IMPROVEMENTS IN THE MANUFACTURE OF PAPER PULP FROM VEGETABLE FIBRES, AND IN APPARATUS THEREFOR, WHICH APPARATUS IS ALSO DESIGNED TO BE EMPLOYED IN MAKING CHLORIDE OF LIME FOR BLEACHING PULP, AND IN OTHER SIMILAR PROCESSES
Year: 1872

page_text: LETTERS PATENT to William Riddell, of Crosby Hall Chambers,
Bishopsgate Street, in the City of London, and of Hurstbourne
Mill, near Whitchurch, in the County of Hants, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF PAPER PULP FROM VEGETABLE
FIBRES, AND IN APPARATUS THEREFOR, WHICH APPARATUS IS ALSO DESIGNED
TO BE EMPLOYED IN MAKING CHLORIDE OF LIME FOR BLEACHING PULP, AND
IN OTHER SIMILAR PROCESSES."
Sealed the 29th November 1872, and dated the 4th June 1872.
'
PROVISIONAL SPECIFICATION left by the said William Riddell at
the Office of the Commissioners of Patents, with his Petition, on
the 4th June 1872.
I, WILLIAM RIDDELL, of Crosby Hall Chambers, Bishopsgate Street,
5 in the City of London, and of Hurstbourne Mill, near Whitchurch, in
the County of Hants, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF PAPER PULP FROM VEGETABLE

page_text: FIBRES, AND IN APPARATUS THEREFOR, WHICH APPARATUS IS ALSO DESIGNED TO BE
EMPLOYED IN MAKING CHLORIDE OF LIME FOR BLEACHING PULP, AND IN OTHER
SIMILAR PROCESSES," to be as follows:-
In the manufacture of paper pulp from wood according to my
Invention the wood is first filamented or cut by the process described
in the Specification of an Invention for which I have obtained Letters
Patent, bearing date the 27th day of June, A.D. 1870, No. 1828. The
same is then soaked in cream of lime, or boiled in plain water or in
cream of lime, as may be desired; then it is washed with warm water,
and pulped in an ordinary pulping engine. It is then bleached by the
addition of a solution of chloride or hypo-chloride of lime, soda, potash,
alumina, or ammonia, or by exposing the beaten pulp to the action of
chlorine gas in the improved apparatus hercin-after described. It is
then again washed, and then treated with a solution of chloride of lime,
or the chloride salts mentioned above.
Esparto and other similar fibres containing a considerable quantity of
silica after being steamed by the process described in the Specification of
an Invention for which I have obtained Letters Patent, bearing date
the 6th day of April. A.D. 1871, No. 923, are afterwards washed with
warm water, and then boiled in cream of lime, and again washed with
warm water. They are then pulped in a pulping engine, and bleached
first by gassing with chlorine gas, washing, and afterwards by steeping
in a weak solution of chloride of lime or of the chlorine salts of soda,
potash, alumina, or ammonia, or the fibres may be first boiled in the
usual manner or prepared in the steaming apparatus, and afterwards
bleached with a solution of the salts mentioned above. The bleaching
may be effected hot or cold, but I prefer a moderate heat.
The gassing may be accomplished by any suitable apparatus, but I
prefer to use an improved apparatus which I will now describe.
The said apparatus has a spiral conductor arranged within a drum
or case. The gas or liquid is admitted into the lower part of this con-
ductor through an aperture in the centre shaft, and the fibres to be
treated are admitted to the same part by means of a small Archimedean
screw working in a connecting tube between a hopper and the aforesaid
conductor, and forming part of the central shaft. By the revolution of
the drum containing this spiral conductor the fibre is carried forward
from the entrance to the delivery aperture, which is also connected with

