dispensed with when there is no more old broom wood, but only broom of two or
three years, will give two qualities of pulp, the first of which, that is to say the
one which is made with small stems, enclosing much fibre and harl, will be of an
altogether superior quality.
Accordingly the treatment will be as follows:
(1) Separation of the thick wood and of the small stems;
(2) Cutting of the wood thus separated into two lots by means of known
apparatus, such as chaff-cutter or the like;
(3) Boiling of the broom thus cut in a boiler open to the air, using a solution of
weak caustic or alkaline soda; then immediately after this boiling the transport of
the broom thus prepared into the digester where it must be lixiviated under
pressure and with stronger caustic liquors. The strength of these more conced-
trated caustic liquors cannot be stated precisely, because it will vary, as it happens

page_text: usually, according as the pressures actually used will be more or less strong. So,
when operating the lixiviation from 4 to 5 atmospheres, as it is indicated hereafter
(at ), the strength of the caustic liquor may be less high if operated at 5 atmo-
spheres than if operated at 4 atmospheres. The strength of these more concentrated
caustic liquors will vary also according as small stems or thick wood, or a mixture
of both are to be treated. For these more concentrated caustic liquors, we may
point out, as example, a liquor made in such a way that the quantity of caustic soda
enclosed in it be 15 per cent. of the weight of the primitive operated broom.
(4) In lieu of causing the broom to be subjected to boiling in the boiler open to
the air as herein before mentioned it may be preferable, for obviating the subsequent
transport into the digester, to subject it to this treatment in the digester itsel*,
wherein it has to be lixiviated afterwards. In this case, we place the broom
directly in the digester where for an hour or two it is submitted to the action of a
dilute caustic liquor of soda (at one or two degrees Baume).
We may raise the pressure towards the end of this operation up to two
atmospheres; but at the commencement it will be necessary to proceed gently and
to attain this pressure slowly and progressively.
When once this operation is terminated we empty the weak liquor which, when
strengthened, can be used several times, and we send into the digester the stronger
caustic liquor, in which the lixiviation of the broom at pressures of from four to five
atmospheres has to be effected.
The lixiviation having been finished we wash the boiled pulp first in the hot
state; then it is washed in the cold state and discoloured by the customary
processes. The last lixiviation at pressures of from four to five atmospheres
may take place either with soda or with other alkalies and alkaline salts, or by
sulphites.
We may observe that the first treatment of the broom at ebullition and at very
low pressure with very weak alkaline solutions, which has hereinbefore been set
forth, is necessary for keeping up the whole strength of the fibres and harl.
By this first lixiviation the broom is moreover partly freed from the pectates
and gummy inaterials and the like coming from the bark.
(B) MANUFACTURE OF THE MECHANICO-CHEMICAL PULP WITH
UNDECORTICATED BROOM.
In this case, the undecorticated broom, after having been cut into pieces of
1 to 3 centimetres in length by means of known apparatus, such as a chaff cutter or
the like, is then crushed by means of disintegrators or other known crushers
appropriately chosen. I may for example use disintegrators carrying beaters, and
in which centrifugal force and beating are employed at the same time. But it is
necessary, in order that these apparatus may operate upon undecorticated broom,
to apply a modification by which the small fibres of the bark, which through the
beating operation are detached from the stems, are prevented from obstructing the
gratings of the disintegrators. This modification consists in arranging at the upper
part of the disintegrator a discharge tube placing the interior of the latter in
communication with a small suction apparatus which draws in the light fibres
in proportion as they are separated, and deposits them in a special settling
chamber.
We regulate the force of the suction current so that the light fibres (barl)
detached from the bark will alone he drawn by the suction apparatus, and that the
wood (even the small stems) will remain in the crusher, whence after crushing it is
discharged through the grates.
The broom may thus be crushed in several states of dryness, but it is preferable
for the same to be already partly dry without however being too much so, for
when it is too moist the crushing does not go on so well, and when too dry it makes
more dust.

page_text: The broom thus crushed, both that which has passed through the grates of
the disintegrator and the small fibres which have been drawn by the suction
apparatus is then sent into a cylindrical boiler of sheet metal open along the whole
of its upper part. A fine grate, which is placed at will at the upper part of this
boiler, forces the wood to dip into the bath then introduced.
This bath consists of a solution of dilute caustic soda (at 1 or 2 degrees Baume).
