IM- PROVED APPARATUS FOR MANUFACTURING PAPER PULP AND RECOVERING THE ALVALL TOED IN SHOW MA WILD A CUTIED
Year: 1862

page_text: LETTERS PATENT to Joseph Bence Palser, of the Crown Hotel, Holborn,
in the County of Middlesex, Paper Maker, for the Invention of "IM-
PROVED APPARATUS FOR MANUFACTURING PAPER PULP AND RECOVERING THE
ALVALL TOED IN SHOW MA WILD A CUTIED "
TT
Sealed the 3rd March 1863, and dated the 9th October 1862.
PROVISIONAL SPECIFICATION left by the said Joseph Bence Palser at
the Office of the Commissioners of Patents, with his Petition, on the
9th October 1862:
I, JOSEPH BENCE PALSER, of the Crown Hotel, Holborn, in the County
of Middlesex, Paper Maker, do hereby declare the nature of the said Inven-
tion for "IMPROVED APPARATUS FOR MANUFACTURING PAPER PULP AND RECOVERING
THE ALKALI USED IN SUCH MANUFACTURE," to be as follows:-
The object of this Invention is to reduce straw and other fibrous materials
to pulp in an economical and expeditious manner. To this end I mount
above a reverberatory furnace two cylindrical boilers, which are capable of
rotating on their axes. The boilers are mounted in separate compartments
formed within the extended side walls of the furnace; above these boilers I
mount vats, which are respectively brought into communication with the
boilers by means of a suitable arrangement of pipes. The boilers are intended
to receive the materials to be operated upon, and the vats the liquor which
has been used in the treatment of the fibrous materials. The bottoms of the
vats are pierced with holes, (which are capable of being closed with plugs,)

page_text: through which the liquid is allowed to drop and flow over the rotary boilers.
Within the wall which separates the two boilers are a longitudinal passage
and a pipe for warming air and water respectively. Air is forced by a
blowing engine into the passage, and it is led off thence in a heated state to
branch pipes, which conduct it through a number of small holes into the
liquid contained in the vats for the purpose of accelerating evaporation. The
water pipe leads from a reservoir of water or other liquid placed on a higher
level than the boilers, and it permits such liquid to be warmed, when needful,
in its passage through this pipe. It is divided into two branch pipes, each of
which turns into one of the boilers through the journals, which are made
hollow for the purpose, and by this means the boilers are filled with water or
other liquid. At the other end of the boilers, pipes enter therein, also through
hollow journals for the purpose of conveying steam thereto. These pipes are
united together by a coupling pipe provided with faucets. The pipes used to
empty. the boilers of liquid extend to the lowest parts of the boilers, and the
liquid which is forced out through them may be discharged into the vats
above, or may be otherwise directed as thought, desirable. The pipes for. dis-
charging the liquor are separated from the "stock" in the boilers by perforated
partitions, and thus they cannot be broken or even bent by the pressure of
the revolving "stock," nor can they be closed by solid matters accidentally
forced into them. The partitions serve also as strainers to retain the "stock"
in its own compartment, and yet permit the drawing off of all the liquid
matters at any desired time during the operation herein-after to be described.
When straw is the material to be operated upon it is first cut into suitable
lengths, subjected to a winnowing process to cleanse it from dirt, and then
crushed between a pair of iron rollers. It is now ready to be acted upon by
boiling. One of the, boilers having been emptied of its contents during the
time the other was boiling, (and this boiling under high pressure being just
completed,) things are ready for another operation, which is conducted as
follows: The empty boiler is filled with straw or other substance to be
boiled through a man-hole, which is then closed. The necessary quantity of
liquid is then run into the boiler, and the fire heat is diverted from the
adjacent boiler to the boiler last charged with fibrous material, and steam
from.the adjacent boiler is turned into it until the temperature and pressure
are equal in both. This operation is important, as the means of raising the
temperature in the one boiler is expedited, while the cooling of, the other
boiler is also facilitated. The steam of the boiling process is charged more or
less, with alkaline matter, which is carried over and mixed with the contents
of the other boiler. The steam remaining in the boiler that is to be cooled is

