AN IMPROVED PROCESS OR METHOD AND APPARATUS FOR PREPARING PLANTS TO RENDER, THEM USEFUL IN THE MANUFACTURE OF PAPER PULP
Year: 1872

page_text: En the Matter of Letters Patent granted to ALBErt Ungerer,
of Simmering, near Vienna, Austria, Chemist, for the Invention
of "AN IMPROVED PROCESS OR METHOD AND APPARATUS FOR PREPARING
PLANTS TO RENDER, THEM USEFUL IN THE MANUFACTURE OF PAPER
PULP," bearing date the Twenty-sixth day of January, One
thousand eight hundred and seventy-two, No. 257.
DISCLAIMER AND MEMORANDUM OF ALTERATION as proposed
to be filed by the said ALBERT UNGERER, in the Great Seal Patent Office,
with the Specification to which the same relates, according to the
Statute in that case made and provided.
WHEREAS since the date of the said Letters Patent, and of the filing
of the said Specification, I have ascertained that a portion of the same,"
and also of the claim as made in the said Specification, bear a wider con-
struction than is warranted by the title of the said Invention, and the
:

page_text: scope of the Provisional Specification thereof lodged by me in the Great
Seal Patent Office:
And whereas I am desirous to disclaim any implied or express claim
to the use of my said Invention for obtaining spinning fibres from plants
and of restricting my claim to the process or method and apparatus for
preparing plants to render them useful in the manufacture of paper
pulp:
«
NOW KNOW YE, that I the said Albert Ungerer, by and with the
leave of Her Majesty's Attorney-General, do hereby alter the said Specifi-
cation by omitting the passage beginning with the word "wherever" in
the first line of the sixth page of the said Specification, as printed under
the authority of the Commissioners of Patents, and ending with the
word "thereby" on the fourth line of such page, and by inserting after
the words "having now described the nature and object of my said
"Invention for an improved process or method and apparatus for
preparing plants to render them useful in the manufacture of paper
pulp, together with the manner in which the same is to be or may be
performed or carried into practical effect, I would remark in con-
"clusion that" beginning on the third line of the thirteenth page of the
said printed Specification, the words "I wish it to be distinctly under-
stood that I do not claim the use or application of the said Invention for
or to any other purpose than the manufacture of paper pulp, but" and
by omitting from the claim contained in the said Specification the words
and for obtaining spinning fibres from plants" on the twelfth line of
the thirteenth page of the printed copy thereof.
66
"
66
and ending on the seventh Hinc
A
And in order that the effect of the said alteration may be fully under-
stood I proceed to set out the said Specification as it will read with my
Disclaimer and Memorandum of Alteration inserted therein.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I ALBERT
UNGERER, of Simmering, near Vienna, Austria, Chemist, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent, bearing date the Twenty-sixth day of January, in the year of 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 Albert Ungerer, Her special license, that I, the said Albert Ungerer,
my executors, administrators, and assigns, should at any time agree with,
or such others as I, the said Albert Ungerer, my executors, administrators, or assigns,
Λ

page_text: 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 "AN IMPROVED.
PROCESS OR METHOD AND APPARATUS FOR PREPARING PLANTS TO RENDER THEM,
USEFUL IN THE MANUFACTURE OF PAPER PULP," upon the condition (amongst
others) that I, the said Albert Ungerer, 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 Albert Ungerer, do hereby declaro.
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 in writing and on reference being had to the.
accompanying Drawings, that is to say :—
This Invention relates to an improved process or method of and also
an arrangement of apparatus for preparing or treating plants so as to.
render them more adaptable or useful in the manufacture of paper pulp,.
the object of the Invention more particularly being to isolate the cells of.
the plates (but so as entirely to preserve their integrity and to free them:
of their natural incrustating substances as well as to bleach or decolorize:
them to a great extent as and for the purposes hereafter described.
I would here remark that although the process herein-after described
can be employed for isolating the cells of plants generally whenever.
such is desirable for different purposes. I consider it particularly useful.
for the purpose of manufacturing "pulp" for the use of papermakers
from wood or from plants of a nature similar to wood, and I shall
therefore in the remainder of my Specification confine myself to the
particular description of a process and apparatus adapted for the manu-
facture of paper pulp from wood, but it will be easily understood that
they can be used for the more general purpose mentioned above, with
such modifications in details as would be required, and would readily
occur to any person practically conversant with such manufactures..
The main features of my process are as follows:-I put the wood,
after cutting it up in small pieces of convenient sizes (by preference in

