IMPROVEMENTS IN MACHINERY OR APPARATUS EMPLOYED IN THE PRODUCTION OF PAPER PULP
Year: 1874

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN MACHINERY OR APPARATUS EMPLOYED IN THE
PRODUCTION OF PAPER PULP."-A communication from abroad by La
Société Anonyme de la Papeterie de Thode, of Hainsberg, Saxony.
Sealed the 3rd February 1875, and dated the 27th October 1874.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 27th October 1874.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS EMPLOYED
IN THE PRODUCTION OF PAPER PULP," a communication to me from abroad by
"La Société Anonyme de la Papeterie de Thode," of Hainsberg, Saxony,
to be as follows:-
1
This Invention relates to the treatment of fibrous substances, such for
example as straw, wood, esparto, and the like, for the production of
paper pulp, and consists in the employment of improved machinery or

page_text: apparatus for comminuting or reducing and pulping the fibres by
preference in the condition of half stuff obtained by chemical processes,
and also of certain peculiar means for effecting and regulating the supply
of the fibres or half stuff to such machinery or apparatus, whereby the
fibres or half stuff are introduced in such quantities only as are capable
of being operated upon at a time, and the uniform and complete com-
minution or reduction and pulping of the same is constantly ensured.
In carrying out this Invention it is proposed to employ two grindstones,
composed by preference of grit stone, and arranged the one above the
other in a similar manner to those of ordinary flour mills, between which
grindstones the half stuff to be comminuted or reduced and pulped is
introduced, a central aperture being provided in the upper stone for
containing a certain quantity of the same, the level of which is regulated
as herein-after described. The lower stone, which is fixed and supported
by screws so as to admit of its being maintained in a horizontal position,
has a hole formed in it at its centre for the reception of a box which is
imbedded in the stone, and through which passes a vertical rotating
shaft for imparting motion to the upper stone. This shaft is driven from
mechanism below, which may be regulated at will, and the upper stone
is carried on the upper end of such shaft through the intervention of a
suitable supporting frame or arms, so as to be properly balanced and
capable of turning therewith, and also so as to admit of its being raised
or lowered, according to the degree of division to which the half stuff is
to be reduced. The rubbing surfaces of the stones are splayed or
hollowed out towards the centre, in order to facilitate the introduction
of the half stuff to be comminuted or reduced and pulped, and are
roughened or provided with projections arranged radially or diverging in
a curvilinear direction from the centre to the circumference or otherwise,
according to the hardness of the stone and the nature of the half stuff to
be operated upon, but in such a manner as to leave an annular surface
or zone at or within the circumference of the two stones, which is very
finely roughened or serrated so as only to admit of the passage or escape
of the pulp therefrom when the fibres have been reduced to the requisite
fine state of division.
The stones are surrounded by a casing which is formed in two parts,
the upper one of which may be removed when it is required to dress the
stones, and an aperture is provided opposite the stationary stone for the

page_text: The half stuff is supplied to the stones automatically from its reservoir
by any convenient conducting passage or channel through the inter-
vention of an intermediate vessel or receptacle, the level of the contents
of which may be varied at will. This intermediate vessel or receptacle
communicates with the chamber in the centre of the stones by an
inverted syphon, the end nearest the stone of which is attached to a pipe
cast in one with the box herein-before referred to, and discharges the
half stuff into the space between the stones through an opening which
may be made of a semi-annular, elliptical, cylindrical, or other suitable
form. The intermediate vessel or receptacle is carried on a hollow cast-
iron column or pedestal (a pump being employed for elevating the half
stuff into the same), and is provided with an overflow pipe fitting in a
stuffing box in the hollow column, and capable of being raised and
lowered by means of a screw which admits of the discharge of the
surplus supply when it exceeds the level to which the pipe is adjusted
through the hollow column, whence it is conducted back again into the
reservoir, by which means the level of the half stuff contained between
the stones which corresponds to the level in the intermediate vessel or
receptacle may be varied, as required.
In starting the apparatus it is simply necessary to adjust the stones to
suit the degree of division to which the half stuff is to be reduced, and
to regulate the height of the overflow pipe, and the half stuff being
introduced in sufficient quantities into the intermediate vessel or
receptacle the supply to the stones will be automatically regulated to
suit the requirements of the machine.
Stuff or half stuff obtained from rags may also be treated in this
30
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Scal Patent
Office on the 21st April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of October, in the year
of our Lord One thousand eight hundred and seventy-four, in the 38th
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said John Henry Johnson, Her special license that I,
the said John Henry Johnson, my executors, administrators, and assigns,
or such others as I, the said John Henry Johnson, my executors, admi-
nistrators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term thercin
expressed, should and lawfully might make, usc, exercise, and vend,
within the United Kingdom of Great Britain and Ircland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MACHINERY
OR APPARATUS EMPLOYED IN THE PRODUCTION OF PAPER PULP," a communication
to me from abroad by La Société Anonyme de la Papoterie de Thode, of
Hainsberg, Saxony, upon the condition (amongst others) that I, the said
John Henry Johnson, my executors or administrators, by an instrument
in writing under my hand and scal, should particularly describe and
ascertain the nature of the said Invention, and in what manner tho
same was to be performed, and cause the same to be filed in the
Great Scal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same.
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying.
Drawings, and to the letters and figures marked thereon, that is to
say :-
The said Invention relates to the treatment of fibrous substances, such
for example as straw, wood, esparto, and the like, for the production of
paper pulp, and consists in the employment of improved machinery or
apparatus for comminuting or reducing and pulping the fibres by
preference in the condition of half stuff obtained by chemical processes,
and also of certain peculiar means for effecting and regulating the
supply of the fibres or half stuff to such machinery or apparatus, whereby
the fibres or half stuff are introduced in such quantities only as are
capable of being operated upon at a time, and the uniform and completo
comminution or reduction and pulping of the same is constantly
ensured.