page_text: a screw working in a tube, which screw delivers the gassed pulp into
the receiver. During their passage the fibres are continually turned
over, and every portion is equally and thoroughly exposed to the action
of the chlorine gas or liquid. The unused or unspent gas is conducted
through water containing lime or into a chamber containing dry lime,
and is thereby condensed or absorbed.
The aforesaid spiral conducter is constructed in the following manner :
-Its central part is a shaft or core of wood, preferably about twelve
inches in diameter and about twenty feet long. On this shaft I turn a
spiral groove or channel extending from end to end of the same. Into
this groove I fit pieces or wings of wood to form a thread or spiral, the
pitch thereof being about six inches and the depth about two feet. Over
this thread I place planks or strips of wood which are well fitted together
and fastened with hoops like a barrel. This barrel is supported to turn
freely upon antifriction rollers, and is provided at one end with a row of
cogs forming a toothed wheel which is geared into another toothed wheel
or pinion, whereby the said barrel is operated. The interior of this
barrel, together with the wings or thread and also the core, may, if
required, have a metallic covering, and in some cases the apparatus may
be made of copper, brass, iron, or other metal.
At the end where the gas or liquid is admitted the shaft is made
hollow, and provided with a tube or pipe, this tube or pipe forming the
shaft of the screw feed. This pipe has at its outer extremity a stuffing
box, whereby it is coupled to a stationary pipe which is connected to a
reservoir or chamber containing the chlorine gas or liquid. These pipes
conduct the said gas or liquid into the centre of the wooden core, whence
it is admitted through a lateral aperture into the first coil of the spiral
conductor.
When the apparatus is used for the manufacture of chloride of lime
the chlorine gas is admitted as above described through the central pipe
into the spiral conductor, and the lime is admitted instead of the pulp
through the screw, and in other chemical operations the substances used
will be admitted to the conductor through the same passages.
When the apparatus is used as a condenser the vapour is passed in
through the gas pipe. The barrel is made of metal, and a thin stream
of water either hot or cold is caused to flow over the outer surface by
means of a serrated trough placed over the barrel. In some chemical

page_text: operations where heat is generated, as in the manufacture of chloride of
lime, the heat can be regulated or reduced by means of a stream of
water flowing over the barrel from the serrated trough.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Riddell in the Great Seal Patent Office
on tho 4th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
RIDDELL, of Crosby Hall Chambers, Bishopsgate Street, in the City of
London, and of Hurstbourne Mill, near Whitchurch, in the County of
Hants, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of June, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Riddell, Her special licenco
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 "IMPROVE-
MENTS IN THE MANUFACTURE OF PAPER PULP FROM VEGETABLE FIBRES, AND IN
APPARATUS THEREFOR, WHICH APPARATUS IS ALSO DESIGNED TO BE EMPLOYED IN
MAKING CHLORIDE OF LIME FOR BLEACHING PULP, AND IN OTHER SIMILAR PRO-
CESSES," upon the condition (amongst others) that I, the said William
Riddell, 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.
NOW KNOW YE, that I, the said William Riddell, do hereby declare
the nature of my said Invention, and in what manner the same is to
Le performed, to be particularly described and ascertained in and by

page_text: the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
In the manufacture of paper pulp from wood according to my
Invention the wood is first filamented or cut by the process described in
the Specification of an Invention for which I have obtained Letters
Patent bearing date the 27th day of June 1870, No. 1828, or by that
described in the Specification of an Invention for which I have also
obtained Letters Patent bearing date the 6th day of April 1871, No. 923,
or by the apparatus shewn in Figures 1 and 2 of the Drawing, of which
Figuro 1 is a side elevation of the said apparatus, and Figure 2 is a
plan of a portion of the same.
a is a strong frame of cast iron or other suitable material on which
are supported the adjustable boxes b wherein I place the blocks or
pieces of wood from which the filaments are to be cut; c, c, are semi-
circular blades, and d, d, are planing blades; e, e, are rollers. These
blades and rollers are carried in the travelling frame ƒ which is moved
to and fro upon the rails g. The blocks of wood are kept in contact with
the blades, and as the filaments are cut therefrom the said blocks are
pressed down by the screws h. The wood filaments are then soaked or
boiled in cream of lime either in an open vessel or a closed boiler, but
I prefer to boil them with the cream of lime at a pressure of five or six
pounds to the inch although such pressure is not essential to my process.
I prefer also to enclose the filaments in a perforated metal cap in the
boiler and to use a vomiting pipe in order to assist the free circulation
of the liquor. Or I may use the boiler described in the Specification of
said Letters Patent No. 923. In the latter case the filaments may be
washed in the manner described in the said Specification. If
any other
form of boiler is used the filaments must be washed after boiling by
percolation with warm or cold water, preferably warm water, before
removing them from the boiler, or they may be removed to the breaking
engine and washed in the same. After the lime has been removed by wash-
ing the filaments are broken in the breaking engine, drained, and then
all or nearly all of the water is pressed out of the mass by any suitable
means. The dry or nearly dry mass is then placed in a poaching engine
and a solution of the ordinary chloride of lime of commerce or a solution
of hypochloride of soda, potash, alumina, or ammonia, is added to it,
or I use a bleaching solution made by the decomposition of chloride of
lime by nitrate of potash which I prefer.