page_text: now caused to force up the exhausted liquid into the vat placed above the
boiler. The plugs before mentioned are then drawn out of the bottom of the
charged vat, and the liquid previously raised to the vat is discharged 'in
suitable quantities at a time upon the top of the boiler that is immediately
below. The exterior of this boiler becoming instantly enveloped by the
descending liquid, a rapid evaporation of the liquid takes place, it being assisted
by the dashing of the liquid from the boiler surface on to the surrounding heated
walls. The descending liquid (thickened by the evaporation) falls into a
basin below the boiler, where it is collected and soon becomes viscous.
Water supplied from the reservoir is used to wash the materials in the boilers,
and the now separated fibres or paper stock is removed therefrom through the
man-hole. For more effectually washing the pulp I place it in a tub fitted.
with a false bottom, and connected with a head of water. By letting in
water below the false bottom the material will be forced upwards and kept
in agitation, whereby the soluble matters combined therewith will be effectually
washed out. After boiling has been going on for the requisite time in the
boiler last charged, the liquid from the preceding operation having become
viscous is pushed over an incline into a lower chamber, where the inflammable
matters take fire, and the boiling proceeds with the heat produced by them.
In such operations as the boiling of rags there is no residuum to burn, the
oven or furnace would in that case be reduced to a flue, and the vats sup-
pressed, except the strength of the liquor used was so sufficient that by
recovering its alkali the expense of evaporating it would be repaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Bence Palser in the Great Seal Patent Office on the
9th April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BENCE PALSER, of the Crown Hotel, Holborn, in the County of Middlesex,
Paper Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of October, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Joseph Bence Palser, Her special license that I, the said Joseph
Bence Palser, my executors, administrators, and assigns, or such others as I,
the said Joseph. Bence Palser, my executors, administrators, and assigns;

page_text: 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 APPARATUS FOR MANUFACTURING PAPER PULP AND RECOVERING THE
ALKALI USED IN SUCH MANUFACTURE," upon the condition (amongst others)
that I, the said Joseph Bence Palser, by an instrument in writing under
my hand and seal, 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 Joseph Bence Palser, 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, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
:-
The object of this Invention is to reduce straw and other fibrous materials
to pulp, in an economical and expeditious manner. The process may be simply
described as the subjecting of straw and other fibrous materials to the action
of an alkaline solution in rotating boilers, under a pressure of from of from
one hundred and ten pounds to one hundred and thirty pounds to the inch or
thereabouts.
In the accompanying Drawing, Fig. 1 represents in longitudinal sectional
elevation the improved apparatus which I employ in carrying out this process;
Fig. 2 is a cross section taken in the line 1, 2, of Fig. 1; and Fig. 3 is a
partial section taken in the line 3, 4, of the same Figure.
A, A, is a reverberatory furnace for supplying heat to a pair of cylindrical
boilers B, B¹, which are intended to receive the stock or material to be
operated upon, and are capable of rotating on their axes. The boilers are
mounted in separate compartments C, C¹, constructed of brickwork, and com-
municating by means of separate flues D, D, with the furnace A. Above
these boilers and supported by the walls of the compartments C, C³, I mount
evaporating pans or vats E, E¹, which are respectively brought into commu-
nication with the boilers by means of a suitable arrangement of pipes, to be
presently described. The pans E, E¹, are intended to receive the alkaline
liquor, which has been used in the treatment of the fibrous materials, and to
assist (by evaporating the watery particles) in the recovery of the alkali.
The bottoms of the pans E, E', are pierced with holes at suitable distances
apart, and these holes are capable of being closed by plugs a, the plugs in

