IMPROVED PROCESSES AND APPARATUS FOR DISIN- TEGRATING, SOFTENING, WASHING, AND BLEACHING WOOD, STRAW, ESPARTO GRASS, AND OTHER VEGETABLE FIBRES, AND FOR EXTRACTING RESIN, SILICA, OR OTHER SUBSTANCES THEREFROM, WHICH INVENTION IS CHIEFLY DESIGNED FOR. MANUFACTURING SUCH FIBRES INTO PAPER PULP
Year: 1871

page_text: LETTERS PATENT to William Riddell, of Crosby Hall Chambers,.
Bishopsgate Street, in the City of London, Civil Engineer, for
the Invention of "IMPROVED PROCESSES AND APPARATUS FOR DISIN-
TEGRATING, SOFTENING, WASHING, AND BLEACHING WOOD, STRAW, ESPARTO
GRASS, AND OTHER VEGETABLE FIBRES, AND FOR EXTRACTING RESIN, SILICA, OR
OTHER SUBSTANCES THEREFROM, WHICH INVENTION IS CHIEFLY DESIGNED FOR.
MANUFACTURING SUCH FIBRES INTO PAPER PULP."
Scaled the 20th June 1871, and dated the 6th April 1871.
PROVISIONAL SPECIFICATION left by the said William Riddell at the
Office of the Commissioners of Patents, with his Petition, on the
6th April 1871.
I, WILLIAM RIDDELL, of Crosby Hall Chambers, Bishopsgate Street,
in the City of London, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVED PROCESSES AND APPARATUS FOR DISIN-
TEGRATING, SOFTENING, WASHING, AND BLEACHING WOOD, STRAW, ESPARTO
GRASS, AND OTHER VEGETABLE FIBRES, AND FOR EXTRACTING RESIN, SILICA, OR

page_text: OTHER SUBSTANCES THEREFROM, WHICH INVENTION IS CHIEFLY DESIGNED FOR
MANUFACTURING SUCH FIBRES INTO PAPER PULP," to be as follows:-
My Invention is chiefly designed for the production of paper pulp or
half stuff from various vegetable fibres, of which wood is the most
important, but the said Invention also supplies the means for advan-
tageously retting flax, developing and cleaning rhea grass, and for
cleaning, softening, or bleaching various other fibrous materials. And
by the same processes and at the same time I extract from these
materials the resin, silica, or other substances which are found com-
bined in them in various proportions, which substances may be after-
wards employed for divers commercial purposes not forming a part of
this Invention.
In the manufacture of wood into paper pulp according to my Inven-
tion, the first operation is the reduction of the wood into thin shavings,
filaments, or chips. This may be accomplished by the apparatus
described in the Specification of my Patent dated February 21, 1867,
No. 477, or by that described in the Specification of my Patent dated
June 27, 1870, No. 1828, or by a roll or drum, in the periphery of which
a series of projecting cutters are placed, which cutters at each revo-
lution of the drum take off a shaving or filament from the wood, which
is forced in contact with them from a bottomless box. Or the wood in
beams or baulks of any length is subjected to the action of a series of
vertical marking blades and horizontal planes. The marking blades
make incisions in the surface of the wood presented to them, and the
planes following these blades shave off the wood to the depth of these
incisions. The marking blades and planes are arranged in a reciprocating
frame, and the said blades are adjusted by excentrics or other suitable
devices to cut to any desired depth. The shavings or filaments of wood
or the straw, esparto grass, or other fibres to be treated are then
subjected to the action of steam in the following manner :—A cylindrical
boiler of plate iron or other material with a conical or egg-shaped
bottom, and a rounded or domed top is erected in a brickwork setting
over a suitable fireplace. This cylindrical portion of the said boiler is
surrounded by a jacket or casing, and the space between the boiler and
the casing is made to contain water. The boiler is closed and made
steam-tight at all parts, and is provided with a safety valve at the top.
Flues extend from the fireplace around the jacket or casing. Near
the top of the boiler is the inlet pipe for the steam, and at the bottom

