IMPROVEMENTS IN THE PRODUCTION OF PULP. SUITABLE FOR THE MANUFACTURE OF PAPER FROM WOOD, STRAW, GRASS, AND OTHER VEGETABLE MATTER
Year: 1870

page_text: LETTERS PATENT to Frederick Arthur Paget, of 1, Seymour Chambers, :
York Buildings, Adelphi, in the County of Middlesex, Engineer,,
for the Invention of "IMPROVEMENTS IN THE PRODUCTION OF PULP.
SUITABLE FOR THE MANUFACTURE OF PAPER FROM WOOD, STRAW, GRASS, AND
OTHER VEGETABLE MATTER." -A communication from abroad by
August Deininger, of Berlin.
Sealed the 17th February 1871, and dated the 22nd August 1870.
PROVISIONAL SPECIFICATION left by the said Frederick Arthur Paget
at the Office of the Commissioners of Patents, with his Petition,
on the 22nd August 1870.
I, FREDERICK ARTHUR PAGET, of 1, Seymour Chambers, York.
5 Buildings, Adelphi, in the County of Middlesex, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
PRODUCTION OF PULP SUITABLE FOR THE MANUFACTURE OF PAPER FROM WOOD; ·

page_text: STRAW, GRASS, AND OTHER VEGETABLE MATTER," (a communication from
abroad by August Deininger, of Berlin) to be as follows:-
The objects of this Invention consist, firstly, in the production from
wood, in a state of subdivision, the straw of graminaceous plants, various
kinds of grasses, and other vegetable substances, a substitute for rags in
the manufacture of paper; and, secondly, in bleaching the fibre some-
times technically termed "first stuff" or "half stuff" obtained by
means of the first part of the process.
The following means are adopted for carrying out the first part of
the Invention, by dissolving the silicic acid, the woody fibre, the pith,
and the colouring matter of the wood, straw, and other substances
whilst leaving their cellular structure intact. A boiler is employed,
preferably constructed in the shape of a cylinder set vertically, and
which boiler I will afterwards designate under the term of "fibre
boiler." The whole of its internal surface is tinned, and its outer surface
is preferably covered with wooden lagging. It is provided with a suit-
able opening or man hole at its top, and another at its bottom side. A
short distance from the bottom of the fibre boiler there is fitted a
perforated tinned false bottom. The fibre boiler is placed by means of
a pipe in communication with any steam generator or boiler. A short
distance outside the fibre boiler this steam supply pipe is fitted with
a tap for regulating the admission of the steam. Inside the fibre boiler
the pipe is fitted with a self-acting cut-off valve, so arranged that should
there be an excess of pressure inside the fibre boiler the lye or wash
cannot be driven out by the pressure into the steam boiler. The steam
supply pipe is carried down to the bottom, where it is jointed to to a
perforated spiral pipe. The top of the fibre boiler is fitted with a steam
gauge and a thermometer in order to obtain indications of the internal
pressure and temperature. At its bottom is a tap for letting off the
lye, which can be received into a tank below. The lye is fed in from
a heater by means of a pipe, the flow through which can be regulated.
by another tap. Two cocks fitted to the boiler at different levels open
into a pipe communicating with the tank or receptacle for the surplus
lye, and by their means the temperature and pressure in the boiler can
be regulated according to the indications of the thermometer and
pressure gauge respectively. The raw material is supplied through the
cover at its top already mentioned, and is removed through the similar