page_text: the same way as is generally done with dye woods, but this is not a
material feature of my process, neither is it necessary in all cases), into
closed vessels, in which it is treated at a gradually increasing pressure
and a temperature corresponding to the same with a caustic soda lye
several times renewed, and heated beforehand. In the same vessels the
stuff is also thoroughly freed washed after the above treatment. By this
treatment the wood or other vegetable matter is thoroughly freed from
incrustating substances, and the connexion between the single cells or
fibres is severed.
My process is based upon a discovery which I have made, viz., that
certain substances contained in the wood, which in the commencement
of the action dissolve at a comparatively low heat, are subsequently pre-
cipitated at a higher temperature as insoluble matter of a humus-like
nature. This induced me to act upon the wood with a previously heated
lye, and at a gradually increasing temperature and pressure. By the
constant change of lye which I cause those substances which once had
entered into solution are carried away by the lye sooner than the
separation of humus-like matter from them can take place in con-
sequence of the rise of temperature; thereby the wood is acted upon
evenly and partly decolorized, so that it becomes more adaptable for the
manufacture of a high class of paper. I also find that the wood is
the more evenly disintegrated and bleached the oftener the lye is
changed, and it is therefore a particular advantage of the apparatus
described hereafter that in it a continuous progressive change of the lye
takes place.
the
The pressure, the duration of the action, and the concentration of the
lye must be regulated according to the particular kind of wood and the
degree of bleaching required. For wood from trees with deciduous
leaves it is sufficient to use a lye containing two or three per cent. of
anhydrous caustic soda and * pressure being caused to rise at the end
to two or three or four atmospheres, and the action lasting five or six
hours. Wood derived from conifers requires for the same time a pressure
up to six atmospheres and a lye containing 3 to four per cent. of anhy-
drous caustic soda.
Within certain limits, an increase of the pressure or of the time of
action or of the concentration of the lyc can be substituted for a decrease
in either of the two other conditions; the above-mentioned figures need

page_text: therefore not be strictly adhered to in practical working, and it will be
understood that freshly cut wood is more easily worked than old wood,
and the treatment will also depend upon which is used.
I am well aware that paper pulp has been manufactured from wood
by chemical means for some time past, but this has been done in a much
more costly manner. The manipulation was generally done in a single
boiler and with one lye, and at very high temperature and pressure, the
latter being a very serious drawback as regards safe working. In conse-
quence of this some substances dissolved at a lower temperature are
partly precipitated again with the rising of the temperature, as humus-
like substances of a brown color as above mentioned, so that the product
can only be bleached by a very large expenditure of chemicals. This
drawback is entirely avoided in my process since I work with a number
of vessels, each of which is exposed to several portions of lye of con-,
stantly increasing temperature, each change or portion of lye carrying,
away such of their natural incrustating substances as it has dissolved.
before. A following and higher temperature can convert them into the
humus-like substance, which would discolor them and render every
subsequent operation, especially that of bleaching, troublesome, difficult,
expensivo
and
A
Another recommendation of my apparatus is its allowing of continuous.
working of large quantities of wood in the smallest possible space, and
which in combination with the progressive treatment allowable therein
effects the object of the Invention with the smallest possible use of
expenditure of chemicals and in a very economical and effective
manner.
The Invention will be more clearly understood on reference being had
to the accompanying Drawings illustrating the apparatus employed.
(which fulfils in a high degree the condition of making wood into a fine
even pulp with the least, possible expense), and to the following descrip-
tion on explanation thereof.
The apparatus consists essentially of a convenient or required number:
of closed vessels or boilers, which I term plant boilers, for boiling the
plants, and which are capable of resisting the required pressure, and
5 chemical action, and therefore most suitably made of iron, and which
vessels are in communication or connected with one another by pipes or
tubes, as hereafter described, in such a manner that liquids can pass,

page_text: from one plant boiler to the other, and seriatim penetrate through the
contents of the whole range, either downwards or upwards, under
controllable condition of temperature and pressure, and ultimately can
be run away.
connection,
^
The size and arrangement of. the apparatus depends on the one hand
upon the special kind of wood used, and on the other upon the special
kind of pulp to be manufactured. Thus if either the raw material is
wood from deciduous trees or if unbleached pulp is required, there are
fewer vessels wanted than for working with wood from conifers or for
stuff intended to be bleached to a white color. For example I will
describe the operation of the apparatus when they are (say) 9 vessels
or plant boilers A, B, C, D, E, F, G, H, and I, in conferred
as above
referred to, and which number will be found sufficient in nearly every
case. Each vessel is surrounded with non-conducting or imperfect
conducting material X, such as ashes or sawdust, or other substance or
substances, for the object of keeping the contents of the vessels at a
high temperature. Under each vessel is also provided a separate fire-
place or grate I, in order to remedy any unavoidable or occasional cooling.
A further provision of man-holes, safety valves, steam guages, water
guages, and other usual mountings, and a system of iron or other pipes
or tubes 2 and 5 allow of the introduction of water and lye separately
into each vessel and from one vessel to another. In addition to these
"plant boilers is a separate lye boiler J, to prepare hot or boiling lyc,
in communication with the pipes or tubes 2, so that the plant boilers can
be filled with the lye direct from the lye boiler J, as described hereafter,
and provided with a fire-place K for heating the soda lye and bringing it
up to the required degree of pressure, and with a force pump (which is
not however illustrated) having an air vessel or regulator L in communi-
cation therewith, and provided for the purpose of filling the vessels A. to I
with cold water as required.
د,
In carrying my Invention into practical effect I proceed as follows,
but, as above referred to, the manipulation may vary in points of detail
according to special circumstances:-First, the whole of the vessels or
plant boilers A to I are filled with cut up wood; then the communi-
cation 2 between the lye boiler J and the first vessel A is opened, and
the latter is filled with hot lye, as well as the five following ones, B to F,
by the lye flowing from one to the other in succession through the
communication 2 provided for that purpose, the lye always traversing