page_text: The operation of refining or reducing fibrous stuff for paper makers,
which was formerly performed with stampers or beaters, formed at the
commencement of the present century the subject of an important
improvement, which consisted in the introduction of comminuting
cylinders revolving in troughs or cisterns, which arrangement is still
universally employed. The troughs or cisterns arc charged with a
certain quantity of half stuff, which remains in the apparatus for a
greater or less period without any guarantee of its being operated upon
in every part by the refining cylinder before leaving the apparatus.
Numerous attempts have been made to substitute for the ordinary
comminuting cylinders other apparatus having a continuous action, and
admitting of the fibrous material being refined at a single operation.
Among these apparatus may be mentioned the pulp engine in its various
forms, which has been tried but is now generally abandoned.
The attention of Inventors has also been specially directed to the
employment of grindstones arranged in a similar manner to those in use
for obtaining flour from cercals, but up to the present time grindstones.
have only given satisfactory results in treating stuff obtained from wood
by mechanical means. This stuff is not at all fibrous in itself, and in its
passage between the grindstones it is only sought to reduce sufficiently
the coarser parts of the wood which have been previously divided by an
apparatus for separating the fibres, and to bring such coarser parts into
such a condition of tenuity as that the introduction of this flour of wood'
into the pulp obtained from rags passes unperceived by the consumer.
The stuff thus obtained is not in anywise a substitute for rags, but is
simply an adulteration.
With stuff obtained by the disintegration of vegetable substances by
chemical agents the case is different, as straw, wood, esparto, and other
vegetable substances suitably treated by chemical processes yield a pulp
which furnishes of itself a paper as good and as strong as that obtained
from rags. In the grinding of this stuff however the use of coupled
grindstones has hitherto given results greatly inferior to those obtained
with the comminuting cylinders, however defective the better may have
been from many points of view. The pulp obtained by the use of
grindstones was irregularly triturated, and the fibre was frequently of
insufficient length, like that of wood treated by mechanical means. The
pulp in order to remain fibrous after its passage between the grindstones.

page_text: requires a regularity of action of the latter which could not be obtained
by the arrangements hitherto tried. The half stuff reached the grind-
stones by a shoot or passage which allowed it to flow into the central
aperture or eye of the upper stone, the level of the half stuff in which it
was requisite to watch attentively in order both to prevent the supply
being so much in excess as to cause the half stuff to run over the stone,
and to avoid a deficiency or an entire cessation in the supply at intervals.
By reason of these inconveniences therefore the use of grindstones for
reducing or refining fibrous half stuff has not been attended with the
success anticipated.
Now according to this Invention a peculiar arrangement of apparatus
is employed for supplying the half stuff automatically, by means of
which apparatus the difficulties above enumerated are obviated, the
grindstones when once regulated so as to produce a pulp suitably
refined and sufficiently fibrous receiving only the quantity of half stuff
which they are capable of grinding, whatever may be their power of
absorption, which varies according to the rapidity with which they
rotate, the condition of their surfaces, and other circumstances. A
homogeneous pulp is thus obtained, which is sufficiently fibrous and
capable of producing a good quality of paper.
And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings,
the same letters of reference indicating corresponding parts in both the
Figures.
Figure 1 represents a vertical section of the apparatus, and Figure 2 is
a sectional plan of a portion of the same.
Two grindstones a, b, of specially selected grit stone are placed, the
one over the other, in a similar manner to those employed in corn mills.
The lower one a, which is stationary, is supported by screws, which
admit of its being adjusted and retained in a horizontal position. It is
perforated at the centre with a hole for the reception of a box c through
which passes a vertical shaft e, to which rotatory motion is imparted by
machinery below, which may be varied or regulated as desired. The
upper grindstone b, which is carried on the top of the vertical shaft e by
means of a rhind f and is suitably balanced, rotates with such vertical
shaft e. The two rubbing surfaces of the stones are splayed or hollowed.