The boiler is heated directly either by steam by means of a double bottom or a
coil or serpentine, or the like. We keep up the boiling for one or two hours, then
we pour off the bath and broom together through a lower orifice into an apparatus
with crushing cylinders placed at a variable distance from each other and furnished
with brushes for detaching the materials adhering thereto.
The arrangement of this apparatus with crushing cylinders is represented
diagrammatically in the accompanying drawing, in which
Figure 1 is a side view of the apparatus with crushing cylinders and
Figure 2 is a front view thereof.
Fig. 3 shows a disintegrating apparatus.
In the apparatus shown in Figs. 1 and 2, the material coming through the
admission pipe A arrives in the hopper B, from which it falls between the slightly
fluted cylinders C C, turning in the indicated direction.
These two cylinders may be moved by the ordinary and known means and ways.
The cylinder Cmay, for instance, be operated by a driving pinion N set up
on the same shaft as the said cylinder, the driving pinion receiving its motion from
the gear G set up on the shaft F on which is disposed a pulley S, receiving by
the belt S its motion from any source; and the rotary motion may, for instance,
be transmitted from this shaft F to the opposite shaft F by means of a belt P;
thence the notion may be transmitted to the cylinder C, as before, by medium of
similar gears G and N.
The parts of material that may stick to these cylinders C C are continually
carried away during the process by means of metallic round brushes bb, to which
are imparted, at the same time, a continuous rotary motion and a backward and
forward motion. This rotary motion is imparted to them by means of cross
belts M M receiving respectively their movement from the shaft of the
cylinders C or C which cylinders are cleaned by the said brushes; as for the
transverse backward and forward motion, it is imparted for each brush, by a
grooved cam H or H' driving a lever V, which operates, by its opposite end, on
the shaft of the brush by compelling it to change its place alternately backward
and forward.
After this passage to the cylinders the broom and bath fall into receptacles
carrying grates at their lower part; thence the bath is conveyed still in a hot
state (after having been enriched if necessary) into a second boiler in the open air,
similar to that herein before referred to and in which the introduction of wood is
already terminated. The broom on the contrary is conducted either into a boiler
open to the air, in which it undergoes a further boiling operation with weak
alkaline liquors or in a digester in which it is treated by alkaline solutions at a
low pressure of 1 to 2 atmospheres.
The fibres of the bark give in this case a chemical pulp which, when mixed with
the mechanical pulp of the wood, increases the value of the same. If it should
still be desired to obtain a proportion of stronger chemical pulp it would only be
necessary to operate in the same manner, but to make use of a digester and to
increase if necessary the pressures and the degree of the liquors; and by operating
in this manner, not only the fibres of the bark would give chemical pulp, but also
the fine stems of the broom wood would readily supply the same, and we should
obtain a mixture of chemical pulp and of mechanical pulp, in which we could
vary at will within certain limits the proportions of one or the other of these
two pulps.
The other operations, such as the washing, discolouring and so on, would be
effected as usual.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
First. The treatment of broom either raw or decorticated with the object
of obtaining paper pulp, both chemical and mechanico-chemical or simply
mechanical.
Second. The whole of the operations set forth for obtaining chemical pulp from
non-decorticated or decorticated broom, and especially the treatment described,
which consists in first heating the broom at a very low pressure with weak alkaline
liquors in order to free it from pectates and other gums contained in the bark
without carbonizing them, and thus preserve the whole strength of the fibres.
Third. The process set forth for obtaining mechanico-chemical pulp with
undecorticated broom, and especially
(a) The modification in crushers or disintegrators for removing the small
fibres detached from the bark during the crushing, consisting in connecting
a suction apparatus with said crushers or disintegrators worked in the
manner described.
() The treatment by weak liquors simply at ebullition or under pressure,
with passages through apparatus having crushing cylinders.
(e.) The special arrangement of this apparatus with crushing cylinders, having
for its object to prevent the cylinders from becoming soiled by means of
brushes which receive a continuous rotary and reciprocating motion and
which serve to clean the cylinders.
Fourth. The processes set forth for obtaining mechanical and mechanico-
chemical pulps with decorticated broom.
Fifth. The application of the processes and apparatus referred to in the second,
third and fourth claims to the manufacture of paper pulp from ramie, heath, osier,
vine-branches.
Dated this 2nd day of October 1808
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.