IMPROVEMENTS IN THE MANUFACTURE OF PAPER-PULP, AND APPARATUS THEREFOR
Year: 1884

page_text: [Communicated from abroad by Goldsburg Horden Pond, of Glens Falls, New
York, and Edmund Alonzo Morse, of Rutland, Vermont, both in the United
States of America.]
I HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF PAPER-PULP,
AND APPARATUS THEREFOR" 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 manufacture of paper pulp from wood, and other
fibrous materials and to apparatus therefor.
Heretofore wood pulp has been made by machines which consume a large
amount of power and which in their operation make a large proportion of the pulp
into a powder with a very small portion of fibre, which pulp is unsuitable for the
manufacture of paper of any commercial value.
Chemical wood pulp is made by digesting pieces of wood in concentrated caustic
soda, a process which produces good pulp and fibre, but the cost of the process
prevents its general use in the manufacture of paper.
The object of this Invention is to produce, in a cheap and expeditious manner
and with a small expenditure of power, wood pulp from sawdust, shavings, chips,
and the waste products of sawmills and from all kinds of wood and fibrous material
suitable for pulp, the said pulp having a clear unbroken fibre as long as the pieces
of material used, and containing no powder.
To carry out the improved process I make use of the apparatus illustrated in the
accompanying Drawing.
Figure 1 is a vertical section of the said apparatus.
Figure 2 is a section on the line a a Figure 1.
Figure 3 is a sectional view showing a modification of one of the rollers, and
Figure 4 is a top view of the same.
A indicates a cylinder turned smooth and true on its inner side from top to
bottom. The said cylinder is filled with a steam-tight cover O having an opening S
also provided with a strong steam-tight cover. Through the said opening the
cylinder A is charged with sawdust or other material.
The cylinder A is provided with a central shaft H on which are securely-fastened
the plates and arms I I. Between these plates and arms are supported, on pins P,
the rollers K. K. One or more rollers may be arranged on each pin or shaft P.
The said rollers are rendered adjustable, by means of the set screws N to set the

page_text: '
rollers up to the face of the cylinder A. Springs J are provided so that when any
large piece of wood or other material gets under the rollers K, K, the said rollers
will yield and pass over the obstacle without disturbing the working of the
machine.
A slow speed is used for a light pressure; a high speed gives a greater pressure
and throws the rollers out against the sides of the cylinder by the centrifugal
motion.
The rollers may be supported so as to work automatically; to accomplish this, a
large hole D is made in the centre of each roller through which a pin P passes as
shown in Figures 3 and 4. The rollers fly outwards by centrifugal force, the holes
in the centres of the rollers being so much larger than the pin P, that they allow
the rollers K to move back over any large pieces of wood or other material that
might get into the charge.
With this mode of supporting the rollers no work would be done, except as the
charge is moved and circulated by the steam in toughening it, until the shaft H
revolves fast enough to throw the rollers K K out to the side of the cylinder.
The cylinder A is charged through the hopper and opening S with sawdust,
shavings, chips or other pieces of wood or fibrous material suitable for making pulp,
and supplied with enough water to float the entire mass, and allow the charge to
be moved round easily by the force of the steam passing through the pipe T
arranged as shown in Figure 2. The cylinder A is then closed by the steam tight
cover and the steam let in from the boiler through the pipe T under a pressure of
not less than fifty pounds to the square inch. The steam quickly heats the mass in
the cylinder up to the heat of the steam in the boiler with a corresponding pressure,
keeping the charge constantly moving and circulating around in the cylinder and
toughening it so that the rollers will not break the fibre.
A small per cent of alkali or alkaline earth, such as lime, soda, or potash may be
added to the charge when it is put into the cylinder, which alkali will help to
toughen the fibre of the wood and other fibrous material of which the charge is
composed, and cleanse it of any impurities it may have.
The charge is kept under pressure and motion by the steam for two hours, when
the particles of wood will be found to be tough, pliable, and strong.
In order that the charge shall be well stirred by the steam and slowly worked
while being toughened, the driving shaft is provided with pulleys C, M of different
sizes. The belt runs on the large pulley during the first part of the operation and
after say two hours the speed is increased by running the belt on the smaller pulley
to finish the working of the charge.
The rollers should commence to work at the first revolution of the shaft H, and
for that purpose are adjusted to the inner side of the cylinder A by the set
screws N, and springs J, so as to press lightly against it, the rollers extending
nearly the whole height of the cylinder, and rolling around continuously on it until
the work is completed. The charge being moved by the force of the steam and the
revolution of the shaft arms and rollers, circulates over the inner surface of the
cylinder distributing the particles and pieces of which the charge is composed over
it and under the rollers, as they roll along.
By this continuous motion of the rollers the particles of wood or fibrous
material are rolled thinner and thinner without breaking across the grain and
shortening the fibre, and are brought again and again under the rollers until the
fibres of the wood are at first loosened and finally entirely separated from each
other, making the whole charge into a mass of fine fibre the same length as the
pieces and particles of wood which first composed the charge.
A charge may be worked without the addition of a small per cent of alkali by
using the steam under pressure to toughen the wood, but it will not be worked as
fast or as well.
The cylinder can be arranged to rotate horizontally or perpendicularly the axis
being provided with rollers or balls running loosely upon the inner side of the said