page_text: out towards the centre in order to facilitate the introduction of the half
stuff to be ground or reduced, and are grooved or channelled in a manner
which will vary according to the hardness of the stone and the nature of
the half stuff to be operated upon, but so as to leave an annular surface
or zone which is very finely roughened or serrated in order to admit of
the passage or escape of the pulp therefrom only when the fibres have
been reduced to the requisite fine state of division.
The two grindstones a, b, are surrounded by a casing 9 (composed of
wood, zinc, or other suitable metal or material) which is formed in two
parts, the upper one being capable of removal when it is required to dress
the stones.
A side aperture furnished with a spout serves for the outlet of the
prepared pulp. The box c, which is composed of cast iron or other
suitable material, is imbedded in the centre of the stationary grind-
stono a, and is perforated at p with an elliptical or cylindrical opening,
which terminates at its lower part in a tube extending as far as q, and
beyond the level of the woodwork which supports the stationary grind-
stone a.
The automatic feed apparatus is composed of reservoir C placed at
the upper part of a hollow cast-iron column i, through which the stuff
to be refined is conducted from the main reservoir B by means of a
suitable pump or elevator. Into the upper end of the column i there is
fitted an adjustable overflow pipe n which passes through a stuffing
box 6' fixed at the bottom of the reservoir C, and is capable of being
raised or lowered at will, and of being fixed at the desired height by
means of a screw m provided with a suitable wheel or nut m¹ for the
convenience of manipulating the same. To a short pipe d, which is
fitted to the bottom of the reservoir C, there is attached one end of a
tube k of india-rubber or of any suitable metal, by which the reservoir O
is placed in communication with the opening 2 of the cast-iron box c of
the grindstone a.
The apparatus is operated in the following manner :-The half stuff is
supplied through an open channel A by means of a suitable pump or
clevator, not as in the ordinary method directly into the eye or opening
in the centre of the rotating grindstone b, but into the reservoir C, and
from the latter by means of the tube k into the central opening 2, and
thence between the rubbing surfaces of the refiner, as shown by the red

page_text: arrows, the surplus supplied by the pump returning by the overflow
pipen to the basin B. It is obvious that the stuff when at rest will rise
to the same height in the central opening in the refiner as in the
reservoir C, the level being readily varied by raising or lowering the
overflow pipe n. This adjustment is regulated by the quality of the
pulp it is desired to produce, and the absorbing power of the refiner.
The tube should be placed at a greater height when the refiner requires
pressure, and lower when the stuff passes through it easily.
When the position of the overflow is once determined the refiner no
longer requires to be attentively watched. Should the speed increase or
the stuff become less thick the apparatus supplies itself from the surplus
of the stuff in the eye l, while in the opposite case no liability is incurred
of the stuff running over. It is simply necessary to take care that
the half stuff is constantly supplied into the reservoir C in sufficient
quantities to maintain the level determined by the respective position of
the overflow.
By means of the arrangement herein-before described fibrous stuff,
such for example as that of straw, wood, csparto, and the like, obtained
by chemical processes, may be refined without injury to the fibres at a
single operation and in a continuous manner, a uniform pulp without
knots or lumps, and sufficiently fibrous to form a good paper, is obtained
with a much less expenditure of motive power than is required in the
case of the ordinary comminuting cylinders to produce the same amount
of work.
Stuff or half stuff obtained from rags may also be treated in this
apparatus after having been sufficiently torn and scratched.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured to me
by the herein-before in part recited Letters Patent is,―
First. The application and use to and in the refining of fibrous stuff
or half stuff, for the manufacture of paper pulp, of grindstones arranged
substantially in the manner herein-before described and illustrated by the
accompanying Drawings.
Second. Automatically supplying the stuff or half stuff to be refined

page_text: stuff is introduced, which vessel is provided with means for maintaining
its contents at a constant level, and for varying the level at will, and
communicates with the chamber situate in the centre of the stones by an
inverted syphon passing through the stationary grindstone, and dis-
charging the stuff or half stuff between the grindstones, the whole being
arranged and operating substantially as and for the purposes herein-
before described and as illustrated by the accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Fifteenth day of
April, One thousand cight hundred and seventy-five.