page_text: the contents of one vessel before it enters the next vessel by entering
from below and passing out at the top. The pressure naturally decreases
in each successive boiler, and is regulated in such a manner by means
of certain cocks or valves 3 that the lye enters the vessel A with a
pressure of 6 atmospheres, but stands in the vessel F only under a
pressure of 1 to 1 atmosphere. After proceeding thus to fill the first
6 of the 9 vessels or plant boilers with the lye, I open the outlet cock 4.
of the 6th F and shut off the communication between the lye boiler and
the first plant boiler, and open the communication between the latter'
and the water pump, which communicates with each of the vessels
A to I by means of pipes 5 and cocks 6, and by filling the same with
cold water therefrom I force the lye of the plant boiler A into the.
second B, and this forces the lye which was in the second B into the
third C, and so on, the lye which was in the sixth F flowing away-
through its outlet 4 into a separate cistern or recovery apparatus, where
it is evaporated to dryness, and calcined and remade into caustic soda,
the pressure in the regulator of the pump being strong enough to force
the cold water into A, and push the liquid forward as described, so that
A becomes filled with water, and the vessels B to F with lye, each con-
taining the lye which had just been in the vessel or plant boiler
immediately preceding. In this and in all future changes of lye the
latter enters cach vessel from the top and passes out at the bottom.
till each in the whole range of vessels under operation has received. a.
new quantity of lye, as above described, viz., that contained in the vessel.
immediately preceding.
When the first plant boiler A is full of water I shut off the communi-
cation 5 between it and the pump, and also the communication 2
between A and B, and cause fresh lye to flow direct from the lye boiler J.
into the vessel B, previously shutting the outlet cock.4 of F and opening.
the communication 2 between F and G, and, as above, the lye is forced
on again through all the plant boilers till G is filled, when the running.
of fresh lye into B is stopped. At this stage A stands filled with water,.
and B to G with lye. Now the communication between A and B is
opened again, and between A and the pump, and fresh cold water is
forced into A, what was in A flowing into B; the outlet cock 4 of G being
previously opened the lye therein, as in F, described above, flows away
and is replaced by the lye which was in the plant boiler F. At this
stage A stands filled with fresh water, B with the water previously.
"

page_text: passed through A, and C with the lye just before in B, and so on to G.
I then proceed in a similarly progressive manner until the 9th plant
boiler I is filled with lye. The water or liquid contents of A (which
by that time would have received 3 waters) are then run off (this can bo
hastened by pressure or suction), and the solid contents, viz., the wood,
now sufficiently and thoroughly liseiniated and washed is taken out.
After which A is again filled with fresh wood, and then forms the vessel
in succession to I by means of the communication 2 provided for the
purpose, as shewn in the annexed Drawings. The water in C, which
has already passed through two preceding vessels A, B, is not forced
from C to D or used for any further for washing, but is run off whilst
fresh water is forced into B. The liquid running off from C is dilute
lye, and can be used in preparing fresh lye, or otherwise. When C is
filled with the water from B, and B with fresh water, C and D are con-
nected, more cold water is pressed into C, and a vessel full of lyc is run
off from I, so that now B, C, D, are full of water, and Ẹ to I full of lye.
Now D and E are disconnected, and I and the freshly charged vessel A
are put into communication with each other, and fresh lye is forced into
E till E, F, G, H, I, and A are all full. The stuff in B, which has had
three waters, is then sufficiently done, and (as above) is taken out (after
running off the water) and B is refilled with fresh wood. Thus the
above described treatment or manipulation is continued without inter-
ruption, the wood being taken out of the successive boilers in turn, and
after they are emptied of the water they contain 5 or 6 vessels always
being filled with lye, and 2 or 3 with water; one sometimes either being
emptied or recharged with wood. When the operation is properly going
on each vessel full of cut wood receives first 5 vessels full of lye passed
through the preceding vessels of wood, then one vessel full of fresh lyc
and then 3 vessels full of fresh water, the first 2 of which have served
for washing before. The pressure is an increasing one in each vessel,
counting backwards from the vessel last filled, and reaches its highest
degree in the first vessel filled with lye at that moment when fresh lyc
is being forced into it from the lye boiler.
One of the essential features in the Invention is that the wood is not
boiled by the application of fire direct to the plant boilers, but the lye
for boiling it is conveyed thereto under pressure direct from the lye
boiler where it is previously sufficiently heated, the provision of the
fire-grates under the plant boilers being merely for keeping the lye at
its required heat.