page_text: nearly filled with water. When the liquid boils and steam is generated
a circulation is established through the central vertical pipe and down
through the mass of fibres in the cage. The pressure of steam in the
boiler during this operation is kept up by means of the safety valve at
about forty pounds per square inch, or more or less, as may be found
desirable. When this boiling has been continued long enough to extract
the residue of the coloring matter and other soluble matter from the
fibrous mass, the liquid is drawn off through the large tube or pipe at
the bottom of the boiler, and, if desired, the said boiler may be exhausted
by means of an air pump. A fresh quantity of clean water cither hot
or cold is then admitted into the boiler and again forced through the
libre and drawn off, this operation being repeated as often as necessary
to thoroughly wash the mass. I then take off the cover of the boiler
and remove the contents either by throwing them from the cage or by
lifting the latter out of the boiler. In the latter case another cage filled
with raw fibres may be placed in the boiler, and the operations above
described immediately recommenced. The liquid drawn from the boiler
is conducted into a tank or other suitable receptacle and subjected to
evaporation, whereby the resin or other substances extracted from the
fibres in the boiler is recovered, which substances may be afterwards
used for various commercial purposes. The disintegrated and softened
mass which has been removed from the boiler is next placed in a
bleaching tank constructed of wood, slate, stone, or other suitable
material. The said tank has a false perforated bottom on which the mass
is laid and a perforated cover which is placed on the top of the same.
The said tank is provided with an inlet and waste pipe. The bleaching
liquor is then added to the contents of the tank and a stream of carbonic
acid gas, or atmospheric air, or both combined, is forced into the tank
through the inlet pipe and rises up through the pulpy mass. When this
process is completed the pulp is washed with clean water which may be
drawn off through the waste pipe, or the pump may be bleached in an
ordinary bleaching apparatus, carbonic acid gas, or atmospheric air, or
both combined, being forced into the mass to facilitate the operation of
bleaching, or I may use chlorine gas for this purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Riddell in the Great Scal Patent Office
on the 6th October 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
RIDDELL, of Crosby Hall Chambers, Bishopsgate Street, in the City of
London, Civil Engineer, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her
Letters Patent, bearing date the Sixth day of April, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Riddell, Her special license
that I, the said William Riddell, my executors, administrators, and
assigns, or such others as I, the said William Riddell, 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 "IMPROVED PROCESSES
AND APPARATUS FOR DISINTEGRATING, SOFTENING, WASHING, AND BLEACHING WOOD,
STRAW, ESPARTO GRASS, AND OTHER VEGETABLE FIBRES, AND FOR EXTRACTING
RESIN, SILICA, OR OTHER SUBSTANCES THEREFROM, WHICH INVENTION IS CHIEFLY
DESIGNED FOR MANUFACTURING SUCH FIBRES INTO PAPER PULP," upon the
condition (amongst others) that I, the said William Riddell, my exccu-
tors or administrators, by an instrument in writing under my, or their, of
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.
NOW KNOW YE, that I, the said William Riddell, 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 forming a part of this Specification:-
My Invention is chiefly designed for the production of paper pulp or
half stuff from wood and various other vegetable fibres, but the said Inven-

page_text: tion also supplies the means for advantageously retting flax, developing
and cleaning rhea grass and ramme, and for preparing for bleaching and
bleaching wood, straw, esparto grass, palm grass, New Zealand flax,
aloes, maize, rice, straw, stringy bark, manilla, jute, adamsonia, gunny
toè, toè, and various other vegetable fibres, and during and by the same
processes I extract from these various materials resin, silica, dextrine
wax, various acids and alkalies, and other substances found combined
with these different fibres in various proportions, which substances may
be afterwards employed for many commercial purposes not forming a
part of this Invention.
Figure 1 is a plan of an apparatus which I use for reducing wood to
filaments; Figure 2 is a longitudinal vertical section on the line x, x,
Figure 1 Figure 3 is a vertical central section of the vessels used in
my process for extracting the resin, silica, and other matters contained
in the fibres.
In the manufacture of wood into paper pulp according to my Invention
the first operation is the reduction of the wood into thin filaments,
shavings, or chips. I accomplish this operation by the apparatus shewn
in Figures 1 and 2. This apparatus has a scries of vertical marking
blades a and horizontal plane irons . The blades a are separated by
division plates a¹. These blades and planes are fixed on a reciprocating
table c.
The wood to be cut is placed in the stationary bottomless
box c', and is pressed down by a weight, lever, or screw; when the latter
is used the feed is adjusted automatically. The blades a cut incisions
in the wood to any required depth, which depth is regulated by raising
or lowering the blades. To enable this to be done the said blades are
fixed by means of a feather on the bar or spindle d, and they are secured
together by the rod c. Underneath this series of blades is a drum
placed eccentrically on the shaft, on which is keyed a toothed wheel ƒ³
controlled by a pinion for other suitable device, by turning which the
blades are adjusted to the proper height above the level of the table.
These blades project through the reciprocating table c in front of the
plane irons b, which are set to any required depth, and which as the table
moves under the box shave off filaments from the wood in the box, the
said filaments being received in a proper receptacle under the table. Or
the said apparatus may have the cutting blades and plane irons fixed in