page_text: I ain aware that two or more rollers running face to face were used for breaking,
crushing and drawing fibres and other materials also that the steaming of various
kinds of material as well as paper stock, has been in use. I am also aware that
concentrated caustic soda has been used to digest wood under a high pressure for
the manufacture of "chemical pulp." I do not claim such as my Invention.
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 :-
First. The combination of the cylinder A having the cover O, the shaft H
provided with plates and arins I, I, the rollers K, K, and the steam pipo T, for
holding and working a charge of saw dust, chips, shavings or other pieces of wood
or fibrous material, and producing a pulp of fine fibre, substantially as set forth.
Second. The cylinder A, provided with a shaft having plates and arms I, I,
between which are supported the rollers K, K, either singly, or in a series one
above the other, substantially as described.
Third. The rollers K, K, supported between the plates and arms I, I, and provided
with the set screws N and springs J whereby the said rollers may be set against
the inner side of the cylinder A with any pressure required and at the same time
allowed to pass over any large pieces that may be in the charge and resume their
normal positions upon the sides of the C linder substantially as described.
Fourth. The cylinder A provided with the shaft H having secured thereto the
plates and arms I, I, and carrying rollers K, K, having openings D as described, the
said rollers revolving loosely upon the pins P, whereby the said rollers are
automatically made to bear on to the inner face of the cylinder by centrifugal force,
substantially as set forth.
Fifth. In a machine for reducing saw dust or other pieces of wood or fibrous
material to pulp, the combination with the cylinder A of the shaft carrying arms
and plates on which are secured rollers adapted to be operated by centrifugal force.
Sixth. In a machine for reducing saw-dust or other pieces of wood or fibrous
material to pulp, the combination with the cylinder A of a shaft carrying arms
and plates to which are attached rollers held in place by set screws and springs.
Seventh. The process of reducing saw dust or other pieces of wood or fibrous
material to a pulp, consisting in enclosing the said material in a tight vessel
containing a sufficient quantity of water to float the charge, causing the charge to
circulate by a jet of steam under pressure thereby toughening the fibres, and
subjecting it to a light pressure by rollers forced outwards, by centrifugal force
against the inner side of the cylinder substantially as described.
Eighth. The process of reducing sawdust or other pieces of wood or other
fibrous material to a pulp, consisting in enclosing the said materials in a tight
vessel containing a sufficient quantity of water to float the charge causing them to
circulate by a jet of steam under pressure thereby toughening the fibres, adding a
small per cent. of alkali and subjecting them to a light pressure by the rollers on
the inner side of the vessel the said rollers being forced outwards by centrifugal
force.