page_text: Another of the essential features is the treatment of the wood under
varying or different pressures, and also washing it in the plant boilers by
changing the hot lye for the cold water.
When first filling a vessel charged with fresh wood the lye should
enter it from below, to have no "false ways "in it, but when it is full
and closed up the cocks should be reversed and the subsequent fillings
should be from the top downwards.
The running off and on is so regulated that for each vessel full of wood
a quantity of lye is employed just sufficient to cover the wood, which
will be about 2 or 3 times the weight of the wood. The wood should
be subjected to the action of the lyc for 6 or 7 hours, the exact time
depending on the nature of the wood, &c., as above referred to. The
lye after passing through 5 or 6 vessels is boiled down and the residue
is calcined, dissolved in water, and again employed for making caustic
lye. The water which has passed through 3 vessels is used as weak lye,
either in bleaching or in making fresh lye.
The lye boiler J in which the caustic lye is kept, and which is shewn
in the annexed Drawings is continually being fed with fresh lyc, and its
contents are there heated under the necessary pressure and conveyed by
their own pressure into the respectively vessels A. to I; but the water for
washing is forced cold water into the regulator or air vessel L, and from
this into the vessels A to I, as required. As it has to pass through two
vessels previously to coming in contact with hot lye it is heated in
advance to some extent, and at the same time the pulp is cooled, which
is of great importance, as thereby the process of manufacture is greatly
expedited. When the third water has been drained off the mass the
latter is put along with water into a "poacher," and is beaten up therein
in order to separate the fibres of the wood which fall asunder almost by
themselves, and it is thus converted into proper "half stuff." Only very
little power is required for this operation, since the mass need not be
cut up as in the ordinary poacher or beating engine, but only disin-
tegrated and stirred up amongst the water.
By the above treatment the wood pulp is decolorized to a considerable
extent and can be used for many purposes without bleaching, but if it is
wanted perfectly white the last remains of coloring matter must be
removed either by any of the ordinary bleaching processes which are
applicable to my wood pulp as well as to paper pulp prepared in other

page_text: ways and from other materials, or by the following method which I
I have found to be most economical. The pulp is treated with a solution
of bleaching powder or bleach liquor corresponding to 3 or 4 parts by
weight of commercial bleaching powder (more or less) to 100 parts of
dry pulp. This can be done in steepers or vessels of the usual sort, or
in a displacement apparatus where the bleaching solution is forced or
pumped from one vessel into another. These vessels are open at the
top, and are best constructed either of brickwork set in cement or of
wood soaked with paraffine. This treatment has for its object less to
bleach the stuff directly than to make the coloring matter soluable by
oxydation, after which it is easily removed by treating with a hot caustic
lye or even with a solution of carbonate of soda and subsequent washing.
Only a weak lye is required for this object, and a very much shorter,
time of treatment is necessary so that this operation is a very simple one
and does not require a more detailed description. In working on a very
large scale especially it may be advisable to employ an apparatus similar
to that described for the first treatment, only consisting of fewer vessels,.
but in most cases this will not be found necessary. After this treatment
perfect bleaching is effected exactly in the same way as with rag.pulp,.
and or one part of bleaching powder for 100 part of dry pulp are
mostly sufficient for this last operation.
My process and apparatus apart from making paper pulp from wood can
be used for disintegrating all vegetable matters into their single cells, and,
by modifying the treatment as necessary for every special case according
to the nature of the plant spinning fibres can be obtained from plants.
(which hitherto could not profitably be employed for this purpose), the
cells retaining their natural size and shape, and not being changed.
chemically or otherwise, but being completely freed from their incrus-
tations.
Having now. described the nature and object of my said Invention for
"An Improved Process or Method and Apparatus for Preparing Plants
to Render them Useful in the Manufacture of Paper Pulp," together
with the manner in which the same is to be or may be performed or
carried into practical effect, I would remark in conclusion that I wish it
to be distinctly understood that I do not claim the use or application of
the said Invention for or to any other purpose than the manufacture of
paper pulp, but I claim as my Invention, the improved process or method
of and the arrangement of apparatus for continuously treating fibrous,

page_text: materials, especially as far as regards the direct conversion of wood into
partially bleached paper pulp, and the employment of the same for
disintegrating all vegetable, matters into their single cells, substantially
as above described, for the purposes set forth, and as illustrated on the
accompanying Drawings, or any mere modification or variation thereof.
In witness whereof, I, the said Albert Ungerer, hath hereunto set
my hand and seal, this Twenty-sixth day of February, in the
year of our Lord One thousand eight hundred and seventy-five.