page_text: each pan being attached by chains 6 to arms carried by a rock shaft c, which
has its bearings on the ends of the pans. These holes are intended to discharge
the liquid from the pans on to a hearth below the boilers, allowing it in its
passage to flow over the rotary boilers 6, 6, and thereby utilizing the surface
heat of the boilers. The rock shafts c are weighted, as shewn at Fig. 3, to
ensure their retaining the position into which they are rocked. Within the
division wall of the chambers C, C₁, a longitudinal passage or flue d is formed.
This flue I employ for heating air, which is forced thereon by a blowing engine
through a pipe d', and is led off thence in a heated state by a pipe d² at the
other end of the flue to branch pipes d³. These branch pipes conduct the air
upwards into the vats or pans, and discharge it into the liquor contained in
the pans through a number of small holes made in the portions of the branch
pipes which lie on the bottom of the vats. By the discharge of air into the
vats, the evaporation of the liquor contained therein is materially accelerated:
Through the flue d I carry a water pipe e, which leads from a reservoir of
water, or it may be alkaline liquid placed on a higher level than the boilers,
the object being to heat the liquid on its passage to the boilers. The
pipe e on its exit from the flue d is divided into two branch pipes e', e¹;
which turn respectively into one of the boilers through fixed hollow stud axles
on which they are mounted. At the opposite end of the boilers to that at
which the branch feed pipes are situated is an arrangement of steam pipes
ff, connected with the hollow fixed axles f¹ of the boilers, for the purpose of
conveying steam thereto, either from an adjacent steam boiler or from one
boiler B to the other, according to the stage of the process at which the steam
pipes are brought into use. These pipes are fitted with faucets for changing
at pleasure the direction of the flow of the stean. The axles f¹ are divided
longitudinally by a partition, as shewn in the enlarged sectional view, Fig. 4,
and leading from these passages, near the inner and closed ends of the axles,
are lateral pipes f², f³. These pipes are intended for supplying their respective
boilers with or exhausting them of steam, and also for withdrawing the liquid
therefrom. The pipes f, which extend to the lowest part of the boilers, form a
vent for the liquid at the end of the process of preparing the pulp, the liquid
being forced out through them, by the pressure of the steam in the boiler and
discharged into the vats above, or the liquid may be otherwise directed as
thought desirable. The pipes for discharging the liquor and admitting and
discharging steam are separated from the "stock" in the boilers by vertical
perforated partitions g, and thus they cannot be broken or even bent by the
pressure of the revolving "stock," nor can they be closed by solid matters
accidentally forced into them. The partitions serve also as strainers for

page_text: retaining the "stock" in its own compartment, and yet permit the drawing off
of all the liquid matters at any desired time during the operation herein-after
to be described.
In order to economise to its full the heat of the reverberatory furnace A, I
mount upon its roof an evaporating pan or vat, into which I discharge liquid
from the pans E, E', by means of pendent pipes h, h. As in the carrying out
of the process of manufacturing paper pulp I find it advisable to use the
bcilers alternately, I provide dampers i for closing the flues D, and thus
diverting at pleasure the course of the gases of combustion from the furnace
to the boiler. These dampers will be alternately raised and lowered, in order
that the heating of one boiler may be proceeding while the other is cooling.
When straw is the material to be operated upon it is first cut into suitable
lengths, subjected to a winnowing process to cleanse it from dirt, and then
crushed between a pair of iron rollers. The straw thus prepared is ready to
be acted upon in my improved apparatus. Supposing one of the boilers to
have been emptied of its contents while the operation of boiling under a high
pressure was proceeding in the other boiler, and that this boiling is just
completed, things are ready for a repetition of the operation, which is con-
ducted as follows:-The empty boiler is filled with the prepared straw or
other substance through a man-hole k, and the man-hole is then closed. A
solution of caustic alkali, of a strength indicating from three and a half
degrees to three and three-quarters degrees Beaumé is next run into the
boiler in the proportion of about sixty gallons of the liquor to every one
hundred pounds of the cut straw, and the boiler is set in rotary motion by
means of suitable driving gear connected with the spur wheel affixed to the
outer extremity of the boiler. The fire heat is now cut off from the adjacent
boiler by dropping the damper i, and admitted by the raising of the other
damper to the boiler last charged with fibrous material. Steam from the
heated boiler is also turned into it until the temperature and pressure are
equal in both boilers. This operation is important, as the means of raising
the temperature in the one boiler is expedited, while the cooling of the other
boiler is also facilitated. The course of the steam from the one boiler to the
other will be readily traced by reference to the Drawing. Thus, supposing
the boiler B (Fig. 1) is required to give up its steam to the boiler B', the
steam will pass down the pipe f³, along the upper division of the axle f¹, up
the pipe f* (Fig. 4), along the upper horizontal pipe f*, down a coupling pipe
to the lower horizontal pipe f, thence into the lower division of the axle f¹ of
the boiler B', and into the boiler by the pendent lateral pipe f³ of that boiler,
thereby heating the liquor contained in the boiler. The steam of the boiling