page_text: cover at the bottom. A tap fitted on this upper cover is employed to
get rid of any air in the boiler, and also for determining whether steam
has formed itself above the regulating or gauge taps. It opens into a
pipe jointed to that placed below the gauge cocks. The vessel in which
the lye is previously heated is by preference of the same capicity as the
fibre boiler. It is first filled with water, to which caustic soda is added
in such quantity as to cause the solution to shew one degree on the
areometer well known under the name of Beaumé, and then heated by
steam or otherwise to about 80 degrees centigrade. Any wood to be
treated is first brought into a state of minute subdivision in the form
of chips or shavings. Straw or other similar materials arc chopped
by means of a chaff cutter or other machine into pieces from a
quarter to one-half of an inch long. The materials are then supplied
into the boiler. On allowing the heated lye from the tank to flow
into the fibre boiler, and soak itself in, the raw material is thereupon
generally found to contract, and the empty space thus formed is filled
up with more wood, chopped straw, or other material, and a further
quantity of heated-lye is run into the boiler. These alternate operations.
are continued until the whole boiler is filled. A current of steam of
about four atmospheres pressure from any ordinary steam boiler is then
supplied into the fibre boiler through the steam pipe already mentioned.
The materials are thereupon left for from four to six and even ten hours
under the influences of this increase of temperature and pressure. It.
will be seen that by this plan the contents of the closed fibre boiler are
simultaneously submitted to both a given temperature and a given.
pressure. At this stage the lye is run off through the bottom tap into
the tank for this purpose. The material is now ready for the stuff
engine or cylinder, and when washed it can be easily formed into
so-called "half stuff" for manufacturing paper.
:
The second part of this Invention relates to a process for bleaching
the half stuff or pulp obtained in the way already described. It is
prepared by being spread in a thin layer on the floor of the factory,
sprinkled with dilute sulphuric acid of about half a degree Beaumé,
and left to itself to ferment for two or three days; it is then supplied
into the bleaching cylinder. The bleaching liquor is prepared by
placing in a suitable vessel the quantities of bleaching powder and
water required to give an indication of about four degrees on Beaumé's'"
:

page_text: arcometer; it is then run off and the lime precipitated with carbonate
of soda. Before the chloride of lime is added it is necessary to get rid
of the colouring matter and vegetable glue of the fibre. It is supplied,
together with the. hypochlorite of soda formed, into the half stuff mill,
and the whole caused to rotate. To ensure the energetic action of the
hypochlorous acid on the fibre the mass is kept at a blood heat.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Arthur Paget in the Great Seal Patent
Office on the 22nd February 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
ARTHUR PAGET, of 1, Seymour Chambers, York Buildings, Adelphi, in
the County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of August, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederick Arthur Paget, Her special
licence that I, the said Frederick Arthur Paget, my executors, adminis-
trators, and assigns, or such others as I, the said Frederick Arthur
Paget, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed; should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
“IMPROVEMENTS IN THE PRODUCTION OF PULP SUITABLE FOR THE MANUFACTUre of
PAPER FROM WOOD, STRAW, GRASS, AND OTHER VEGETABLE MATTER," upon the
condition (amongst others) that I, the said Frederick Arthur Paget, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Frederick Arthur Paget, 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:-
The objects of this Invention consist firstly, in the production from
straw, various kinds of grasses, and other vegetable substances a sub-
stitute for rags in the manufacture of paper; and, secondly, in bleaching
the fibre sometimes technically termed "first stuff or half stuff obtained
by means of the first part of the process.
'
Tlie following means are adopted for carrying out the first part of the
Invention by dissolving the silicic acid, the pith, and the colouring
matter of the plants whilst leaving their cellular structure intact. A
boiler is employed preferably constructed in the shape of a cylinder set
vertically, and which boiler I will afterwards designate under the term
of "fibre boiler." The whole of its internal iron surface is tinned or
coppered, or otherwise protected against the chemical action of its
.contents. The outer surface is preferably covered with wooden lagging,
or with any other slow conductor of heat, such as felt. It is provided
with a suitable opening or man-hole at its top and another at its bottom
side. A short distance from the bottom of the fibre. boiler there
is fitted a perforated tinned iron bottom. The fibre boiler is placed
by means of a pipe in communication with any steam generator or
boiler. A short distance outside the fibre boiler this steam supply pipe
is fitted with a tap for regulating the admission of the steam. Inside
the fibre boiler the pipe is fitted with a self-acting cut-off valve so
arranged that should there be an excess of pressure inside the fibre
boiler the lye or wash cannot be driven out by the pressure into the
steam boiler. The steam supply pipe is carried down to the bottom,
where it is jointed to a perforated spiral pipe. The top of the fibre
b boiler is fitted with a steam gauge and a thermometer in order to obtain
indications of the internal pressure and temperature. At its bottom is
a tap for letting off the lye, which can be received into a tank below.
The lye is fed in from a heater by means of a pipe, the flow through
which can be regulated by another tap. Two or more cocks fitted to the
5 boiler at different levels open into a pipe communicating with the tank
or receptacle for the surplus lye, and by their means the temperature
and pressure in the boiler can be regulated according to the indications