page_text: LETTERS PATENT to Albert Ungerer, of Simmering, near Vienna,
Austria, Chemist, for the Invention of "AN IMPROVED PROCESS OR
METHOD AND APPARATUS FOR PREPARING PLANTS TO RENDER THEM USEFUL IN
THE MANUFACTURE OF PAPER PULP."
Sealed the 11th June 1872, and dated the 26th January 1872.
PROVISIONAL SPECIFICATION left by the said Albert Ungerer at the
Office of the Commissioners of Patents, with his Petition, on the
26th January 1872.
I, ALBERT UNGERER, of Simmering, near Vienna, Austria, Chemist,
do hereby declare the nature of the said Invention for "AN IMPROVED
PROCESS OR METHOD AND APPARATUS FOR PREPARING PLANTS TO RENDER THEM
USEFUL IN THE MANUFACTURE OF PAPER PULP," to be as follows:-
This Invention relates to an improved process or method of and
apparatus for preparing or treating plants so as to render them more
adaptable or useful in the manufacture of paper pulp; the object of the
Invention more particularly being to isolate the cells of the plants (but

page_text: so as entirely to preserve their integrity), and to free them of their
natural incrustating substances, as well as to bleach them, so as to
render them more adaptable to the said manufacture.
In carrying my Invention into practical effect I prefer that the plants
should be first cut in pieces or lengths of convenient size by cutting|
machines or other suitable means, previously to the treatment to which
they are subsequently subjected as herein-after described, but in some
cases it will not be necessary that they should be first cut.
The apparatus employed for the above object is constructed and
arranged as follows:-It consists essentially of a convenient number of
iron boilers (which I term "plant boilers ") for boiling the plants, in
communication with each other by iron pipes or tubes provided with
suitable cocks, valves, or their equivalents, so that the communications
may be opened or closed at pleasure. Under each of these boilers is
placed a fire-grate. In addition to these plant boilers is a separate lye
boiler (to prepare hot or boiling lye) in communication with the pipes or
tubes of the plant boilers, so that the plant boilers can be filled with the
boiling lye direct from the lye boiler, as hereafter described. A water
pump is also provided and communicates with the series of plant boilers,
so that the latter can be filled with cold water.
The improved process or method of preparing or treating the plants is
as follows:-The plant boilers are first filled with the plants and with
a previously heated caustic lye at a variable pressure, the height of which
as well as the concentration of the lye is dependant upon the nature of
the plants being treated.
For example I will describe the operation of the apparatus when there
are, say, nine plant boilers in connection, as above described. After
filling all the plant boilers with the plants, I open the communication
between the lye boiler and the first plant boiler, and so cause the boiling
lye to flow from the former to the latter, and when it gets full I open
the communication between the first and second plant boilers, and let
the lye flow on through the first to the second, and when this one gets
full I open the communication between the second & third plant
boilers and let the lye flow on through the first and second to the third,
and so on till, say, six of the nine plant boilers have been filled with the
boiling lye, and by means of the cocks or valves above mentioned, I so
regulate the pressure in the successive boilers that the first plant boiler

page_text: has the same pressure as the lye boiler, whilst in each successive plant
boiler the pressure is diminished, and in the sixth boiler the pressure is
reduced almost to a minimum. After proceeding thus to fill the first
six of the nine plant boilers with the lye from the lye boiler, I shut off
the communication between the first plant boiler and the lye boiler, and
open the communication between the first plant boiler and the water
pump and fill the former with cold water; I thus force the lye out of
the first plant boiler into the second, and this forces the lye which was
in the second into the third, and so on, whilst at the same time the
lye which was in the sixth plant boiler flows away into a separate
cistern.
.
When the first boiler is full of water I shut the communication
between the first and second plant boilers, and cause fresh lye to flow
direct from the lye boiler to the second plant boiler, previously opening
the communication between the sixth and seventh plant boilers, and as
above the lye is forced through all the plant boilers till the seventh is
full. I then shut the communication between the lye boiler and the
second plant boiler, and open the communication between the first and
second plant boilers, and by means of the pump I force fresh water into
the first plant boiler until the second plant boiler is full of water, and so
drive the lye from out of the second plant boiler into the third, & what
was in the third into the fourth, and so on, the lye which was in the
seventh boiler flowing away into the cistern as above, and being replaced
by the lye which was in the sixth plant boiler.
As the apparatus is now the first and second plant boilers are full of
water, and the third, fourth, fifth, and sixth, and seventh full of lye, I
then proceed in a similarly progressive manner until the ninth boiler is
filled with the lye. The water in the first plant boiler is then allowed
to flow away, and as the plants therein are sufficiently treated I take
them out and put fresh ones in and proceed as above described, taking
the plants out of the successive boilers as they are emptied of the water.
they contain.
By the employment of this improved process and treatment I carry
away from the plants by the, change of lye all their natural incrustating
substances, which the lye has dissolved at the different temperatures
and pressures before they get changed into an insoluble dark humus
like substance, which would; discolor them and render every sub-

