IMPROVEMENTS IN TREATING WOOD FOR THE PRODUCTION OF PAPER PULP, AND IN THE APPARATUS EMPLOYED THEREFOR, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE MAKING OF STEAM-TIGHT JOINTS FOR VARIOUS PURPOSES
Year: 1872

page_text: LETTERS PATENT to Robert Mc Farlane, of Loudwater Mills, Rick-
mansworth, in the County of Herts, Paper Manufacturer, for the
Invention of "IMPROVEMENTS IN TREATING WOOD FOR THE PRODUCTION OF
PAPER PULP, AND IN THE APPARATUS EMPLOYED THEREFOR, PARTS OF WHICH
IMPROVEMENTS ARE APPLICABLE TO THE MAKING OF STEAM-TIGHT JOINTS FOR
VARIOUS PURPOSES.”
Sealed the 22nd November 1872, and dated the 12th June 1872.
PROVISIONAL SPECIFICATION left by the said Robert Mc Farlane at the
Office of the Commissioners of Patents, with his Petition, on the
12th June 1872.
I, ROBERT MCFARLANE, of Loudwater Mills, Rickmansworth, in the
'County of Herts, Paper Manufacturer, do hereby declare the nature
of my said Invention for "IMPROVEMENTS IN TREATING WOOD FOR THE PRO-
DUCTION OF PAPER PULP, AND IN THE APPARATUS EMPLOYED THEREFOR, PARTS OF
WHICH IMPROVEMENTS ARE APPLICABLE TO THE MAKING OF STEAM-TIGHT JOINTS FOR
VARIOUS PURPOSES," to be as follows :-
This Invention relates to improvements in the boiling of wood for
the manufacture of what is known as half stuff, and in the apparatus

page_text: employed therein, whereby economy in fuel is effected and greater safety
and cleanliness are ensured.
My improvement consists essentially in substituting high-pressure
steam obtained from a separate generator for the direct fire heat or
furnace for heating the boilers employed in reducing wood to a pulp
or half stuff. The pressure of steam which I employ ranges from 150
to 200 lbs. per square inch. The result is a much better fibre and less
waste. Further, by this system of heating I am enabled to dispense
with, and do dispense with the costly inner casing heretofore rendered
necessary when heating by direct action of the flames from a furnace to
prevent charring the fibre, and hence I can introduce a much larger
quantity of wood into a boiler of the same size. The boiling vessel is
moreover according to my improved arrangement set in much lighter
and less costly brickwork, as the external surrounding flues are entirely
dispensed with as well as the costly covers to such flues. I am also
enabled to shorten considerably the lateral discharge pipe at the bottom
of the boiler, whereby the same is much more casily and expeditiously
emptied of its contents.
The steam joints employed in connection with the above described
boiler and steam generator are made tight by interposing between the
flanges or junction surfaces a ring of vulcanized india-rubber or other
suitable material which is strengthened by having one or more rings of
copper wire laced or embedded therein. The same system of steam-tight
joints is applicable in all cases where steam-tight joints are required, the
said joints lasting much longer than those ordinary joints now in use for
any purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Mc Farlane in the Great Seal Patent Office
on the 12th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT 30
MCFARLANE, of Loudwater Mills, Rickmansworth, in the County of
Herts, Paper Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of June, in the year of

page_text: our Lord One thousand eight hundred and seventy-two, in the 35th
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Robert M. Farlane, Her special license that I,
the said Robert McFarlane, my executors, administrators, and assigns,
or such others as I, the said Robert Mc Farlane, my exccutors, admini-
strators, or 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, usc, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN TREATING
WOOD FOR THE PREPARATION OF PAPER PULP, AND IN THE APPARATUS EMPLOYED
THEREFOR, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE MAKING OF
STEAM-TIGHT JOINTS FOR VARIOUS PURPOSES," upon the condition (amongst
others) that I, the said Robert Mc Farlane, my executors or admini-
strators, 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 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.
NOW KNOW YE, that I, the said Robert Mc Farlane, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, that is to say:-
My said Invention relates to improvements in the boiling of wood for
the manufacture of what is known as half stuff, and in the apparatus
employed therein, whereby economy in fuel is effected and greater safety
and cleanliness arc ensured.
My improvement consists essentially in substituting high-pressure
steam obtained from a separate generator for the direct fire heat or
furnace for heating the boilers employed in reducing wood to a pulp
or half stuff. The pressure of steam which I have found to answer well
in practice ranges from about 120 to 150 lbs. per square inch. The
result is a much better fibre and less waste. Further, by this system
of heating I am enabled to dispense with, and do dispense with the
costly inner casing heretofore rendered necessary when heating by direct
action of the flames from a furnace to prevent charring the fibre, and
hence I can introduce a much larger quantity of wood into a boiler of
the same size. The boiling vessel is moreover according to my improved