page_text: process is charged more or less with alkaline matter, which is carried over and
mixes with the contents of the boiler B'. The steam pressure in the two
boilers being now equalized the tap 1 is turned to close the steamway, and the
tap 2 is open end in the lower horizontal pipe f. The steam remaining in the
boiler B, that is to be cooled, will now force up the exhausted liquid into the vat
E above the boiler, where, being still subjected to the furnace heat, and also to
the influence of the hot blast of air before mentioned, supplied by the pipe d³,
a rapid evaporation will ensue. The liquor having been thus, to a certain extent,
concentrated, the plugs before mentioned are drawn out of the bottom of the
charged vat, and the concentrated liquid is discharged in suitable quantities at
a time on to the top of the rotating boiler that is immediately below. The
exterior of this boiler becoming instantly enveloped by the descending liquid a
rapid evaporation of the liquid takes place, it being assisted by the dashing of
the liquid from the boiler surface on to the surrounding heated walls. The
descending liquid (thickened by the evaporation) falls into the basin or hearth
below the boiler, where it is collected, and under the action of the heat-
absorbing surfaces with which it is in contact it soon becomes viscous. When
in this state it is raked on to the hearth of the reverberatory furnace, and being
subjected there to the direct action of the fire all the moisture is driven off the
solvent matters extracted from the straw under treatment, and combined with
the alkali are then consumed, and the residuum is the recovered alkali which
when cool is fit for use.
The fibrous material in the boiler B having been subjected to a pressure of
about one hundred and thirty pounds for, say, about four hours, more or less,
according to the quality of the material under treatment, will be found to
have parted with its resinous or soluble ingredients, the fibres losing thereby
their adherent character. Water is now to be supplied freely to the boiler to
wash the separated fibres or paper stock, and after thorough cleansing the
stock is removed from the boiler through the man-hole. If it should be thought
desirable to subject the pulp or paper stock thus produced to more severe
washing the pulp may be placed in a tub fitted with a false bottom, and
connected with a head of water; by letting in water below the false bottom
the material will be forced upwards and kept in agitation, whereby any
dissolved matters remaining therewith will be effectually washed out. The
fibrous material reduced as above described is now ready to be subjected to
the well-known processes requisite for converting it into paper.
Having now set forth the nature of my Invention of "Improved Apparatus
for Manufacturing Paper Pulp and Recovering the Alkali used in such
Manufacture," and explained the manner of carrying the same into effect, I

page_text: wish it to be understood that under the above in part recited Letters Patent
I claim the construction of apparatus above described with reference to the
Drawing, or any mere modification thereof, for reducing fibrous materials or
separating their filaments and rendering them fit for conversion into paper,
and. also for recovering the alkali used in the treatment of the fibrous
materials.
In witness whereof, I, the said Joseph Bence Palser, have hereunto
set my hand and seal, the Eighth day of April, in the year of our
Lord One thousand eight hundred and sixty-three.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
JOSEPH BENCE PALSER. (L.S.)