page_text: sequent operation, especially that of bleaching, troublesome, difficult,
and expensive.
One of the essential features in this Invention is that the plants are
not boiled by the application of fire direct to the plant boilers, but the
lye for boiling them is conveyed thereto under pressure by means of
pipes direct from the lye boiler, where it is previously sufficiently heated,
the provision of the fire-grates under the plant boilers being merely for
keeping the lye at its required heat.
Another of the essential features is the treatment of the plants under
varying or different pressures, and also washing them in the plant boilers
by changing the lye for the cold water.
The boiling lye in each plant boiler is kept therein until the plants'
under treatment in such plant boiler are sufficiently boiled, and as
above described, by causing the lye from the first plant boiler, after
it has performed its functions therein, to flow into the second plant
boiler, and so on, the plants in each successive plant boiler are pro-
gressively treated, which besides being very economical in the use or
expenditure of the lye, effects the object of the Invention in a very
effective manner.
€
·
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Albert Ungerer in the Great Seal Patent Office
on the 26th July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALBERT
UNGERER, of Simmering, near Vienna, Austria, Chemist, send
greeting.
: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of January, 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 Albert Ungerer, Her special licence &
that I, the said Albert Ungerer, my executors, administrators, and
assigns, or such others as I, the said Albert Ungerer, my executors,
administrators, and assigns, should at any time agree with, and no

page_text: 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 "AN IMPROVED
PROCESS OR METHOD AND APPARATUS FOR PREPARING PLANTS TO RENDER THEM
USEFUL IN THE MANUFACTURE OF PAPER PULP," upon the condition (amongst
others) that I, the said Albert Ungerer, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of my said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Scal Patent
Office within six calendar months next and immediately after the date'
of the said Letters Patent.
NOW KNOW YE, that I, the said Albert Ungerer, 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 in writing, and on reference being had to the
accompanying Drawings, that is to say :-
This Invention relates to an improved process or method of and
also an arrangement of apparatus for preparing or treating plants so
as to render them more adaptable or useful in the manufacture of paper
pulp; the object of the Invention more particularly being to isolate the
cells of the plants, (but so as entirely to preserve their integrity and
to free them of their natural incrustating substances as well as to bleach
or decolorize them to a great extent as and for the purposes hereafter
described.
I would here remark that although the process hercin-after described
can be employed for isolating the cells of plants generally whenever
such is desirable for different purposes, I consider it particularly useful
for the purpose of manufacturing "pulp" for the use of paper makers
from wood or from plants of a nature similar to wood, and I shall
therefore in the remainder of my Specification confine myself to the:
particular description of a process and apparatus adapted for the manu-
facture of paper pulp from wood; but it will be easily understood
that they can be used for the more general purpose mentioned above,
with such modifications in details as would be required, and would.
readily occur to any person practically conversant with such manu-

page_text: factures. Wherever therefore in the remainder of my Specification
I use the words "wood" and "pulp" it must be understood that other
plants the cells of which have to be isolated, and other purposes than
paper making are likewise comprehended thereby.
The main features of my process are as follows:-I put the wood after
cutting it up in small pieces of convenient sizes (by preference in the
same way as is generally done with dye woods, but this is not a material
feature of my process, neither is it necessary in all cases,) into closed
vessels, in which it is treated at a gradually increasing pressure, and
a temperature corresponding to the same, with a caustic soda lye, several
times renewed and heated beforehand. In the same vessels the stuff
is also thoroughly washed after the above treatment. By this treatment
the wood or other vegetable matter is thoroughly freed from incrus-
tating substances, and the connexion between the single cells or fibres
is severed. My process is based upon a discovery which I have made,
viz., that certain substances contained in the wood which in the com-
mencement of the action dissolve at a comparatively low heat, are
subsequently precipitated at a higher temperaturé as insoluble matter
of a humus like nature. This induced me to act upon the wood with
a previously heated lye, and at a gradually increasing temperature and
pressure. By the constant change of lye which I cause those substances
which once have entered into solution are carried away by the lye
sooner than the separation of humus like matter from them can take
place, in consequence of the rise of temperature; thereby the wood
is acted upon evenly, and partly decolorized so that it becomes more
adaptable for the manufacture of a high class of paper.
I also find that the wood is the more evenly disintegrated and
bleached the oftener the lye is changed, and it is therefore a particular
advantage of the apparatus described hereafter that in it a continuous
progressive change of the lye takes place.
The pressure, the duration of the action, and the concentration
of the lye must be regulated according to the particular kind of wood
and the degree of bleaching required. For wood from trees with
deciduous leaves it is sufficient to use a lye containing 2 or 3
per cent. of anhydrous caustic soda, the pressure being caused to rise
at the end to 3 or 4 atmospheres, and the action lasting 5
or 6 hours. Wood derived from conifers requires for the same time