page_text: a stationary table or frame, the balks, deals, or other pieces of timber
being moved over or under them by rollers, drums, or other suitablo
means. The said apparatus besides its use for cutting the wood into
filaments or shavings to be afterwards treated as herein set forth may be
advantageously employed in the manufacture of match splints. The
filaments of wood or other fibres to be operated upon are then placed in
the cage A, Figure 3. This cage is made of sheet or plate iron or other
suitable metal. It is open at the top and is fitted with a bottom piece A'
of perforated metal or wood or of wire gauze. This cage is formed to fit
a strong cylindrical vessel B made of boiler plate or other suitable metal.
At the top of the cage A, between the same and the outer cylindrical
vessel B, is a packing C of india-rubber or other suitable material which
prevents the passage of the steam or liquor between the cage and the
outer vessel. Rings or other suitable contrivances are fixed at the top
of the cage A to enable it to be lifted to place it in or remove it from the
outer vessel, for which purpose I may use any suitable apparatus. The
cylindrical vessel B has a conical or egg-shaped bottom B' and a rounded
or domed top B. In the bottom is fixed a discharge pipe E fitted with
a tap or valve. A waste pipe F provided with a tap is also fitted in this
bottom at such a height as to leave about six inches of liquor in the
vessel B. Another pipe G also provided with a stop cock is fitted in
the bottom B', and this pipe is attached to an air pump of any suitable
construction. The top B of this vessel is fitted with a safety valve H.
A vertical tube I open at both ends is passed through the centre of the
cage A.
The top of this tube must be a few inches above the top of
the cage and the bottom must be at least two inches below the waste
pipe F. Over the tube I and from four to six inches above the same is
a domed iron plate J, which is suspended over or supported on the cage
and is of the same diameter as the said cage. Steam of any required
pressure is admitted into the vessel B by a pipe K, which is turned a
little upward at the end K¹ under the dome J in order to spread the
steam over the top surface of the contents of the cage. A pipe L serves
to admit water or liquor for washing or preparing the material, the
end L of this pipe is also turned upward under the dome J for the
purpose of distributing the water or liquor equally over the contents of
the cage. Around the cylindrical portion of the vessel B is an annular
jacket or casing M for containing water; this casing is open at the top,
and has a waste pipe N and tap. A pipe O serves for blowing steam into
this casing or may be connected with a worm for boiling or heating the

page_text: water contained therein to any desired temperature. The vessel Bis
fixed in brickwork over a fireplace or furnace P. Flues P from this
fireplace after passing around the egg-shaped or conical bottom B
extend around the annular casing M nearly to the top and thence to
the chimney or shaft. The pipe L is connected with a cistern for con
taining water or any liquor or solution required in preparing or washing
the materials operated upon in the cage, which water or liquor can b
boiled or heated by steam or otherwise.
The operations are conducted as follows:-The cage A is filled with
the wood or other fibres, which are pressed down as evenly as possible
without making them too hard or close. The said cage is then lowered
into the cylindrical vessel B, the packing C is properly arranged, and
the domed spreader J fixed over the cage. The top cover B is then
screwed down and made steam-tight. The taps and valves must be
closed, and the vessel made steam-tight in all parts. After this has
been done water, or in some cases water containing a cream of lime, is
admitted by the pipe L; then by the heat of the furnace P the contents
of the vessel are boiled under a pressure of about 20 lbs., more or less,
for a sufficient time according to the nature of the fibre employed. The
liquor is then withdrawn and the material washed with hot water, after
which steam of any desired pressure is admitted by the pipe K. The
waste pipe F is then opened to permit the exit of the condensed water
and a slight escape of steam, which will regulate the pressure during
the operation. This condensed liquor will be found to contain the
greater portion of the colouring matter, resin, silica, or other substances
extracted from the wood or other fibres or materials operated upon, and
this liquor is collected in a vessel to be afterwards evaporated or other-
wise treated as may be required. These condensed liquors may be used
for various useful purposes; that obtained from wood may be used in
the manufacture of soap, resin, size, and other articles of commerce.
The condensed liquor from straw, esparto grass, flax, and other fibres
which contain a considerable quantity of starch, dextrine, silica, wax,
and gummy matters may be advantageously used for feeding cattle;
that liquor which contains the largest proportion of silica may be used
also in the manufacture of soap, and for mixing with clay and other
materials for the purpose of giving hardness to bricks for building pur-
poses. When by the condition of the water of condensation it is found
that the materials have been sufliciently operated upon the steam is