page_text: I
arrangement set in much lighter and less costly brickwork, or the
brickwork may be entirely dispensed with, as the external surrounding
flues as well as the costly covers to such flues are no longer required.
am also enabled to shorten considerably the lateral discharge pipe at the
bottom of the boiler, whereby the same is much more easily and expedi-
tiously emptied of its contents.
The steam joints employed in connection with the above described
boiler and steam generator are made tight by interposing between the
flanges or junction surfaces a ring of vulcanized india-rubber or other
suitable material, which is strengthened by having copper wire, one
or more rings of copper wire or wire cloth laced or embedded therein.
The same system of steam-tight joints is applicable in all cases where
steam-tight joints are required, the said joints lasting much longer than
the ordinary joints now in use for any purpose.
The boiler may be of any convenient form or construction, but I
prefer to make it of a cylindrical form of ordinary strong boiler plates,
and to place it vertically. The said boiler needs no surrounding brick-
work or flues, but may be simply clothed with felt or other good
non-conductor of heat to prevent loss of heat by radiation. At the
upper end of the boiler there is fitted a cover, screwed or otherwise,
firmly and tightly secured to the neck of the boiler for the introduction
therein of the wood to be treated. A safety and blow-off valve weighted
to the pressure required are also fitted to the boiler. At the bottom of
the boiler on one side thereof is provided a discharging. aperture also
fitted with a tightly secured lid or cover for the discharge of the wood
after it has been boiled. This cover may be supported in a ring fitting
loosely in a groove, which ring is suspended by a link from a bracket
attached to the side of the boiler, the link being free to run along the
bracket as the cover is being opened or closed. The cover turns freely
in its ring so as to allow of it being screwed up or unscrewed by means
of bars inserted into lateral openings made for that purpose in the cover,
the same method of screwing and unscrewing being adopted for the
lid or cover of the charging aperture before referred to. A. steam and
vomit pipe extends down the centre of the boiler from a short distance
below the top to a perforated false bottom, which pipe communicates
with a short perforated pipe in a well or chamber beneath the false
bottom. The top of the vomit pipe may be screwed for the attachment
of a socket on the end of a rod when it is required to withdraw or lift

page_text: out the said pipe. Into the bottom of the well and opening into the
bottom of the short perforated pipe there is fitted a steam pipe which
conveys high-pressure steam from a separate generator to the interior
of the boiler. This pipe is provided with a cock for drawing off the
liquid contents of the boiling vessel when required, and with a check
valve and a stop valve, the check valve serving to prevent any back
pressure from the boiler acting upon the generator in the event of the
pressure in the generator falling below that in the boiling vessel. The
stop valve enables the supply of steam to be shut off from the particular
boiler in connection with the steam pipe when required. I prefer in
practice to employ two or more boiling vessels, both connected by their
respective steam pipes with a branch common to the two, such branch
leading into the upper part of the steam chamber of the generator, and
being also provided with a check valve and stop valve of its own, which
operate on both the pipes in case either of the valves in the separate
branches should get out of order.
The generator may be of any well-known construction capable of
generating high-pressure steam, and may be fed with the ley to be
employed in boiling the wood, such ley being by this means heated to a
considerably elevated temperature before it is allowed to enter the wood
or pulp boiler.
The wood having been placed in the boiler and the
requisite quantity of water and chemicals introduced therein, the top
cover is screwed down tightly and the high-pressure steam from the
water or ley in the separate generator is turned on, which steam passes
into the boiler and so on till the whole of the charge of wood has been
sufficiently boiled. The steam is then blown off at the top, the drain
cock opened to draw off the liquid and the wood is withdrawn through
the discharge aperture into a small truck or other convenient receptacle
By having two or more boiling vessels any one or more of such vessels
can be discharged whilst the others are in operation, so that the process
may be carried on continuously.
Having now described and particularly ascertained the nature of my
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 treating of wood by boiling the same in a close vessel by

page_text: means of high-pressure steam obtained from a separate generator, sub-
stantially as and for the purpose herein-before mentioned.
Second. The strengthening of the india-rubber rings employed in
making steam-tight joints by combining therewith copper or other wire,
or wire cloth, substantially in the manner herein-before described.
In witness whereof, I, the said Robert McFarlane have to this my
Specification set my hand and scal this Eleventh day of December,
One thousand eight hundred and seventy-two.