page_text: a pressure up to 6 atmospheres, and a lye containing 3 to 4 per cent.
of anhydrous caustic soda.
Within certain limits an increase of the pressure or of the time
of action, or of the concentration of the lye, can be substituted for
a decrease in either of the two other conditions; the above-mentioned
figures need therefore not be strictly adhered to in practical working,
and it will be understood that freshly cut wood is more easily worked
than old wood, and the treatment will also depend upon which is used.
I am well aware that paper pulp has been manufactured from wood
by chemical means for some time past, but this has been done in
a much more costly manner. The manipulation was generally done
in a single boiler, and with one lye and at a very high temperature and
pressure, the latter being a very serious drawback, as regards safe
working. In consequence of this some substances dissolved at a lower
temperature are partly precipitated again with the rising of the tem-
perature as humus like substances of a brown color as above mentioned,
so that the product can only be bleached by a very large expenditure of
chemicals. This drawback is entirely avoided in my process, since I
work with a number of vessels, cach of which is exposed to several
portions of lye, of constantly increasing temperature, cach change or
portion of lye carrying away such of their natural incrustating sub-
stances as it has dissolved, before a following and higher temperature
can convert them into the humus like substance which would discolor
them and render every subsequent operation, especially that of bleaching,
troublesome, difficult, and expensive.
Another recommendation of my apparatus is its allowing of con-
tinuous working of large quantities of wood in the smallest possible
space, and which in combination with the progressive treatment allow-
able therein effects the object of the Invention with the smallest
possible use or expenditure of chemicals, and in a very cconomical and
effective manner.
The Invention will be more clearly understood on reference being had
to the accompanying Drawings illustrating the apparatus employed,
(which fulfils in a high degree the condition of making wood into a fine
even pulp with the least possible expence,) and to the following descrip-
tion or explanation thereof.

page_text: The apparatus consists essentially of a convenient or required
number of closed vessels or boilers which I term plant boilers for
boiling the plants, and which are capable of resisting the required
pressure and chemical action and therefore most suitably made of iron,
and which vessels are in communication or connected with one another
by pipes or tubes as hereafter described, in such a manner that liquids
can pass from one plant boiler to the other, and seriatim penetrate
through the contents of the whole range either downwards or upwards,
under controllable conditions of temperature and pressure, and ulti-
mately can be run away. The size and arrangement of the apparatus
depends on the one hand upon the special kind of wood used, and
on the other upon the special kind of pulp to be manufactured. Thus
if either the raw material is wood from deciduous trees, or if unbleached
pulp is required there are fewer vessels wanted than for working
with wood from conifers or for stuff intended to be bleached to a white
color.
For example, I will describe the operation of the apparatus when
there are (say) 9 vessels or plant boilers A, B, C, D, E, F, G, H,
and I, in connexion as above referred to, and which number will be
found sufficient in nearly every case. Each vessel is surrounded with
non-conducting or imperfect conducting material X, such as ashes or
sawdust, or other substance or substances for the object of keeping
the contents of the vessels at a high temperature. Under each vessel
is also provided a separate fire-place or grate 1, in order to remedy any
unavoidable or occasional cooling. A further provision of man-holes,
safety valves, steam guages, water guages, and other usual mountings,
and a system of iron or other pipes or tubes 2 and 5, allow of the
introduction of water and lye separately into each vessel, and from one
vessel to another. In addition to these "plant boilers" is a separate lye
boiler J to prepare hot or boiling lye in communication with the pipes
or tubes 2, so that the plant boilers can be filled with the lye direct
from the lye boiler J, as described hereafter and provided with a fire-
place K for heating the soda lye, and bringing it up to the required
degree of pressure, and with a force pump (which is not however
illustrated) having an air vessel or regulator L in communication there-
with, and provided for the purpose of filling the vessels A to I with cold
water as required.

page_text: stopped. At this stage A stands filled with water and B to G with lye.
Now the communication between A and B is opened again and between
A and the pump, and fresh cold water is forced into A, what was in A
flowing into B, the outlet cock 4 of G being previously opened; the lye
therein as in F, described above, flows away and is replaced by the lye
which was in the plant boiler F. At this stage A stands filled with
fresh water, B with the water previously passed through A, and C with
the lye just before in B, and so on to G.
I then proceed in a similarly progressive manner until the 9th plant
boiler I is filled with lye. The water or liquid contents of A (which by
that time would have received 3 waters) are then run off (this can be
hastened by pressure or suction), and the solid contents, viz., the wood,
now sufficiently and thoroughly liseiniated and washed is taken out.
After which A is again filled with fresh wood and then forms the vessel
in succession to I, by means of the communication 2, provided for the
purpose as shewn in the annexed Drawings. The water in C which has
already passed through two preceding vessels A, B, is not forced from
C to D, or used any farther for washing, but is run off whilst fresh water
is forced into B. The liquid running off from C is dilute lye, and can
be used in preparing fresh lye or otherwise. When C is filled with the
water from B, and B with fresh water, C and D are connected; more cold
water is pressed into C, and a vessel full of lye is run off from I, so that
now B, C, D, are full of water, and E to I full of lye. Now D and E are
disconnected, and I and the freshly charged vessel A are put into
communication with each other and fresh lye is forced into E, till
E, F, G, H, I, and A, are all full. The stuff in B which has had three
waters is then sufficiently done, and (as above) is taken out (after
running off the water), and B is refilled with fresh wood.
.
Thus the above-described treatment or manipulation is continued
without interruption, the wood being taken out of the successive boilers
in turn, and after they are emptied of the water they contain, 5 or 6
vessels always being filled with lye, and 2 or 3 with water, one
sometimes either being emptied or re-charged with wood. When the
operation is properly going on each vessel full of cut wood receives first
5 vessels full of lye, passed through the preceding vessels of wood,
then 1 vessel full of fresh lye, and then 3 vessels full of water,
the first two of which have served for washing before. The pressure is
an increasing one in each vessel, counting backwards from the vessel.