page_text: of the thermometer and pressure gauge respectively. The raw material
is supplied through the man-hole cover at its top already mentioned,
and is removed through the similar cover at the bottom.
A tap
fitted on this upper man-hole cover is employed to get rid of any air in
the boiler, and also for determining whether steam has formed itself
above the regulating or gauge taps. It opens into a pipe jointed to that
placed below the gauge cocks. The vessel in which the lye is previously
heated is by preference of the same capacity as the "fibre boiler." It
is first filled with water, to which caustic soda is added in such quantity
as to cause the solution to shew one degree on the well-known
areometer, known under the name of Baumé, and then heated by steam or
otherwise to 80 degrees centigrade. The straw or other material to be
treated is chopped by means of a chaff cutter or other machine into
pieces from a quarter to one-half of an inch long and is then supplied
into the boiler. No sorting or cleansing of the straw or other material
is needed. On allowing the heated lye from the tank to flow into the
fibre boiler, and soak itself in, the raw material is thereupon generally
found to contract, and the empty space thus formed is filled up with
more chopped straw or other material and a further quantity of heated
lye is run into the boiler. These alternate operations are continued
until the whole boiler is filled. A current of steam of about four
atmospheres pressure from any ordinary steam boiler is then supplied
into the fibre boiler through the steam pipe already mentioned. The
materials are thereupon left for from four to six or more hours as may be
found necessary under the influences of this increase of temperature and
pressure. It will be seen that by this plan the contents of the closed
fibre boiler are simultaneously submitted to both a given temperature
and a given pressure. At this stage the lye is run off through the
bottom tap into the tank for this purpose. The material is now ready
for the stuff engine or cylinder, and it is washed, when it can be easily a
formed into so-called half-stuff for manufacturing paper.
The second part of this Invention relates to a process for bleaching
the half-stuff or pulp obtained in the way already described. It is
prepared by being spread in a thin layer on the floor of the factory
sprinkled with diluted sulphuric acid of about half a degree Baumé, 3
and left to itself to ferment for two or three days, it is then supplied
into the bleaching cylinder. The bleaching liquor is prepared by placing

page_text: in a suitable vessel the quantities of bleaching powder and water
required to give an indication of about four degrees on Baumé's
areometer; it is then run off, and the lime precipitated with carbonate
of soda. Before the chloride of lime is added it is necessary to get rid
of the colouring matter and vegetable glue of the fibre. It is supplied
together with the hypochlorite of soda formed into the half-stuff mill
and the whole caused to rotate. To ensure the energetic action of the
hypochlorous acid on the fibre the mass is kept at a blood heat. It is
found that the spent lye run out of the apparatus, though it contains.
large proportions of the colouring matter and other residuary constituents
of the straw, grass, and other raw materials employed, can yet be
rendered capable of being used over again. One hundred cubic feet of
lye contain about three litres of soda, which can be precipitated by
about three-quarters of a litre of sulphuric acid of about 66° Baumé
more or less. Glauber salts are formed, and all the foreign matters are
precipitated. The lye is then passed over fresh burnt lime, by which
gypsum is produced, and caustic soda lye is again formed.
on being brought to a consistency of 1° Baumé can be used for fresh
operations. The residues left in the lime can also be separated by.
roasting the same, so that the lime thus treated can be used over
again.
This lye
And in order to render the arrangement employed still more fully
understood, reference is made to the Drawings hereunto annexed, in
which the different parts of the apparatus are denoted by letters.
A is the vertical fibre boiler shewn in sectional elevation and in
cross sections through horizontal planes denoted by F, G, and H, I,
respectively. The inner sides of its iron plates are tinned or otherwise
protected from corrosion, and its outside is lagged or otherwise protected
from thermal loss. a is a perforated iron false bottom similarly pro-
tected against corrosion. The cock or other valve B regulates the
admission of steam from any steam generator into a pipe b. At d is
the self-acting cut-off valve for preventing the lye being driven back by
internal pressure. Below this valve there is jointed the spiral perforated
tube c, e.
On the top of the fibre boiler are a steam gauge fand a
thermometer g, and at the bottom is a tap h for letting off the lye into
the tank C below. The lye is supplied from the upper tank D through
a pipe regulated by a tap i. The taps kan open over the funnelled

page_text: tops of a pipe communicating with the tank C. The raw material is
supplied in by temporarily removing the man-hole cover m, and is
removed through the hinged cover or door n below. A tap p screwed
on the upper cover and opening into a branch pipe leading to the tank C
is opened when it is wished to get rid of any air in the fibre boiler or
for determining whether any steam has formed itself above the gauge
cocks.
In witness whereof, I, the said Frederick Arthur Paget, have
hereunto set my hand and seal, this Twenty-second day of
February, in the year of our Lord One thousand eight hundred
and seventy-one.