page_text: shut off, the waste pipe closed, and the steam in the vessel B allowed to
condense; or it may be condensed by artificial means or drawn off with
the air by the air pump which is attached to the pipe G. By this means
a vacuum or partial vacuum is obtained in the vessel B. At this stage
of the operation hot or cold water, or alkaline or any suitable solution,
is admitted to the vessel B through the pipe L from the aforesaid cistern,
and is forced through the mass of fibres by atmospheric pressure. The
pipes from the cistern and to the air pump are then closed, the annular
vessel is filled with water and heated, and a fire is lighted in the
furnace P to boil the water or liquor in the inner vessel under any
desired pressure, which is to be regulated by the safety valve H. When
the liquor boils a circulation is established and maintained in the vessel,
the liquor flowing up the pipe I against the domed spreader J being
thereby distributed over the entire surface of the materials, and per-
colating through them. When the material has been sufficiently boiled
the fire is withdrawn, the annular vessel M emptied, and the liquor
drawn off from the inner vessel B (preferably by an air pump). When
all the liquor is drawn off, and a partial or complete vacuum is formed
in the interior of the said vessel, a fresh supply of water is admitted
through the pipe L for washing the fibres, and is also drawn off, these
operations being repeated until the material is sufficiently washed.
The cover B of the vessel B is then removed, the cage A containing
the material is taken out or emptied in any suitable manner, and the
operations on a fresh quantity of fibre or other material can then be
commenced. If the material thus treated is required for the manu-
facture of paper pulp it can be prepared in the usual manner, and it
may be further operated upon in a beating engine to bring it into a
proper condition for bleaching. The bleaching can be effected by any
ordinary process, but I prefer to use chlorine gas passed into a chamber
or vessel containing the material with or without a stream of atmo-
spheric air, after which treatment the material is washed, and a solution
of chloride of lime, chlorine liquor, chlorite of lime or chlorate salts, is
added according to the fibre used. During the time this operation
is carried on I pass a stream of carbonic acid gas and atmospheric air
(either separately or both combined) through the material and bleaching
liquor. I thereby greatly accelerate the action of the bleach and
diminish the quantity required. After being washed the bleached pulp
is ready for the subsequent ordinary operations employed in the manu-
facture of paper. When the fibres or materials operated upon in the

page_text: vessel B are not to be used for the manufacture of paper, but are
required for other purposes, such materials after being removed from
the cage A are ready for hackling, scutching, cleaning, washing,
bleaching, or other treatment as may be required, which operations may
be conducted in the ordinary manner or as previously described.
For the manufacture of paper pulp for sale the material before or
after being bleached may be made into boards, which are pressed, dried,
and packed in bales or cases. Other materials not required for paper
manufacture can either be finished. in the ordinary manner or pressed,
dried, and baled for shipment.
I wish it understood that I do not limit myself to the precise form or
construction of the apparatus or details of operation herein described,
but may make such variations therein as will facilitate the accomplish-
ment, under any circumstances, of the object of my Invention; and I
claim,―
First. The apparatus for reducing the wood to small filaments,
shavings, or pieces constructed and operating substantially as set forth.
Second. The extraction of the silica, resin, colouring matter, and other
substances from wood or other vegetable fibres by subjecting them to
the action of steam in a closed vessel provided with means whereby the
pressure may be regulated according to the nature of the materials
operated upon, substantially as specified for the purposes set forth.
Third. The employment of carbonic acid gas or atmospheric air, or
both combined, in the process of bleaching the fibres either with or
without chlorine gas, chlorites and chlorates, as specified for the purpose
set forth.
In witness whereof, I, the said William Riddell, have hereunto sct
my hand and scal, this Fifth day of October, in the year of our
Lord One thousand eight hundred and seventy-onc.
Witness,
CHRIS. J. Goocit.
WILLIAM RIDDELL. (L.S.)