page_text: Jye at that moment when fresh lye is being forced into it from the lye
boiler.
One of the essential features in the Invention is that the wood is not
boiled by the application of fire direct to the plant boilers, but the lye.
for boiling it is conveyed thereto under pressure direct from the lye
boiler where it is previously sufficiently heated, the provision of the fire-
grates under the plant boilers being merely for keeping the lye at its
required heat.
Another of the essential features is the treatment of the wood under
varying or different pressures, and also washing it in the plant.
boilers by changing the hot lye for the cold water.
When first filling a vessel charged with fresh wood the lye should
enter it from below to have no " 'false' ways" in it, but when it is full
and closed up the cocks should be reversed, and the subsequent fillings
should be from the top downwards.
The running off and on is so regulated that for each vessel full
of wood a quantity of lye is employed just sufficient to cover the
wood, which will be about 2 or 3 times the weight of the wood.
The wood should be subjected to the action of the lye for 6 or 7
hours, the exact time depending upon the nature of the wood, &c.,
as above referred to. The lye after passing through 5 or 6 vessels
is boiled down, and the residue is calcined, dissolved in water, and again
employed for making caustic lye. The water which has passed through
3 vessels is used as weak lye either in bleaching or in making fresh
lye.
The lye boiler J, in which the caustic lye is kept, and which is shewn
in the annexed Drawings, is continually being fed with fresh lye, and
its contents are there heated under the necessary pressure, and conveyed
by their own pressure into the respective vessels A to I; but the water
for washing is forced cold into the regulator or air vessel L, and from
this into the vessels A to I as required. As it has to pass through two
vessels previously to coming in contact with hot lye it is heated in
advance to some extent, and at the same time the pulp is cooled, which
is of great importance, as thereby the process of manufacture is greatly
expedited. When the third water has been: drained off the mass the

page_text: latter is put along with water into a "poacher," and is beaten up therein
in order to separate the fibres of the wood, which fall asunder almost by
themselves, and it is thus converted into proper "half stuff." Only very
little power is required for this operation, since the mass need not be cut
up as in the ordinary poacher or beating engine, but only disintegrated
and stirred up amongst the water.
By the above treatment the wood pulp is decolorized to a considerable
extent, and can be used for many purposes without bleaching; but if it
is wanted perfectly white the last remains of coloring matter must be
removed either by any of the ordinary bleaching processes which are
applicable to my wood pulp, as well as to paper pulp prepared in other
ways; and from other materials; or by the following method, which I
have found to be most economical:-The pulp is.treated with a solution
of bleaching powder or bleach liquor corresponding to 3 or 4
parts by weight of commercial, bleaching powder (more or less) to 100
parts of dry pulp. This can be done in steepers or vessels of the usual
sort, or in a displacement apparatus, where the bleaching solution is
forced or pumped from one vessel into another. These vessels are open
at the top, and are best constructed either of brickwork set in cement, or
of wood soaked with paraffine. This treatment has for its object less to
bleach the stuff directly than to make the coloring matter soluble by
oxydation, after which it is easily removed by treating with a hot caustic
lye, or even with a solution of carbonate of soda, and subsequent
washing. Only a weak lye is required for this object, and a very much
shorter time of treatment is necessary, so that this operation is a very
simple one, and does not require a more detailed description. In
working on a very large scale, especially, it may be advisable to employ
an apparatus similar to that described for the first treatment, only con-
sisting of fewer vessels; but in most cases this will not be found
necessary. After this treatment perfect bleaching is effected exactly in
the same way as with rag pulp, and ½ or one part of bleaching powder
for 100 parts of dry pulp are mostly sufficient for this last operation.
.
My process and apparatus apart from making paper pulp from wood,
can be used for disintegrating all vegetable matters into their single
cells; and by modifying the treatment as necessary for every special
case, according to the nature of the plants, spinning fibres can be
obtained from plants (which hitherto could not profitably be employed
for this purpose), the cells retaining their natural size and shape, and not

page_text: being changed chemically or otherwise, but being completely freed from
their incrustations.
Having now described the nature and object of my said Invention for
'An Improved Process or Method and Apparatus for Preparing Plants
to render them Useful in the Manufacture of Paper Pulp," together
with the manner in which the same is to be or may be performed or carried
into practical effect, I would remark in conclusion that I claim as my
Invention, the improved process or method of and the arrangement of
apparatus for continuously treating fibrous materials, especially as far as
regards the direct conversion of wood into partially bleached paper pulp,
and the employment of the same for disintegrating all vegetable matters
into their single cells, and for obtaining spinning fibres from plants,
substantially as above described, for the purposes set forth, and as
illustrated on the accompanying Drawings, or any mere modification or
variation thereof.
In witness whereof, I, the said Albert Ungerer, have hereunto set
my hand and seal, this Fifteenth day of July in the year of
our Lord One thousand eight hundred and seventy-two.
ALBERT UNGERER. (L.S.)
Chemiker.