IMPROVEMENTS IN THE PROCESS OF DISINTEGRATING WOOD
Year: 1873

page_text: LETTERS PATENT to Thomas Burt Armitage, of the City, County, and
State of New York, in the United States of America, for the
Invention of "IMPROVEMENTS IN THE PROCESS OF DISINTEGRATING WOOD
COMPLETE SPECIFICATION filed by the said Thomas Burt Armitage at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 5th July 1873, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BURT ARMITAGE, of the City, County, and State of New York, in the
United States of America, send greeting.
WHEREAS I am in possession of "IMPROVEMENTS IN THE PROCESS OF
DISINTEGRATING WOOD OR WOODY FIBRE, AND REDUCING THE SAME TO PULP,"
have petioned Her Majesty to grant unto me, my executors, adminis-
trators, and assigns, Her Royal Letters Patent for the same, and have
made solemn Declaration that I am the truc and first Inventor thereof.

page_text: NOW KNOW YE, that I, the said Thomas Burt Armitage, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed in and by the following
statement, that is to say :—
The object of this Invention is to disintegrate or reduce wood or woody
fibre to pulp in order that the same may be employed in the manufacture
of paper and for other purposes, and it consists,―
Firstly. In subjecting wood or woody fibre which has been previously
cut or divided into lengths of (by preference) uniform size, and saturated
with an alkaline solution to the direct action of superheated steam in a
chamber or cylinder revolving on a horizontal axis, such superheated
steam being discharged into the cylinder or chamber at one end, and
allowed to pass out freely at the opposite end.
According to another modification of my Invention the steam instead
of being superheated is conducted directly to the revolving cylinder or
chamber, and discharged into the same at one end, and allowed to pass
out freely at the opposite end.
According to the third modification of my Invention I place the
saturated wood or woody fibre in a steam-tight revolving cylinder or
chamber (such as before referred to), and admit highly heated steam
under pressure directly upon and into the wood or woody fibre, the
cylinder or chamber being continually rotated during the process.
In carrying out the first modification of my Invention I generate
steam at the usual temperature in any suitable vessel, and conduct it
away from the generator as fast as made, and through a superheating
tube or apparatus, which is exposed to a high temperature.
The woody matter having been previously prepared by first reducing
the same to small chips or blocks of as nearly a uniform size as possible,
giving preference to small sized pieces, such chips or pieces having then
been placed in a suitable vessel, and the air exhausted therefrom, and
afterwards saturated with a solution of caustic alkali of about 2° or 2, 5°.
specific gravity.
(As some kinds of wood will reduce with a weaker solution while
other kinds may require a stronger solution the specific gravity may be
varied as occasion requires).

page_text: I put the woody matter thus prepared into a suitable vessel mounted
upon an axis horizontal, or nearly so, which vessel is so connected with
the steam pipe as to permit of its being revolved without being dis-
connected from the pipe. I then discharge the current of superheated
steam into and through the said prepared wood or woody fibre at one
end of the apparatus, and allow the steam to then escape as freely as it
entered from the vessel at the opposite end into the atmosphere, keeping
the temperature of the wood about 350° to 400° Fahrenheit during the
application of the superheated steam, and for about the period of an
hour if the lower temperature is used, or about half an hour if the higher
temperature is used, and in either case depending upon the size of the
mass under treatment and the strength of the alkali used; and during
the whole time the steam is being applied to the chips the vessel is
slowly revolved upon its axis, so as to prevent the alkaline solution
dripping from one piece of wood or woody fibre to the other, and conse-
quently producing an ununiform state of moisture among such chips or
pieces. At the same time the revolution of the apparatus and the
passage of the steam will so agitate the mass as to cause the steam to
act with uniformity upon every chip or piece. At this stage the fibre
will be found in a completely disintegrated state, and merely requiring
the customary washing in the ordinary vessels or machines used for such
purposes to be ready for use. This after treatment however forms no part
of my Invention

page_text: process. Coloring compounds are also kept in dilute form, in which
condition they will act very slowly in discoloring the fibre.
Fourth. The action is so uniform and rapid that disintegration is com-
pletely effected without any portion of the mass having been so long
under action of the alkali as to have lost its strength of fibre, and the
dying process has had so little time to act, and any dying matter in the
liquid is in so dilute a form that subsequent washing of the mass leaves
the fibre nearly colorless.
-
Fifth. All pressure is avoided, as I use the superheated steam
applied directly upon and into the matter under treatment and without
pressure, depending entirely upon its temperature and disintegrating
qualities for the result.
°
In carrying out the second modification of my Invention the process
is carried on in identically the same manner as in the first modification,
except that in place of conducting the steam from the boiler or
generator through a superheating tube or apparatus it is conducted
directly to the revolving cylinder, and discharged through the same to
operate upon the wood or woody fibre therein, and is then allowed to
escape freely.
In carrying out the third modification of my Invention I place the
saturated wood or wody fibre in a revolving horizontal cylinder or
chamber, which is fitted steam-tight, and admit highly heated steam
therein under pressure directly upon and into the wood or woody fibre
under treatment. In other respects the process is exactly similar to the
modification of my Invention already described.
Having thus described my Invention, and means by which the same
may be carried into effect, I would have it understood that I make no
claim to reducing the wood or woody fibre to blocks, chips, or pieces,
nor to any mode or process of saturating the same with alkaline solu-
tions; but what I do claim is,-
Firstly. The process of disintegrating wood or woody fibre, which has
been previously saturated with alkaline solutions by subjecting the
same to the action of superheated steam in a revolving cylinder
or chamber, substantially as described under the first head of my
Invention.

page_text: Secondly. The process of disintegrating wood or woody fibre, which
has been previously saturated with alkaline solutions by subjecting the
same to the action of free steam in a revolving cylinder or chamber,
substantially as described under the second head of my Invention.
Thirdly. The process of disintegrating wood or woody fibre, which has
been previously saturated with alkine solutions, by subjecting the same
to the action of steam under pressure in a steam-tight revolving cylinder,
substantially as described under the third head of my Invention.
In witness whereof, I, the said Thomas Burt Armitage, have
hereunto set my hand and seal, this Fourteenth day of
June One thousand eight hundred and seventy-three.
THOMAS BURT ARMITAGE. (L.S.)