page_text: operation of bleaching. The bleach liquor is then drained, pressed out,
and kept for use in future operations, after which the pulp is washed,
soured with sulphuric acid, and again washed, when it is ready to be
converted into paper. The half stuff when received from the breaking
engine may be bleached in the same manner as herein-before described
for wood, without the use of chlorine gas. During the operation of
bleaching I prefer to keep the pulp warm. Or the fibres may be
prepared in the usual manner by boiling with alkali, and afterwards
bleached as herein-before described.
As herein-before explained I prefer to conduct the operation of
gassing in my improved apparatus, which I will now describe: Figure 3
is a longitudinal vertical section of the same. The said apparatus has
a spiral conductor, as shown at A, fixed within a drum or case B. The
gas or liquid is admitted into the first thread of the conductor through
a hollow shaft E, and the fibres to be treated are admitted to the first
thread by means of a small Archimedean screw D, fixed on the hollow
shaft E, and working in a connecting tube between the hopper F and the
first thread of the conductor which is fixed in the drum or case. By the
revolution of this drum the fibre after leaving the Archimedean feed is
carried gradually forward from the entrance to the delivery aperture G,
which is made at the further extremity of the drum or case; this
aperture is also connected with an Archimedean screw H working in the
same manner as the first screw, by which the gassed pulp is delivered
to the receiver. By the revolution of the drum containing the conductor,
the fibre is turned over continually throughout the whole length of the
screw or conductor, and every portion is equally and thoroughly exposed
to the action of the chlorine gas. or liquid throughout the entire length,
and this length in the apparatus I prefer to use is from 700 to 800 feet.
The unused or unspent gas is conducted from the drum by a hollow
tube I, which is the shaft of the delivery screw, and is conducted into
water or cream of lime, or into a chamber containing lime, and is thereby
condensed or absorbed.
The aforesaid spiral conductor may be constructed in the following
manner-Its central part may be a shaft or core of wood preferably
about 12 inches diameter and about 20 feet long. On this shaft I turn
a spiral groove or channel extending from end to end of the same. Into
this groove I fit pieces or wings of wood to form a thread or spiral,

page_text: the pitch thereof being from 6 to 12 inches as required, and the depth
about 4 feet. Over this thread I fit planks or strips of wood into which
the outer edge of the wings is grooved in the same manner as round
the core; these planks are well fitted together and fastened with
screw hoops. The drum is supported upon a number of antifriction
rollers or wheels and is provided at one end with a ring or row of cogs
forming a toothed wheel which is geared into another toothed wheel or
pinion, by which the said drum is made to revolve slowly. The interior
of this drum is preferred to be entirely of wood when used for chlorine
gas or it may be covered with sheet lead, but for other purposes the
apparatus may be made entirely of copper, brass, iron, or other metal.
At the end where the gas or liquid is admitted the shaft is made hollow
and provided with a tube or pipe. This tube or pipe forming the shaft
of the screw feed has at its outer extremity a stuffing box, whereby it
is coupled to a stationary pipe which is conducted to a reservoir or
chamber of chlorine gas or direct to the generating vessel. The hollow
shaft conducts the gas or liquid into the first coil of the screw
conductor.
When the apparatus is used for the manufacture of chloride of lime
the gas is conducted into the drum, and the lime admitted in the same
manner as the paper pulp or fibre. In other chemical processes the
materials and the gasses or liquids are admitted at the same inlet:
round the outer case of the conductor at intervals strong glass peeps
are inserted in order that the progress of the gassing may be seen, and
also at various intervals man-holes are placed in order to clear the screw,
should it become clogged.
When this apparatus is used as a condenser the vapor is passed in
through the gas pipe. The drum is made of metal. A thin stream of
water either hot or cold is caused to flow over the outer surface of the
drum by means of a serrated trough placed over the same.
In some
chemical operations when heat is generated, as in the manufacture of
chloride of lime, this heat can be regulated or reduced by means of a
stream of water flowing over the drum from the serrated trough.
Having thus fully described the said Invention, and the manner of
performing the same, I wish it understood that I claim,-
First. A bleaching solution formed by the decomposition of chloride.
of lime with nitrate of potash.

page_text: Second. The gassing apparatus constructed and operating as herein
described.
Third. The manufacture of paper pulp from vegetable fibres by the
process or series of operations herein described.
In witness whereof, I, the said William Riddell, have hereunto set
my hand and seal, this Thirtieth day of November, in the year of
our Lord One thousand eight hundred and seventy-two.
Witness,
W. Rob. Lake,
8, Southampton Buildings,
London.
WILLIAM RIDDELL. (L.S.)